2016
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 (347) 

P. Cottet, C. Bleschke, M. G. Capdevila, M. Tissot, A. Alexakis "Catalytic Enantioselective Total Synthesis of Riccardiphenol B" Adv. Synth. Catal. 2016, 358, 417-425.

The first catalytic enantioselective total synthesis of riccardiphenol B, a sesquiterpene derivative isolated from a Japanese collection of the liverwort Riccardia crassa, has been achieved. A copper-catalyzed asymmetric conjugate addition of trimethylaluminum was used at an early stage to generate the quaternary stereogenic center with high enantiomeric excess. The corresponding sterically encumbered aluminum enolate was directly trapped with an α-amino ether, allowing after oxidation, the release of a key intermediate in the total synthesis of the target natural product.

[] open archive unige:80311 full text [restricted access]   

 2015
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 (346) 

J. Praz, J. Graff, L. Egger, L. Guénée, S. Wagschal, E. P. Kündig, A. Alexakis "Asymmetric bromine–lithium exchange: on the importance of both the diamine ligand and the organolithium reagent" Chem. Commun. 2015, 51, 16912-16915.

The asymmetric lithium-bromine exchange is described on a series of prochiral biphenyls. As in many asymmetric organolithium reactions, the chiral ligand (here a diamine) is considered as the enantiocontroling element. We demonstrate herein that the organolithium reagent, which undergoes the exchange, also plays an important role.

[] open archive unige:77587 full text [restricted access]   

 (345) 

D. Grassi, A. Alexakis "Improvements and Applications of the Transition Metal-Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates" Adv. Synth. Catal. 2015, 357, 3171-3186.

Two new N-heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal-free asymmetric allylic alkylation (AAA) mediated by Grignard reagents and magnesium alanates. The employment of these ligands showed high yields and improved regio- and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%) and high scalability (up to 10 mmol) of this improved methodology provide a convenient access to biologically active compounds and synthetically valuable intermediates.

[] open archive unige:76518 full text [restricted access]   

 (344) 

J. Graff, E. Łastawiecka, L. Guénée, F. Leroux, A. Alexakis "Asymmetric Bromine-Lithium Exchange: Application toward the Synthesis of New Biaryl-Diphosphine Ligands" Adv. Synth. Catal. 2015, 357, 2833-2839.

The desymmetrization of the prochiral tetrabromobiphenyl via asymmetric bromine–lithium exchange as a key step of synthesis of novel biphenyl-diphosphine ligands is reported. This new approach allows an easy access to twelve new enantiomerically pure atropisomeric ligands in one- to three-step reactions in good to excellent yields.

[] open archive unige:75306 full text [restricted access]   

 (343) 

N. Germain, A. Alexakis "Formation of Contiguous Quaternary and Tertiary Stereocenters by Sequential Asymmetric Conjugate Addition of Grignard Reagents to 2-Substituted Enones and Mg-Enolate Trapping" Chem. Eur. J. 2015, 21, 8597-8606.

Herein a comprehensive study is provided on the asymmetric conjugate addition (ACA) of Grignard reagents to α-substituted cyclic enones. After the elucidation of the optimal experimental conditions, the scope of Grignard reagents and Michael acceptors was examined. Whereas secondary Grignards gave better enantioselectivities with 2-cyclopentenones, both linear and branched Grignard reagents were tolerated for the ACA to 2-methylcyclohexenone. The sequential ACA–enolate trapping, which leads to quaternary stereocenters, was then studied. Thus, many electrophiles have been tested, thereby giving rise to highly functionalized cyclic ketones with contiguous α-quaternary and β-tertiary centers. The present technique is believed to bring a new approach to versatile terpenoid-like skeletons of bioactive natural products. Straightforward derivatizations of enantioenriched saturated cyclic ketones further support the potential of the present methodology in synthesis.

[] open archive unige:72891 full text [restricted access]   

 (342) 

F. Romanov-Michailidis, M. Romanova-Michaelides, M. Pupier, A. Alexakis "Enantioselective Halogenative Semi-Pinacol Rearrangement: Extension of Substrate Scope and Mechanistic Investigations" Chem. Eur. J. 2015, 21, 5561-5583.

The present Full Paper article discloses a survey of our recent results obtained in the context of the enantioselective halogenation-initiated semi-pinacol rearrangement. Commencing with the fluorination/semi-pinacol reaction first and moving to the heavier halogens (bromine and iodine) second, the scope and limitations of the halogenative phase-transfer methodology will be discussed and compared. An extension of the fluorination/semi-pinacol reaction to the ring-expansion of five-membered allylic cyclopentanols will be also described, as well as some preliminary results on substrates prone to desymmetrization will be given. Finally, the present manuscript will culminate with a detailed mechanistic investigation of the canonical fluorination/semi-pinacol reaction. Our mechanistic discussion will be based on in situ reaction progress monitoring, complemented with substituent effect, kinetic isotopic effect and non-linear behaviour studies.

[] open archive unige:55654 full text [restricted access]   

 (341) 

P. Garcia, N. Germain, S. Woodward, A. Alexakis "Copper-Catalyzed Asymmetric Conjugate Addition to α-Alkylidene Cycloalkanones" Synlett 2015, 26, 901-906.

The asymmetric copper-catalyzed conjugate addition to α-alkylidene cycloalkanones, substituted at their terminal position with aromatic and aliphatic groups, is reported. While high enantioselectivity is reached using chiral phosphoramidite ligands, with R3Al reagents, moderate diastereoselectivity was observed upon hydrolysis of the aluminium enolates. A Grignard reagent also react with high diastereo­selectivity.

[] open archive unige:55652 full text [restricted access]   

 2014
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 (340) 

A. Lefranc, L. Guénée, S. Goncalves-Contal, A. Alexakis "Direct Organocatalytic Construction of Bicyclo[3.2.1]octanes by Domino Michael/Aldol Reaction with β,γ-Unsaturated 1,2-Keto Amides" Synlett 2014, 25, 2947-2952.

A direct construction of bicyclo[3.2.1]octanes by an organocatalytic domino Michael/Aldol reaction of cyclic 1,3-keto esters with β,γ-unsaturated 1,2-keto amides is reported. Formation of a precipitate corresponding to the racemic co-crystals of the bicyclic compound was observed in toluene, whereas a homogeneous solution was obtained in dichloromethane. Preliminary mechanistic investigations on the reversibility of the system allowed enhancing the selectivity (>20:1 dr, 73% ee). Relative configuration of the bicyclic compound was determined by X-ray crystal structure analyses.

[] open archive unige:43001 full text [restricted access]   

 (339) 

H. Li, D. Grassi, L. Guénée, T. Bürgi, A. Alexakis "Copper-Catalyzed Propargylic Substitution of Dichloro Substrates: Enantioselective Synthesis of Trisubstituted Allenes and Formation of Propargylic Quaternary Stereogenic Centers" Chem. Eur. J. 2014, 20, 16694-16706.

An easy and versatile Cu-catalyzed propargylic substitution process is presented. Using easily prepared prochiral dichloro substrates, readily available Grignard reagents together with catalytic amount of copper salt and chiral ligand, we accessed a range of synthetically interesting trisubstituted chloroallenes. Substrate scope and nucleophile scope are broad, providing generally high enantioselectivity for the desired 1,3-substitution products. The enantioenriched chloroallenes could be further transformed into the corresponding trisubstituted allenes or terminal alkynes bearing all-carbon quaternary stereogenic centers, through the copper-catalyzed enantiospecific 1,1/1,3-substitutions. The two successive copper-catalyzed reactions could be eventually combined into a one-pot procedure and different desired allenes or alkynes were obtained respectively with high enantiomeric excesses.

[] open archive unige:43540 full text [restricted access]   

 (338) 

A. Lefranc, L. Gremaud, A. Alexakis "Construction of Bicyclo[3.2.1]octanes with Four Stereogenic Centers by Organocatalytic Domino Michael/Aldol Reaction" Org. Lett. 2014, 16, 5242-5245.

An enantio- and diastereoselective organocatalytic domino Michael/Aldol reaction for the direct preparation of synthetically and medicinally relevant bicyclo[3.2.1]octane derivatives with four stereogenic centers, including two quaternary carbons, has been described. The reaction tolerates a large variety of substituents on β,γ-unsaturated 1,2-ketoesters and cyclic 1,3-ketoesters. It allows for the formation of various bicyclo[3.2.1]octanes in good yields (53–98%), diastereoselectivities (1:1 to 5:1 dr), and enantioselectivities (up to 95:5 ee).

[] open archive unige:41533 full text [restricted access]   

 (337) 

F. Romanov-Michailidis, M. Pupier, C. Besnard, T. Bürgi, A. Alexakis "Enantioselective Catalytic Fluorinative Aza-semipinacol Rearrangement" Org. Lett. 2014, 16, 4988-4991.

An efficient and highly stereoselective fluorinative aza-semipinacol rearrangement is described. The catalytic reaction requires use of Selectfluor in combination with the chiral, enantiopure phosphate anion derived from acid L3. Under optimized conditions, cyclopropylamines A were transformed into β-fluoro cyclobutylimines B in good yields and high levels of diastereo- and enantiocontrol. Furthermore, the optically active cyclobutylimines were reduced diastereoselectively with L-Selectride in the corresponding fluorinated amines C, compounds of significant interest in the pharmacological industry.

[] open archive unige:41312 full text [restricted access]   

 (336) 

A. Alexakis, F. Romanov-Michailidis, M. Pupier, L. Guénée "Enantioselective halogenative semi-pinacol rearrangement: a stereodivergent reaction on a racemic mixture" Chem. Commun. 2014, 50, 13461-13464.

An efficient, quantitative deracemization strategy of optically inactive allylic cycloalkanols has been achieved using the biphasic halogenative semi-pinacol reaction protocol. The resultant β-halo spiroketones, containing three contiguous stereogenic centers, were easily recovered with high diastereomeric and enantiomeric purities following conventional silica gel chromatography. The optically active products could be further manipulated chemically, affording synthetically interesting scaffolds with complete preservation of stereoisomeric integrity.

[] open archive unige:40861 full text [restricted access]   

 (335) 

D. Grassi, A. Alexakis "Transition metal-free asymmetric and diastereoselective allylic alkylation using Grignard reagents: construction of vicinal stereogenic centers via kinetic resolution" Chem. Sci. 2014, 5, 3803-3807.

The first transition metal-free diastereoselective and enantioselective asymmetric allylic alkylation (AAA) has been disclosed leading to the construction of vicinal tertiary/quaternary centers via a kinetic resolution protocol starting from readily available starting materials. This procedure is chemically appealing since no consecutive AAA or stereoselective metal-catalyzed/chiral ligand AAAs are required to construct the two stereocenters.

[] open archive unige:41530 full text [restricted access]   

 (334) 

N. Germain, D. Schlaefli, M. Chellat, S. Rosset, A. Alexakis "Domino Asymmetric Conjugate Addition-Conjugate Addition" Org. Lett. 2014, 16, 2006-2009.

Enantioenriched Al-, Mg-, and Zn-enolates undergo electrophilic trapping by nitroolefins and vinylsulfones to afford 1,4-diketones and 2-(bis(phenylsulfonyl)ethyl)ketones in good yield and excellent diastereoselectivity. A one-pot preparation of indenes and enantiopure syntheses of tetrahydrobenzofurans, tetrahydrobenzopyrroles, and azulenes are disclosed. A site-selective two-step sequence of three conjugate additions is also demonstrated.

[] open archive unige:35768 full text [restricted access]   

 (333) 

M. Tissot, H. Li, A. Alexakis "Copper-Catalyzed Asymmetric Conjugate Addition and Allylic Substitution of Organometallic Reagents to Extended Multiple-Bond Systems" In Copper-Catalyzed Asymmetric Synthesis; A. Alexakis, N. Krause, S. Woodward (Eds.); Wiley-VCH 2014; Chapter 3; p. 69-85.

[] open archive unige:35381 full text [restricted access]   

 (332) 

A. Alexakis, N. Krause, S. Woodward "Copper-Catalyzed Asymmetric Conjugate Addition" In Copper-Catalyzed Asymmetric Synthesis; A. Alexakis, N. Krause, S. Woodward (Eds.); Wiley-VCH 2014; Chapter 2; p. 33-69.

[] open archive unige:35379 full text [restricted access]   

 (331) 

A. Alexakis, N. Krause, S. Woodward (Eds.) "Copper-Catalyzed Asymmetric Synthesis" Wiley-VCH 2014. open archive unige:35383   

 (330) 

D. Willcox, S. Woodward, A. Alexakis "Enantioselective 1,4-additions of ClMeAl(CH=CHR) (R = alkyl, alkenyl, Ph) to cyclohexenones" Chem. Commun. 2014, 50, 1655-1657.

Chloromethylvinyl alanes (E)-ClMeAl(CH=CHR) prepared directly from terminal alkynes undergo 1,4-addition to cyclohexenone and 3-methylcyclohexenone in moderate to good yield (30–70%) and good to excellent stereoselectivity (80–98% ee) using readily available copper(I) sources and chiral ligands.

[] open archive unige:33671 full text [restricted access]   

 (329) 

N. Germain, L. Guénée, M. Mauduit, A. Alexakis "Asymmetric Conjugate Addition to α-Substituted Enones/Enolate Trapping" Org. Lett. 2014, 16, 118-121.

An NHC–Cu complex catalyzed the asymmetric conjugate addition (ACA) of various Grignard reagents to nonactivated α-substituted cyclic enones to give 2,3-dialkylated cyclopentanones and cyclohexanones. The Michael addition features the formation of a magnesium enolate intermediate. One-pot diastereoselective trapping of this enolate by alkyl, propargyl, allyl, and benzyl halides led to ketones with contiguous α-quaternary and β-tertiary centers.

[] open archive unige:32843 full text [restricted access]   

 2013
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 (328) 

A. Quintard, A. Alexakis "Organocatalytic conjugate addition in stereoselective synthesis" In Stereoselective Synthesis of Drugs and Natural Products; V. Andrushko, N. Andrushko (Eds.); Wiley 2013; Chapter 11; p. 319-346.

[] open archive unige:34812 full text [restricted access]   

 (327) 

D. Grassi, A. Alexakis "Copper-Free Asymmetric Allylic Alkylation of Trisubstituted Cyclic Allyl Bromides Using Grignard Reagents" Angew. Chem. Int. Ed. 2013, 52, 13642-13646.

AAA: The asymmetric allylic alkylation (AAA) of trisubstituted cyclic allyl bromides with Grignard reagents is catalytic (2 mol % of ligand) and regioselective (SN2’/SN2=91:9→100:0). The quaternary carbon centers are formed with good to high enantioselectivity (e.r.=81.5:19.5→96:4).

[] open archive unige:32651 full text [restricted access]   

 (326) 

S. Goncalves-Contal, L. Gremaud, A. Alexakis "Enantioselective Copper-Catalyzed Conjugate Addition of Trimethylaluminium to β,γ-Unsaturated α-Ketoamides: Efficient Access to γ-Methyl-Substituted Carbonyl Compounds" Angew. Chem. Int. Ed. 2013, 52, 12701-12704.

Picture perfect: By using the reagent trimethylaluminium and β,γ-unsaturated α-ketoamides, 1,4-adducts were obtained with perfect 1,4-regioselectivity and good to excellent yields and ee values. The potential synthetic utility of the methodology was highlighted by preparation of γ-methyl-substituted carbonyls, key synthons to many natural products. binap=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, TC=thiophene carboxylate.

[] open archive unige:31130 full text [restricted access]   

 (325) 

F. Romanov-Michailidis, L. Guénée, A. Alexakis "Enantioselective Organocatalytic Iodination-Initiated Wagner-Meerwein Rearrangement" Org. Lett. 2013, 15, 5890-5893.

The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent S9 and the lipophilic phosphoric acid L9 act as an efficient source of chiral iodine that performs the semipinacol transposition of strained allylic alcohols Ax to β-iodo spiroketones Bx in good yields and with high levels of diastereo- and enantio-induction. The product β-iodo spiroketones could be derivatized stereospecifically and without stereoerosion, giving rise to products inaccessible directly from a semipinacol rearrangement.

[] open archive unige:31110 full text [restricted access]   

 (324) 

D. Müller, A. Alexakis "Formation of Quaternary Stereogenic Centers by Copper-Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones" Chem. Eur. J. 2013, 19, 15226-15239.

Alkenylaluminums undergo asymmetric copper-catalyzed conjugate addition (ACA) to β-substituted enones allowing the formation of stereogenic all-carbon quaternary centers. Phosphinamine–copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β-substituted enones. Two strategies for the generation of the requisite alkenylaluminums were explored allowing for the introduction of aryl- and alkyl-substituted alkenyl nucleophiles. Moreover, alkyl-substituted phosphinamine (SimplePhos) ligands were identified for the first time as highly efficient ligands for the Cu-catalyzed ACA.

[] open archive unige:30742 full text [restricted access]   

 (323) 

F. Giacomina, A. Alexakis "Construction of Enantioenriched Cyclic Compounds by Asymmetric Allylic Alkylation and Ring-Closing Metathesis" Eur. J. Org. Chem. 2013, 6710-6721.

A new approach to highly enantioenriched cyclic compounds (up to 98 % ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands.

[] open archive unige:30348 full text [restricted access]   

 (322) 

M. Magrez-Chiquet, M. S. T. Morin, J. Wencel-Delord, S. Drissi Amraoui, O. Baslé, A. Alexakis, C. Crévisy, M. Mauduit "Enantioselective 1,6-Conjugate Addition of Dialkylzinc Reagents to Acyclic Dienones Catalyzed by Cu-DiPPAM Complex-Extension to Asymmetric Sequential 1,6/1,4-Conjugate Addition" Chem. Eur. J. 2013, 19, 13663-13667.

C—C coupling: DiPPAM 1 and BINAP 2 ligands led to divergent behaviors in the asymmetric conjugate addition (ACA) of dialkylzinc reagents to linear aryldienones, which were applied to the development of a highly selective sequential asymmetric 1,6/1,4-ACA process (see scheme).

[] open archive unige:30104 full text [restricted access]   

 (321) 

D. Müller, L. Guénée, A. Alexakis "Practical Synthesis of SimplePhos Ligands: Further Development of Alkyl-Substituted Phosphanamines" Eur. J. Org. Chem. 2013, 6335-6343.

Herein we disclose a rapid and easy synthetic procedure to access aryl- and alkyl-substituted phosphanamines (SimplePhos ligands). During the synthesis of a library of diverse aryl-substituted phosphanamine ligands we also found that alkyl-substituted phosphanamines can be synthesized and handled easily. This was unexpected as a previous report described them as highly air-sensitive compounds. Subsequently, we created a library of alkyl-substituted phosphanamines and found some to be highly efficient ligands in copper-catalyzed reactions such as the Cu-catalyzed asymmetric conjugate addition and propargylic alkylation reactions. Moreover, our efforts towards the synthesis of SimplePhos ligands led to the development of an easy and practical synthesis of diaryl(chloro)phosphanes, which is also presented in this paper.

[] open archive unige:29943 full text [restricted access]   

 (320) 

J. Graff, T. Debande, J. Praz, L. Guénée, A. Alexakis "Asymmetric Bromine–Lithium Exchange: Application toward the Synthesis of Natural Product" Org. Lett. 2013, 15, 4270-4273.

Asymmetric bromine–lithium exchange has been successfully employed to synthesize bicoumarin chiral building blocks of (+)-isokotanin A and (−)-kotanin in good yields and with an excellent level of enantioselectivity. This is the first reported example of formal syntheses, using this direct methodology, leading to the single (M)-atropoisomer of (+)-isokotanin A and (−)-kotanin building blocks, without any resolution step.

[] open archive unige:29559 full text [restricted access]   

 (319) 

F. Romanov-Michailidis, L. Guénée, A. Alexakis "Enantioselective Organocatalytic Fluorination-Induced Wagner-Meerwein Rearrangement" Angew. Chem. Int. Ed. 2013, 52, 9266-9270.

Cracked under strain: Strained allylic cyclobutanols and cyclopropanols readily undergo a ring expansion described by the title rearrangement. This reaction is promoted by catalytic amounts of 1 and displays high tolerance with respect to the substrate scope. The corresponding β-fluoro spiroketone products are isolated in high yields and with excellent stereoselectivities. EDG=electron-donating group, EWG=electron-withdrawing group.

[] open archive unige:29563 full text [restricted access]   

 (318) 

M. Tissot, A. Alexakis "Enantio- and Regioselective Conjugate Addition of Organometallic Reagents to Linear Polyconjugated Nitroolefins" Chem. Eur. J. 2013, 19, 11352-11363.

The copper-catalysed conjugate addition of trialkylaluminium and dialkylzinc reagents to polyconjugated nitroolefins (nitrodiene and nitroenyne derivatives) is reported. A reversed Josiphos ligand L7 allows for the selective 1,4- or 1,6-addition with high enantioselectivities.

[] open archive unige:29564 full text [restricted access]   

 (317) 

B. Pezzati, M. F. Chellat, J. J. Murphy, C. Besnard, G. Reginato, J. C. Stephens, A. Alexakis "Organocatalytic Asymmetric Annulation of 1,3-Bis(alkoxycarbonyl)buta-1,3-dienes and Aldehydes" Org. Lett. 2013, 15, 2950-2953.

Asymmetric organocatalytic annulation of E/Z isomeric mixtures of bis(alkyl carboxylate)buta-1,3-dienes and aldehydes has been realized via enamine catalysis. In the presence of α,α-diphenyl-2-pyrrolidinemethanol trimethylsilyl ether, excellent stereo- and enantioselectivities were achieved for a broad spectrum of substrates.

[] open archive unige:28702 full text [restricted access]   

 (316) 

C. Bleschke, M. Tissot, D. Müller, A. Alexakis "Direct Trapping of Sterically Encumbered Aluminum Enolates" Org. Lett. 2013, 15, 2152-2155.

The formation of chiral and sterically congested cyclohexanone derivatives has been achieved through a multistep sequence with one single purification step. (n-Butoxymethyl)-diethylamine was identified as a highly efficient reagent for the direct trapping of aluminum enolates. The Lewis acidic character of aluminum suffices to activate the α-aminoether to form in situ an electrophilic iminium species. In return the aluminum enolate is rendered more nucleophilic by coordination of the butoxy group and formation of an aluminate.

[] open archive unige:27733 full text [restricted access]   

 (315) 

A. Lefranc, L. Guénée, A. Alexakis "Highly Diastereo- and Enantioselective Organocatalytic Domino Michael/Aldol Reaction of Acyclic 3-Halogeno-1,2-Diones to α,β-Unsaturated Aldehydes" Org. Lett. 2013, 15, 2172-2175.

The first organocatalytic diastereo- and enantioselective domino Michael/aldol reaction of 3-halogeno-1,2-diones to α,β-unsaturated aldehydes has been achieved. This transformation tolerates a large variety of electronically different substituents on both reactive partners and allows the synthesis of challenging cyclopentanone derivatives with four contiguous stereogenic centers in excellent diastereoselectivities (>20:1 dr) as well as good yields (69–97%), and enantioselectivities (up to 94% ee).

[] open archive unige:27720 full text [restricted access]   

 (314) 

D. Müller, A. Alexakis "Creation of Highly Congested Quaternary Centers via Cu-catalyzed Conjugate Addition of Alkenyl Alanates to β-Substituted Cyclic Enones" Org. Lett. 2013, 15, 1594-1597.

Easily prepared alkenylalanates proved to be excellent nucleophiles for the creation of highly congested quaternary centers via copper-catalyzed conjugate addition. In addition, functionalized cis-decaline systems can now be prepared in a simple two-step sequence involving Cu-catalyzed conjugate addition with functionalized alkenylalanates.

[] open archive unige:27319 full text [restricted access]   

 (313) 

P. Cottet, D. Müller, A. Alexakis "Copper-Catalyzed Asymmetric Conjugate Addition of Alkenyl- and Alkylalanes to α,β-Unsaturated Lactams" Org. Lett. 2013, 15, 828-831.

Alkenyl and alkyl groups have been successfully introduced to six-membered α,β-unsaturated lactams via a copper-catalyzed asymmetric 1,4-addition of the corresponding alanes. Moderate to good yields and good to excellent enantioselectivities are achieved by using a combination of the very cheap copper(II) naphthenate and a readily available phosphine amine ligand. The creation of an all-carbon quaternary stereogenic center, via Michael addition to a trisubstituted conjugated lactam, is also disclosed for the first time.

[] open archive unige:26461 full text [restricted access]   

 (312) 

D. Grassi, C. Dolka, O. Jackowski, A. Alexakis "Copper-Free Asymmetric Allylic Alkylation with a Grignard Reagent: Design of the Ligand and Mechanistic Studies" Chem. Eur. J. 2013, 19, 1466-1475.

The Cu-free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92 % ee). The methodology developed was found to be complementary with the Cu-catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species.

[] open archive unige:25800 full text [restricted access]   

 2012
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 (311) 

H. Li, D. Müller, L. Guénée, A. Alexakis "Copper-Catalyzed Enantioselective Synthesis of Axially Chiral Allenes" Org. Lett. 2012, 14, 5880-5883.

A simple copper-catalyzed enantioselective synthesis of axially chiral chloroallenes from the propargylic dichlorides is reported, employing a catalytic amount of easily prepared SimplePhos ligand. Exclusive formation of the desired allenes was observed with good enantioselectivities (ee’s 62–96%). Further transformations to trisubstituted allenes or terminal alkynes with a propargylic quaternary carbon center keep a high level of enantiopurity.

[] open archive unige:25120 full text [restricted access]   

 (310) 

D. Muller, A. Alexakis "Rhodium and Copper-catalyzed asymmetric conjugate addition of alkenyl nucleophiles" Chem. Commun. 2012, 48, 12037-12049.

Since the initial reports in the mid 90s, metal catalyzed asymmetric conjugate addition (ACA) reactions evolved as an important tool for the synthetic chemist. Most of the research efforts have been done in the field of rhodium and copper catalyzed ACA reactions employing aryl and alkyl nucleophiles. Despite the great synthetic value of the double bond, the addition of alkenyl nucleophiles remains insufficiently explored. In this account, an overview of the developments in the field of rhodium and copper catalyzed ACA reactions with organometallic alkenyl reagents (B,Mg, Al, Si, Zr, Sn) will be provided. The account is intended to give a comprehensive overview of all the existing methods. However, in many cases only selected examples are displayed in order to facilitate comparison of different ligands and methodologies.

[] open archive unige:24330 full text [restricted access]   

 (309) 

D. Grassi, H. Li, A. Alexakis "Formation of chiral fluoroalkyl products through copper-free enantioselective allylic alkylation catalyzed by an NHC ligand" Chem. Commun. 2012, 48, 11404-11406.

A valuable Cu-free protocol is reported where NHC ligand has been employed to form quaternary centers bearing fluoroalkyl unities. Importantly the results obtained, from this allylic substitution, are better in terms of enantioselectivity and regioselectivity compared to the copper catalyzed system. Moreover the catalysis is performed directly on the substrate containing the fluoroalkyl moiety. The use of FSBM as fluoromethide equivalent is not anymore required. The reaction has been extended to CF2H group (isosteric to carbinol function) and to CF3 group.

[] open archive unige:23740 full text [restricted access]   

 (308) 

F. Romanov-Michailidis, C. Besnard, A. Alexakis "N-Heterocyclic Carbene-Catalyzed Annulation of α-Cyano-1,4-diketones with Ynals" Org. Lett. 2012, 14, 4906-4909.

In this paper, the first stereoselective annulation reaction between α-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61–90% isolated yields and with up to 20:1 diastereomeric preference.

[] open archive unige:23520 full text [restricted access]   

 (307) 

N. Germain, M. Magrez, S. Kehrli, M. Mauduit, A. Alexakis "Chiral NHC Ligands for the Copper-Catalyzed Asymmetric Conjugate Addition of Grignard Reagents" Eur. J. Org. Chem. 2012, 5301-5306.

In this paper, we disclose our recent advances in the copper-catalyzed enantioselective conjugate addition of Grignard reagents to 3-substituted cyclic enones. Several new N-heterocyclic carbene (NHC) ligands have been synthesized in high yields by starting from inexpensive materials. These new NHCs were evaluated as ligands for copper, for the Michaeladdition of ethylmagnesium bromide leading to chiral 3,3-disubstituted cyclohexanones (up to 93 % ee). The best ligand was then engaged in conjugate additions of various Grignard reagents, allowing the formation of quaternary centers with high levels of regio- and enantioselectivity with only 0.75 mol-% catalyst loading. The reaction is also robust to scale-up. The addition of ethylmagnesium bromide for the construction of a 3,3-disubstituted cyclopentanone (up to 86 % ee), a synthetically useful chiral synthon, is noteworthy. A tentative mechanism for the catalytic cycle is also discussed.

[] open archive unige:22911 full text [restricted access]   

 (306) 

M. Magrez, J. Wencel-Delord, A. Alexakis, C. Crévisy, M. Mauduit "Significant Asymmetric Amplification in Enantioselective Cu/DiPPAM-catalyzed 1,6- and 1,4-Conjugate Additions of Diethylzinc to (Di)enones" Org. Lett. 2012, 14, 3576-3579.

An unprecedented and strong positive nonlinear effect (NLE) was observed in Cu/DiPPAM-catalyzed asymmetric 1,6-conjugate addition of Et2Zn on (E)-3-(prop-1-en-1-yl)cyclohex-2-enone (71% ee reached with a 40% ee ligand). Moreover, similar behaviors were observed in Cu/DiPPAM-catalyzed 1,4-asymmetric conjugate additions of Et2Zn on both cyclohexenone and (E)-3-non-3-en-2-one (83% and 70% ee, respectively, reached with a 40% ee ligand).

[] open archive unige:21934 full text [restricted access]   

 (305) 

M. Tissot, D. Poggiali, H. Hénon, D. Müller, L. Guénée, M. Mauduit, A. Alexakis "Formation of Quaternary Stereogenic Centers by NHC–Cu-Catalyzed Asymmetric Conjugate Addition Reactions with Grignard Reagents on Polyconjugated Cyclic Enones" Chem. Eur. J. 2012, 18, 8731-8747.

The copper-catalyzed conjugate addition of various Grignard reagents to polyconjugated enones (dienone and enynone derivatives) is reported. The catalyst system, composed of copper triflate and an NHC ligand, led to the unusual selective formation of the 1,4-addition products. This reaction allows for the creation of all-carbon chiral quaternary centers with enantiomeric excesses up to 99 %. The remaining unsaturation on the 1,4 adducts give access to valuable synthetic transformations.

[] open archive unige:21875 full text [restricted access]   

 (304) 

J. Praz, L. Guénée, S. Aziz, A. Berkessel, A. Alexakis "Evaluation of the Chiral DIANANE Backbone as Ligand for Organolithium Reagents" Adv. Synth. Catal. 2012, 354, 1780-1790.

Novel endo,endo-2,5-diaminonorbonanederived tertiary C2-symmetrical diamines were synthesized via the one-pot reductive amination of enantiomerically pure norbornane-2,5-dione. These ligands were applied to various catalytic reactions such as asymmetric deprotonation, asymmetric bromine-lithium exchange, and enantioselective addition of aryl- and allkylithium reagents to aromatic aldimines.

[] open archive unige:21681 full text [restricted access]   

 (303) 

L. Gremaud, L. Palais, A. Alexakis "Copper-catalyzed Asymmetric Conjugate Addition to Challenging Michael Acceptors and Synthesis of Relevant Target Molecules" CHIMIA 2012, 66, 196-200.

We report herein the enantioselective Cu-catalyzed conjugate addition of organometallic reagents to sensitive Michael acceptors and their application to the synthesis of relevant target molecules. This is one of the most important methodologies to form a C–C bond in an enantioselective manner. A wide range of α,β-unsaturated aldehydes and β,γ-unsaturated-α-ketoesters has been successfully used. Reactivity, regioand enantioselectivities were strongly dependent on the reaction conditions, therefore moderate to very good results were obtained. Furthermore, γ-substituted-α-ketoesters were used as chiral building blocks for further derivatization with complete retention of the chiral information to obtain key compounds.

[] open archive unige:20284 full text [restricted access]   

 (302) 

D. Müller, A. Alexakis "Copper-Catalyzed Asymmetric 1,4-Addition of Alkenyl Alanes to N-Substituted-2-3-dehydro-4-piperidones" Org. Lett. 2012, 14, 1842-1845.

Readily available vinyl alanes are used in the Cu-catalyzed asymmetric conjugate addition reaction to N-substituted-2-3-dehydro-4-piperidones. The enhanced reactivity of recently developed and easily prepared phosphine amine ligands in combination with inexpensive Cu(II)naphtenate (CuNp) allows the introduction of a great variety of alkenyl, alkyl, and aryl aluminums in high enantioselectivity.

[] open archive unige:19416 full text [restricted access]   

 (301) 

D. Grassi, A. Alexakis "Copper-Free Asymmetric Allylic Alkylation Using Grignard Reagents on Bifunctional Allylic Bromides" Org. Lett. 2012, 14, 1568-1571.

A series of substrates containing a vinylic bromide were employed in a copper-free methodology using bidendate NHC ligands. The desired compounds are generally obtained with good enantioselectivity and good regioselectivity. Importantly the copper-catalyzed system afforded a lower enantioselectivity value. The catalytic products could be transformed into a broad scope of new 1,1-disubstituted olefins in a single step transformation without erosion of the enantioselectivity.

[] open archive unige:18861 full text [restricted access]   

 (300) 

M. Magre, J. Mazuela, M. Diéguez, O. Pàmies, A. Alexakis "Furanoside phosphite–phosphoroamidite and diphosphoroamidite ligands applied to asymmetric Cu-catalyzed allylic substitution reactions" Tetrahedron: Asymmetry 2012, 23, 67-71.

A phosphite-phosphoroamidite and diphosphoroamidite ligand library was applied in the Cu-catalyzed allylic substitution of a range of cinnamyl-type substrates using several organometallic nucleophiles. Results indicated that selectivity depended strongly on the ligand parameters (position of the phosphoroamidite group at either C-5 or C-3 of the furanoside backbone, as well as the configuration of C-3, the introduction of a second phosphoroamidite moiety, the substituents and configurations in the biaryl phosphite/phosphoroamidite moieties), the nature of the leaving group of the substrate and the alkylating reagent. Good enantioselectivities (up to 76%) and activity combined with high regioselectivities were obtained.

[] open archive unige:18837 full text [restricted access]   

 (299) 

J.-B. Langlois, D. Emery, J. Mareda, A. Alexakis "Mechanistic identification and improvement of a direct enantioconvergent transformation in copper-catalyzed asymmetric allylic alkylation" Chem. Sci. 2012, 3, 1062-1069.

Recently, our group reported on the development of an unprecedented process in copper-catalyzed Asymmetric Allylic Alkylation. This method allowed for the quantitative transformation of a racemic substrate into an enantioenriched product. While a high level of asymmetric induction (up to 99% ee) was observed, the mechanistic understanding of the reaction remained fuzzy. In the present article, a thorough mechanistic analysis, based on computational investigations, led to the identification of the reaction pathway. Notably, it uncovered that both enantiomers of the starting material converged independently to the same product via two different mechanistic routes. This specific feature established this process as a rare example of Direct Enantioconvergent Transformation. Finally, the modelling results prompted a valuable improvement of the reaction, relying on the use of a more accessible range of substrates.

[] open archive unige:18777 full text [restricted access]   

 (298) 

H. Li, A. Alexakis "Enyne Chlorides: Substrates for Copper-Catalyzed Asymmetric Allylic Alkylation" Angew. Chem. Int. Ed. 2012, 51, 1055-1058.

A select few: Several prochiral enyne chlorides were employed as substrates in the title reaction using Grignard reagents as the alkylation reagents (see scheme; CuTC=copper(I) thiophenecarboxylate). Excellent 1,3 substitution regioselectivities and good to excellent enantioselectivities were obtained. The substrate scope is additionally extended to diene chlorides.

[] open archive unige:18209 full text [restricted access]   

 (297) 

L. Gremaud, A. Alexakis "Enantioselective Copper-Catalyzed Conjugate Addition of Trimethylaluminium to β,γ-Unsaturated α-Ketoesters" Angew. Chem. Int. Ed. 2012, 51, 794-797.

Not a cop out: The copper-catalyzed asymmetric conjugate addition of organometallic reagents to Michael acceptors is an important methodology for forming a C—C bond in an enantioselective manner. Such an addition of Me3Al to β,γ-unsaturated α-ketoesters is described to proceed in high yield and selectivity. CuTC=copper(I) thiophene-2-carboxylate.

[] open archive unige:18073 full text [restricted access]   

 (296) 

J.-B. Langlois, A. Alexakis "Copper-catalyzed Enantioselective Allylic Substitution" In Transition Metal Catalyzed Enantioselective Allylic Substitution in Organic Synthesis; U. Kazmaier (Ed.); Topics in Organometallic Chemistry, Vol. 38; Springer: Berlin / Heidelberg, 2012; p. 235-268.

The efficiency of organocopper reagents in the displacement of allylic leaving groups has been well established during the past five decades. In sharp contrast, catalytic asymmetric version of this reaction using a chiral catalyst is a more recent field of research. This chapter presents an overview of tremendous studies towards the development of an “ideally” active catalyst achieving high regio- and enantioselectivities. The comparative reactivity and generality of peptides, phosphorus, as well as N-heterocyclic carbenes based catalysts are discussed in the first part. Then, relevant scope and synthetic applications are reviewed. Noteworthily, this chapter is restricted to C–C bond formation processes, excluding C–B and C–Si bond formations.

[] open archive unige:17513 full text [restricted access]   

 2011
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 (295) 

A. Quintard, J.-B. Langlois, D. Emery, J. Mareda, L. Guénée, A. Alexakis "Conformationally Stabilized Catalysts by Fluorine Insertion: Tool for Enantioselectivity Improvement" Chem. Eur. J. 2011, 17, 13433-13437.

Frigid cats: The power of conformationally stabilized catalysts is demonstrated. By taking appropriate advantage of fluorine insertion (see scheme), purely conformational catalyst design led to a notable improvement in enantioselectivities from around 70 % to 91-98.5 % ee. The other advantage of this approach is the better understanding of the origin of the stereoselectivity in the given catalytic system.

[] open archive unige:17736 full text [restricted access]   

 (294) 

D. Müller, M. Tissot, A. Alexakis "New Experimental Conditions for Tandem hydroalumination/Cu-Catalyzed Asymmetric Conjugate Additions to β-Substituted Cyclic Enones" Org. Lett. 2011, 13, 3040-3043.

Readily available alkenylalanes, arising from hydroalumination of unprotected terminal alkynes, have been directly employed for the copper-catalyzed asymmetric conjugate addition (ACA) to β-substituted cyclic enones. The desired products, containing a quaternary stereogenic center, are generally obtained in good yields and enantioselectivities.

[] open archive unige:16318   

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A. Quintard, A. Alexakis "Highly enantioselective organocascade intermolecular iminium/enamine Michael addition on enals" Chem. Commun. 2011, 47, 7212-7214.

An unprecedented intermolecular iminium/enamine Michael addition on enals has been developed by taking advantage of the high reactivity of vinyl sulfones. This powerful organocascade allows for the rapid construction of attractive synthons in high enantioselectivities (typically 99% ee).

[] open archive unige:16317 full text [restricted access]   

 (292) 

J. J. Murphy, A. Quintard, P. McArdle, A. Alexakis, J. C. Stephens "Asymmetric Organocatalytic 1,6-Conjugate Addition of Aldehydes to Dienic Sulfones" Angew. Chem. Int. Ed. 2011, 50, 5095-5098.

An unprecedented 1,6-enamine conjugate addition exploiting the charge delocalization in 1,3-bis(sulfonyl) butadienes has been developed. By appropriately designing a Michael acceptor, unique reactivities were obtained for the formation of highly valuable dienes containing two versatile vinyl sulfones (see scheme, TMS=trimethylsilyl).

[] open archive unige:15871 full text [restricted access]   

 (291) 

M. Tissot, A. Pérez Hernández, D. Müller, M. Mauduit, A. Alexakis "Highly Enantioselective and Regioselective Copper-Catalyzed 1,4 Addition of Grignard Reagents to Cyclic Enynones" Org. Lett. 2011, 13, 1524-1527.

In this letter we describe an unusual result in terms of regioselectivity with respect to copper-catalyzed conjugate additions of various Grignard reagents to cyclic enynones. The use of Cu(OTf)2 and NHC ligand L1 as the catalyst combination in CH2Cl2 led to the unique formation of the 1,4 adduct. This selectivity does not follow the general trend previously observed in the literature using extended Michael acceptors. Moreover these reactions allowed for the creation of a quarternary stereogenic center with enantioselectivities up to 97% ee.

[] open archive unige:14606 full text [restricted access]   

 (290) 

A. Quintard, A. Lefranc, A. Alexakis "Highly Enantioselective Direct Vinylogous Michael Addition of γ-Butenolide to Enals" Org. Lett. 2011, 13, 1540-1543.

An unprecedented and simple direct vinylogous addition of deconjugated butenolide to enals has been developed in excellent stereoselectivities (>95% ee), with Aminal-PYrrolidine (APY) catalyst. This methodology allows for the efficient preparation of complex γ-butenolide from readily available renewable resources. Furthermore, preliminary mechanistic investigations have allowed for the better understanding of the origin of both stereoselectivities and of the observed high reactivities.

[] open archive unige:14608 full text [restricted access]   

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A. Quintard, A. Alexakis, C. Mazet "Access to High Levels of Molecular Complexity by One-Pot Iridium/Enamine Asymmetric Catalysis" Angew. Chem. Int. Ed. 2011, 50, 2354-2358.

Independent workers with team spirit: A catalytic sequence that exploits the compatibility of (chiral) cationic iridium catalysts for the isomerization of primary allylic alcohols to aldehydes with organocatalysts has been developed for the highly enantioselective α functionalization of aldehydes (see scheme: up to 66 % yield, d.r. 49:1, 99 % ee). The reaction displayed useful generality with respect to both the nucleophile and the electrophile.

[] open archive unige:14494 full text [restricted access]   

 (288) 

J.-B. Langlois, A. Alexakis "Identification of a Valuable Kinetic Process in Copper-Catalyzed Asymmetric Allylic Alkylation" Angew. Chem. Int. Ed. 2011, 50, 1877-1881.

Copper bottomed: The application of a previously described process of dynamic kinetic asymmetric transformation to acyclic substrates allowed the identification of a relevant kinetic process in the title reaction (see scheme; CuTC= copper(I) thiophencarboxylate, Naphth= naphthyl). The optimization of the reaction conditions and generality of the method, as well as mechanistic considerations are disclosed.

[] open archive unige:14468 full text [restricted access]   

 (287) 

A. Quintard, A. Alexakis "1,2-Sulfone rearrangement in organocatalytic reactions" Org. Biomol. Chem. 2011, 9, 1407-1418.

The 1,2-sulfone rearrangement resulting from nucleophilic addition to bis activated vinyl-sulfones has been studied in more detail. Various nucleophiles activated by different types of catalysts (enamine, Brönsted base, thiourea) are able to promote such rearrangement in excellent yields and moderate to excellent enantioselectivities (up to 94% ee). Mechanistic studies have led to a better understanding of the mechanism and allowed its application to other electrophiles such as vinyl-sulfone acrylates.

[] open archive unige:14466 full text [restricted access]   

 2010
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 (286) 

C. Hawner, D. Müller, L. Gremaud, A. Felouat, S. Woodward, A. Alexakis "Rhodium-Catalyzed Asymmetric 1,4-Addition of Aryl Alanes to Trisubstituted Enones: Binap as an Effective Ligand in the Formation of Quaternary Stereocenters" Angew. Chem. Int. Ed. 2010, 49, 7769-7772.

All for one and 1,4-all: Readily available aryl alanes are used in the rhodium-catalyzed asymmetric conjugate addition reaction with a variety of cyclic and acyclic enones. The enhanced reactivity of the system allows the use of the common binap ligand for the generation of quaternary benzylic stereocenters in excellent enantioselectivity (see scheme).

[] open archive unige:12230 full text [restricted access]   

 (285) 

Q. Perron, A. Alexakis "Catalytic Asymmetric Bromine-Lithium Exchange: A New Tool to Build Axial Chirality" Adv. Synth. Catal. 2010, 352, 2611-2620.

We present here the first catalytic desymmetrization of the 2,2′,6,6-tetrabromobiphenyl 1 and analogues, by a bromine-lithium exchange catalyzed by either diamines or diether derivatives (0.5 equiv.), yielding axially chiral compounds in high yield (up to 89%) and high enantioselectivity (up to 82%).

[] open archive unige:12231 full text [restricted access]   

 (284) 

J. Mazuela, O. Pàmies, M. Diéguez, L. Palais, S. Rosset, A. Alexakis "Fine-tunable monodentate phosphoroamidite and aminophosphine ligands for Rh-catalyzed asymmetric hydroformylation" Tetrahedron: Asymmetry 2010, 21, 2153-2157.

A biaryl-based monophosphoroamidite L1-L4a-f and aminophosphine L5-L7a-f ligand library was screened in the Rh-catalyzed asymmetric hydroformylation of several vinylarenes and heterocyclic olefins. Our results indicate that the selectivity is strongly dependent on the ligand parameters and on the substrate type. Enantioselectivities (up to 46%) were moderate in the hydroformylation of several vinylarenes S1-S5 and promising (up to 58%) for the more challenging heterocyclic olefins S6-S9.

[] open archive unige:12132 full text [restricted access]   

 (283) 

C. Hawner, A. Alexakis "Metal-catalyzed asymmetric conjugate addition reaction: formation of quaternary stereocenters" Chem. Commun. 2010, 46, 7295-7306.

All-carbon quaternary stereocenters are ubiquitous motifs in biological products and pharmaceutical agents. However, due to sterical reasons, these centers are not always easily accessible. The metalcatalyzed conjugate addition reaction to trisubstituted conjugated substrates presents a viable methodology to create quaternary centers. In this article, different ways of activating the conjugate system towards nucleophilic addition will be described. An overview will be given on the different types of quaternary centers that are accessible through the conjugate addition reaction.

[] open archive unige:12131 full text [restricted access]   

 (282) 

J. Wencel-Delord, A. Alexakis, C. Crévisy, M. Mauduit "Enantioselective 1,6-Conjugate Additionto Cyclic Dienones Catalyzed by theCu-DiPPAM Complex" Org. Lett. 2010, 12, 4335-4337.

In the presence of a Cu/DiPPAM catalytic system, various diorganozinc reagents realize 1,6-asymmetric conjugate addition on various cyclic five- and six-membered cyclic dienones, with complete regioselectivity and high ee’s (93-99%).

[] open archive unige:12130 full text [restricted access]   

 (281) 

A. Quintard, A. Alexakis "Highly Enantioselective One-Pot Copper-Catalyzed 1,4 Addition/Organocatalyzed α-Substitution of Enals" Adv. Synth. Catal. 2010, 352, 1856-1860.

The asymmetric copper-catalyzed addition of dialkylzinc to enals followed by organocatalyzed one-pot aldehyde α-functionalization has been accomplished providing CC, CCl or CF bond formation. These simple procedures led to the creation of two contiguous stereocenters in excellent enantioselectivities (typical ee=99%). This methodology has been applied in the synthesis of (2S,3S) isomer of Valnoctamide®.

[] open archive unige:11964 full text [restricted access]   

 (280) 

S. Kehrli, D. Martin, D. Rix, M. Mauduit, A. Alexakis "Formation of Quaternary Chiral Centers by N-Heterocyclic Carbene–Cu-Catalyzed Asymmetric Conjugate Addition Reactions with Grignard Reagents on Trisubstituted Cyclic Enones" Chem. Eur. J. 2010, 16, 9890-9904.

The copper-catalyzed conjugate addition of Grignard reagents to 3-substituted cyclic enones allows the formation of all-carbon chiral quaternary centers. We demonstrate in this article that N-heterocyclic carbenes act as efficient chiral ligands for this transformation. High enantioselectivities (up to 96 % ee) could be obtained for a variety of substrates.

[] open archive unige:11963 full text [restricted access]   

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C. Bournaud, E. Marchal, A. Quintard, S. Sulzer-Mossé, A. Alexakis "Organocatalyst-mediated enantioselective intramolecular Michael addition of aldehydes to vinyl sulfones" Tetrahedron: Asymmetry 2010, 21, 1666-1673.

Chiral amines with a hydrogen bond donor promote the intramolecular conjugate addition of aldehydes to vinyl sulfones. Chiral cyclic sulfone-aldehydes are obtained in good yields with an ee of up to 82%.

[] open archive unige:11039 full text [restricted access]   

 (278) 

D. Müller, C. Hawner, M. Tissot, L. Palais, A. Alexakis "Creation of Quaternary Stereogenic Centers via Copper-Catalyzed Asymmetric Conjugate Addition of Alkenyl Alanes to α,β-Unsaturated Cyclic Ketones" Synlett 2010, 1694-1698.

SimplePhos ligands proved to be very powerful ligands in the generation of quaternary stereogenic centers by Michael addition of alkenyl-aluminum reagents to cyclic enones. Using commercially available and easily accessible alkenylbromides as alane precursors the present procedure offers a facile access to β-alkenyl-substituted cyclohexanones with high enantioselectivities up to 96%.

[] open archive unige:8488 full text [restricted access]   

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M. Tissot, D. Müller, S. Belot, A. Alexakis "Enantioselective and Regiodivergent Copper-Catalyzed Conjugate Addition of Trialkylaluminium Reagents to Extended Nitro-Michael Acceptors" Org. Lett. 2010, 12, 2770-2773.

The first highly enantioselective and regiodivergent conjugate addition of trialkylaluminium reagents to nitrodienes and nitroenynes is described. By a design of the substrate and a fine-tuning of the reaction conditions, it is possible to selectively form the 1,4- or 1,6-adduct. The same combination of catalyst, copper source, and a ferrocene-based phosphine ligand afforded enantioselectivities up to 95% and 91%, respectively.

[] open archive unige:8487 full text [restricted access]   

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A. Quintard, A. Alexakis "Asymmetric addition of α-hetero-disubstituted aldehydes to vinyl sulfones; formation of highly functionalized tetrasubstituted carbon centres" Chem. Commun. 2010, 46, 4085-4087.

Aminal–pyrrolidine catalysed addition of α-hetero-disubstituted aldehydes to vinyl sulfones is described in high enantioselectivity (ee up to 97%). The obtained adducts can easily be converted to enantioenriched synthons as for example 2,2-dialkylepoxide. Evidence for a kinetic resolution is also observed.

[] open archive unige:6780 full text [restricted access]   

 (275) 

L. Palais, L. Babel, A. Quintard, S. Belot, A. Alexakis "Copper-Catalyzed Enantioselective 1,4-Addition to α,β-Unsaturated Aldehydes" Org. Lett. 2010, 12, 1988-1991.

The first asymmetric Cu-catalyzed conjugate addition of dialkylzinc zinc reagents to a large scope of enals in presence of phosphoramidite, SimplePhos, or (R)-BINAP ligands with enantiomeric excesses up to 90% is reported. Moreover, ACA of Grignard reagents afforded moderate to good 1,4-regioselectivities with enantioselectivities up to 90%.

[] open archive unige:6581 full text [restricted access]   

 (274) 

O. Jackowski, A. Alexakis "Copper-Free Asymmetric Allylic Alkylation with Grignard Reagents" Angew. Chem. Int. Ed. 2010, 49, 3346-3350.

Open wide and say AAA: The copper-free asymmetric allylic alkylation reaction of Grignard reagents, catalyzed by N-heterocyclic carbenes, is reported for allyl bromide derivatives. This reaction offers good enantioselectivity and good to excellent γ regioselectivity, particularly for the formation of quaternary chiral centers (see scheme; Mes=mesityl).

[] open archive unige:6580 full text [restricted access]   

 (273) 

F. Giacomina, D. Riat, A. Alexakis "ω-Ethylenic Allylic Substrates as Alternatives to Cyclic Substrates in Copper- and Iridium-Catalyzed Asymmetric Allylic Alkylation" Org. Lett. 2010, 12, 1156-1159.

A new strategy to access highly enantioenriched cyclic compounds (up to 98%) is proposed using ω-ethylenic allylic substrates through a one-pot asymmetric allylic alkylation and ring-closing metathesis. Such starting compounds can be seen as synthetic equivalents of cyclic allylic substrates.

[] open archive unige:6362 full text [restricted access]   

 (272) 

S. Belot, A. Quintard, N. Krause, A. Alexakis "Organocatalyzed Conjugate Addition of Carbonyl Compounds to Nitrodienes/Nitroenynes and Synthetic Applications" Adv. Synth. Catal. 2010, 352, 667-695.

The purpose of this study is to point out the synthetic utility of a new class of Michael acceptors (nitrodienes and nitroenynes). The highly enantioselective organocatalytic Michael addition of carbonyl compounds to these functionalized nitroolefins has been carried out in the presence of (S)-diphenylprolinol silyl ether to achieve some interesting building blocks in high selectivities. The adducts thus obtained can be easily converted by taking advantage of the corresponding unsaturated carbon-carbon bond. In presence of the double bond, metathesis or electrophilic activation could be carried out whereas in the presence of the triple bond electrophilic activation could be conducted. We thus focused on a gold-catalyzed cyclization of the bis-homopropargylic alcohol to afford the corresponding substituted tetrahydrofuran. Then, we also demonstrated that organic and gold catalysts were compatible in a one-pot process. Indeed, we developed a one-pot enantioselective organocatalytic Michael addition to a nitroenyne followed by a gold-catalyzed acetalization/cyclization to achieve tetrahydrofuranyl ethers in high diastereo- and enantioselectivities with excellent yields.

[] open archive unige:6357 full text [restricted access]   

 (271) 

J.-B. Langlois, A. Alexakis "Copper-Catalyzed Asymmetric Allylic Alkylation of Racemic Cyclic Substrates: Application of Dynamic Kinetic Asymmetric Transformation (DYKAT)" Adv. Synth. Catal. 2010, 352, 447-457.

The copper-catalyzed asymmetric allylic alkylation (AAA) is of great interest in organic synthesis. This reaction was extensively studied using a broad range of substrates, ligands and organometallic reagents. However, the use of racemic substrates was still limited. Although some processes of kinetic resolution are reported in the literature, no examples of quantitative deracemization are described as is the case for the Pd-catalyzed allylic alkylation. We present here a full account of our investigations through the development of the first example of such a process in copper-catalyzed AAA. High enantioselectivities (up to 99% ee), scope of the reaction and mechanistic considerations are reported herein.

[] open archive unige:5261 full text [restricted access]   

 (270) 

L. Palais, C. Bournaud, L. Micouin, A. Alexakis "Copper-Catalysed Ring Opening of Polycyclic meso-Hydrazines with Trialkylaluminium Reagents and SimplePhos Ligands" Chem. Eur. J. 2010, 16, 2567-2573.

meso-Hydrazines could be desymmetrised by ring-opening reactions by using various metal catalysts to form substituted cyclopentenes, which have a high synthetic potential. Herein, we report the asymmetric copper-catalysed ring opening of a range of polycyclic hydrazines with trialkylaluminium reagents and SimplePhos ligands with both high isolated yields and enantioselectivities of up to 95 %.

[] open archive unige:5287 full text [restricted access]   

 (269) 

A. Quintard, S. Belot, E. Marchal, A. Alexakis "Aminal-Pyrrolidine Organocatalysts - Highly Efficient and Modular Catalysts for α-Functionalization of Carbonyl Compounds" Eur. J. Org. Chem. 2010, 927-936.

The substitution of the 4-position of hydroxyproline by aphenol group, together with an aminal on the 2-position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the α-functionalization of a wide range of linear/branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and α-amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol-%). As a proof of efficiency, TOFs of up to 1000 h-1 could be obtained.

[] open archive unige:5223 full text [restricted access]   

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M. Welker, S. Woodward, A. Alexakis "Tandem Reactions with Chiral Enolates: Preparation of Allylic Alcohols via Trapping with Vinyl Oxiranes" Org. Lett. 2010, 12, 576-579.

An opening of vinyl oxiranes has been accomplished with Zn and Al enolates resulting from asymmetric conjugate addition reactions on cyclic enones. This novel tandem procedure affords the adducts in moderate to good yields, enantioselectivities up to 98%, and moderate to good cis/trans selectivities. This provides potentially useful synthetic substrates to prepare complex bicyclic compounds.

[] open archive unige:5224 full text [restricted access]   

 (267) 

C. Ladjel, N. Fuchs, L. Gremaud, A. Alexakis "Copper catalysed kinetic resolution of cyclic alkenyl cyclopropane malonate with organoaluminiun and grignard reaggents" Synlett 2010, 317-320.

We report herein the first copper-catalysed kinetic resolution of alkenyl cyclopropane malonates with organoaluminium and Grignard reagents. The conjugate products were exclusively obtained on five- and six-membered-ring substrates. After optimization of the reaction conditions, we observed good conversions and enantiomeric excesses using ferrocene-based ligands on five-membered-ring substrates, and phosphoramidite ligands on six-membered rings.

[] open archive unige:5090 full text [restricted access]   

 2009
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 (266) 

L. Palais, A. Alexakis "Copper-catalyzed asymmetric conjugate addition with Grignard reagents and SimplePhos ligands" Tetrahedron: Asymmetry 2009, 20, 2866-2870.

Herein we report the copper-catalyzed asymmetric conjugate addition of Grignard reagents to cyclic and acyclic enones, with SimplePhos as chiral ligands. A variety of Grignard reagents can be added to a range of cyclic and acyclic enones, with moderate to good enantioselectivities (ee’s up to 86%).

[] open archive unige:8459 full text [restricted access]   

 (265) 

D. Polet, A. Alexakis "Copper-catalyzed enantioselective conjugate addition" In The Chemistry of organocopper compounds; Z. Rappoport, I. Marek (Eds.); John Wiley and sons: London, 2009; Chap. 14; p. 693-730.

[] open archive unige:8485 full text [restricted access]   

 (264) 

S. Belot, K. A. Vogt, C. Besnard, N. Krause, A. Alexakis "Enantioselective One-Pot Organocatalytic Michael Addition/Gold-Catalyzed Tandem Acetalization/Cyclization" Angew. Chem. Int. Ed. 2009, 48, 8923-8926.

Au-rganocatalytic reaction: A one-pot process consisting of a Michael addition to a nitroenyne and a subsequent acetalization/cyclization is reported (see scheme; TMS=trimethylsilyl), which results in the formation of nitro-substituted tetrahydrofuranyl ethers with high diastereo- and enantioselectivities. Organocatalysis and gold catalysis are compatible and complementary in a one-pot process.

[] open archive unige:8103 full text [restricted access]   

 (263) 

E. Raluy, O. Pàmies, M. Diéguez, S. Rosset, A. Alexakis "Sugar-based phosphite and phosphoroamidite ligands for the Cu-catalyzedasymmetric 1,4-addition to enones" Tetrahedron: Asymmetry 2009, 20, 2167-2172.

A modular sugar-based phosphoroamidite L1L5ag and phosphite L6L9ag ligand library was tested in the asymmetric Cu-catalyzed 1,4-conjugate addition reactions of β-substituted (cyclic and linear) and β,β′-disubstituted (cyclic) enones. The selectivity depended strongly on the configuration of carbon atom C-3, the size of the sugar backbone ring, the flexibility of the ligand backbone, the substituents and configurations in the biaryl phosphoroamidite moieties ag, the type of functional group attached to the ligand backbone and the substrate structure. Therefore, by carefully selecting the ligand parameters, enantioselectivities of up to 60% for cyclic substrates and 72% for linear ones were achieved.

[] open archive unige:8119 full text [restricted access]   

 (262) 

J. Wencel, M. Mauduit, H. Hénon, S. Kehrli, A. Alexakis "Chiral, Chelating, Hydroxyalkyl and Hydroxyaryl N-Heterocyclic Carbenes: Design, Synthesis, and Application in Copper-Catalyzed Asymmetric Conjugate Addition (Cu-ACA)" Aldrichim. Acta 2009, 42, 43-50.

Since their discovery in 1968 by Öfele and Wanzlick, and their first isolation in the free state by Arduengo in the early 1990s, N-heterocyclic carbene (NHC) ligands have received a growing attention from the scientific community, notably in organometallic chemistry. These ligands are likely to surpass in popularity well-known phosphorus-based ligands because of their remarkable ability to establish strong bonds with the metal center and their capacity to permit significant doping of catalyst activity in a wide range of chemical transformations such as olefin metathesis, carbon-carbon and carbon-nitrogen cross-coupling reactions, hydrogenation, and hydrosilylation.

[] open archive unige:8476 full text [restricted access]   

 (261) 

A. Quintard, A. Alexakis "Organocatalytic Addition on 1,2-Bis(sulfone)vinylenes Leading to an Unprecedented Rearrangement" Chem. Eur. J. 2009, 15, 11109-11113.

An unprecedented rearrangement of 1,2-bis(sulfone)vinylenes used in aminocatalysis led to the formation of highly useful gem-disulfones (see scheme). By using aminal-pyrrolidine organocatalysts, the 1,2-sulfone shift was generalised, leading to highly versatile adducts using both ketones and aldehydes. It represents a valuable alternative for the -alkylation of carbonyl compounds.

[] open archive unige:8230 full text [restricted access]   

 (260) 

L. Palais, A. Alexakis "Copper-Catalyzed Asymmetric Conjugate Addition with Chiral SimplePhos Ligands" Chem. Eur. J. 2009, 15, 10473-10485.

SimplePhos ligands represent a novel class of monodentate chiral ligands based on a chiral amine moiety and flexible diaryl groups on the phosphorous atom. They can be easily prepared by two different pathways and they can be highly functionalised. Herein we report the copper-catalysed asymmetric conjugate addition of diethyl zinc and trialkylaluminium reagents with SimplePhos ligands, which gives high enantioselectivity with cyclic enones, acyclic enones and nitro-olefins, with up to 98.6 % ee. Of particular interest is the reaction of trialkylaluminium reagents with a wide range of 3-substituted enones, thus allowing the formation of stereogenic quaternary carbon centres.

[] open archive unige:8229 full text [restricted access]   

 (259) 

C. Ladjel, N. Fuchs, J. Zhao, G. Bernardinelli, A. Alexakis "New Bifunctional Substrates for Copper-Catalyzed Asymmetric Conjugate Addition Reactions with Trialkylaluminium" Eur. J. Org. Chem. 2009, 4949-4955.

Trialkylaluminium reagents have been found to undergo a copper-catalyzed asymmetric conjugate addition (ACA) reaction with oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylates with the simultaneous creation of two stereocenters. Different types of ligands were tested, and chiral phosphoramidite ligands allowed the reaction to proceed with good yields and good to excellent enantioselectivity. Thesyn substitution product observed by X-ray analysis suggests an exo attack of the nucleophile. Herein we report the results obtained in the development of this copper-catalyzed ACA methodology, which affords an all-carbon quaternary center with unsubstituted and substituted oxacyclic Michael acceptors. The study was completed by mechanistic investigations performed to elucidate the original reaction pathway.

[] open archive unige:8235 full text [restricted access]   

 (258) 

E. Raluy, O. Pàmies, M. Diéguez, S. Rosset, A. Alexakis "Furanoside phosphite-phosphoroamidite and diphosphoroamidite ligands for Cu-catalyzed asymmetric 1,4-addition reactions" Tetrahedron: Asymmetry 2009, 20, 1930-1935.

A sugar-based phosphite–phosphoroamidite and diphosphoroamidite ligand libraryL1L5ag was tested in the asymmetric Cu-catalyzed 1,4-conjugate addition reactions of β-substituted and β,β′-disubstituted enones. Our results indicated that the selectivity was strongly dependent on the ligand parameters and on the substrate structure. Moderate-to-good enantioselectivities (ees up to 84%) were obtained in the 1,4-addition of several types of β-substituted cyclic and linear substrates. Of particular note is the high enantioselectivity (ees up to 90%) obtained for the more challenging β,β′-disubstituted 3-methyl-cyclohexenone.

[] open archive unige:8106 full text [restricted access]   

 (257) 

K. N. Gavrilov, E. B. Benetskiy, T. B. Grishina, E. A. Rastorguev, M. G. Maksimova, S. V. Zheglov, V. A. Davankov, B. Schäffner, A. Börner, S. Rosset, G. Bailat, A. Alexakis "Bulky P*-Chirogenic Diazaphospholidines as monodentate ligands for asymmetric catalysis" Eur. J. Org. Chem. 2009, 3923-3929.

A series of easily prepared bulky P*-chiral diamidophosphites based on (2R,5S)-3-phenyl-1,3-diaza-2-phosphabicyclo[3.3.0]octane and (2R,5S)-3-(p-bromophenyl)-1,3-diaza-2-phosphabicyclo[3.3.0]octane backbones have been designed and developed. Ligands of this type exhibited high enantioselectivities in Pd-catalysed allylic substitution reactions of (E)-1,3-diphenylallyl acetate with NaSO2pTol (up to 87 %ee), CH2(CO2Me)2 (up to 92 % ee), (C3H7)2NH (up to 93 % ee) and (CH2)4NH (up to 99 % ee). These novel stereoselectors have also been successfully employed in Rh-catalysed asymmetric hydrogenations of dimethyl itaconate (up to 76 % ee), methyl (Z)-2-acetamido-3-phenylacrylate (up to 73 % ee) and methyl 2-acetamidoacrylate (up to 98 % ee). Cu-catalysed conjugate addition of diethylzinc to cyclohexenone leads to a maximum of 70 % ee with quantitative conversion.

[] open archive unige:8234 full text [restricted access]   

 (256) 

J.-B. Langlois, A. Alexakis "Dynamic kinetic asymmetric transformation in copper catalyzed allylic alkylation" Chem. Commun. 2009, 3868-3870.

The first dynamic kinetic asymmetric transformation in copper catalyzed allylic alkylation is reported, with enantioselectivities up to 92%.

[] open archive unige:8011 full text [restricted access]   

 (255) 

R. Millet, L. Gremaud, T. Bernardez, L. Palais, A. Alexakis "Copper catalysed asymmetric ring opening reaction of oxabenzonorbornadienes with grignard and aluminium reaggents" Synthesis 2009, 2101-2112.

A highly enantioselective method for the copper-catalyzed desymmetrization of oxabenzonorbornadienes with aluminum reagents and SimplePhos as chiral ligand has been developed. The same reaction with Grignard reagents is also reported. A wide range of alkyl chains have been used with moderate to high enantio­selectivity and high trans selectivity. The transfer of a methyl group is also reported with high enantiomeric and diastereomeric excess and yields for different substrates. We finally have been able to perform the first trans enantioselective desymmetrization of oxabenzonorbornadienes with an aromatic group.

[] open archive unige:8238 full text [restricted access]   

 (254) 

Q. Perron, J. Praz, A. Alexakis "Chiral Bromide-Lithium exchange catalysed by diamines" Tetrahedron: Asymmetry 2009, 20, 1004-1007.

Different classes of prochiral polyhalide compounds have been tested in a chiral bromine-lithium exchange in the presence of different diamines with enantiomeric excesses of up to 63%.

[] open archive unige:8239 full text [restricted access]   

 (253) 

R. Millet, T. Bernardez, L. Palais, A. Alexakis "Copper-catalyzed desymmetrization of oxabenzonorbornadienes with aluminum reagents" Tetrahedron Lett. 2009, 50, 3474-3477.

The desymmetrization of oxabenzonorbornadienes with aluminum reagents and SimplePhos as chiral ligand is described. The corresponding homoallylic alcohols are obtained in high yield, diastereoselectivity, and enantiomeric excess. Furthermore the first anti enantioselective desymmetrization with aromatic nucleophiles is reported.

[] open archive unige:8478 full text [restricted access]   

 (252) 

S. Sulzer-Mossé, A. Alexakis, J. Mareda, G. Bollot, G. Bernardinelli, Y. Filinchuk "Enantioselective organocatalytic conjugate addition of aldehydes to vinyl sulfones and vinyl phosphonates as challenging Michael accepptors" Chem. Eur. J. 2009, 15, 3204-3220.

Chiral amines with a pyrrolidine framework catalyze the enantioselective conjugate addition of a broad range of aldehydes to various vinyl sulfones and vinyl phosphonates in high yields and with enantioselectivities up to >99% ee. This novel process provides synthetically useful chiral γ-gem-sulfonyl or phosphonyl aldehydes which can be widely functionalized with retention of the enantiomeric excess. Mechanistic insights including DFT calculations are explored in detail.

[] open archive unige:1234 full text [restricted access]   

 (251) 

D. Polet, X. Rathgeb, C. A. Falciola, J.-B. Langlois, S. El Hajjaji, A. Alexakis "Enantioselective Iridium-catalysed allylic arylation" Chem. Eur. J. 2009, 15, 1205-1216.

We describe herein the development of the first iridium-catalyzed allylic substitution using arylzinc nucleophiles. High enantioselectivities were obtained from the reactions, which used commercially available Grignard reagents as the starting materials. This methodology was also shown to be compatible with halogen/metal exchange reactions. Its synthetic potential is demonstrated by its application towards the formal synthesis of (+)-sertraline.

[] open archive unige:7937 full text [restricted access]   

 2008
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 (250) 

E. B. Benetskii, V. A. Davankov, P. V. Petrovskii, E. A. Rastorguev, T. B. Grishina, K. N. Gavrilov, S. Rosset, G. Bailat, A. Alexakis "New P-Chiral polyfluoroalkyl phosphoramidite ligand in asymmetric transformations catalysed by palladium and copper complexes" Russ. J. Org. Chem. 2008, 44, 1846-1848.

[] open archive unige:8236 full text [restricted access]   

 (249) 

C. A. Falciola, A. Alexakis "High diversity on simple substrates: 1,4 dihalo-2-butenes and other difunctionalised allylic halides for copper-catalysed SN2' reactions" Chem. Eur. J. 2008, 14, 10615-10627.

Enantioselective allylic alkylation with an organomagnesium reagent catalyzed by copper thiophene carboxylate (CuTC) was carried out on difunctionalized substrates, such as commercially available 1,4-dichloro-2-butene and 1,4-dibromo-2-butene, and on similar compounds of higher substitution pattern of the olefin for the formation of all-carbon chiral quaternary centers. The high regioselectivity obtained throughout the reactions favored good regiocontrol for the addition of phenyl Grignard reagents. Other difunctionalized substrates (allylic ethers and allylic alcohols) also underwent asymmetric SN2′ substitution.

[] open archive unige:8105 full text [restricted access]   

 (248) 

H. Hénon, M. Mauduit, A. Alexakis "Regiodivergent 1,4 versus 1,6 Asymmetric Copper-catalysed conjugate addition" Angew. Chem. Int. Ed. 2008, 47, 9122-9124.

[] open archive unige:8102 full text [restricted access]   

 (247) 

C. Hawner, K. Li, V. Cirriez, A. Alexakis "Copper-catalysed asymmetric conjugate addition of aryl aluminium reaggents to trisubstituted enones: construction of aryl-substituted quaternary centers" Angew. Chem. Int. Ed. 2008, 47, 8211-8214.

Al be back: Novel aryl and alkenyl aluminum reagents are generated through a halogen/Li exchange–Li/Al transmetalation sequence. These aryl alanes are used in the copper-catalyzed asymmetric conjugate addition reaction to a variety of cyclic enones giving chiral aryl-substituted quaternary centers (see scheme). Both, electron-donating and electron-withdrawing groups give full conversion and very good ee values.

[] open archive unige:8101 full text [restricted access]   

 (246) 

S. Belot, A. Massaro, A. Tenti, A. Mordini, A. Alexakis "Enantioselective organocatalytic conjugate addition of aldehydes to nitrodienes" Org. Lett. 2008, 10, 4557-4560.

The asymmetric organocatalyzed Michael addition of aldehydes to α,β-γ,δ-unsaturated nitro compounds has been accomplished using only 5 mol % of (S)-diphenylprolinol silyl ether and 2 equiv of aldehyde in a mixture of ethanol and water (5% v/v). The Michael adducts were obtained in good yields, diastereoselectivities up to 94/6, and ee’s up to 99%. This process provides synthetically useful compounds which can easily lead to more complex molecules, as exemplified with substituted tetrahydropyran or cyclohexene.

[] open archive unige:8013 full text [restricted access]   

 (245) 

S. Belot, S. Sulzer-Mossé, S. Kehrli, A. Alexakis "Enantioselective organocatalytic conjugate addition of α-aminoketone to nitroolefins" Chem. Commun. 2008, 4694-4696.

The enantioselective organocatalytic conjugate addition of α-aminoketone to nitroolefins is reported.

[] open archive unige:8012 full text [restricted access]   

 (244) 

A. Quintard, C. Bournaud, A. Alexakis "Diversity-Oriented Synthesis towards Conceptually New Highly Modular Aminal-Pyrrolidine Organocatalysts" Chem. Eur. J. 2008, 14, 7504-7507.

New family member: A conceptually new family of modular aminal-pyrrolidine organocatalysts was prepared by diversity-oriented synthesis. The catalytic properties of these organocatalysts could easily be tuned by varying the different substituents on the aminal part. Good yields and enantioselectivities up to 91 % were obtained in Michael additions to nitroolefins or vinyl sulfones.

[] open archive unige:8104 full text [restricted access]   

 (243) 

Q. Perron, A. Alexakis "Copper-catalysed asymmetric addition of diethylzinc to Boc-protected imines" Tetrahedron: Asymmetry 2008, 19, 1871-1874.

A new class of substrates has been tested in the addition of Et2Zn, catalyzed by copper and phosphoramidite, providing the expected α branched protected amine in quantitative conversion, good yield and excellent enantioselectivity up to 97%.

[] open archive unige:8118 full text [restricted access]   

 (242) 

A. Alexakis, J. E. Bäckvall, N. Krause, O. Pàmies, M. Diéguez "Enantioselective copper-catalysed conjugate addition and allylic substitution reactions" Chem. Rev. 2008, 108, 2796-2823.

[] open archive unige:8231 full text [restricted access]   

 (241) 

C. A. Falciola, A. Alexakis "Copper-Catalyzed Asymmetric Allylic Alkylation" Eur. J. Org. Chem. 2008, 3765-3780.

Over the past decade, much effort has been put on designing efficient chiral ligands and screening of the different parameters that govern the main challenges of asymmetric SN2′ reactions, namely chemo-, regio- and enantioselectivity. This review traces the evolution of the methodologies for creating stereogenic centers through asymmetric copper-catalyzed allylic alkylation with the use of different organometallic reagents and their subsequent applications.

[] open archive unige:8233 full text [restricted access]   

 (240) 

R. Millet, A. Alexakis "Simplephos as efficient ligands for the copper-catalysed kinetic resolution of cyclic vinyloxiranes with grognard reaggents" Synlett 2008, 12, 1797-1800.

Cyclic vinyloxiranes react with Grignard reagents under copper catalysis. Highly efficient kinetic resolution is achieved with the new SimplePhos family of chiral phosphorus ligands. Stereodivergence could be exploited to get either the SN2 or SN2′ product with up to 96% ee.

[] open archive unige:8237 full text [restricted access]   

 (239) 

A. Alexakis, M. Vuagnoux-d'Augustin, D. Martin, S. Kehrli, L. Palais, H. Hénon, C. Hawner "Formation of all-carbon quaternary centers by copper-catalysed asymmetric conjugate addition" CHIMIA 2008, 62, 461-464.

This mini-review deals with a special, and challenging, aspect of the asymmetric conjugate addition: the formation of all-carbon quaternary centers by reaction with Michael acceptors bearing a polysubstituted unsaturation. Only copper catalysts allow this transformation, along with a careful choice of primary organometallics and chiral ligand. The resulting adducts are useful intermediates for the synthesis of more complex natural products.

[] open archive unige:8232 full text [restricted access]   

 (238) 

C. A. Falciola, K. Tissot-Croset, H. Reyneri, A. Alexakis "β- and γ-disubstituted olefins: susbtrates for copper-catalysed asymmetric allylic substitution" Adv. Synth. Catal. 2008, 350, 1090-1100.

The copper-catalyzed asymmetric allylic alkylation has shown through many examples that it is a powerful means to generate stereogenic centers with mono β- and γ-substituted olefinic substrates. However, little has been reported about more substituted olefinic patterns, such as β-disubstituted allylic electrophiles. In this paper, we show that a simple procedure using easily accessible Grignard reagents and as low as 3 mol% of copper/ligand can promote high to nearly perfect enantioselectivities (up to >99% ee) with very good γ-selectivities on a wide panel of aliphatic or aromatic β-disubstituted substrates.

[] open archive unige:8100 full text [restricted access]   

 2007
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 (237) 

A. Alexakis, M. Vuagnoux-d'Augustin, D. Martin, S. Kehrli "Formation of all-carbon chiral quaternary centers by copper catalysed asymmetric cojugate addition" Latvija kimijas zurnals 2007, 373-377.

In summary, the copper-​catalyzed asym. conjugate addn. of both organoaluminum and organomagnesium reagents affords a viable methodol. for the creation of all-​carbon chiral quaternary centers.  Several applications in natural product synthesis are possible, particularly when an angular Me group is needed on bicyclic systems.

[] open archive unige:8133 full text [restricted access]   

 (236) 

M. Vuagnoux-d'Augustin, A. Alexakis "Influence of the double-bond geometry of the Michael acceptor on copper-catalysed asymmetric conjugate addition" Eur. J. Org. Chem. 2007, 5852-5860.

Focusing on mechanistic aspects, a study of the influence of the (E)/(Z) double-bond geometry of the Michael acceptor on the enantioselectivity of copper-catalyzed asymmetric conjugate addition reactions has been realized. In spite of numerous articles concerning copper-catalyzed asymmetric conjugate addition reactions, the major factors of such a reaction are quite difficult to elucidate. Although our experiments have not allowed us to define strict rules, they have highlighted some factors not to be neglected when considering the approach of the copper reagent to the double bond, such as (E)/(Z) isomerization and steric aspects, which could change the reactive conformation of the substrate. Electronic effects could also modify the polarization of the double bond and influence the nucleophilic attack.

[] open archive unige:8131 full text [restricted access]   

 (235) 

Q. Perron, A. Alexakis "Synthesis and application of a new pseudo C2-symmetric tertiary diamine for the enantioselective addition of MeLi to aromatic imines" Tetrahedron: Asymmetry 2007, 18, 2503-2506.

A new tertiary pseudo C2-symmetric diamine derived from (1S,2S)-(+)-pseudoephedrine was synthesized and tested in the enantioselective addition of methyllithium on different aromatic imines. A comparative study with a similar C2-symmetric ligand derived from the cyclohexane diamine showed better reactivity and enantioselectivity up to 91%.

[] open archive unige:8117 full text [restricted access]   

 (234) 

M. Vuagnoux-d'Augustin, A. Alexakis "Copper catalysed asymmetric conjugate addition of trialkylaluminuim reaggents to trisubstituted enones: construction of chiral quaternary centers" Chem. Eur. J. 2007, 13, 9647-9662.

Me3Al, Et3Al, and vinylalane species undergo enantioselective conjugate addition to a wide range of 2- or 3-substituted enones (cyclopent-2-enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3CN)4]BF4 or [CuOTf]2⋅C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternary centers can be built, with up to 98 % ee after rigorous optimization of experimental conditions. It was shown that the main important parameter was the order of the introduction of the reagents. Then, the generated enantioenriched aluminium enolates and the chiral conjugate adducts were functionalized and used for subsequent reactions.

[] open archive unige:8127 full text [restricted access]   

 (233) 

D. Polet, A. Alexakis "Asymmetric allylic alkylation catalysed by iridium" Chimici Oggi / Chemistry Today 2007, 25, 31-32.

The most advanced work in the iridium-catalysed allylic alkylation is reviewed herein. Particular emphasis is given to the use of stabilised nucleophiles with catalyst C2, which allows the reaction of a wide range of electrophiles and nucleophiles. High regio- and enantioselectivities are obtained together with improved kinetics. The role of the - OMe substituents is discussed as well as the synthetic applications of this catalyst system.

[] open archive unige:8130 full text [restricted access]   

 (232) 

L. Palais, I. S. Mikhel, C. Bournaud, L. Micouin, C. A. Falciola, M. Vuagnoux-d'Augustin, S. Rosset, G. Bernardinelli, A. Alexakis "SimplePhos monodentate ligands: Synthesis and application in copper-catalysed reactions" Angew. Chem. Int. Ed. 2007, 46, 7462-7465.

A simple choice: Ligands termed SimplePhos (L*), based on a chiral amino and flexible aryl groups on the phosphorus atom, induce high enantioselectivity in the copper-catalyzed conjugate addition and allylic substitution of dialkyl zinc and trialkyl aluminum reagents (see scheme; CuTC=copper thiophene carboxylate).

[] open archive unige:8017 full text [restricted access]   

 (231) 

M. Vuagnoux-d'Augustin, A. Alexakis "Tandem asymmetric conjugate addition-enolacetates formation of enantiomerically enriched zinc and aluminium enolates" Tetrahedron Lett. 2007, 48, 7408-7412.

The metal enolates, resulting from the copper-catalyzed enantioselective conjugate addition of organometallic reagents (Et2Zn or R3Al) to cyclic and acyclic enones are quantitatively trapped as enolacetates with acetic anhydride.

[] open archive unige:8108 full text [restricted access]   

 (230) 

S. Sulzer-Mossé, M. Tissot, A. Alexakis "First enantioselective organocatalytic conjugate addition of aldehydes to vinyl phosphonates" Org. Lett. 2007, 9, 3749-3752.

Chiral amines catalyze the enantioselective conjugate addition of aldehydes to vinyl phosphonates in high yields and with enantioselectivities up to 97% ee. This novel process provides synthetically useful chiral γ-geminal phosphonate aldehydes which can be easily converted in a few steps into chiral β-substituted vinyl phosphonates with conservation of the optical purity.

[] open archive unige:8025 full text [restricted access]   

 (229) 

A. Alexakis, S. El Hajjaji, D. Polet, X. Rathgeb "Iridium-Catalyzed Asymmetric Allylic Substitution with Aryl Zinc Reagents" Org. Lett. 2007, 9, 3393-3395.

Thanks to iridium catalysis, arylzinc reagents undergo regioselective allylic substitution with very high enantioselectivity, when associated with phosphoramidite ligands.

[] open archive unige:8024 full text [restricted access]   

 (228) 

M. Vuagnoux-d'Augustin, S. Kehrli, A. Alexakis "Enantioselective copper catalysed conjugate addition to 2- or 3- substituted cyclopent-2-ene-1-ones: Construction of stereogenic quaternary carbon centers" Synlett 2007, 2057-2060.

Trimethyl- and triethylaluminum undergo enantioselective conjugate addition to 2- and 3-substituted cyclopent-2-en-1-ones in the presence of catalytic amount of a copper salt and a phosphoramidite or a diphosphite ligand. Thus, chiral quaternary centers can be built with up to 93% ee.

[] open archive unige:8026 full text [restricted access]   

 (227) 

S. Sulzer-Mossé, A. Alexakis "Chiral amines as organocatalysts for asymmetric conjugate addition to nitroolefins and vinyl sulfones via enamine activation" Chem. Commun. 2007, 3123-3135.

Over the last decade the potential of organocatalysis has successfully been demonstrated. In particular, chiral amines such as pyrrolidine analogues have emerged as a broadly applicable class of organocatalyst for asymmetric conjugate addition viaenamine activation. This Feature Article documents the development of these catalysts, emphasizing the design and mechanistic features that supply high selectivity in asymmetric Michael reactions.

[] open archive unige:8018 full text [restricted access]   

 (226) 

S. Sulzer-Mossé, M. Laars, K. Kriis, T. Kanger, A. Alexakis "Synthesis and use of 3,3'-bimorpholine derivatives in asymmetric Michael addition and intramolecular aldol reaction" Synthesis 2007, 1729-1732.

The synthesis of 3,3′-bimorpholine and its N-alkyl derivatives is described. These new diamine derivatives were revealed to be efficient organocatalysts for the asymmetric Michael addition of aldehydes to nitroalkenes with excellent enantioselectivity (up to 90% ee). The potential of these organocatalysts was also demonstrated for the highly enantioselective intramolecular aldol reaction affording the Wieland-Miescher ketone with tremendous enantioselectivity (up to 95% ee).

[] open archive unige:8028 full text [restricted access]   

 (225) 

K. Li, A. Alexakis "Copper-Catalyzed Enantioselective Intramolecular Conjugate Addition/Trapping Reactions: Synthesis of Cyclic Compounds with Multichiral Centers" Chem. Eur. J. 2007, 13, 3765-3771.

The Cu-catalyzed enantioselective conjugate addition of dialkylzinc to bis-α,β-unsaturated carbonyl compounds followed by the intramolecular trapping of the zinc enolate in the presence of chiral phosphoramidite ligands was investigated. Cyclic and heterocyclic compounds with multichiral centers were formed as a mixture of two diastereomers with excellent diastereoselectivities (up to 99:1) and enantioselectivities (up to 94 % ee,ee=enantiomeric excess). The stereochemistry was determined to be trans,trans for the major products and trans,cis for the minor products. The absolute configuration of the cyclic compounds was assigned by comparison with the analogous adduct derived fromtrans-3-nonen-2-one and Et2Zn or the adduct obtained through conjugate addition of Me2Zn to trans-1-phenyl-non-2-en-1-one. Further transformation of these cyclic products into more complex compounds is under investigation in our laboratory.

[] open archive unige:8126 full text [restricted access]   

 (224) 

C. A. Falciola, A. Alexakis "1,4-Dichloro- and 1,4-Dibromo-2-butenes as Substrate for Cu-catalyzed Asymmetric Allylic Substitution" Angew. Chem. Int. Ed. 2007, 46, 2619-2622.

Cu at the AAA meeting: Difunctionalized allylic substrates can undergo Cu-catalyzed asymmetric allylic alkylation (AAA) reactions with high enantioselectivities. The products have a functional group that remains for further transformation through substitution with a nucleophile (Nu) or electrophile (E) with conservation of optical purity (see scheme; TC=thiophene carboxylate).

[] open archive unige:8016 full text [restricted access]   

 (223) 

R. Millet, A. Alexakis "Copper-catalyzed kinetic resolution of 1,3-cyclohexadiene monoepoxide with Grignard reagents" Synlett 2007, 435-438.

Chiral ferrocenyl-based diphosphines lead to kinetic ­resolution of 1,3-cyclohexadiene monoepoxide with moderate to good enantioselectivity (up to 90% ee) and good regioselectivity with various Grignard reagents through an anti-SN2′ pathway.

[] open archive unige:8027 full text [restricted access]   

 2006
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 (222) 

K. Li, A. Alexakis "Asymmetric conjugate addition to α-halo enones : Dramatic effect of styrene on the enantioselectivity" Angew. Chem. Int. Ed. 2006, 45, 7600-7603.

[] open archive unige:8015 full text [restricted access]   

 (221) 

A.-S. Chauvin, G. Bernardinelli, A. Alexakis "Determination of the absolute configuration of chiral cyclic alcohols using diamine derivatizing agents by 31P NMR spectroscopy" Tetrahedron: Asymmetry 2006, 17, 2203-2209.

[] open archive unige:8116 full text [restricted access]   

 (220) 

C. A. Falciola, K. Tissot-Croset, A. Alexakis "β-Disubstituted Allylic Chloride: Substrate for th Cu-Catalyzed Asymmetric SN2' Reaction" Angew. Chem. Int. Ed. 2006, 45, 5995-5998.

[] open archive unige:8014 full text [restricted access]   

 (219) 

C. Bournaud, C. Falciola, T. Lecourt, S. Rosset, A. Alexakis, L. Micouin "On the use of phosphramidite ligands in copper-catalyzed asymmetric transformations with trialkylaluminium reagents" Org. Lett. 2006, 8, 3581-3584.

[] open archive unige:8023 full text [restricted access]   

 (218) 

S. Mossé, A. Alexakis "Organocatalyzed asymmetric reactions via microwave activation" Org. Lett. 2006, 8, 3577-3580.

[] open archive unige:8022 full text [restricted access]   

 (217) 

X. Rathgeb, S. March, A. Alexakis "One-pot conjugate addition-trapping of zinc enolates by activated electrophiles" J. Org. Chem. 2006, 71, 5737-5742.

[] open archive unige:8019 full text [restricted access]   

 (216) 

D. Martin, S. Kehrli, M. d'Augustin, H. Clavier, M. Mauduit, A. Alexakis "Copper-catalyzed asymmetric conjugate addition of Grignard reagents to trisubstituted enones. Construction of all-carbon quaternary centers" J. Am. Chem. Soc. 2006, 128, 8416-8417.

[] open archive unige:8020 full text [restricted access]   

 (215) 

A.-S. Chauvin, A. Alexakis "Chiral trimethylsilylated C2-symmetrical diamines as phosphorous derivatizing agents for the determination of the enantiomeric excess of chiral alcohols by 1H NMR" Beilstein J. Org. Chem 2006, 2, No. 6.

[] open archive unige:8124 full text [restricted access]   

 (214) 

S. Mossé, M. Laars, K. Kriis, T. Kanger, A. Alexakis "3,3'-Bimorpholine derivatives as a new class of organocatalysts for asymmetric michael addition" Org. Lett. 2006, 8, 2559-2562.

[] open archive unige:8021 full text [restricted access]   

 (213) 

S. Gille, N. Cabello, J.-C. Kizirian, A. Alexakis "A new pseudo C2-symmetric tertiary diamine for the enantioselective addition of MeLi to aromatic imines" Tetrahedron: Asymmetry 2006, 17, 1045-1047.

[] open archive unige:8107 full text [restricted access]   

 (212) 

S. Mossé, O. Andrey, A. Alexakis "The use of N-iPr-2,2'-bipyrrolidine derivatives as organocatalysts for asymmetric Michael additions" CHIMIA 2006, 60, 216-219.

[] open archive unige:8129 full text [restricted access]   

 (211) 

D. Polet, A. Alexakis, K. Tissot-Croset, C. Corminboeuf, K. Ditrich "Phosphoramidite Ligands in Iridium-Catalyzed Allylic Substitution" Chem. Eur. J. 2006, 12, 3596-3609.

[] open archive unige:8125 full text [restricted access]   

 (210) 

A. Alexakis, C. Malan, L. Lea, K. Tissot-Croset, D. Polet, C. Falciola "The copper-catalyzed asymmetric allylic substitution" CHIMIA 2006, 60, 124-130.

[] open archive unige:8128 full text [restricted access]   

 (209) 

I. S. Mikhel, G. Bernardinelli, A. Alexakis "Chiral P-monodentate phosphoramidite and phosphite ligands forthe enantioselective Pd-catalyzed allylic alkylation" Inorg. Chim. Acta 2006, 359, 1826-1836.

[] open archive unige:8132 full text [restricted access]   

 2005
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 (208) 

A. Alexakis, D. Polet, C. Bournaud, M. Bonin, L. Micouin "Phophoramidite ligands for the enantioselective iridium-catalyzed asymmetric hydroboration of meso-bicyclic hydrazines" Tetrahedron: Asymmetry 2005, 16, 3672-3675.

[] open archive unige:8114 full text [restricted access]   

 (207) 

N. Cabello, J.-C. Kizirian, S. Gille, A. Alexakis, G. Bernardinelli, L. Pinchard, J.-C. Caille "Simple 1,2-Diamine Ligands for Asymmetric Addition of Aryllithium Reagents to Imines" Eur. J. Org. Chem. 2005, 4835-4842.

[] open archive unige:8032 full text [restricted access]   

 (206) 

N. Fuchs, M. d’Augustin, M. Humam, A. Alexakis, R. Taras, S. Gladiali "Asymmetric conjugate addition of metal alkyl reagents catalyzed by copper complexes with BINPO, a hemilabile P,O-heterobidentate axially chiral ligand" Tetrahedron: Asymmetry 2005, 16, 3143-3146.

[] open archive unige:8113 full text [restricted access]   

 (205) 

K. Li, A. Alexakis "Copper catalyzed tandem asymmetric conjugate addition cyclization reaction in presence of chiral phosphoramidite ligands" Tetrahedron Lett. 2005, 46, 8019-8022.

[] open archive unige:8122 full text [restricted access]   

 (204) 

S. Mossé, A. Alexakis "First organocatalyzed asymmetric Michael addition of aldehydes to vinyl sufones" Org. Lett. 2005, 7, 4361-4364.

[] open archive unige:8042 full text [restricted access]   

 (203) 

C. L. Winn, F. Guillen, J. Pytkowicz, S. Roland, P. Mangeney, A. Alexakis "Enantioselective copper catalysed 1,4-conjugate addition reactions using chiral N-heterocyclic carbenes" J. Organomet. Chem. 2005, 690, 5672-5695.

[] open archive unige:8109 full text [restricted access]   

 (202) 

J.-C. Kizirian, N. Cabello, L. Pinchard, J.-C. Caille, A. Alexakis "Enantioselective addition of MeLi to aromatic imines catalyzed by C2-symmetric tertiary diamine" Tetrahedron 2005, 61, 8939-8946.

[] open archive unige:8047 full text [restricted access]   

 (201) 

K. Li, A. Alexakis "Copper catalyzed asymmetric conjugate addition-bromination of α, β unsaturated ketones : a highly effective one pot reaction for the synthesis of chiral α bromo β alkyl ketone" Tetrahedron Lett. 2005, 46, 5823-5826.

[] open archive unige:8121 full text [restricted access]   

 (200) 

A. Alexakis, V. Albrow, K. Biswas, M. d'Augustin, O. Prieto, S. Woodward "Highly enantioselective copper(I)-phosphoramidite-catalysed additions of organoaluminium reagents to enones" Chem. Commun. 2005, 2843-2845.

[] open archive unige:8044 full text [restricted access]   

 (199) 

E. Vrancken, A. Alexakis, P. Mangeney "Organolithium chiral Lewis base BF3 : versatile combination for the enantioselective desymmetrisation of meso-epoxides" Eur. J. Org. Chem. 2005, 1354-1366.

[] open archive unige:8034 full text [restricted access]   

 (198) 

A. Alexakis, A. Tomassini, O. Andrey, G. Bernardinelli "Diastereoselective alkylation of (Arene)tricarbonyl-chromium and ferrocene complexes using a chiral C2-symmetrical 1,2 diamine as auxiliary" Eur. J. Org. Chem. 2005, 1332-1339.

[] open archive unige:8033 full text [restricted access]   

 (197) 

D. Polet, A. Alexakis "Kinetic study of various phosphoramidite ligands in the iridium-catalyzed allylic substitution" Org. Lett. 2005, 7, 1621-1624.

[] open archive unige:8043 full text [restricted access]   

 (196) 

L. Cointeaux, A. Alexakis "Enantioselective addition of organolithium reagents to quinoline catalyzed by 1,2-diamines" Tetrahedron: Asymmetry 2005, 16, 925-929.

[] open archive unige:8115 full text [restricted access]   

 (195) 

M. d'Augustin, L. Palais, A. Alexakis "Enantioselective copper-catalyzed conjugate addition to trisubstituted cyclohexenones: construction of stereogenic quaternary centers" Angew. Chem. Int. Ed. 2005, 44, 1376-1378.

[] open archive unige:8176 full text [restricted access]   

 (194) 

D. Polet, A. Alexakis "Cu-catalyzed asymmetric 1,4-addition of Me3Al to nitroalkenes. Synthesis of (+)-Ibuprofen" Tetrahedron Lett. 2005, 46, 1529-1532.

[] open archive unige:8123 full text [restricted access]   

 2004
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 (193) 

A. Alexakis "The conjugate addition reaction" In Transition Metals for Organic Synthesis, Vol. 1; C. Bolm, M. Beller (Eds.); Wiley-VCH 2004; Ch. 3.8; p. 553-562.

[] open archive unige:6721 full text [restricted access]   

 (192) 

K. Tissot-Croset, D. Polet, S. Gille, C. Hawner, A. Alexakis "Synthesis and use of a phosphoramidite ligand for the copper-catalyzed enantioselective allylic substitution. Tandem allylic substitution-ring closing metathesis" Synthesis 2004, 2586-2590.

[] open archive unige:8110 full text [restricted access]   

 (191) 

O. Andrey, A. Alexakis, A. Tomassini, G. Bernardinelli "The use of N-alkyl-2,2'-bipyrrolidine derivatives as organocatalysts for the asymmetric Michael addition of ketones and aldehydes to nitroolefins" Adv. Synth. Catal. 2004, 346, 1147-1168.

[] open archive unige:8215 full text [restricted access]   

 (190) 

A. Alexakis, A. Tomassini, S. Leconte "Synthesis and applications of chiral bis-THF in asymmetric synthesis" Tetrahedron 2004, 60, 9479-9484.

[] open archive unige:8112 full text [restricted access]   

 (189) 

A. Alexakis, D. Polet "Very efficient phosphoramidite ligand for asymmetric iridium-catalyzed allylic alkylation" Org. Lett. 2004, 6, 3529-3552.

[] open archive unige:8041 full text [restricted access]   

 (188) 

K. Tissot-Croset, A. Alexakis "Copper catalyzed enantioselective allylic substitution by MeMgX" Tetrahedron Lett. 2004, 45, 7375-7378.

[] open archive unige:8120 full text [restricted access]   

 (187) 

A. Alexakis, D. Polet, S. Rosset, S. March "Biphenol-based phosphoramidite ligands for the enantioselective copper-catalyzed conjugate addition of diethylzinc" J. Org. Chem 2004, 69, 5660-5667.

[] open archive unige:8031 full text [restricted access]   

 (186) 

A. Alexakis, D. Polet, C. Benhaim, S. Rosset "Biphenol-based ligands for Cu-catalyzed asymmetric conjugate addition" Tetrahedron: Asymmetry 2004, 15, 2199-2203.

[] open archive unige:8055 full text [restricted access]   

 (185) 

F. Amiot, L. Cointeaux, E. J. Silve, A. Alexakis "Enantioselective nucleophilic addition of organometallic reagents to quinoline: regio-, stereo- and enantioselectivity" Tetrahedron 2004, 60, 8221-8231.

[] open archive unige:8111 full text [restricted access]   

 (184) 

A. Alexakis "Asymmetric organocopper chemistry: Cu-catalyzed conjugate addition and allylic substitution" In Methodologies in Asymmetric Catalysis; S. V. Malhotra (Ed.); ACS Symposium Series, Volume 880: Washington, 2004; Ch. 4; p. 43-59.

[] open archive unige:6722 full text [restricted access]   

 (183) 

A.-S. Chauvin, G. Bernardinelli, A. Alexakis "Determination of the Absolute Configuration of Chiral Aryl-alkyl Carbinols using Organophosphorous Diamine Derivatizing Agents by 31P NMR Spectroscopy" Tetrahedron: Asymmetry 2004, 15, 1857-1879.

[] open archive unige:8061 full text [restricted access]   

 (182) 

A. M. Arink, T. W. Braam, R. Keeris, J. T. B. H. Jastrzebski, C. Benhaim, S. Rosset, A. Alexakis, G. van Koten "Copper(I) thiolate catalysts in asymmetric conjugate addition reactions" Organic Lett. 2004, 6, 1959-1962.

[] open archive unige:8040 full text [restricted access]   

 (181) 

N. Cabello, J.-C. Kizirian, A. Alexakis "Enantioselective addition of aryllithium reagents to aromatic imines mediated by 1,2-diamine ligands" Tetrahedron Lett. 2004, 45, 4639-4642.

[] open archive unige:8096 full text [restricted access]   

 (180) 

O. Equey, A. Alexakis "Enantioselective opening of cyclic vinyl epoxides with organoaluminium reagents catalysed by copper salts" Tetrahedron: Asymmetry 2004, 15, 1531-1536.

[] open archive unige:8054 full text [restricted access]   

 (179) 

O. Equey, E. Vrancken, A. Alexakis "Regioselective SN2 opening of vinylic epoxides with trialkylzincates and tetralkylaluminates" Eur. J. Org. Chem. 2004, 2151-2159.

[] open archive unige:8151 full text [restricted access]   

 (178) 

K. Tissot-Croset, D. Polet, A. Alexakis "A highly effective phosphoramidite ligand for asymmetric allylic substitution" Angew. Chem. Int. Ed. 2004, 43, 2426-2428.

[] open archive unige:8048 full text [restricted access]   

 (177) 

O. Equey, A. Alexakis "Enantioselective catalytic rearrangement of cyclohexene oxide with new homochiral bis-lithium amide bases" Tetrahedron: Asymmetry 2004, 15, 1069-1072.

[] open archive unige:8056 full text [restricted access]   

 (176) 

A. Alexakis, S. Gille, F. Prian, S. Rosset, K. Ditrich "Practical, solvent-free, one-pot synthesis of C2-symmetrical secondary amines" Tetrahedron Lett. 2004, 45, 1449-1451.

[] open archive unige:8212 full text [restricted access]   

 2003
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 (175) 

J.-C. Kizirian, J.-C. Caille, A. Alexakis "Conceptually new chiral tertiary C2 symmetric diamines in asymmetric synthesis" Tetrahedron Lett. 2003, 44, 8893-8895.

[] open archive unige:8095 full text [restricted access]   

 (174) 

O. Andrey, A. Vidonne, A. Alexakis "Organocatalytic Michael addition, a convenient tool in total synthesis. First asymmetric synthesis of (-)-botryodiplodin" Tetrahedron Lett. 2003, 44, 7901-7904.

[] open archive unige:8094 full text [restricted access]   

 (173) 

O. Andrey, A. Alexakis, G. Bernardinelli "Asymmetric Michael addition of α-hydroxy aldehydes to nitroolefins catalyzed by chiral diamine" Org. Lett. 2003, 5, 2559-2561.

[] open archive unige:8039 full text [restricted access]   

 (172) 

A. Alexakis, C. L. Winn, F. Guillen, J. Pytkowicz, S. Roland, P. Mangeney "Asymmetric synthesis with N-heterocyclic carbenes. Application to the copper catalyzed conjugate addition" Adv. Synth. Catal. 2003, 345, 345-348.

[] open archive unige:8214 full text [restricted access]   

 2002
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 (171) 

A. Alexakis, S. March "Tandem enantioselective conjugate addition-cyclopropanation. Application to natural product synthesis" J. Org. Chem 2002, 67, 8753-8757.

[] open archive unige:8030 full text [restricted access]   

 (170) 

A. Alexakis, O. Andrey "Diamine-catalyzed asymmetric Michael additions of aldehydes and ketones to nitrostyrene" Org. Lett. 2002, 4, 3611-3614.

[] open archive unige:8036 full text [restricted access]   

 (169) 

A. Alexakis, F. Amiot "Enantioselective addition of organolithium reagents on isoquinoline" Tetrahedron: Asymmetry 2002, 13, 2117-2122.

[] open archive unige:8053 full text [restricted access]   

 (168) 

A. Alexakis, K. Croset "Tandem Copper-Catalyzed Enantioselective Allylation-Metathesis" Org. Lett. 2002, 4, 4147-4149.

[] open archive unige:8038 full text [restricted access]   

 (167) 

O. Knopff, A. Alexakis "Tandem asymmetric conjugate addition-silylation of enantiomerically enriched zinc enolates. Synthetic importance and mechanistic implications" Org. Lett. 2002, 4, 3835-3837.

[] open archive unige:8037 full text [restricted access]   

 (166) 

L. Mediavilla Urbaneja, A. Alexakis, N. Krause "Epimerization and kinetic resolution in copper-catalyzed enantioselective 1,4-additions of organozinc reagents to 6-substituted cyclohex-2-enones" Tetrahedron Lett. 2002, 43, 7887-7890.

[] open archive unige:8093 full text [restricted access]   

 (165) 

A. Alexakis, C. Benhaim "Enantioselective Copper-Catalysed Conjugate Addition" Eur. J. Org. Chem. 2002, 3221-3236.

[] open archive unige:8152 full text [restricted access]   

 (164) 

A. Alexakis, C. Benhaim, S. Rosset, M. Humam "Dramatic enhancement of the enantiomeric excess in asymmetric conjugate addition reaction using new experimental conditions" J. Am. Chem. Soc. 2002, 124, 5262-5263.

[] open archive unige:8066 full text [restricted access]   

 (163) 

A. Alexakis "Copper-mediated asymmetric transformations" Pure & Appl. Chem. 2002, 74, 37-42.

[] open archive unige:9591 full text [restricted access]   

 2001
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 (162) 

F. Guillen, C. L. Winn, A. Alexakis "Enantioselective copper-catalyzed conjugate addition using chiral diaminocarbene ligands" Tetrahedron: Asymmetry 2001, 12, 2083-2086.

[] open archive unige:8050 full text [restricted access]   

 (161) 

A. Alexakis, S. Rosset, J. Allamand, S. March, F. Guillen, C. Benhaim "Novel biphenol phosphoramidite ligands for the enantioselective copper-catalyzed conjugate addition of dialkyl zincs" Synlett 2001, 1375-1378.

[] open archive unige:6318   

 (160) 

F. Mazé, M. Purpura, F. Bernaud, P. Mangeney, A. Alexakis "Regio- and diastereoselective SN2' or SN2'' reactions on chiral acetals of cyclic aldehydes promoted by PhCu, BF3" Tetrahedron: Asymmetry 2001, 12, 1957-1960.

[] open archive unige:6983 full text [restricted access]   

 (159) 

A. Alexakis, A.-S. Chauvin "Determination of the enantiomeric excess of chiral carboxylic acids by 31P NMR with C2 symmetrical diamines" Tetrahedron: Asymmetry 2001, 12, 1411-1415.

[] open archive unige:8049 full text [restricted access]   

 (158) 

A. Alexakis, A.-S. Chauvin, R. Stouvenel, E. Vrancken, S. Mutti, P. Mangeney "A practical and efficient synthesis of chiral N,N-disubstituted C2 symmetric diamines derived from (R,R)-1,2-diaminocyclohexane" Tetrahedron: Asymmetry 2001, 12, 1171-1178.

[] open archive unige:8052 full text [restricted access]   

 (157) 

A. Alexakis, C. Benhaim "Asymmetric conjugate addition to alkylidene malonates" Tetrahedron: Asymmetry 2001, 12, 1151-1157.

[] open archive unige:8051 full text [restricted access]   

 (156) 

A. Alexakis, C. Malan, L. Lea, C. Benhaim, X. Fournioux "Enantioselective copper-catalyzed SN2' substitution with Grignard reagents" Synlett 2001, 927-930.

[] open archive unige:8155 full text [restricted access]   

 (155) 

A. Alexakis, I. Aujard, J. Pytkowicz, S. Roland, P. Mangeney "Unusually facile palladium catalysed oxidation of imidazolidines and oxazolidines" J. Chem. Soc., Perkin Trans. 1 2001, 949-951.

[] open archive unige:8099 full text [restricted access]   

 (154) 

A. Alexakis, G. P. Trevitt, G. Bernardinelli "Tandem enantioselective conjugate addition-electrophile trapping reactions. Application in the formation of syn or anti aldols" J. Am. Chem. Soc. 2001, 123, 4358-4359.

[] open archive unige:8186 full text [restricted access]   

 2000
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 (153) 

A. Alexakis, J. Burton, J. Vastra, C. Benhaim, X. Fournioux, A. van den Heuvel, J.-M. Levêque, F. Mazé, S. Rosset "Synthesis and application of chiral phosphorus ligands derived from TADDOL for the asymmetric conjugate addition of diethylzinc to enones" Eur. J. Org. Chem. 2000, 4011-4027.

[] open archive unige:8153 full text [restricted access]   

 (152) 

A. Alexakis, A.-S. Chauvin "TADDOL organophosphorus derivatising agents for the determination of the enantiomeric excess of alcohols and carboxylic acids by 31P and 1H NMR spectroscopy" Tetrahedron: Asymmetry 2000, 11, 4245-4248.

[] open archive unige:8177 full text [restricted access]   

 (151) 

A. Alexakis, A. Tomassini, C. Chouillet, S. Roland, P. Mangeney, G. Bernardinelli "A new efficient synthesis of (R,R)-2,2'-bipyrrolidine: an interesting chiral 1,2-diamine with C2 symmetry." Angew. Chem. Int. Ed. 2000, 39, 4093-4095.

[] open archive unige:8175 full text [restricted access]   

 (150) 

A. Alexakis, E. Vrancken, P. Mangeney "Effect of BF3·Et2O reagent on the base-promoted rearrangements of epoxides attached to eight-membered rings" J. Chem. Soc., Perkin Trans. 1 2000, 3354-3355.

[] open archive unige:8218 full text [restricted access]   

 (149) 

A. Alexakis, E. Vrancken, P. Mangeney, F. Chemla "Regioselective SN2 opening of α,β-ethylenic epoxides by RLi-BF3 combination" J. Chem. Soc., Perkin Trans. 1 2000, 3352-3353.

[] open archive unige:8217 full text [restricted access]   

 (148) 

A. Alexakis, C. Benhaim "Enantioselective copper-catalyzed conjugate addition of dialkylzinc to nitro-olefins" Org. Lett. 2000, 2, 2579-2581.

[] open archive unige:8035 full text [restricted access]   

 (147) 

A. Alexakis "Asymmetric synthesis using organocopper reagents" CHIMIA 2000, 54, 55-56.

[] open archive unige:8154 full text [restricted access]   

 1999
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 (146) 

A. Alexakis, C. Benhaïm, X. Fournioux, A. van den Heuvel, J.-M. Levêque, S. March, S. Rosset "Catalytic asymmetric conjugate addition on macrocyclic and acyclic enones. Synthesis of R-(-)-Muscone" Synlett 1999, 1811-1813.

[] open archive unige:8157 full text [restricted access]   

 (145) 

F. Rose-Munch, V. Gagliardini, A. Perrotey, J.-P. Tranchier, E. Rose, P. Mangeney, A. Alexakis, T. Kanger, J. Vaissermann "Two-step synthesis of homochiral monoaminals of tricarbonylphthalaldehydechromium complex" Chem. Commun. 1999, 2061-2062.

[] open archive unige:8162 full text [restricted access]   

 (144) 

F. Rezgui, P. Mangeney, A. Alexakis "Asymmetric synthesis of 1,2- and 1,4-dihydroquinolines" Tetrahedron Lett. 1999, 40, 6241-6244.

[] open archive unige:8092 full text [restricted access]   

 (143) 

S. Roland, P. Mangeney, A. Alexakis "A practical and efficient synthesis of enantiomerically pure di-tert-butyl-ethanediamine" Synthesis 1999, 228-230.

[] open archive unige:8143 full text [restricted access]   

 (142) 

A. Alexakis "Copper (I) promoted asymmetric transformations : a long standing challenge" In Transition Metal Catalysed Reactions; S.-I. Murahashi, S. G. Davies (Eds.); Blackwell Science, IUPAC: Oxford, 1999; Ch. 15; p. 303-316.

[] open archive unige:8380   

 (141) 

A. Alexakis, I. Aujard, T. Kanger, P. Mangeney "(R,R)- and (S,S)-N,N'-dimethyl-1,2-diphenylethylene-1,2-diamine" Org. Synth. 1999, 76, 23-36.

[] open archive unige:8098 full text [restricted access]   

 1998
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 (140) 

A. Alexakis "The conjugate addition reaction" In Transition Metals for Organic Synthesis, Vol. 1; M. Beller, C. Bolm (Eds.); Wiley-VCH: Weinheim, 1998; Ch. 3.10; p. 504-513.

[] 

 (139) 

A. Alexakis, J. Vastra, J. Burton, C. Benhaim, P. Mangeney "Asymmetric conjugate addition of diethylzinc to enones with chiral phosphorus ligands derived from TADDOL" Tetrahedron Lett. 1998, 39, 7869-7872.

[] open archive unige:8091 full text [restricted access]   

 (138) 

A. Alexakis, E. Vrancken, P. Mangeney "Enantioselective nucleophilic opening of meso epoxides by organolithium reagents" Synlett 1998, 1165-1167.

[] open archive unige:8156 full text [restricted access]   

 (137) 

P. Mangeney, L. Hamon, S. Raussou, N. Urbain, A. Alexakis "Radical cyclizations of 1,4-dihydropyridines. Synthesis of chiral fused nitrogen heterocycles. Synthesis of Lupinine and Epilupinine" Tetrahedron 1998, 54, 10349-10362.

[] open archive unige:8046 full text [restricted access]   

 (136) 

A. Alexakis, I. Aujard, P. Mangeney "Isomerization of meso diamines into their C2 symmetrical d,l isomers" Synlett 1998, 875-876.

[] open archive unige:8160 full text [restricted access]   

 (135) 

A. Alexakis, I. Aujard, P. Mangeney "Practical and efficient synthesis of C2 symmetrical diamines with Zn/Me3SiCl" Synlett 1998, 873-874.

[] open archive unige:8159 full text [restricted access]   

 (134) 

D. Brasseur, H. Rezaei, A. Fuxa, A. Alexakis, P. Mangeney, I. Marek, J. F. Normant "First diastereoselective asymmetric carbometallation of chiral vinyl metals" Tetrahedron Lett. 1998, 39, 4821-4824.

[] open archive unige:8090 full text [restricted access]   

 1997
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 (133) 

A. Alexakis, J. Burton, J. Vastra, P. Mangeney "Asymmetric conjugate addition of diethyl zinc to enones with chiral phosphine ligands" Tetrahedron: Asymmetry 1997, 8, 3987-3990.

[] open archive unige:8059 full text [restricted access]   

 (132) 

A. Alexakis, J. Vasta, P. Mangeney "Acceleration of the conjugate addition of diethyl zinc to enones by either Cu(OTf)2 or trivalent phosphorus ligands" Tetrahedron Lett. 1997, 38, 7745-7748.

[] open archive unige:8089 full text [restricted access]   

 (131) 

A. Alexakis, J. Varta, J. Burton, P. Mangeney "Asymmetric conjugate addition of diethyl zinc to enones with tartrate chiral phosphite ligands" Tetrahedron: Asymmetry 1997, 8, 3193-3196.

[] open archive unige:8058 full text [restricted access]   

 (130) 

F. M. Bohnen, R. Goddard, A. B. E. Minidis, A. Alexakis, A. Pfaltz "A copper (II) complex of a new chiral tridentate imidazoline ligand" Acta Crystallographica 1997, C53, 1236-1238.

[] open archive unige:8221 full text [restricted access]   

 (129) 

J. P. Tierney, A. Alexakis, P. Mangeney "Catalytic enantioselective deprotonation of meso-epoxides utilising homochiral bis-lithium amide bases" Tetrahedron: Asymmetry 1997, 8, 1019-1022.

[] open archive unige:8060 full text [restricted access]   

 1996
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 (128) 

A. Alexakis, F. Mhamdi, F. Lagasse, P. Mangeney "Asymmetric cleavage of chiral α,β-ethylenic acetals by organolithium reagents" Tetrahedron: Asymmetry 1996, 7, 3343-3346.

[] open archive unige:8057 full text [restricted access]   

 (127) 

H. Rakotoarisoa, R. Guttierez Perez, P. Mangeney, A. Alexakis "Remote asymmetric induction. New mechanistic insights concerning the SN' and SN" substitution in organocopper chemistry" Organometallics 1996, 15, 1957-1959.

[] open archive unige:8029 full text [restricted access]   

 (126) 

S. Raussou, N. Urbain, P. Mangeney, A. Alexakis, N. Platzer "Preparation of chiral hexahydroquinolizinones and tetrahydroindolizinones by regio- and diastereoselective sonochemical cyclization of chiral dihydropyridines" Tetrahedron Lett. 1996, 37, 1599-1602.

[] open archive unige:8088 full text [restricted access]   

 (125) 

A. Alexakis, P. Mangeney, N. Lensen, J.-P. Tranchier, R. Gosmini, S. Raussou "Chiral Aminals: Powerful auxiliaries in asymmetric synthesis" Pure Appl. Chem. 1996, 68, 531-534.

[] open archive unige:8244 full text [restricted access]   

 (124) 

A. Alexakis, P. Mangeney "Chiral aminals in asymmetric synthesis" In Advanced Asymmetric Synthesis; G. R. Stephenson (Ed.); Chapman & Hall: London, 1996; Ch. 5; p. 93-110.

[] open archive unige:8378   

 1995
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 (123) 

A. Alexakis, J.-P. Tranchier, N. Lensen, P. Mangeney "Monoaminals of glyoxal : versatile chirons" J. Am. Chem. Soc. 1995, 117, 10767-10768.

[] open archive unige:8185 full text [restricted access]   

 (122) 

A. Alexakis, T. Kanger, P. Mangeney, F. Rose-Munch, A. Perrotey, E. Rose "Enantioselective ortho-lithiation of benzaldehyde chromiumtricarbonyl complex" Tetrahedron: Asymmetry 1995, 6, 2135-2138.

[] open archive unige:8064 full text [restricted access]   

 (121) 

A. Alexakis, N. Lensen, J.-P. Tranchier, P. Mangeney, J. Feneau-Dupont, J.-P. Declercq "Chiral aminal templates: Diastereoselective addition to hydrazones; an asymmetric synthesis of α-amino aldehydes" Synthesis 1995, 1038-1050.

[] open archive unige:8145 full text [restricted access]   

 (120) 

J.-M. Duffault, J. Einhorn, A. Alexakis "Synthesis of regioselectively deuterated hydroxy conjugated dienes" Tetrahedron Lett. 1995, 36, 2765-2768.

[] open archive unige:8087 full text [restricted access]   

 (119) 

A. Alexakis, P. Mangeney "Chiral diamines in asymmetric synthesis" Acros Chimica Acta 1995, 1, 22-23.

[] 

 (118) 

A. Alexakis, T. Kanger, P. Mangeney, F. Rose-Munch, A. Perrotey, E. Rose "Enantioselective ortho-lithiation of aminals of benzaldehyde chromiumtricarbonyl complex" Tetrahedron: Asymmetry 1995, 6, 47-50.

[] open archive unige:8065 full text [restricted access]   

 1994
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 (117) 

A. Alexakis "Asymmetric conjugate addition" In Organocopper Reagents; R. J. K. Taylor (Ed.); Oxford University Press 1994; Ch. 8; p. 159-193.

[] open archive unige:8377   

 (116) 

A. Alexakis, J. C. Frutos, P. Mangeney, A. I. Meyers, H. Moorlag "Determination of enantiomeric purity of hydroxy biaryls using 1H and 31P NMR on their diazaphospholidine derivatives" Tetrahedron Lett. 1994, 35, 5125-5128.

[] open archive unige:8085 full text [restricted access]   

 (115) 

S. Raussou, R. Gosmini, P. Mangeney, A. Alexakis, M. Commerçon "Regio and enantioselective synthesis of 4-carbomethoxymethy-1,4-dihydropyridines" Tetrahedron Lett. 1994, 35, 5433-5436.

[] open archive unige:8086 full text [restricted access]   

 (114) 

A. Alexakis, J. C. Frutos, S. Mutti, P. Mangeney "Chiral diamines for a new protocol to determine the enantiomeric composition of alcohols, thiols and amines by 31P, 1H, 13C and 19F NMR" J. Org. Chem. 1994, 59, 3326-3334.

[] open archive unige:8149 full text [restricted access]   

 (113) 

P. Mangeney, R. Gosmini, S. Raussou, M. Commercon, A. Alexakis "Preparation and utilization of chiral dihydropyridines. Synthesis of chiral indoloquinolizines and benziquinolizines" J. Org. Chem. 1994, 59, 1877-1888.

[] open archive unige:8150 full text [restricted access]   

 1993
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 (112) 

A. Alexakis, J. C. Frutos, P. Mangeney "An easy and fast way to determine the enantiomeric purity of substituted cyclanones" Tetrahedron: Asymmetry 1993, 4, 2431-2434.

[] open archive unige:8062 full text [restricted access]   

 (111) 

A. Alexakis, J. Frutos, P. Mangeney "Chiral phosphorus ligands for the asymmetric conjugate addition of organocopper reagents" Tetrahedron: Asymmetry 1993, 4, 2427-2430.

[] open archive unige:8063 full text [restricted access]   

 (110) 

A. Alexakis, R. Sedrani, N. Lensen, P. Mangeney "Chiral aminal templates. Diastereo- and enantioselectivity in 1,4 (conjugate) and 1,2 additions with organometallic reagents" In Organic Synthesis via Organometallics; D. Enders, H.-J. Gais, W. Keim (Eds.); Vieweg: Wiesbaden, 1993; p. 1-9.

Chiral diamines, with a C2 axis of symmetry, form very easily aminals. These aminals act as very efficient chiral controller on both 1,4 (conjugate) and 1,2 additions to prochiral substrates. Steric control or chelation control may account of the high diastereoselectivity observed in these reactions, according to the organometallic reagent and to the solvent.

[] open archive unige:8292   

 1992
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 (109) 

A. Alexakis, P. Mangeney, I. Marek, F. Rose-Munch, E. Rose, A. Semra, F. Robert "Resolution and asymmetric synthesis of ortho-substituted benzaldehydetricarbonylchromium complexes" J. Am. Chem. Soc. 1992, 114, 8288-8290.

[] open archive unige:8184 full text [restricted access]   

 (108) 

A. Alexakis, N. Lensen, J.-P. Tranchier, P. Mangeney "Reactivity and diastereoselectivity of Grignard reagents toward the hydrazone functionality in toluene solvent" J. Org. Chem. 1992, 57, 4563-4565.

[] open archive unige:8147 full text [restricted access]   

 (107) 

A. Alexakis, A.-M. Barthel, J. F. Normant, C. Fugier, M. Leroux "A new efficient and stereoselective synthesis of 1,3E, 5Z-undecatriene" Synthetic Communications 1992, 22, 1839-1844.

[] open archive unige:6321   

 (106) 

I. Marek, A. Alexakis, P. Mangeney, J. F. Normant "Synthèse d'alcoxy-allènes chiraux par carbocupration d'acétals propargyliques. Etude de leur réactivité à l'égard d'organocuprates" Bull. Soc. Chim. Fr. 1992, 129, 171-190.

[] open archive unige:6319   

 (105) 

A. Alexakis "Stereochemical aspects on the formation of chiral allenes from propargylic ethers and epoxides" Pure Appl. Chem. 1992, 64, 387-392.

[] open archive unige:8243 full text [restricted access]   

 (104) 

A. Alexakis, S. Mutti, P. Mangeney "A new reagent for the determination of the optical purity of primary, secondary and tertiary chiral alcohols and of thiols" J. Org. Chem. 1992, 57, 1224-1237.

[] open archive unige:8148 full text [restricted access]   

 (103) 

G. Courtemanche, A. Alexakis, J. Vaissermann, J. F. Normant "Conjugate addition of organocuprates on γ-methyl-δ-oxy-α,β-enones. Influence of the alkoxy substituent on the diastereoselection" J. Organomet. Chem. 1992, 423, 238-305.

[] open archive unige:8135 full text [restricted access]   

 1991
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 (102) 

I. Marek, A. Alexakis, J. F. Normant "γ-Tributylstannyl-β-metallated acrolein : a versatile synthon" Tetrahedron Lett. 1991, 32, 6337-6340.

[] open archive unige:8083 full text [restricted access]   

 (101) 

I. Marek, A. Alexakis, J.-F. Normant "A highly efficient synthesis of (Z) γ-iodo allylic alcohols" Tetrahedron Lett. 1991, 32, 5329-5332.

[] open archive unige:8082 full text [restricted access]   

 (100) 

A. Alexakis, N. Lensen, P. Mangeney "Ultrasound assisted cleavage of hydrazines by Raney nickel" Synlett 1991, 625-626.

[] open archive unige:8161 full text [restricted access]   

 (99) 

A. Alexakis, S. Mutti, P. Mangeney, J. F. Normant "A new chiral ligand for the asymmetric conjugate addition of organocopper reagents to enones" J. Am. Chem. Soc. 1991, 113, 6332-6334.

[] open archive unige:8183 full text [restricted access]   

 (98) 

P. Mangeney, R. Gosmini, A. Alexakis "Enantioselective synthesis of indoloquinolizidines" Tetrahedron Lett. 1991, 32, 3981-3984.

[] open archive unige:8081 full text [restricted access]   

 (97) 

J.-M. Duffault, J. Einhorn, A. Alexakis "Expeditions synthesis of the four isomers of methyl dimorphecolate" Tetrahedron Lett. 1991, 32, 3701-3704.

[] open archive unige:8080 full text [restricted access]   

 (96) 

A. Alexakis, N. Lensen, P. Mangeney "Chiral aminal templates 6. Diastereoselectivity of hydrazo-ne alkylation. Asymmetric synthesis of α-amino-aldehydes" Tetrahedron Lett. 1991, 32, 1171-1174.

[] open archive unige:8084 full text [restricted access]   

 (95) 

A. Alexakis, I. Marek, P. Mangeney, J. F. Normant "Diastereoselective syn or anti opening of propargylic epoxides. Synthesis of α-allenic alcohols" Tetrahedron 1991, 47, 1677-1696.

[] open archive unige:8045 full text [restricted access]   

 (94) 

R. Gosmini, P. Mangeney, A. Alexakis, M. Commerçon, J. F. Normant "Chiral aminal templates 5. Preparation of chiral 3-carboxaldehydes-1,4-dihydropyridines" Synlett 1991, 111-113.

[] open archive unige:8158 full text [restricted access]   

 1990
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 (93) 

A. Alexakis, P. Mangeney "Chiral acetals in asymmetric synthesis" Tetrahedron: Asymmetry 1990, 1, 477-511.

[] open archive unige:8181 full text [restricted access]   

 (92) 

A. Alexakis, S. Mutti, J. F. Normant, P. Mangeney "A new reagent for a very simple and efficient determination of enantiomeric purity of alcohols by 31P NMR" Tetrahedron: Asymmetry 1990, 1, 437-440.

[] open archive unige:8180 full text [restricted access]   

 (91) 

A. Alexakis, I. Marek, P. Mangeney, J. F. Normant "Mechanistic aspects on the formation of chiral allenes from propargylic ethers and organocopper reagents" J. Am. Chem. Soc. 1990, 112, 8042-8047.

[] open archive unige:8182 full text [restricted access]   

 (90) 

J. F. Normant, J. C. Quirion, Y. Masuda, A. Alexakis "Reactivity of allyl-zinc (and copper) reagents towards allenic ethers and α-metallated allenic ethers" Tetrahedron Lett. 1990, 31, 2879-2882.

[] open archive unige:8077 full text [restricted access]   

 (89) 

M. Commerçon, P. Mangeney, T. Tejero, A. Alexakis "Chiral aminal templates 4. Chiral aryl metallic reagents: reactions with aldehydes" Tetrahedron: Asymmetry 1990, 1, 287-289.

[] open archive unige:8179 full text [restricted access]   

 (88) 

A. Alexakis, R. Sedrani, J. F. Normant, P. Mangeney "Chiral aminal templates 3. Diastereoselectivity of organo-metallic attack on aldehydes bearing a chiral imidazolidine group" Tetrahedron: Asymmetry 1990, 1, 283-286.

[] open archive unige:8178 full text [restricted access]   

 (87) 

A. Alexakis, J. Hanaïzi, D. Jachiet, J. F. Normant "Unusual 1,2-migration in organoaluminium chemistry, promoted by BF3.OEt2" Tetrahedron Lett. 1990, 31, 1271-1274.

[] open archive unige:8079 full text [restricted access]   

 (86) 

A. Alexakis, R. Sedrani, P. Mangeney "Stereochemical effects of trimethylsilyl chloride (TMSCl) on the conjugate addition of organocopper reagents" Tetrahedron Lett. 1990, 31, 345-348.

[] open archive unige:8078 full text [restricted access]   

 1989
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 (85) 

A. Alexakis, D. Jachiet "A completely stereoselective intramolecular Diels-Alder reaction in the substituted cyclohexanol series" Tetrahedron 1989, 45, 6203-6210.

[] open archive unige:8172 full text [restricted access]   

 (84) 

A. Alexakis, D. Jachiet "Boron trifluoride assisted opening of epoxides by lithium alkenyl aluminate reagents" Tetrahedron 1989, 45, 6197-6202.

[] open archive unige:8171 full text [restricted access]   

 (83) 

J. F. Normant, J. C. Quirion, A. Alexakis, Y. Masuda "Allylic organobismetallic reagents - Part 1" Tetrahedron Lett. 1989, 30, 3955-3958.

[] open archive unige:8211 full text [restricted access]   

 (82) 

A. Alexakis, I. Marek, P. Mangeney, J. F. Normant "Copper catalyzed reductive metallation of a propargylic epoxide to an allenyl lithium reagent" Tetrahedron Lett. 1989, 30, 2391-2392.

[] open archive unige:8076 full text [restricted access]   

 (81) 

A. Alexakis, I. Marek, P. Mangeney, J. F. Normant "Diastereoselective synthesis of α-allenic alcohols from propargylic epoxides" Tetrahedron Lett. 1989, 30, 2387-2390.

[] open archive unige:8075 full text [restricted access]   

 (80) 

D. Cuvinot, P. Mangeney, A. Alexakis, J. F. Normant, J. P. Lellouche "Chiral trifluoro diamines as convenient reagents for determining the enantiomeric purity of aldehydes by use of 19F NMR spectroscopy" J. Org. Chem. 1989, 54, 2420-2425.

[] open archive unige:8146 full text [restricted access]   

 (79) 

J. F. Normant, A. Alexakis, A. Ghribi, P. Mangeney "Boron fluoride promoted cleavage of acetals by organocopper reagents. Application to asymmetric synthesis" Tetrahedron 1989, 45, 507-516.

[] open archive unige:8174 full text [restricted access]   

 (78) 

A. Alexakis, D. Jachiet "A new approach to conjugate dienes. Synthesis of the pheromones of Lobesia Botrana and Bombyx Mori" Tetrahedron 1989, 45, 381-389.

[] open archive unige:8173 full text [restricted access]   

 1988
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 (77) 

A. Alexakis, J.-M. Duffault "The hydroalumination of ω-terbutoxy alkynes an easy access to ω-hydroxy alkenyl iodides. Application to the synthesis of dienic insect pheromone" Tetrahedron Lett. 1988, 29, 6243-6246.

[] open archive unige:8074   

 (76) 

A. Alexakis, P. Mangeney, A. Ghribi, D. Jachiet, J. F. Normant "Some aspects of the reactivity of RCu/BF3 reagents towards the ether linkage" Philosoph. Trans. Royal Society, London 1988, 326, 557-564.

[] open archive unige:8226 full text [restricted access]   

 (75) 

A. Alexakis, R. Sedrani, P. Mangeney, J. F. Normant "Diastereoselective conjugate addition with acetals, oxazolidines and imidazolidines as chiral auxiliaries" Tetrahedron Lett. 1988, 29, 4411-4414.

[] open archive unige:8073 full text [restricted access]   

 (74) 

A. Alexakis, M. Gardette, S. Colin "Mild protection and deprotection of alcohols as ter-butyl ethers in the field of pheromone synthesis" Tetrahedron Lett. 1988, 29, 2951-2954.

[] open archive unige:8072 full text [restricted access]   

 (73) 

P. Mangeney, A. Alexakis, J. F. Normant "Resolution and determination of enantiomeric excesses of chiral aldehydes via chiral imidazolidines" Tetrahedron Lett. 1988, 29, 2677-2680.

[] open archive unige:8071 full text [restricted access]   

 (72) 

P. Mangeney, A. Alexakis, J. F. Normant "Improved optical resolution of R*,R* N,N'-dimethyl 1,2-diphenyl ethylene diamine" Tetrahedron Lett. 1988, 29, 2675-2676.

[] open archive unige:8070 full text [restricted access]   

 (71) 

A. Alexakis, D. Jachiet "A new strategy for the synthesis of the pheromones of Lobesia Botrana and Bombyx Mori" Tetrahedron Lett. 1988, 29, 217-218.

[] open archive unige:8069 full text [restricted access]   

 (70) 

C. Fugier, M. Leroux, R. Mauge, A. Alexakis, J. F. Normant "Nouveau procédé de préparation énantiospécifique du (S) éthylamino-2 (trifluorométhyl-3 phényl)-1 propane" Brevet d'Invention 1988, n° 5614.

[] 

 (69) 

P. Mangeney, T. Tejero, A. Alexakis, F. Grosjean, J. F. Normant "Titanium induced coupling of imines to symmetrical vicinal (R*,R*)-diamines" Synthesis 1988, 255-259.

[] open archive unige:8137 full text [restricted access]   

 (68) 

A. Alexakis, P. Mangeney, A. Ghribi, I. Marek, R. Sedrani, C. Guir, J.-F. Normant "Chiral acetals in enantio- and diastereoselective substitution or elimination reactions" Pure Appl. Chem. 1988, 60, 49-56.

[] open archive unige:8242 full text [restricted access]   

 1987
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 (67) 

P. Mangeney, A. Alexakis, J. F. Normant "Acetals as chiral auxiliaries. Part 4. Asymmetric synthesis of γ,δ-ethylenic aldehydes. An approach to the California Red Scale Pheromone" Tetrahedron Lett. 1987, 28, 2363-2366.

[] open archive unige:8210 full text [restricted access]   

 (66) 

A. Alexakis "La carbocupration: un puissant outil de synthèse de phéromones sexuelles d'insectes" L'actualité Chimique 1987, 203-217.

[] open archive unige:6326 full text [restricted access]   

 1986
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 (65) 

A. Alexakis, D. Jachiet, J. F. Normant "Boron fluoride promoted opening of epoxides by organocopper or cuprates reagents" Tetrahedron 1986, 42, 5607-5619.

[] open archive unige:8169 full text [restricted access]   

 (64) 

I. Marek, P. Mangeney, A. Alexakis, J. F. Normant "Are allenes formed from propargylic ethers through a syn or anti displacement α" Tetrahedron Lett. 1986, 27, 5499-5502.

[] open archive unige:8068 full text [restricted access]   

 (63) 

C. Fugier, M. Leroux, J. F. Normant, A. Alexakis "Nouveau procédé de préparation des undécatriènes-1,3,5" Brevet d'invention Européen 1986, n° 86 107 380.7.

[] 

 (62) 

P. Mangeney, A. Alexakis, J. F. Normant "Diastereoselective conjugate addition to chiral α,β-ethylenic acetals" Tetrahedron Lett. 1986, 27, 3143-3146.

[] open archive unige:8067 full text [restricted access]   

 (61) 

N. Jabri, A. Alexakis, J. F. Normant "Palladium mediated synthesis of conjugate (E) or (Z) enones and unsymmetrical divinyl ketones. One-pot preparation of Isoegomaketone" Tetrahedron 1986, 42, 1369-1380.

[] open archive unige:8170 full text [restricted access]   

 (60) 

A. Alexakis, J. Berlan, Y. Besace "Organocopper conjugate addition reaction in the presence of trimethylchlorosilane" Tetrahedron Lett. 1986, 27, 1047-1050.

[] open archive unige:8209 full text [restricted access]   

 1985
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 (59) 

M. Gardette, A. Alexakis, J. F. Normant "Alkenyl copper reagents 26. Carbocupration of alkynes by reagents bearing a protected hydroxy or thiol function" Tetrahedron 1985, 41, 5887-5899.

[] open archive unige:8168 full text [restricted access]   

 (58) 

A. Alexakis, P. Mangeney, J. F. Normant "Diastereoselective β-elimination. Synthesis of chiral alkoxy-allenes" Tetrahedron Lett. 1985, 26, 4197-4200.

[] open archive unige:8208 full text [restricted access]   

 (57) 

C. Fugier, M. Leroux, J. F. Normant, A. Alexakis "Nouveau procédé de préparation des undécatriènes" Brevet d'invention, Institut National de la Propriété Industrielle 1985, n° 85 08181.

[] 

 (56) 

A. Alexakis, J. F. Normant "Alkenylcopper Derivatives; 27. Synthesis of 1-Alkenyl Thioethers by Cleavage of Disulfides with 1-Alkenyl-copper Reagents" Synthesis 1985, 72-74.

[] open archive unige:8140 full text [restricted access]   

 1984
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 (55) 

C. Germon, A. Alexakis, J. F. Normant "Alkenyl copper derivatives 28. Stereospecific synthesis of tertiary allylic amines of (E) or (Z) configuration" Bull. Soc. Chim. France II 1984, 377-389.

[] open archive unige:6320 full text [restricted access]   

 (54) 

M. Gardette, N. Jabri, A. Alexakis, J. F. Normant "General methodology for the synthesis of conjugated dienic insect sex pheromones" Tetrahedron 1984, 40, 2741-2750.

[] open archive unige:8165 full text [restricted access]   

 (53) 

A. Alexakis, J. F. Normant "Alkenyl copper derivatives 25. Synthesis of (E) or (Z) enol ethers by carbocupration of alkoxy-allenes" Israel J. Chem. 1984, 24, 113-117.

[] open archive unige:6325   

 (52) 

A. Ghribi, A. Alexakis, J. F. Normant "Asymmetric cleavage of chiral acetals by R2CuLi,BF3 reagents" Tetrahedron Lett. 1984, 25, 3083-3086.

[] open archive unige:8207 full text [restricted access]   

 (51) 

A. Ghribi, A. Alexakis, J. F. Normant "Reactivity of RCu,BF3 and R2CuLi,BF3 towards allylic acetals and ethers" Tetrahedron Lett. 1984, 25, 3079-3082.

[] open archive unige:8206 full text [restricted access]   

 (50) 

A. Ghribi, A. Alexakis, J. F. Normant "Reactivity of RCu,BF3 and R2CuLi,BF3 toward the ether linkage. Epoxides, acetals and orthoformates" Tetrahedron Lett. 1984, 25, 3075-3078.

[] open archive unige:8205 full text [restricted access]   

 (49) 

P. Mangeney, A. Alexakis, J. F. Normant "Etude d'un modele d'induction asymetrique: Les oxazolidines α,β-insaturées issues de l'éphédrine" Tetrahedron 1984, 40, 1803-1808.

[] open archive unige:8164 full text [restricted access]   

 (48) 

A. Alexakis, A. Commercon, C. Coulentianos, J. F. Normant "Alkenyl copper reagents - 18. Carbocupration of acetylenic acetals and ketals. Synthesis of manicone, geranial and 2,4-(E,Z)-dienals" Tetrahedron 1984, 40, 715-731.

[] open archive unige:9167 full text [restricted access]   

 (47) 

G. Friour, A. Alexakis, G. Cahiez, J. Normant "Reactivity of organomanganese derivatives. VIII. Preparation of ketones by acylation of organomanganese compounds. Effect of acylating agent, solvents, and ligands" Tetrahedron 1984, 40, 683-693.

[] open archive unige:8166 full text [restricted access]   

 (46) 

A. Alexakis, C. Chuit, M. Commercon-Bourgain, J. P. Foulon, N. Jabri, P. Mangeney, J. F. Normant "Organocopper reagents for the synthesis of saturated, and a,b-ethylenic aldehydes and ketones" Pure Appl. Chem. 1984, 56, 91-98.

[] open archive unige:8241 full text [restricted access]   

 (45) 

C. Germon, A. Alexakis, J. F. Normant "Alkenylcopper derivatives; 22. Stereoselective synthesis of allylic thioethers" Synthesis 1984, 43-46.

[] open archive unige:8139 full text [restricted access]   

 (44) 

C. Germon, A. Alexakis, J. F. Normant "Alkenylcopper derivatives; 21. Synthesis of allylic amides and amines by amidomethylation of alkenylcopper and -cuprate reagents" Synthesis 1984, 40-43.

[] open archive unige:8138 full text [restricted access]   

 (43) 

A. Alexakis, G. Cahiez, J. F. Normant "Z-1-Iodohexene" Organic Syntheses 1984, 62, 1-8.

[] open archive unige:8097 full text [restricted access]   

 1983
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 (42) 

N. Jabri, A. Alexakis, J. F. Normant "Alkenyl-copper derivatives. 20. Preparation of polysubstituted conjugated dienes by coupling of alkenyl halides with alkenyl copper reagents" Bull. Chem. Soc. Fr. 1983, 332-338.

[] open archive unige:6324 full text [restricted access]   

 (41) 

N. Jabri, A. Alexakis, J. F. Normant "Alkenyl-copper derivatives. 19. Synthesis of conjugated dienes and styrenes by coupling of alkenyl cuprates with alkenyl and aryl halides" Bull. Chem. Soc. Fr. 1983, 321-331.

[] open archive unige:6323 full text [restricted access]   

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F. Scott, B. G. Mafunda, J. F. Normant, A. Alexakis "Spiroannelation via gem-dihalocyclopropane substrates and a cyclocuprate species" Tetrahedron Lett. 1983, 24, 5767-5770.

[] open archive unige:8204 full text [restricted access]   

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N. Jabri, A. Alexakis, J. F. Normant "Alkenylcopper derivatives. 24. Stereospecific synthesis of enones by palladium-catalyzed acylation of alkenylcopper reagents" Tetrahedron Lett. 1983, 24, 5081-5084.

[] open archive unige:8203 full text [restricted access]   

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A. Alexakis, A. Commercon, C. Coulentianos, J. F. Normant "Carbocupration of acetylenic acetals and ketals: synthesis of α,β ethylenic acetals, and of dienals and dienones" Pure Appl. Chem. 1983, 55, 1759-1766.

[] open archive unige:8240 full text [restricted access]   

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J. F. Normant, A. Alexakis "Preparation of conjugated dienes and enynes via organocopper reagents" In Transition Metals in Organic Synthesis; R. Scheffold (Ed.); Salle + Sauerlander 5527, John Wiley 1983; Vol. 3; p. 139-171.

[] open archive unige:8376 full text [restricted access]   

 (36) 

M. Gardette, A. Alexakis, J. F. Normant "Synthesis of (Z,Z)-3,13-octadecadien-1-yl acetate. Component of the sex pheromone of Synanthedon tenuis" J. Chem. Ecology 1983, 9, 225-233.

[] open archive unige:8220 full text [restricted access]   

 (35) 

M. Gardette, A. Alexakis, J. F. Normant "Synthesis of (Z)-13-Hexadecen-11-yn-1-yl acetate, major component of the sex pheromone of the Processionary moth" J. Chem. Ecology 1983, 9, 219-223.

[] open archive unige:8219 full text [restricted access]   

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J. F. Normant, A. Alexakis "New access to conjugated dienes via carbocupration of alkynes" In Current Trends in Organic Synthesis; H. Nozaki (Ed.); Pergamon: Oxford, 1983; p. 291-302.

[] open archive unige:6720 full text [restricted access]   

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P. Mangeney, A. Alexakis, J. F. Normant "Synthèse asymétrique d'aldéhydes à partir d'oxazolidines chirales α,β-insaturées et d'organocuprates" Tetrahedron Lett. 1983, 24, 373-374.

[] open archive unige:8202 full text [restricted access]   

 1982
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M. Gardette, A. Alexakis, J. F. Normant "Organocuivreux vinyliques 17. Carbocupration d'alcynes par des organocuprates et cuivreux fonctionnels" Tetrahedron Lett. 1982, 23, 5155-5158.

[] open archive unige:8201 full text [restricted access]   

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A. Alexakis, J. F. Normant "Vinyl-copper reagents 16. Synthesis of conjugated dienes via the addition of vinyl cuprates to acetylene" Tetrahedron Lett. 1982, 23, 5151-5154.

[] open archive unige:8200 full text [restricted access]   

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N. Jabri, A. Alexakis, J. F. Normant "Vinyl-copper derivatives 15. An efficient synthesis of polysubstituted conjugated dienes" Tetrahedron Lett. 1982, 23, 1589-1592.

[] open archive unige:8199 full text [restricted access]   

 (29) 

A. Alexakis "Réactifs organo-cuivreux : nouveaux agents de synthèse de pheromone sexuelle d'insectes" In Les mediateurs chimiques agissant sur le comportement des insectes; Les colloques de l'INRA, Vol. 7; 1982; p. 33-41.

[] open archive unige:8261 full text [restricted access]   

 1981
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 (28) 

J. F. Normant, A. Alexakis "Carbometallation (C-Metallation) of Alkynes: Stereospecific Synthesis of Alkenyl Derivatives" Synthesis 1981, 841-870.

[] open archive unige:8142 full text [restricted access]   

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N. Jabri, A. Alexakis, J. F. Normant "Organo-cuivreux vinyliques 14. Arylation des cuprates vinyliques" Tetrahedron Lett. 1981, 22, 3851-3852.

[] open archive unige:8198 full text [restricted access]   

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N. Jabri, A. Alexakis, J. F. Normant "Vinyl-copper derivatives XIII: Synthesis of conjugated dienes of very high stereoisomeric purity" Tetrahedron Lett. 1981, 22, 959-962.

[] open archive unige:8197 full text [restricted access]   

 1980
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 (25) 

C. Germon, A. Alexakis, J. F. Normant "Vinyl-copper derivatives. XII. Stereospecific synthesis of allylic amines by aminomethylation of organocopper reagents" Tetrahedron Lett. 1980, 21, 3763-3766.

[] open archive unige:8196 full text [restricted access]   

 (24) 

A. Alexakis, G. Cahiez, J. F. Normant "Vinylcopper derivatives. XI. Reactivity of Z-alkenylcuprates towards various electrophiles. Application to the synthesis of some natural products" Tetrahedron 1980, 36, 1961-1969.

[] open archive unige:8163 full text [restricted access]   

 (23) 

G. Cahiez, A. Alexakis, J. F. Normant "Simple stereospecific synthesis of the insect sex pheromones of Cossus cossus, Eupoecilia ambiguella, and Orgyia pseudotsugata" Tetrahedron Lett. 1980, 21, 1433-1436.

[] open archive unige:8195 full text [restricted access]   

 (22) 

J. F. Normant, A. Alexakis, G. Cahiez "Action d'organolithiens et organomagnésiens sur la propiolactone en présence de sels cuivreux. Synthèse d'acides carboxyliques" Tetrahedron Lett. 1980, 21, 935-938.

[] open archive unige:8194 full text [restricted access]   

 1979
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 (21) 

A. Alexakis, G. Cahiez, J. F. Normant "Vinyl-copper derivatives X. Alkylation of (Z) dialkenyl cuprates" Synthesis 1979, 826-830.

[] open archive unige:8141 full text [restricted access]   

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A. Alexakis, G. Cahiez, J. F. Normant "Organocuivreux vinyliques IX. Addition de dérivés organiques du cuivre sur l'acétylène" J. Organomet. Chem. 1979, 177, 293-298.

[] open archive unige:6315 full text [restricted access]   

 (19) 

G. Friour, A. Alexakis, G. Cahiez, J. F. Normant "Réactivité des dérivés organomanganeux VI. Carbonatation" Bull. Soc. Chim. Fr. 1979, 515-517.

[] open archive unige:8213 full text [restricted access]   

 (18) 

G. Cahiez, A. Alexakis, J. F. Normant "Organomanganese(II) reagents. V. Organomanganous chlorides as a new reagent for ketone synthesis via mixed or symmetrical anhydrides" Synthetic Comm. 1979, 9, 639-645.

[] open archive unige:8216 full text [restricted access]   

 1978
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 (17) 

A. Alexakis, M. J. Chapdelaine, G. H. Posner "A new approach to the bicyclo[3.2.1]octane ring system: Intramolecular michael and aldol reactions of 3-(5-oxohexyl)-2-cyclopentenones" Tetrahedron Lett. 1978, 19, 4209-4212.

[] open archive unige:8193 full text [restricted access]   

 (16) 

A. Alexakis, M. J. Chapdelaine, G. H. Posner, A. W. Runquist "A new synthetic approach to Pseudoguaianes" Tetrahedron Lett. 1978, 19, 4205-4208.

[] open archive unige:8192 full text [restricted access]   

 (15) 

J. F. Normant, T. Mulamba, F. Scott, A. Alexakis, G. Cahiez "Substitution directe de l'halogène d'halohydrines 1-2 par des organomagnésiens et lithiens en présence de sels cuivreux" Tetrahedron Lett. 1978, 19, 3711-3712.

[] open archive unige:8486 full text [restricted access]   

 (14) 

G. Cahiez, A. Alexakis, J. F. Normant "Dérivés organomagnésiens ω-alcoolates : préparation et réactivité" Tetrahedron Lett. 1978, 19, 3013-3014.

[] open archive unige:8190 full text [restricted access]   

 (13) 

G. Cahiez, A. Alexakis, J. F. Normant "A highly stereoselective preparation of 1,4- and 1,5 alkadienes" Synthesis 1978, 528-30.

[] open archive unige:8144 full text [restricted access]   

 (12) 

A. Alexakis, G. Cahiez, J. F. Normant "Highly stereoselective synthesis of the insect sex pheromone of Phthorimaea operculella and of propylure" Tetrahedron Lett. 1978, 2027-2030.

[] open archive unige:8187 full text [restricted access]   

 1977
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 (11) 

J. G. Duboudin, B. Jousseaume, A. Alexakis, G. Cahiez, J. Villieras, J. F. Normant "Addition comparée d'organocuivreux, d'organocuprates et d'organomagnésiens en présence de Cu(I) en quantité catalytique sur l'alcool propargylique" C. R. Acad. Sc. Paris, Ser. C. 1977, 285, 29-31.

[] open archive unige:8228 full text [restricted access]   

 (10) 

G. H. Posner, C. E. Whitten, J. J. Sterling, D. J. Brunelle, C. M. Lentz, A. W. Runquist, A. Alexakis "New organocopper synthetic methods. α,β-dialkylation of α,β-ethylenic ketones : synthesis of sesquiterpenes" Ann. New York Acad. Sci. 1977, 295, 249-253.

[] open archive unige:8222 full text [restricted access]   

 (9) 

A. Alexakis, G. Cahiez, J. F. Normant, J. Villieras "Organo-cuivreux vinyliques VIII. Etude de la régio-sélectivité de l'addition des dérivés organo-cuivreux sur les alcynes hétérosubstitués. Utilisation en synthèse des complexes organo-cuivreux obtenus" Bull. Soc. Chim. Fr. 1977, 693-698.

[] open archive unige:8191 full text [restricted access]   

 1976
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 (8) 

A. Alexakis, J. Normant, J. Villieras "Dérivés organo-cuivreux vinyliques VII. Addition de l'acétylène sur des cuprates lithiens : synthèse d'homo et d'hétéro-vinyl cuprates lithiens (Z)" Tetrahedron Lett. 1976, 17, 3461-3462.

[] open archive unige:8189 full text [restricted access]   

 (7) 

A. Alexakis, A. Commerçon, J. Villieras, J. F. Normant "Dérivés organo-cuivreux vinyliques VI. Addition régiosélective d'organocuprates sur des acétals α-acétyléniques. Synthèse d'un acétal du Géranial" Tetrahedron Lett. 1976, 17, 2313-2316.

[] open archive unige:8188 full text [restricted access]   

 1975
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 (6) 

A. Alexakis "Etude de la régiosélectivité de l'addition d'organo-cuivreux sur des alcynes fonctionnels" Thèse de doctorat d\'Etat Paris 1975, 23 Jan., N° CNRS : AO 12960.

[] 

 (5) 

A. Alexakis, J. F. Normant, J. Villieras "Organo-vinyl-copper compounds V. Regioselectivity in the addition of alkyl-copper-magnesium bromide reagents on various propargyl derivatives" J. Mol. Catal. 1975, 1, 43-58.

[] open archive unige:8225 full text [restricted access]   

 (4) 

A. Alexakis, J. Normant, J. Villieras "Organocuivreux vinyliques : IV. Etude de la régiosélectivité de l'addition d'un alkyl-cuivre sur des alcynes β et γ fonctionnels" J. Organomet. Chem. 1975, 96, 471-485.

[] open archive unige:8136 full text [restricted access]   

 1974
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 (3) 

J. F. Normant, A. Alexakis, A. Commercon, G. Cahiez, J. Villieras "Organocuivreux alcoxy et alkylthio-vinyliques : intermédiaires de synthèse d'alcènes hétérosubstitués stéréospécifiquement" C. R. Acad. Sc. Paris, Ser. C. 1974, 279, 763-765.

[] open archive unige:8223 full text [restricted access]   

 1973
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 (2) 

J. F. Normant, A. Alexakis, J. Villieras "Addition d'alkyl-cuivres sur divers dérivés propargyliques" J. Organomet. Chem. 1973, 57, C99-C102.

[] open archive unige:6317 full text [restricted access]   

 1972
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 (1) 

J. F. Normant, G. Cahiez, C. Chuit, A. Alexakis, J. Villieras "Synthèse stéréospécifique d'oléfines di- et trisubstituées par alcoylation des vinyl cuivres" J. Organomet. Chem. 1972, 40, C49-C52.

[] open archive unige:6316 full text [restricted access]   


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