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.

DOI : 10.1002/ejoc.200900058 

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