@Article{AdvSynthesis&Catal_359_2918, author = {L. Egger and L. Gu{\'e}n{\'e}e and T. B{\"u}rgi and J. Lacour}, title = {{Regioselective and Enantiospecific Synthesis of Dioxepines by (Cyclopentadienyl)ruthenium-Catalyzed Condensations of Diazocarbonyls and Oxetanes}}, journal= {Adv. Synthesis & Catal.}, ISSN = {1615-4150}, volume= {359}, number= {17}, pages = {2918-2923}, url = {http://doi.wiley.com/10.1002/adsc.201700638}, eprint= {http://www.unige.ch/sciences/chifi/publis/refs_pdf/ref01602.pdf}, doi= {10.1002/adsc.201700638}, keywords= {diazo compounds;insertion;metal carbenes;oxetanes;oxonium ylides;retention of configuration}, abstract = {{1,4-Dioxepines result from the decomposition of $\alpha$-diazo-$\beta$-keto esters in the presence of oxetanes using the catalytic combination of the (cyclopentadienyl)ruthenium complex [CpRu(CH$_3$CN)$_3$][BAr$_F$] and 1,10-phenanthroline. The regioselective [4+3] insertions follow an S$_N$1-like mechanism and occur yet enantiospecifically (es 74%). The retention of configuration was ascertained by vibrational circular dichroism (VCD) and solid state analyses. Furans, products of [4+1] insertions, are only observed as traces in the above protocol. To promote their formation under CpRu catalysis, it is necessary to use a two-step process with $\gamma$-halogenated alcohols as substrates.}}, year = {2017} }