Copper-Free Asymmetric Allylic Alkylation with a Grignard Reagent: Design of the Ligand and Mechanistic Studies

Article Article scientifique Article Copper-Free Asymmetric Allylic Alkylation with a Grignard Reagent: Design of the Ligand and Mechanistic Studies eng 2013 author Grassi David 633809 author Dolka Chrysanthi 703935 author Jackowski Olivier 687315 author Alexakis Alexandre 123950 1466-1475 10.1002/chem.201202318 0947-6539 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. Allylic compounds Asymmetric synthesis Grignard reagents Heterocyclic carbenes Quaternary stereocentres Dewey 540 36 Département de chimie organique 141 false Chemistry 19 4 f576709a-dc46-42c7-954f-ffed15922ff6 Article (Published version) Restricted 1466_ftp.pdf 535279 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie organique

Title	Published in	Access level	OA Policy	Year	Views	Downloads

Copper-Free Asymmetric Allylic Alkylation with a Grignard Reagent: Design of the Ligand and Mechanistic Studies	Chemistry			2013	658	0

Archive ouverte UNIGE

Dolka, Chrysanthi