Highly stereoselective C-allylation of an enantiopure alpha-sulfinyl thioacetamide.
The alkylation of the lithium enolate of enantiopure alpha-cyclohexylsulfinyl thioacetamide 1 with allyl bromides 5 possessing an electron-withdrawing group at the vinylic position does not occur at the sulfur center - as expected in the sulfur series - but at the carbon center through conjugate addition followed by bromide elimination. The modest to excellent 1,2-asymmetric induction achieved by the alkylsulfinyl group (dr up to 100:0) is explained by an electronic model.
Nowaczyk
Stéphanie
S
Laboratoire de Chimie Moléculaire et Thio-organique (UMR CNRS 6507), ISMRA-Université de Caen, 6 Boulevard du Maréchal Juin, F-14050 Caen, France.
Alayrac
Carole
C
Metzner
Patrick
P
Averbuch-Pouchot
Marie-Thérèse
MT