Highly diastereoselective preparation of (E)-alkenylsilanes bearing an alpha-chiral center.

The copper(I)-mediated anti-S(N)2' allylic substitution allows a highly stereoselective preparation of alkenylsilanes bearing a chiral center in the alpha-position with high transfer of chirality. These alkenylsilanes were converted into alpha,beta-unsaturated ketones or into the corresponding boronic esters without loss of the chiral information. [reaction: see text]