The conjugate addition of Grignard reagents RMgX to α, β-unsaturated ketones and esters is effectively catalyzed by soluble copper ate-complexes of the type CuX3Li2, eg CuI· 2LiCl. In the presence of Me3SiCl the corresponding ketone enolsilanes are formed in high yield and selectivity. Diasteroselectivity in the case of chiral ketones is similar to that observed by using stoichiometric amounts of cuprates R2CuLi. Thus CuX3Li2-catalyzed 1, 4-additions ...
