Enantioselective Copper-Catalyzed 1,4-Addition of Dialkylzincs to Enones Followed by Trapping with Allyl Iodide Derivatives

The asymmetric 1,4-addition of dimethylzinc and diethylzinc to enones (II) in the presence of Cu(O-Tf)2 and chiral N,N,P-ligands (I) proceeds with high enantioselectivities, whereas the addition of dibutylzinc leads to butylated ketones such as (IVc) with low enantioselectivity.