Chiral Phosphine—Phosphite Ligands in the Enantioselective 1,4-Addition of Grignard Reagents to α,β-Unsaturated Carbonyl Compounds.

Copper-catalyzed asymmetric 1,4-addition of Grignard reagents towards cyclic ketones proceeds efficiently in the presence of novel chiral phosphine—phosphite ligands (I) to give the adducts (IV) and (VI) in up to 93% optical purity.