Conjugate addition of diethylzinc to α,β-unsaturated lactones catalyzed by copper–phosphite complexes

Highly enantioselective conjugate addition of diethylzinc to α,β-unsaturated lactones was achieved by using chiral diphosphite–copper catalysts; the structure of a chiral diphosphite–copper(I) catalyst was determined by single crystal X-ray diffraction.