Highly Enantioselective 1,4-Addition of Diorganozinc Reagents to Cyclic Enones Using Chiral Diphosphite Ligands Derived from H8-Binaphthol

High enantioselectivities have been achieved in the 1,4-addition of dialkylzincs to 2-cyclopentenone, 2-cyclohexenone, and 2-cycloheptenone with ee values up to 99% by using chiral aryl diphosphite ligands derived from H8-binaphthol.