Catalytic enantioselective addition of diorganozinc reagents to vinyl sulfones

An efficient method for the catalytic asymmetric conjugate addition of diorganozinc reagents to vinyl sulfones is reported. Using a Binap circle Cu complex, enantioselectivities up to 98% ee and high yields can be attained for a variety of substrates. Several dialkylzinc reagents are also compatible with this procedure.