Enantioselective Alkynylation of Ketones Catalyzed by Zn(Salen) Complexes

The new frontier in asymmetric catalysis is the selective formation of quaternary stereocenters. The enantioselective addition of nucleophiles to ketones is a particular challenge. Readily prepared Zn(salen) complexes promote the straightforward synthesis of tertiary alcohols from commercially available starting materials (see scheme), thus allowing the preparation of functionalizable chiral building blocks in a catalytic enantioselective procedure that shows broad scope.