Development of the first practical catalyst for the asymmetric addition of alkyl- and arylzinc reagents to ketones

A long-standing problem in organic synthesis is the catalytic asymmetric addition of alkyl groups to ketones to establish chiral quaternary centers. Such compounds are valuable chiral building blocks that can be further elaborated. In this account, we describe the previously unreported story of the development of the first effective catalyst for the enantioselective addition of dialkyland diphenylzinc reagents to ketones. The scope of this reaction is outlined, including a tandem enantioselective addition to cyclic enones/diastereoselective epoxidation protocol that establishes three contiguous stereocenters in a one-pot procedure.