Ir/Zn Dual Catalysis: Enantioselective and Diastereodivergent α-Allylation of Unprotected α-Hydroxy Indanones

A one-step enantioselective and diastereodivergent α-allylation of unprotected α-hydroxy indanones has been developed using an Ir/Zn dual catalyst system; no additional base is required. The cyclic tertiary α-hydroxyketones containing vicinal stereocenters can be synthesized with excellent enantioselectivity (up to >99% ee) and good diastereoselectivity (up to 12:1 dr). By a simple choice of the appropriate chiral metal catalyst combination, all four product stereoisomers could be obtained from the same starting materials and under identical conditions.