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.