Asymmetric α‐Pentadienylation of β‐Ketocarbonyls and Aldehydes by Synergistic Pd/Chiral Primary Amine Catalysis†

Abstract

Comprehensive SummaryDirect alkylation with skipped enynes or cyclopropropylacetylenes represents an ideal process for the installation of pentadienyl group in terms of atom‐ and step‐economy. The development of catalytic asymmetric versions has been frequently pursued and most of the successes have been achieved with enolizable aldehydes. We herein describe a synergistic chiral primary amine/Pd catalysis for asymmetric α‐pentadienylation of β‐ketocarbonyls and aldehydes with skipped enynes or cyclopropropylacetylenes. The reaction features the construction of acyclic all‐carbon quaternary centers with high enantioselectivity, and good functional group tolerance and scalability.