First Example of the Intermolecular Palladium-Catalyzed Asymmetric Allylic Alkylation of Hydroxyacrylates: Synthesis of All-Carbon [alpha]-Aryl Quaternary Aldehydes

A set of acyclic all-carbon [alpha]-aryl quaternary aldehydes was synthesized by intermolecular palladium-catalyzed asymmetric allylic alkylation (Pd-AAA). Hydroxyacrylates were used as unprecedented nucleophilic counterparts instead of widely used ketone substrates. This produced a very rare all-carbon quaternary aldehyde. Chiral ligand (R,R)-L3 was found to be optimal in this Pd-AAA reaction and provided good to excellent yields (75-99%) and enantioselectivities (75-94%) with a range of analogs.