Contemporaneous Dual Catalysis by Coupling Highly Transient Nucleophilic and Electrophilic Intermediates Generated in Situ

We report herein a new process, which we call contemporaneous dual catalysis, that selectively couples two highly reactive catalytic intermediates while overcoming competing trapping by stoichiometric reactive species also present in the reaction. The reaction proceeds via the convergence of a vanadium-catalyzed propargylic rearrangement and a palladium-catalyzed allylic alkylation. It generates a variety of alpha-allylated alpha,beta-unsaturated ketones, which are not readily accessible by other means. Notably, this dual catalysis is achieved using low catalyst loadings (1.0 mol % [Pd], 1.5 mol % [V]) and gives good to excellent yields (up to 98%) of the desired products.