Palladium(II)-Catalyzed Oxidative Asymmetric Coupling of Allylic Alcohols and Vinyl Ethers: Nature of Palladium and Copper Bimetallic Catalyst

摘要

Since we reported the first asymmetric, intramolecular Wacker type cyclization in 1978, several groups made advances in its utility for synthesizing O-atom containing heterocycles in high ee. However, still lacking is information on the intermolecular version that involves intermolecular oxy-palladation of O-nucleophiles toward prochiral alkenes where the enantioface is differentiated by Pd(II). Herein we report such a reaction which represents the first asymmetric coupling of cinnamyl alcohols 1 and vinyl ethers 2 to give optically active 2-alkoxy-4-benzylidenetetrahydrofurans 3 (Scheme 1).