Palladium-Catalyzed Construction of Phthalides Bearing Two Adjacent Stereocenters through Retro-oxa-Michael Addition

Optically active phthalides are prevalent in many natural and bioactive products. Herein, a novel dynamic kinetic resolution of isobenzofuranone derivatives through palladium-catalyzed asymmetric allylic alkylation has been developed to synthesize phthalide derivatives bearing vicinal quaternary and tertiary stereocenters with high yields, showing excellent chemo-, enantio- and diastereoselectivity. Furthermore, gram-scale experiment underwent smoothly and the transformation of product could build a bridged bicyclic skeleton.