Palladium‐Catalyzed,Chelation‐Assisted Stereo‐ and Regioselective Synthesis of Tetrasubstituted Olefins by Oxidative Heck Arylation

An efficient synthesis of tetrasubstituted olefins was achieved via a palladium‐catalyzed, chelation‐assisted oxidative Heck arylation protocol from trisubstituted olefins bearing a tether with a directing group in a completely stereo‐ and regioselective manner. The stereo‐ and regioselectivity as well as excellent yields of tetrasubstituted olefins originated from the stabilization of a palladium intermediate by chelation between the palladium center and a directing group.