Pd-Catalyzed Regioselective C-H Alkenylation and Alkynylation of Allylic Alcohols with the Assistance of a Bidentate Phenanthroline Auxiliary

A Pd-catalyzed regioselective C-H alkenylation of allylic alcohols with electron-deficient alkenes has been developed. The key to success is the introduction of bidentately coordinating phenanthroline directing group, which enables the otherwise challenging and regioselective C-H activation at the proximal alkenyl C-H bonds over the conceivably competitive allylic C-O bond activation. The same Pd/phenanthroline system is efficient for the C-H alkynylation of allylic alcohols with alkynyl bromides.