Pd-Catalyzed Chelation-Assisted Regioselective and Site Selective Cyclative C–H Annulation of Alkynyl Oximes with Activated Alkynes

Electrophilic cyclization and concomitant C–H annulation constitute an expedient cascade strategy for the construction of multicyclic scaffolds with precise substitutional patterns. We report here a novel Pd-catalyzed cyclative annulation of ynone oxime with activated alkynes. The cascade features a dual regioselectivity including site selective C–H activation and chelation-assisted selective insertion of alkynes. Control experiments together with kinetic experiments give insights into the mechanism.