Efficient assembly of ynones via palladium-catalyzed sequential carbonylation/alkynylation

Based on the intramolecular Heck-type reaction, a convenient and efficient strategy to construct functionalized ynones by a palladium-catalyzed cascade annulation reaction has been developed. This reaction possesses good functional group compatibility, a broad substrate scope, and high atom- and step-economy. Furthermore, this approach could also be extended to direct alkynylation that gave another route to synthesize dihydrobenzofurans.