Synthesis of C₃-alkylated benzofurans via palladium-catalyzed regiocontrolled hydrofuranization of unactivated alkenes

A new chelation-controlled hydrofuranization of unactivated olefins with a-alkynyl arylols is reported for the first time, and used to produce a wide range of C-3-alkylated benzofurans with generally good yields under mild conditions. A bidentate directing group is used to suppress beta-hydride elimination and in turn facilitate a protodepalladation event. In addition to 100% atom utilization, good functional group tolerance and mild conditions, the present catalysis did not demand any additional ligand, additives and bases/acids, making the transformation simple and facile and it thus opens new avenues for catalytic difunctionalization of alkynes and olefins.