Cobalt-Catalyzed Carbocyclization of o-lodobenzaldehydes and o-lodophenylketones with Alkynes

摘要

Treatment of various o-iodobenzaldehydes and o-iodophenyl ketones with alkynes in the presence of Co(dppe)I_2 and Zn powder in acetonitrile at 80 ℃ afforded the corresponding indenols in moderate to excellent yields with exceedingly high regioselectivity. For most unsymmetrical alkynes tested, the carbocyclization gave a single regioisomer.