Palladium-Catalyzed Intramolecular O-Arylation of Enolates:  Application to Benzo[b]furan Synthesis

A catalyst generated from Pd₂(dba)₃ and the ligand DPEphos effects intramolecular C−O bond formation between enolates and aryl halides in the conversion of 1-(2-haloaryl)ketones directly into the corresponding benzofurans. Both cyclic and acyclic ketones are efficient substrates. Thio ketones can also be employed allowing the preparation of the corresponding benzothiophenes.