Facile Benzo-Ring Construction via Palladium-Catalyzed Functionalization of Unactivated sp3 C-H Bonds under Mild Reaction Conditions

A practical synthetic method for the annulation of benzo-rings by the intramolecular coupling of an aryl Iodide and a methylene C H bond is described. The palladium-catalyzed C-H functionalization Is directed by an aminoquinoline carboxamide group, which can be easily installed and removed. High yields and broad substrate scope were achieved. An additive of ortho-phenyl benzoic acid, identified from a systematic screening, functions as a critical ligand for the catalytic process under mild condition, even at near room temperature.