CuI/I-2-Mediated Intramolecular Oxidative Cyclization Reaction of N-(2-pyridyl)amidines by the Direct Double C-H Functionalization of a C(sp(3))-H Bond

摘要

A facile approach to a rare class of 3,3-disubstituted 2-iminoimidazo[1,2-a]-pyridines bearing a hydroxyl group at the 3 position in good to excellent yields from N-(2-pyridyl)amidines substrates in the presence of CuI/I-2/KI/KOtBu is described. According to the investigation, the use of a Cu catalyst and the presence of sulfonyl groups in the substrates has a remarkable influence on the success of the oxidative cyclization reaction. Moreover, the oxygen source of the hydroxyl group may be from the incorporation of water in the reaction system or KOtBu. The successful implementation of the reaction further indicates that amidines have abundant reactivity under various reaction conditions. The methodology is operationally simple and has a broad substrate scope.