A Novel Route to 2-Arylquinolines: Reductive Cleavage of 2′-Nitroaryl-∆2-isoxazolines

A novel synthetic route for the synthesis of quinolines starting from Δ 2 -isoxazolines under reductive conditions is reported. The ­reductive cyclization to quinolines is achieved under both metal and metal-free conditions. The reaction proceeds via an intramolecular N–H···O hydrogen bond intermediate, accelerating the reductive cleavage 1000-fold (DFT calculations) in comparison with non-hydrogen bonded system.