A Novel Route to 2-Arylquinolines: Reductive Cleavage of 2'-Nitroaryl-Δ²-isoxazolines.

A novel synthetic route for the synthesis of quinolines starting from Δ²-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. [ABSTRACT FROM AUTHOR]