Metal-Free Br?nsted Acid Catalyzed Transfer Hydrogenation - New Organocatalytic Reduction of Quinolines

The first metal-free Br?nsted acid catalyzed hydrogenation of quinolines using Hantzsch dihydropyridine as the hydrogen source has been developed. This, so far unprecedented organocatalytic reduction of heteroaromatic compounds provides a variety of differently substituted 1,2,3,4-tetrahydroquinolines in excellent yields under mild reaction conditions using a remarkably low amount of Br(phi)nsted acid catalyst.