A Highly Enantioselective Brønsted Acid Catalyzed Cascade Reaction: Organocatalytic Transfer Hydrogenation of Quinolines and their Application in the Synthesis of Alkaloids

Abstract

A categorical success: A Brønsted acid catalyzed cascade transfer hydrogenation provides direct access to 2-aryl- and 2-alkyl-substituted tetrahydroquinolines with excellent enantioselectivities under mild conditions and using very low amounts of catalyst (see scheme). The best results were achieved with the binol phosphate catalyst, where Ar=9-phenanthryl, used successfully in the Strecker reaction.