Cobalt-catalysed transfer hydrogenation of quinolines and related heterocycles using formic acid under mild conditions

Abstract

Herein, we report the first example of homogeneous non-noble metal-catalyzed transfer hydrogenation of N-heteroarenes. The combination of Co(BF₄)₂·6H₂O with tris(2-(diphenylphosphino)phenyl)phosphine L1 is able to selectively reduce quinolines in the presence of other sensitive functional groups, under mild conditions, using formic acid as a hydrogen source.