Ytterbium pentafluorobenzoate as a novel fluorous Lewis acid catalyst in the synthesis of 2,4-disubstituted quinolines

A series of simple, efficient, stable and recoverable rare earth metal pentafluorobenzoates [RE(Pfb)3] have been synthesized for the first time. A highly efficient and environmentally friendly synthesis of 2,4-disubstituted quinolines catalyzed by Yb(Pfb)3 via one-pot reaction of aldehydes, alkynes and amines under solvent-free conditions has been explored.