Synthesis of Tetrasubstituted Enamines through Borane-Catalyzed Hydrogenations.

This paper describes a B(C 6 F 5 ) 3 -catalyzed hydrogenation of β-substituted α,β-unsaturated imines by using as low as 0.2 mol % catalyst. A variety of tetrasubstituted enamines were afforded in 95-99% yields. It provides an efficient and facile way without the need for column chromatography purification.