alpha-Alkylation of ketimines using visible light photoredox catalysis

摘要

A novel alpha-alkylation of N-diphenylphosphinoyl ketimines with alpha-bromocarbonyl compounds has been accomplished using visible light photoredox catalysis. The reaction proceeds under remarkably mild conditions: at 35 degrees C, in 20 hours, under blue light irradiation (1 W), in the presence of a tertiary amine and catalytic amounts of Ru- and Ni-based complexes. Chemoselective transformation of the products provides access to 1,4-dicarbonyl compounds, protected GABA analogues and gamma-lactams.