Visible Light Promoted β-C-H Alkylation of β-Ketocarbonyls via a β-Enaminyl Radical Intermediate

A 5 pi e carbonyl activation mode is reported on the basis of photo-induced single-electron-transfer (SET) oxidation of a secondary enamine. The resultant beta-enaminyl radical intermediate was trapped by a wide range of Michael acceptors, producing beta-alkylation products of beta-ketocarbonyls in a highly efficient manner.