Photo-Induced Difluoromethylation-Cyclization and Domino Amination-Defluorination to 4-(Aminomethyl)-3-fluoro-quinolinones.

Herein, we report a visible light-induced difluoromethylation cyclization and subsequent amination-defluorination reaction. This protocol allows efficient to valuable 3-fluoro-quinolinones in moderate to excellent yields. A sequential difluoromethylation-cyclization-amination-defluorination mechanism was proposed based on a mechanism study. Further density functional theory (DFT) calculations revealed that the base KHPO could lower the energy due to the C═O···K electrostatic interaction to assist the elimination process, while the six-membered transition state located in situ was essential for the cleavage of N-H and C-F bonds during this S2'-type process.