Photoredox-Catalzyed Halo-trifluoromethylation of 1,7-Enynes for Synthesis of 3,4-Dihydroquinolin-2(1H)-ones

An efficient photoredox-catalyzed halo-trifluoromethylation reaction of 1,7-enynes has been developed under mild conditions. This photocatalytic protocol provides an efficient and functional strategy leading to CF3- and halogen-containing 3,4-dihydroquinolin-2(1H)-ones from a wide range of 1,7-enynes through two different radical pathways. The reaction mechanism was proposed based on the control experiments.