Visible-Light-Induced Trifluoromethylation/Cyclization of 1,7-Enynes in Continuous Flow

In the present study, we describe the successful development of a photoredox-catalyzed trifluoromethylation/cyclization of 1,7-enynes in a continuous-flow regime for the generation of several CF3-containing heterocyclic scaffolds. When using this protocol, a readily prepared Ph2SCF3OTf reagent was employed as the trifluoromethylation reagent, and various benzo[j]phenanthridines and indeno[1,2-c]quinolines were obtained in good to moderate yields. This transformation featured mild reaction conditions, a broad substrate scope, and ease of scale-up. Moreover, the continuous-flow processing in a photomicroreactor accelerated the reaction (5 min reaction time) and increased the product yields (up to 89%).