Visible-Light-Induced Trifluoromethylation/Cyclization of 1,7-Enynes in Continuous Flow
Kai‐Qiang Zhuang, Yu‐Sheng Cui, Xin Yuan, Long‐Zhou Qin, Qi Sun, Xiu Duan, Lin Chen, Xinpeng Zhang, Jiang‐Kai Qiu, Kai Guo
Abstract
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%).