Light‐Induced Tetrafluoroethylation/Cyclization of N‐Methacryloyl‐2‐phenylbenzoimidazoles with 1,2‐Dibromotetrafluoroethane

Various N‐methacryloyl‐2‐arylbenzoimidazoles react with 1,2‐dibromotetrafluoroethane in the presence of photocatalyst 4CzIPN irradiated by 10 W blue LED to provide 5‐(3‐bromo‐2,2,3,3‐tetrafluoropropyl)‐5‐methylbenzo[4,5]‐imidazo[2,1‐a]isoquinolin‐6(5H)‐ones in good yield. The reaction proceeds through a sequential tetrafluoroethyl radical addition/cyclization pathway. The wide substrate scope, good functional group tolerance, and ease of scale‐up of this protocol are expected to promote its potential applications in pharmacy.