Visible-light-induced perfluoroalkylation cyclization to access perfluoroalkylated benzazepines and benzoxepines by EDA complexes

Abstract

A visible-light-mediated perfluoroalkylation/cyclization of N-allyl-N-(2-(3,3-bis(methylthio)acryloyl)aryl)-4-methylbenzenesulfon-amides and 1-(2-(allyloxy)aryl)-3,3-bis(methylthio)prop-2-en-1-ones for the synthesis of perfluoroalkylated benzazepines and benzoxepines has been developed. This protocol is photocatalyst-free, and features simple operation and good regioselectivity, providing a novel environmentally friendly strategy to access the seven-membered heterocycles. Preliminary mechanistic studies reveal that the formation of EDA complexes between the perfluoroalkyl iodides and K₂CO₃ initiates the reaction process.