Photocatalytic Fluoroalkylative Cyclization of o -Alkenylbenzamides Enabled by Fluoroalkylsulfonyl Chlorides

Photocatalytic fluoroalkylative cyclization of alkenes provides an efficient approach to fluorinated heterocycles, yet existing methods generally require distinct radical precursors for different fluoroalkyl groups. Herein, we report a visible-light-induced ruthenium-catalyzed fluoroalkylative cyclization of o-alkenylbenzamides using readily available fluoroalkylsulfonyl chlorides as a unified family of radical precursors. This protocol enables the efficient synthesis of a broad range of fluoroalkylated iminoisobenzofurans bearing trifluoromethyl, difluoromethyl, and perfluoroalkyl substituents under mild conditions with a broad substrate scope and good functional group compatibility. Mechanistic studies support a photocatalytic radical pathway initiated by single-electron reduction of the fluoroalkylsulfonyl chlorides.