Light-Mediated Ring-Opening Functionalization of Epoxides via a Fluorinated Thiolate Mediator

A metal-free approach to the regioselective radical ring-opening of epoxides is described. The method involves nucleophilic opening of the epoxide with a redox-active perfluorinated thiol and subsequent single-electron reduction under blue light irradiation in the presence of a stoichiometric reductant or a photocatalyst. The approach is complementary to the titanium-catalyzed processes, allows radical addition to both electron-deficient and -rich alkenes, and is also applicable to the functionalization of aziridines and bicyclobutanes.