Iron-Catalyzed Markovnikov-Selective Radical Hydrochalcogenation of Unactivated Alkenes

A Markovnikov-selective radical hydrochalcogenation reaction of unactivated alkenes via iron-catalyzed hydrogen atom transfer was reported. Using N-(arylsulfenyl)arenesulfonamide, PhSO2SCD3, S-alkyl thiosulfonate, S-alkyl dithiosulfonate and Ebselen derivatives as versatile radicalophiles, a wide range of unsymmetrical alkyl-aryl, dialkyl and SCD3 (D > 99%) containing sulfides, dialkyl disulfides, as well as organoselenides have been collectively synthesized under mild conditions. As a powerful alternative to the classical thiol-ene reaction, this protocol features exclusive Markovnikov selectivity, good functional group tolerance and broad substrate scope. A number of radical probe experiments suggest the hydrochalcogenation proceeds through the radical pathway. The synthetic utility of this transformation was also demonstrated through the late-stage modifications of diverse natural products and bioactive molecules.