Visible-light-promoted photocatalyst- and additive-free intermolecular trifluoromethyl-thio(seleno)cyanation of alkenes

A visible-light-promoted highly selective and efficient strategy for the trifluoromethyl-thiocyanation of alkenes under transition-metal-, photocatalyst- and additive-free conditions has been reported using stable and recyclable Umemoto reagent II as the CF(3)source and inexpensive ammonium thiocyanate as the thiocyanating agent. This economical and environmentally benign protocol is suitable for styrenes, acrylates and unactivated alkenes and delivers various trifluoromethyl-thiocyanates in good to excellent yields. In addition, trifluoromethyl-selenocyanation of alkenes is also demonstrated for the first time using this protocol with potassium selenocyanate.