Synthesis of Trifluoromethylated Sultones from Alkenols Using a Copper Photoredox Catalyst

A photo-redox-catalyzed procedure for the one-step formation of sultones from alpha,omega-alkenols and trifluoromethylsulfonyl chloride is described. Using [Cu(dap)(2)]Cl (1 mol %), a wide range of substrates can be cleanly converted to the target compounds, while commonly employed photoelectron transfer catalysts such as [Ru(bpy)(3)]Cl-2 or fac-Ir(ppy)(3) fail in this transformation. The obtained fluorinated sultones are attractive as potential electrolyte additives or as structural motifs in drug synthesis, with the latter being demonstrated with the synthesis of a trifluoroethyl-substituted analogue of a benzoxathiin that has high anti-arrhythmic activity.