Tetraphenylphosphonium Tetrafluoroborate/1,1,1,3,3,3-Hexafluoroisopropanol (Ph₄PBF₄/HFIP) Effecting Epoxide-Initiated Cation–Olefin Polycyclizations

Abstract

The use of an excess amount of tetraphenylphosphonium tetrafluoroborate in 1,1,1,3,3,3-hexafluoroisopropanol, which can stabilize the intermediate cation in the reaction, efficiently promoted epoxide-initiated cation-olefin polycyclization reactions with broad functional group tolerance and water and oxygen tolerance.