New hydrofluorocarbon (HFC) solvents for antimony pentafluoride: Generation and characterization of 1-alkoxypentafluoroallyl cations

Certain hydrofluorocarbons (HFC) stable towards the strong Lewis acid, antimony pentafluoride, were found to function as a solvent for this aggressive reagent. CF3CF2CH2F (HFC-236cb) was demonstrated to be an excellent solvent for SbF5 and was used for the generation of stable polyfluorinated benzyl and allyl cations. Using this solvent 1-methoxypentafluoroallyl cation and RFOCFCFCF2+ (RF = n-C3F7 and n-C4F9), were generated and characterized by NMR spectroscopy.