Electrophilic, catalytic alkylation of polyfluoroolefins by some fluoroalkanes

New data are presented on the antimony pentafluoride catalyzed reaction of hydrofluorocarbons such as CH3F, CH2F2, CH3CHF2 and RfCH2CH2F with fluoroolefins. The condensation of CH2F2 and fluoroolefins CF2CFX (X=F, CF3) proceeds under mild conditions producing the corresponding propanes FCH2CFXCF3 in moderate to high yield. Under similar conditions methyl fluoride reacts with tetrafluoroethylene giving CH3CF2CF3. However, a complex mixture of products forms in the analogous reaction with hexafluoropropene. The structures of the products of the reactions of CH3CHF2 and tetrafluoroethylene and F-butylethylene were determined.