Fluorine-containing?-sultones

Synthesis of 3,6-dioxa-Δ7-4-trifluoromethyl perfluorooctyl trifluoromethyl sulfonimide: bis[(perfluoroalkyl)sulfonyl] superacid monomer and polymer

“…Because the b-sultone 1 slowly isomerizes to the corresponding acyl fluoride, compound 4 is also observed in this reaction in small amounts. The isomerization of fluorinated b-sultones to their corresponding acyl fluorides is very slow at lower temperatures [38][39][40]. Because the isomerized product 4 is desired, triethylamine is added as a catalyst to the reaction.…”