Generation of Perfluoro- and 1-Chloroperfluoro-Indanyl and -Benzocyclobutenyl Cations with Perfluoroalkyl Groups in the Aliphatic Ring

Perfluoro(alkylbenzocycloalken-1-yl) cations were generated in a SbF ₅ −SO ₂ ClF medium from perfluorinated indane and benzocyclobutene derivatives containing perfluoroalkyl groups in the alicyclic fragment. The cations exist in equilibrium with their precursors. Adding SO ₂ Cl ₂ to the system led to the formation of polyfluoroalkylbenzocycloalken-1-yl cations with a chlorine substituent at the cationic center. The structures of the cations were determined by ¹⁹ F and ¹³ C NMR spectroscopy and confirmed by the structures of perfluoroketones formed on their hydrolysis.