Reactions of (nonafluorocyclohexen-1-yl)xenon(II) hexafluoroarsenate with halide anions

The products of the reaction between the electrophilic alkenylxenonium cation [1-Xe+-C6F9] and the halide anions I- Br-, Cl- and F- depend on the hardness of the halide amen. With the soft halides I- and Br- Xe(II) is formally displaced by halogen as well in basic MeCN as in superacidic AHF(1)), whereas with hard fluoride and chloride no reaction takes place in AHF. In MeCN F- initiates the formation of alkenyl radicals, which abstract hydrogen from the solvent, whereas Cl- exhibits borderline character: RH and RCl formation. Possible reaction paths are discussed. The reactivity of the arylxenonium cation [C6F5Xe](+) in AHF toward halide ions is reported and the relative electrophilicity of the cations [C6F5Xe](+) and [1-Xe+-C6F9] is determined by the competitive reaction with Cl-. In addition the synthesis of cyclohexene 1-CF3-C6F9 from C6F5CF3 and XeF2 is performed and its electrophilicity is compared with that of the aromatic compound C6F5CF3.