Stable Fluoroaliphatic Radicals Containing Functional Groups: Synthesis and Reactivity.

Abstract β -Fluorosulphatoperfluoroalkyl radicals ( 3, 7 and 8 ) are obtained by the reaction of fluoroolefins (HFP trimer and dimer, and perfluoro4 4-dimethylpent-2-ene, respectively) with (FSO 3 ) 2 . The pure β -fluorosulphatotetrafluoroethylperfluorodiisopropylmethyl radical ( 3 ) has been isolated and converted to the perfluoroacetyldiisopropylmethyl radical ( 4 ) under the action of CsF. The reaction of radicals 3,7 and 8 with SbF 5 leads to the replacement of the FSO 3 group by a fluorine atom. The ability of the FSO 3 group in β -fluorosulphatoperfluoroalkyl radicals to play the role of a leaving group is explained by the stabilizing effect of the unshared electron on the adjacent carbocation centre.