Abstract: A process for preparing inert or functional, tertiary carbon-containing perfluorochemicals comprises the step of electrochemically fluorinating, in the presence of anhydrous hydrogen fluoride, a composition comprising at least one starting compound selected from the group consisting of those fluoroalkanes, fluoroalkenes, fluoroalcohols, fluorocarboxylic acids, fluorocarboxylic acid halides, fluorocarboxylic acid esters, and combinations thereof which contain at least one (preferably, only one) --CX.sub.2 --C(R.sub.f).sub.2 -- group, wherein each X is independently selected from the group consisting of hydrogen, fluorine, and CH.sub.2 OH, with the proviso that only one X can be CH.sub.2 OH, and each R.sub.f group is independently perfluoroalkyl. The process enables preservation of the highly-branched structure of the starting compounds resulting in high product yields.

Abstract: A process for preparing perfluoroalkanesulfonyl fluorides, e.g., perfluoromethanesulfonyl fluoride, comprises electrochemically fluorinating in the presence of anhydrous hydrogen fluoride at least one precursor compound selected from the group consisting of .alpha.,.beta.-difluoroalkane-.beta.-sultones, e.g., 1,1,2,2-tetrafluoroethane sultone, and the corresponding .alpha.-halocarbonylfluoroalkanesulfonyl halides, e.g., fluorocarbonyldifluoromethanesulfonyl fluoride. The process can be used to prepare perfluoroalkanesulfonyl fluorides in good yield and can be, for example, both more electrically-efficient and more fluorine-efficient than the conventional preparative method involving the electrochemical fluorination of hydrocarbon alkanesulfonyl halides.