Vanadiumpentafluoride reacts with polyfluorinated and polychlorinated olefins, alkadienes, cycloalkenes and cyclodienes in CFCl3 or without a solvent at −25° to 100°C, forming products of addition of two fluorine atoms across the CC bond.
1-bromononafluorocyclohexeneand 1-bromoheptafluorocyclopentene undergo reductivecoupling reactions when heated with copper bronze to give 1,4-dichlorotetrafluorobuta-1,3-diene and perfluorobicyclo-hex-1,1′-enyl and -pent-1,1′-enyl, respectively. The same olefins undergo crossed coupling reactions with phenyl and pentafluorophenyl halides and, in the first case, with 1-iodoheptafluoropropane.