Thermolytic transformations of polyfluoroorganic compounds

The reaction of α,α-dichlorooctafluoroethylbenzene with tetrafluoroethylene as a source of difluorocarbene has been studied. The copyrolysis of these compounds gave not only the expected products, decafluoro-α-methylstyrene and α-chloroheptafluorostyrene, but also noticeable amounts of perfluoro-1-methylindan and perfluoro-7-methylbicyclo4.3.0]nona-1,4,6-triene along with perfluoro-3-methylindene and octafluorostyrene. It has been suggested that indan and the triene are formed with the participation of the C₆F₅CCICF₃ radical through sigmatropic shifts of fluorine atoms in the intermediate bicyclic compounds. The reaction of α,α-dichlorodecafluoropropylbenzene with tetrafluoroethylene afforded α-chloroheptafluorostyrene as the main product.