Skeletal transformations of perfluoro-1-phenylindan under the action of antimony pentafluoride

The alicyclic ring contraction of perfluoro-1-phenyltetralin in reaction with antimony pentafluoride

“…The latter then undergoes fluorination to form compound 7, which isomerizes to product 8. Transformation of compound 7 to product 8 was found by us earlier [5].…”

“…It should be noted that compounds 7 and 8 were obtained in the reaction of perfluoro-1-phenylindan with SbF 5 in the absence of HF [5].…”

“…The process may be represented, for example, by Scheme 3, similar to that for skeletal transformations of perfluoro-1-phenylindan under the action of antimony pentafluoride [5].…”

“…Thus, the alicyclic ring contraction of 2-halopolyfluorotetralins in the reaction with SbF 5 [1] and the ring opening of perfluorocyclopropane derivatives under the action of antimony pentafluoride [2,3] or aluminium chlorofluoride [4] are both known. Skeletal transformations of the four-, five-and sixmembered alicyclic fragments of perfluorinated benzocyclobutene, indan, tetralin, and their perfluoroalkyl derivatives in an SbF 5 medium have been investigated, see for example [1][2][3][4][5][6][7] cited in our previous work [5].…”

“…Recently, we have found that the carbon framework in perfluoro-1-phenylindan changes under the action of SbF 5 to give perfluoro-9-methylfluorene and perfluorinated di-, tetra-or octa-hydro derivatives of anthracene and bnaphthindan [5]. When heated with antimony pentafluoride, perfluoro-1-(2-ethylphenyl)benzocyclobutene is converted to perfluoro-8,9-dimethyl-1,2,3,4-tetrahydrofluorene while perfluoro-1-(4-ethylphenyl)benzocyclobutene gives 2-ethyl-9,10-dihydroanthracene and perfluoro-6-ethyl-1,2,3,4-tetrahydroanthracene [6].…”