Analysis of the 19F and 1H NMR Spectra of a Number of Polyfluoroindenes

Article abstract of DOI:10.1002/mrc.1270140408

19F and 1H NMR spetra of the products of nucleophilic attack on octafluoroindene are analysed and structures assigned.The major product in the reaction of butyllithium with octafluoroindene is 3-methylheptafluoroindene, with sodium borohydride it is 2-hydroheptafluoroindene and with sodium methoxide it is 3-methoxyheptafluoroindene.Vacuum pyrolysis of undecafluorotricyclo<5.2.2.0^2,6>undeca-2,5,8-triene, with elimination of C2F4, gives 6-hydroheptafluoroindene as the major product.The NMR assignments are based on the unambiguous synthesis via vacuum pyrolysis of 5,6-dihydrohexafluoroindene, 3-hydro- and 3-methyl-heptafluoroindene and the large long-range coupling of 15 Hz assigned to the F-2, F-6 interaction.