Polyfluorocyclopentadienes. Part VII. Reaction of phenyl azide with 2,3,4,5,5,6-hexafluorotricyclo[5,2,1,02, 6]deca-3,8-diene and endo-perfluorotricyclo[5,2,1,02, 6]deca-3,8-diene, and long-range 19F–19F couplings in the product from the latter

Abstract

2,3,4,5,5,6-Hexafluorotricyclo[5,2,1,0^{2, 6}]deca-3,8-diene combines with phenyl azide at room temperature to yield a mixture of the triazolines 2,3,4,5,5,6-hexafluoro-9-phenyl-9,10,11-triazatetracyclo[5,5,1,0^2,6,0^{8, 12}]trideca-3,10-diene and 2,3,4,5,5,6-hexafluoro-11-phenyl-9,10,11-triazatetracyclo[5,5,1,0^{2, 6},0^{8, 12}]trideca-3,9-diene. No reaction occurs between endo-perfluorotricyclo[5,2,1,0^{2, 6}]deca-3,8-diene and phenyl azide under the same conditions, but at 70 °C 1,2,3,4,5,5,6,7,8,10,11,11-dodecafluoro-9-phenyl-9-azatetracyclo[5,3,1,0^{2, 6},0^{8, 10}]-undec-3-ene is formed; detailed analysis of the ¹⁹F n.m.r. spectrum of this aziridine, which displays large splittings ascribed to spin–spin coupling between spatially close fluorines separated by several saturated bonds, indicates that the heterocyclic ring lies exo with respect to the basic molecular skeleton.