Perfluorocyclopentadiene Partakes IN The Diels–Alder reaction (a) as a diene in its thermal reactions with dimethyl acetylenedicarboxylate (→ dimethyl 1,2,3,4,7,7-hexafluorobicylo[2,2,1]hepta-2,5-diene-5,6-dicarboxylate), ethylene (→ 1,2,3,4,7,7-hexafluorobicyclo[2,2,1]hept-2-ene), acetylene (→ 1,2,3,4,7,7-hexafluorobicyclo[2,2,1] hepta-2,5-diene), maleic anhydride (→ 1,2,3,4,7,7-hexafluorobicyclo[2,2,1]hept-2-ene-5,6-anhydride), butadiene (→ 1,2,3,4,7,7-hexafluoro-5-vinylbicyclo[2,2,1]hept-2-ene), norbornadiene (→ two stereoisomers of 3,4,5,6,12,12-hexafluorotetracyclo[6,2,1,1^3,6,0^2,7]dodeca-4,9-diene), trifluoronitrosomethane {→ perfluoro-(3-methyl-2-oxa-3-azabicyclo[2,2,1]hept-5-ene)}, but (b) as a dienophile when heated with anthracene [→ 9,10-dihydro-9,10-(11,12-hexafluorocyclopent-13-eno)anthracene], and (c) as both a diene (→ 1,7,8,9,10,10-hexafluorotricyclo[5,2,1,0^2,6]deca-3,8-diene) and a dienophile (→ 2,3,4,5,5,6-hexafluorotricyclo[5,2,1,0^2,6]deca-3,8-diene) in its reaction with cyclopentadiene. The structures of the Diels–Alder adducts were determined by a combination of chemical and spectroscopic methods; the n.m.r. spectra of the adducts are discussed in detail, and a correlation between structure and ¹⁹F n.m.r. spectral parameters is presented. No Diels–Alder adducts were obtained when perfluorocyclopentadiene was heated with tetracyanoethylene, tetrafluoroethylene, perfluorobutadiene, perchlorocyclopentadiene, or perchlorobutadiene.

Pyrolysis of dimethyl 1,2,3,4,7,7-hexafluoro[2,2,1]hepta-2,5-diene-5,6-dicarboxylate gave dimethyl tetrafluorophthalate and difluorocarbene, which was trapped with cyclohexene. Pyrolysis of perfluoro-(3-methyl-2-oxa-3-azabicyclo[2,2,1]hept-5-ene) was investigated, and its fluorination with cobalt trifluoride gave a compound believed to be perfluoro-(3-methyl-2-oxa-3-azabicyclo[2,2,1]heptane).