Ferrocenylacetylene 1 protonates a superacidic polymer Nafion in sc-CO2 (35 °C, 9 MPa) to form the α-ferrocenylvinyl cation, FcC+=CH2 (2, Fc = ferrocenyl). Carbocation 2 alkenylatesin situ 1,3-dithiane or 1,3,5-trithiane (35 °C, 35 MPa) to give the mono and disulfonium salts with Nafion anion. An anion exchange in the last ones for tetrafluoroborate afforded the disulfonium salts 4 and 12, whose deprotonation produced, after a sequence of transformations, the neutral unsaturated 8-membered heterocycles, 2-ferrocenyl-3,7-dithiacyclooct-1-ene 10 and 2-ferrocenyl-3,5,7-tritiacyclooct-1-ene 14. Along with 14, the reaction of 1 with 1,3,5-trithiane furnished two other neutral sulfur heterocycles, 2,4-diferrocenyl-5-thiacyclohexa-1,3-diene 18, and 1-ferrocenyl-3,5-dithiacyclohex-1-ene 23. These transformations proceed at room temperature via the C-S bond scission followed by a formation of new CC bond. Compounds 10, 14, 18, 23 were fully characterized by the NMR spectra. The molecular structures of 10, 14, 18, 23 were elucidated by X-ray study.