Reaction of quadricyclane with fluorinated sulfur-containing compounds

Remarkable effect of metal fluoride catalyst on reaction of hexafluoropropene, sulfur and vinyl ethers. Convenient synthesis of 2,2-bis(trifluoromethyl)-4-R-thietanes, 3,3-bis(trifluoromethyl)-5-R-1,2-dithiolanes and 2,2-bis(trifluoromethyl)-4-R-1,3-dithiolanes

“…(5) and (6)). We also found that both norbonenthietane 9 [20] and thietane 3k are inert towards the action of CsF or the mixture of S x \CsF or (25 8C, DMF, 2-5 days, NMR, Eq. (12)).…”

Hexafluorothioacetone based synthesis of fluorinated heterocycles

“…Recently, we reported that 3-thia-4,4-bis(trifluoromethyl)-tricyclo[5.2.1.0 2,5 ]non-7-ene can be prepared by a direct reaction of sulfur/HFP and quadricyclane in the presence of KF [17]. In the present work this methodology was extended to other dienes.…”

“…Interesting results were obtained in reaction of 1 with (1Z,3Z,5Z)-cyclohepta-1,3,5-triene (16) and (1Z,3Z,5Z,7Z)-cycloocta-1,3,5,7-tetraene (17). The treatment of cycloheptatriene 16 by mixture 1/CsF in THF at ambient temperature resulted in exclusive formation of cycloadduct 18 (Eq.…”

“…Higher isolated yield of 11a,b is also the reflection of proper ratio of HFTA to substrate 10 (1:2, based on amount of sulfur used in reaction, Table 2, entry). It should be pointed out, that the formation of ring opening by-products, observed in the reaction of quadricyclane with KF/S/HFP mixture [17,33] (as the result of attack of (CF 3 ) 2 CF À on sulfur of highly reactive 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0 2,5 ]non-7-ene) were not detected in one-pot synthesis of cycloadducts 4, 8, 11a,b and 18. We believed that absence of by-products in this case is the result of significantly lower sensitivity of compounds 4, 8, 11a,b and 18 towards nucleophilic reagents.…”

“…In recent years it was demonstrated that readily available 1 [5,6] treated with alkali metal fluoride in polar solvent generates HFTA which can be subsequently trapped by a variety of electron-rich dienes [7][8][9][10][11]. Quadricyclane, which is known to have high reactivity towards electron deficient unsaturated hydrocarbons [12] and polyfluorinated materials [13][14][15][16], was reported recently to undergo cycloaddition with HTFA, producing 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0 2,5 ]non-7-ene [17]. This paper, reports new data on cycloaddition reactions of generated in situ HFTA with a variety of electron-rich dienes, and cyclic polyenes.…”