Hexafluorothioacetone based synthesis of fluorinated heterocycles

Reactivity of fluorinated sulfur-containing heterocycles towards nucleophilic and oxidizing reagents

“…GC and GC/MS analysis were carried out on a HP-6890 instrument, using HP FFAP capillary column and either TCD (GC) or mass selective detector (GS/MS), respectively. Compounds 1,4,6,8,10,19 were prepared according to literature procedure [4]. MCPBA (60-75%, Aldrich) was concentrated by washing with buffer pH 7.5 and drying under vacuum.…”

“…1 indicates there is essentially no entropic driving force for reactions of 8, 10 (Eqs. (4) and (5), respectively).…”

“…Ignoring the large internal energy reaction Scheme 1. (4) difference from this contribution and computing the remaining Gibbs reaction energy from temperature-dependent contributions including the zero-point vibrational energy corrections, we find reactions represented by Eqs. (1) and (2) are far most strongly favored and reactions of 8 and 10 (Eqs.…”

“…(1) and (2) are far most strongly favored and reactions of 8 and 10 (Eqs. (4) and (5)) are very minimal exergonic. There is much higher ring strain release in ring opening reactions of 1 and 4 (Eqs.…”

“…A variety of cyclic polyfluorinated sulfides are readily available through the reaction of cyclic dimer of hexafluorothioacetone (HTFA) -2,2,4,4-tetrakis-(trifluoromethyl)-1, 3-dithietane -with hydrocarbon dienes, polyenes and activated olefins [1][2][3][4][5]. Surprisingly, the chemistry of the cycloadducts is limited to a few chemical transformations reported for 4-alkoxy-2,2-bis(trifluoromethyl)thietanes (cycloadducts of HFTA with vinyl ethers) [3] and 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0 2,5 ]non-7-ene (1, cycloadduct of HFTA and quadricyclane) [6].…”