Synthesis of trans-Tetrafluoro(trifluoromethyl)-λ⁶-sulfanyl (CF₃SF₄)-Containing Olefins via Cross Metathesis

Abstract

The cross-metathesis reactions of trans-tetrafluoro(trifluoromethyl)-λ6-sulfanyl (CF3SF4)-containing olefins expand the repertoire of synthetic transformations of CF3SF4-substituted molecules. Treatment of a primary alkene and 3-CF3SF4–propene with a second-generation Hoveyda–Grubbs catalyst yielded the cross-metathesis product in good yield under very mild conditions (room temperature). CF3SF4–propene undergoes cross metathesis with substrates containing electron-withdrawing groups or electron-donating groups at room temperature or under dichloromethane reflux. The formation of the CF3SF4–propene homodimer and the utility of that dimer to undergo selective cross-metathesis reactions are described.

Fluoroalkylated hypervalent sulfur fluorides: radical addition of arylchlorotetrafluoro-λ6-sulfanes to tetrafluoroethylene

“…The more hydrophobic SF 4 R F (R F = polyfluoroalkyl) group is a promising option for the enhancement of biological activity. 9 For instance, the synthesis of aryltetrafluoro(trifluoromethyl)-λ 6 -sulfanes (ArSF 4 CF 3 ) and the π Ph constant of the SF 4 CF 3 group (2.13) were first reported in 2006, demonstrating the high hydrophobicity of the SF 4 R F group ( Scheme 1B ). 9 c However, direct fluorination is not feasible without deactivating the aromatic ring with a nitro group because of the high reactivity of fluorine gas.…”