trans-Trifluoromethyltetrafluorosulfanyl Chloride: Selective Synthesis and Reaction with Diazo Compounds

trans-Trifluoromethyltetrafluorosulfanyl chloride (trans-CF3SF4Cl) is a unique reagent for the incorporation of the CF3SF4 group into organic compounds. However, CF3SF4Cl was prepared from hazardous reagents or formed as mixture of trans and cis isomers in low yield. Herein, a silver-promoted selective synthesis of trans-CF3SF4Cl under safe gas-reagent-free conditions is described. Furthermore, the synthetic application of trans-CF3SF4Cl is demonstrated through the new trifluoromethyltetrafluorosulfanylation of α-diazo carbonyl compounds.