Direct trifluoromethylthiolation of terminal alkynes mediated by a hypervalent trifluoromethylthio-iodine(iii) reagent; boosting effect of fluorinated alcohol

Abstract

The direct trifluoromethylthiolation of terminal alkynes is an important strategy for accessing CF₃S-containing compounds. Herein, we report a direct trifluoromethylthiolation reaction of various terminal alkynes employing a new hypervalent trifluoromethylthio-iodine(III) reagent TFTI in a fluorinated alcohol, either 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) or perfluoro-tert-butanol (PFTB). The reaction mechanism is proposed on the basis of experiments and DFT calculations. The sustainability of TFTI and the recovery of PFTB make the reaction environmentally friendly. And, the protocol was found to be an excellent one in the context of green chemistry based on green chemistry metrics evaluation and EcoScale score.