Study On The Trifluoromethylthiolation Reaction Of Ph₃P⁺CF₂CO₂^-

Purpose:Fluorinated organic compounds are found everywhere in our daily lives,especially compounds containing trifluoromethylthio groups are often used in pharmaceuticals and agriculture.We hope to use the difluorocarbene reagent developed by our research group to construct the trifluoromethylthio group in situ,and introduce a trifluoromethylthio block into the organic molecule by a novel trifluoromethylthiolation reaction.Methods:The inner salt of difluoroacetic acid was synthesized by a two-step reaction.The sulfonium salt and the sulphur element are generated in situ by the action of cesium carbonate to form SCF₃^-,and the SCF₃^-and the alkyl halide are nucleophilic substituted to obtain a trifluoromethylthioalkane,thereby realizing the trifluoromethyl group of the alkyl halide.Sulfuration.Results:The internal salt of difluoroacetic acid was used as the source of fluoride anion and the source of difluorocarbene.Under the action of cesium carbonate,the trifluoromethylation was achieved with the elemental and substrate of sulfur.The reaction conditions were screened and optimized to obtain the most Excellent reaction conditions.The universality of the substrate was investigated and 18 target compounds were successfully synthesized.The structure of the compound was confirmed by hydrogen,fluorine,carbon,mass spectrometry,infrared spectroscopy and melting point determination.Conclusion:The reaction is rapid and can be completed within 10minutes.No expensive metal fluoride is needed as a fluorine source,and the reaction raw material is inexpensive,which provides a certain basis for the industrialization of alkyl halide trifluoromethane sulfide.As a difluorocarbene reagent,Ph₃P⁺CF₂CO₂^-is simple to prepare and convenient to operate,and is expected to be used for the synthesis of bioactive molecules containing C-SCF₃ in the future.