Trimethylsilyl fluorosulfonyldifluoroacetate

Handling, Storage, and Precautions best generated in situ and used immediately. THF solutions are unstable above —20 °C. The solid is unstable, and all such copper(I) acetylides are potentially explosive. Use in a fume hood. 

Ruitenba-g, K. Kleijn, H. Westmijze, H. Meijer, J. Vermeer, R, Reel. Trav. ChirtL Pays-Bas 1982,101,405. 

Graham B. Jones Brant J. Chapman Clemson University, Clemson, SC, USA 

A list of General Abbreviations appears on the front Endpapers 

FO2SCF2CO2H with (CH3)3SiCl.l-2 Purity 3-4% of residual acid (FO2SCF2CO2H) may be removed by treatment with NEt3 if necessary. 

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As mentioned in the Introduction, imidazole is found in biologic systems and, as mentioned, is quite robust chemically. For example, the imidazole ring system is not readily oxidized Y-oxidation does not readily occur. Very powerful oxidizing agents are required to oxidize the imidazole ring. Chemically, this was recently reported by the use of trimethylsilyl fluorosulfonyldifluoroacetate (TFDA). Mechanistically, this proceeds similar to the acyl transfer reaction described earlier. 

Synthesis of gem-Difluorocyclopropanes. Trimethylsilyl fluorosulfonyldifluoroacetate is slowly added to a mixture of catalytic amounts of NaF, olefin, and solvent at a moderate temperature under N2 for several hours to give the gem-difluorocyclo-propanes. The reactions proceed cleanly and with unprecedented efficiency, as shown in eq... 

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