Zinc triflinate

In contrast to the carbonyl condensations, where no reaction occurred between the substrate and the metal, an initial attack on zinc by sulfur dioxide in DMF was actually observed. Then, introduction of trifluoromethyl bromide under slight pressure led to the formation of zinc triflinate. 

We have interpreted the formation of zinc triflinate by a SET process (Fig. 15). In order to test for the presence of the electrophilic trifluoromethyl radical in this reaction, we have added anilines to the medium. Indeed, alkylation at electron-rich positions of the ring was observed (Fig. 19) (ref. 26). 

For many years now, the reactivity of trifluoromethyl bromide has been underestimated. During the past decade the major breakthrough in this area has been the realisation that trifluoromethylation of organic compounds with this halide can be induced by mild reductants such as thiolates, zinc or sulfoxylate radical anion. Nowadays, a great variety of fluorinated products are available by these new methods sodium triflinate and triflic acid, trifluoromethylated alcohols, trifluoromethyl-containing aromatic compounds, ethyl trifluoropyruvate, trifluoromethylsulfides. ... 

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See also in sourсe #XX -- [ ]

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