Copper-mediated trifluoromethylation of heteroaromatic compounds by trifluoromethyl sulfonium salts
Copper is king! A convenient method for the synthesis of trifluoromethylated heteroaromatic compounds under mild conditions has been developed based on the observation that 1 can be reduced by certain metals (see scheme). Substrate 1 is assumed to be reduced by copper via a single-electron transfer mechanism, and CuCF3 is the most probable intermediate in this reaction. DMF=N,N-dimethylformamide, Tf=triflate.