Conversion of Iodides to CF3 groups

Trifluoromethyl groups are becoming ever more common in fine chemicals, pharmaceuticals and agrochemicals, and new methods of introducing these groups are being developed.  In this paper a copper mediated trifluoromethylation of hetero-aryl iodides is carried out using a trifluoromethylsulphonium salt.

19 examples, yields 85-98% apart from the sterically hindered tritylimidazole – see above.  The only drawback for this reaction is the stoichiometry, which requires 2 equivalents of trifluoromethylsulphonium salt and 3 equivalents of copper.

C.-P. Zhang, Z.-L. Wang, Q.-Y. Chen, C.-T. Zhang, Y.-C. Gu, and J.-C. Xiao,* Angew. Chem. Internat. Ed., 2011, 50, 1896-1900.