Vergleich der trifluormethylierungseigenschaften von(CF3)Hg,CF3I und (CF3)2te am beispiel der reaktionen mit cyclohexen,benzol und pyridin

The trifluoromethylation reactions of (CF₃)₂Hg, CF₃I and (CF₃)₂Te with cyclohexene, benzene and pyridine are compared under similar conditions. Photochemical as well as thermal reactions result in an increase of the reactivity in the series (CF₃)₂Hg < CF₃I ? (CF₃)2Te. The yields and the kind of products vary depending on the time of irradiation and the temperature. In all cases the best yields are obtained from the thermal reactions with (CF₃)₂Te. With cyclohexene only trifluoromethylated addition products are observed. The substitution reactions with pyridine yield a mixture of isomeric trifluoromethylpyridines. (CF₃)₂Hg and CF₃I react with benzene to yield only benzotrifluoride C₆H₅CF₃. The main product of the reaction of (CF₃)2Te with benzene is also benzotrifluoride; in addition to this the disubstituted bis(trifluoromethyl)benzene isomers and trifluoromethyl- cyclohexadienes are formed. ¹H, ¹⁹F n.m.r. and mass spectra are described.