铜介导芳基卤化物的三氟甲基化反应自1965年McLoughlin and Thrower首次报道以来，已发展成为合成三氟甲基取代的芳烃与杂芳烃的主要方法。对于该反应的机理，一般认为是通过一个三价铜中间体[Ar-Cu^III-CF₃]发生还原消除而得。另外一类三氟甲基取代的芳基化合物的合成方法是在铜催化下，芳基硼酸和亲核或亲电三氟甲基试剂的反应。机理上，也认为是生成芳基三价铜物种[Ar-Cu^III-CF₃]，随后发生还原消除，得到最终三氟甲基化产物。然而，上述两类反应中的关键中间体[Ar-Cu^III-CF₃]从未被检测或分离鉴定。我们成功地首次分离了芳基与三氟甲基配位的三价铜络合物nBu₄N⁺[Cu(Ar)(CF₃)₃]，并通过核磁及对其单晶的X-射线衍射对该结构做了表征。该络合物在室温下稳定，在加热条件下以几乎定量的产率发生还原消除得到三氟甲基取代的芳烃。通过对该还原消除的动力学、溶剂效应及自由基捕获基/单电子转移抑制剂的影响，以及DFT理论计算，我们得出结论三价铜络合物nBu₄N⁺[Cu(Ar)(CF₃)₃]上的还原消除反应是一个协同成键过程 (Angew. Chem. Int. Ed. 2019, 58, 8510)。

Ar-CF₃ Reductive-elimination from stable Cu(III) complex. The first general method for the preparation of trifluoromethylarene was reported in 1969 by McLoughlin and Thrower by reaction of iodobenzene with trifluoroiodomethane in the presence of copper powder at high temperature. Since then, a plethora of copper-mediated protocols have been reported. Mechanistically, it was proposed that an active Cu(I) species [CuCF₃] is initially formed, which then reacts with aryl halide to generate a copper(III) intermediate [Ar-Cu(III)-CF₃]. Reductive elimination from this active species generates ArCF₃. Nevertheless, due to high reactivity of Cu(III) complex, this species has not been previously observed or isolated. The Shen group prepared the first stable trifluoromethylated Cu(III) complex that is able to reductive eliminate to give ArCF₃ in quantitative yield, for the very first time. Mechanistic study showed that reductive elimination from this complex proceeds via a classic concerted bond-forming pathway (Angew. Chem. Int. Ed. 2019, 58, 8510).

在此基础上，我们成功地首次分离合成了非刚性骨架配体络合的中性五配位三价铜络合物[(bpy)Cu(CF₃)₂(CH₃)]，该络合物在室温下稳定，在50 ^oC条件下以几乎定量的产率发生还原消除得到三氟乙烷。通过机理研究以及DFT理论计算，我们得出结论三价铜络合物[(bpy)Cu(CF₃)₂(CH₃)]上的还原消除反应是一个协同成键过程 (J. Am. Chem. Soc. 2020, 142, 9785)。

In 2020, we further isolated the first neutral five-coordinate Cu(III) complex [(bpy)Cu(CF₃)₂(CH₃)]. Mechanistic studies showed CH₃-CF₃reductive elimination occurred via a similar classic concerted bond-forming pathway (J. Am. Chem. Soc. 2020, 142, 9785).