State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China.
College of Chemistry and Chemical Engineering, Yangzhou University , Yangzhou 225002, China.
J Am Chem Soc. 2015 Sep 30;137(38):12231-40. doi: 10.1021/jacs.5b06758. Epub 2015 Sep 22.
By developing a new Ir(III)-catalyzed C-C cross-coupling, a versatile method for direct arylation of sp(2) and sp(3) C-H bonds in ketoximes, nitrogen-containing heterocycles, various arenes, and olefins has been established. The key to this arylation depends on the appropriate choice of catalyst and the use of diaryliodonium triflate salts as the coupling partners. This transformation has good functional group compatibility and can serve as a powerful synthetic tool for late-stage C-H arylation of complex compounds. Mechanistic studies by density functional theory calculations suggested that the sp(3) C-H activation was realized by a triflate-involved concerted metalation-deprotonation process, and the following oxidation of Ir(III) to Ir(V) is the most favorable when a bistriflimide is contained in the diaryliodonium salt. Calculations indicated that both steps are enabled by initial anion exchange between the reactant complexes.
通过开发一种新的 Ir(III)催化 C-C 交叉偶联反应，建立了一种在酮肟、含氮杂环、各种芳基和烯烃中 sp(2)和 sp(3) C-H 键直接芳基化的通用方法。该芳基化反应的关键取决于催化剂的适当选择以及使用二芳基碘鎓三氟甲磺酸酯盐作为偶联试剂。该转化具有良好的官能团兼容性，可作为复杂化合物后期 C-H 芳基化的有力合成工具。通过密度泛函理论计算进行的机理研究表明，sp(3) C-H 的活化是通过三氟甲磺酸酯参与的协同金属化-去质子化过程实现的，当二芳基碘鎓盐中含有双三氟甲磺酰亚胺时，Ir(III)氧化为 Ir(V)是最有利的。计算表明，两个步骤都可以通过反应物配合物之间的初始阴离子交换来实现。
