金属配位下吡啶环上α位C-H键活化途径

Alpha C-H Bond Activation Processes of Pyridine Mediated by Metal Complexes

探讨吡啶环上N邻位C-H键在金属配位环境下的活化反应。结合笔者本人及所在课题组的研究成果,参考相关文献,对不同类型的金属试剂作用下的吡啶和苯并吡啶(喹啉)等α位C-H键活化反应进行了分类综述,认为:在金属或金属配合物的作用下发生自由基反应或金属化反应,生成α位取代的吡啶偶联衍生物及取代吡啶衍生物小分子,吡啶环或喹啉环等配位到金属原子上后,更易发生2-位取代反应;生成的吡啶偶联衍生物能更好地稳定金属离子。该类反应可以用来合成一些重要的吡啶衍生物小分子。

Direct functionalization of C-H bonds is one of the most attractive research subjects in organic and organometallic chemistry.This paper attempts to explore alpha C-H bond activation reaction of pyridine ring in metal coordination environment.Refer to author and author's group and other research team's research results,alpha C-H bond activation processes of pyridine mediated by the different types of metal reagents have been investigated in this paper.After the pyridine or quinoline ring coordinates to metal atoms,C-H σ-bond activation reactions of pyridine assumedly proceeds via a free radical or metalation reaction mechanism and to give some α-substituted pyridine coupling ligands and substituted pyridine molecules.The pyridine is more susceptible to produce alpha C-H bond nucleophilic substitution reaction under the condition of coordinating to metal atoms.The coupling ligands generated are better at stabilizing metal ions.Chemists are also using these reactions to synthesize special pyridine(quinoline) derivatives.