Synthesis Of Polyfunctional Pyridines Via Copper-catalyzed Oxidative Coupling Reactions

Pyridine compounds are a class of highly valuable nitrogen-containing six-membered heterocyclic compounds that are important in natural products,pharmaceuticals and functional materials.Due to the valuable application of pyridine compounds,researchers in the chemical field have been trying to explore the synthesis of pyridine compounds and their application value,and achieved a series of fruitful results.Especially the transition metal catalytic synthesis of pyridine compounds has been a field of pyridine synthesis of a hot spot,attracting a lot of chemical researchers to join the ranks of this study.This paper introduces the research and progress of synthetic pyridine compounds in recent decades,and introduces a new method for the synthesis of poly-substituted pyridine compounds by copper catalyzed by our experimental group.The paper consists of the following three chapters:The first chapter is a review of the application of pyridine compounds and the synthesis of synthetic methods.We mainly introduced the methods of synthesizing pyridine compounds reported by researchers at home and abroad in recent decades,and summarized the synthesis methods according to the different kinds of catalysts used in the reaction.In the second chapter,based on the research results presented above,a new method for the synthesis of Multi-substituted pyridines by copper catalyzed oxidative coupling in our research group is introduced in detail.The new method was based on oxime ester acetate as the substrate,and reacted with toluene.The reaction was carried out with copper trifluoromethanesulfonate as catalyst to obtain a series of poly-substituted pyridine compounds by oxidative coupling reaction.The synthesis method is characterized by the activation of sp3 C-H bond,which has the advantages of low cost,mild reaction condition,high yield and good substrate applicability.The third chapter is based on this new method,the multi-substituted pyridine compound synthesis system has been expanded.We introduced benzylamine and p-toluenesulfonyl hydrazone as structural units,and further developed a new preparation method of poly-substituted pyridine compounds.