Design,synthesis And Catalytic Applications Of Naphthoquinone Derivatives

Quinone derivatives as a redox substance with a long history in organic chemistry,were used in many fields,such as C-H activation reactions,medicinal chemistry,natural products,dyes,and synthetic ligands.Due to the electronic characteristics of their spatial structure,quinone compounds often play the role of stoichiometric oxidants and ligands in organic synthesis,but they were rarely used in the biomimetic catalysis reaction of amine molecules.According to the importance of electron and proton transfer of quinone derivatives in the oxidation of organisms,through the study of the electronic and steric hindrance effects of substituents on the quinone ring,the development of a catalytic oxidation system by using molecular oxygen as an oxidant under mild conditions was the main research purpose of quinone catalysis.Taking account of the characteristics of homogeneous catalysis,active quinones often lose their original stabilizer structure after their catalytic effects was exerted and exist as reaction intermediates such as phenolquinone and iminoquinone.Increasing the dissolution of organic matter made the workload of target product separation larger and the difficulty of catalyst recovery higher.This subject was dedicated to the synthesis and preparation of quinone derivatives with catalytic activity,and development of a green heterogeneous system supported by quinone catalysis.The main research ideas and contents were summarized as follows:(1)First,a polycyclic quinone structure with biological anti-cancer activity and excellent thermal stability was synthesized and grafted onto the surface of chloromethyl polystyrene microspheres to prepare a recyclable quinone catalyst HBND-MR successfully for the first time.Then,FT-IR?SEM?EDX?XPS?EA and other characterization methods have proved the success of the load.This supported quinone can effectively act on the amine-amine coupling reaction in a metal-free?base-free and alcohol solvent system to obtain imine life intermediates,so it has biomimetic catalytic properties.Finally,the reaction mechanism was speculated,and the possibility of reaction intermediate was verified by kinetic experiments.(2)Secondly,the next subject was based on the previous work,2-hydroxy-3-chloro-1,4-naphthoquinone was applied successfully in the dehydrogenation coupling reaction of benzylamine and acetophenone in the process of screening catalysts to obtain 2,4,6-triphenylpyridine compounds.Based on the shortcomings of too many intermediates during the quinone catalysis process,above active quinone was tried to be grafted onto the surface of Merrifield resin spheres and the graft chemical bonds was analyzed by a series of characterizations,such as FT-IR?EDX?XPS methods.And further the heterogeneous catalyst NQ-MR was obtained.At the same time,biomimetic synthesis of substituted pyridine under green conditions was achieved.The universality of substrates supported by quinone-catalyzed reactions was tested and the reaction range was widened in the later stage.Finally,the reaction path was guessed and obtained through experimental verification.(3)Finally,in this paper,a functionalized polymer resin-immobilized 4,4'-dihydroxy-2,2'-bipyridine was used as the Cu(II)coordination terminal,and with the participation of 10-phenanthroline-5,6-dione,a heterogeneous bifunctional complex catalyst MR-Cu(II)was prepared.Then,the characterization and analysis of this newly supported copper complex catalyst were performed by means of FT-IR?SEM?EDX?XPS and other characterization methods.Later,it was applied to the hydrogen borrowing reaction of amine substrates.Good catalytic effect and improved product separation efficiency were achieved.The last but not the least,reaction mechanism was proposed and then verification test was designed to obtain the reaction pathway.At the same time,the catalyst was found to have good recycling performance.