Transition Metal-Catalyzed Amination Of Tetrachloroanthraquinone With Aryl Amines To Access Organic Dyes

Nitrogen-containing compounds have diverse biological activities and important significance in organic chemistry.Therefore,the construction of carbon-nitrogen bond is particularly important,which can open the way for the introduction of nitrogen atom into organic molecules.Although significant progress has been made in this research field,the formation of C-N bond is still a major challenge for organic chemists due to harsh reaction conditions or the use of expensive catalysts in many cases.The preparation of anthraquinone dye is a representative for the construction of C-N bonds.Nitrogen-containing anthraquinones are an important class of organic compounds,which are widely used in dyes,colorants and coatings.The synthesis of such skeleton compounds is usually obtained by C-N cross coupling reaction of 1,4,5,8-tetrachloroanthraquinone and anilines.Each step of the reaction will increase the steric hindrance and electron cloud density of intermediates,which obviously increases the difficulty of preparing the target products.In previous literatures,palladium-and copper-catalyzed synthesis of traditional anthraquinone dyes were reported.However,these methods suffered some disadvantages,such as the need for stoichiometric palladium and copper catalysts,the use of large amounts of expensive ligands and harsh anhydrous and oxygen-free reaction conditions Many by-products were also formed and could hardly be separated.In this thesis,we mainly used carbene palladium complex and copper oxide to catalyze Buchwald-Hartwig amination reaction of1,4,5,8-tetrachloroanthraquinone and anilines to synthesize organic dyes,It is divided into the following four chapters:Chapter 1:Research progress of C-N coupling reaction catalyzed by palladium and copperThe research progress of C-N coupling catalyzed by palladium and copper was reviewed in this chapter.Ligands used in palladium-and copper-catalyzed C-N coupling reaction were also introduced.The innovations,advantages and disadvantages of these synthetic methods were compared with each other.The reaction mechanism was also discussed.Based on the previous studies,we came up with our own research project.Chapter 2:Carbene palladium-catalyzed Buchwald-Hartwig amination of1,4,5,8-tetrachloroanthraquinone with anilines to synthesize organic dyesUsing 1,4,5,8-tetrachloroanthraquinone and aniline compounds as raw materials,theBuchwaldHartwigaminationreactionof1,4,5,8-tetrachloroanthraquinone and aniline catalyzed by carbene palladium was studied.The reaction was conducted in toluence at 150 ~oC.A series of anthraquinone organic dye compounds were synthesized in up to 92%yield.The gram-scale experiment shows that this method is reliable and accessible to prepare anthraquinone derivatives.These compounds can be widely used in dye and colorant industries.The It is a simple and efficient method for the synthesis of anthraquinone dyes.Chapter 3:Copper Oxide-Catalyzed Buchwald-Hartwig amination of1,4,5,8-tetrachloroanthraquinone with anilines to synthesize Organic DyesCopper oxide-catalyzed Buchwald Hartwig amination of 1,4,5,8-tetrachloroanthraquinone with anilines to synthesize anthraquinone-type organic dyes is studied.After screening and optimization of reaction conditions,20target compounds were obtained in toluence in yield of 27-73%.The method shows some advantages,such as cheap and readily available raw materials,wide substrate scope,simple operation and low cost.Chapter 4:Summary and ProspectIn this chapter,we describe the main content of the two parts of work,and summarize their advantages and disadvantages.We find that new catalysts were introduced and catalyze the synthesis of organic dyes from tetrachloroanthraquinone and aromatic amines,but the two parts of work still have many shortcomings and need to be improved.