Catalysis Research On Supported Catalysts Of Multi-nitrogen Aromatic Heterocyclic Ligands

With the development of the chemical industry,people are increasingly dependent on fossil resources.And alcohols could be processed from biomass,so the organic synthesis which using alcohols has attracted much attention.Using hydrogen-borrowing reaction,which as a green and high-efficiency organicconversion method,could effectively convert alcohol and only produce hydrogen or water as by-products.However,the hydrogen-borrowing reaction still has the problems that most of the catalysts could not be recovered and the reaction solvent did not meet the requirements of green chemistry.In this paper,works starting from the ligand in the hydrogen-borrowing reaction catalyst,a series of multi-nitrogen aromatic heterocyclic ligands were designed to try to improve the current situation of the hydrogen-borrowing reaction.The contents of this paper are divided into the following parts:(1)Introduced the preparation of a multi-nitrogen aromatic heterocyclic ligand with benzotriazole as the basic framework,which was complexed with cuprous iodide to form a metal complex PPT-Cu,and then the metal complex PPT-Cu loaded on the mesoporous material SBA-15 to prepare heterogeneous catalyst PPT-Cu@SBA-15,after that the catalyst was characterized by a series of tests.When the catalyst was applied to the reaction of1-tetralone and benzyl alcohol,PPT-Cu@SBA-15 exhibited high catalytic activity and selectivity to obtain single bond products with excellent yields.Subsequently,PPT-Cu@SBA-15 was applied to the hydrogen-borrowing reaction of benzyl alcohol and aniline,the good reaction yields and substrate applicability could also be obtained.(2)Introduced the synthesis of a multi-nitrogen aromatic heterocyclic ligand which based on the ligand with benzotriazole as the framework.Then it complexed wit h iridium salt and copper salt,and finally loaded on the surface of silica by chemical bonding between silicon-oxygen bonds to make heterogeneous catalysts.The two catalysts were characterized and analyzed by a series of tests.Applying these two catalysts to the hydrogen-borrowing reaction,it was found that the iridium catalyst based on the ligand had high reactivity for the reaction of sulfenamide and benzyl alcohol,while the copper catalyst had very high selectivity for the reaction of acetophenone and benzyl alcohol,double bonds products could be synthesized in a very high proportion.(3)Introduced the design of a multi-nitrogen aromatic heterocyclic ligand,which was modified with pyrene ring and supported by graphene oxide to obtain a heterogeneous catalyst.By applying the catalyst to the cyclization reaction of o-phenylenediamine and benzyl alcohol,it was found that using water as solvent could synthesize phenylbenzimidazole without the need of a base as an additive when the reaction time was extended to 60 h.(4)Introduced the design and synthesis of a new type of multi-nitrogen aromatic heterocyclic ligand,and combined it with organozinc and molecular sieve through a one-pot method to synthesize a precatalyst,finally the precatalyst was calcined at 800 ~oC to obtain a heterogeneous zinc catalyst.When exploring the application of this catalyst in the hydrogen-borrowing reaction,it was found that the reaction of acetophenone and benzyl alcohol,and the reaction of aniline and benzyl alcohol could be catalyzed in water.By fine-tuning the reaction conditions,the formation of different reaction products of benzyl alcohol and acetophenone could also be realized.The unique reactivity of the zinc catalyst was improved.(5)The synthesis of a new heteronuclear bimetallic catalyst was introduced,and the catalyst was analyzed by TEM,XPS,XRD,EDS characterization methods.Finally,the catalyst was applied to different hydrogen-borrowing reactions.All five reactions had good reactivity.The successful application of this catalyst provided a new idea for the preparation of hydrogen-borrowing reaction catalyst.