Application Of Supported Manganese Catalysts In Hydrogen Borrowing Reaction

The use of commercial materials to develop efficient catalytic systems and highly selective reactions is one of the reasonable goals of modern industry in organic synthesis.The environmentally friendly hydrogen borrowing reaction has become the first choice for organic synthesis because its byproduct is only water.In the process of exploration,the homogeneous catalytic system involving various metals can effectively promote the reaction process,such as precious metals Ir,Au,Ru,Pt and cheap metals Fe,Mn,Cu,etc.,and has attracted the attention of contemporary scientists.However,these homogeneous catalysts have shortcomings:it is difficult to separate them from the reaction mixture.In this paper,several green supported manganese catalysis systems with high recovery performance were developed,which have the characteristics of high efficiency and sustainability.Main contributions of this work are as follows:(1)For the first time,manganese dioxide nanoparticles were prepared by a simple method and fixed on the surface of modified poly 2,4-dichlorophenylethylene.The hybrid materials were characterized by SEM,EDS,XRD and XPS.This cheap heterogeneous manganese catalyst has good activity and stability.It can directly alkylate primary alcohols and ketones by hydrogen borrow.In addition,the ?-MnO2@PDCS can be recovered for more than 5 times,its high catalytic activity can be retained.(2)TEM,XPS and EDS were used to characterize the recoverable manganese phthalocyanine modified barium titanate nanospheres.This cheap manganese composite has good catalytic activity for N-alkylation of alcohol and amine.It has a wide range of substrates and excellent functional group tolerance,and realizes amine alkylation in a simple,efficient and mild way.Compared with traditional precious metal catalysts and classic metal complexes,this cheap,recyclable manganese phthalide.The cyanine composite material has high catalytic activity and good recovery performance for N-alkylation of alcohol and amine and C-alkylation of ketone and alcohol.(3)The synthetic manganese phthalocyanine catalyst was supported on N-doped graphene.The supported catalyst was characterized by SEM,EDS,XRD and XPS.One-pot synthesis of 1,5-dione derivatives.The results show that this highly selective and reusable nitrogen-doped graphene nanomanganese catalyst has good catalytic activity.At room temperature,under the condition of the coexistence of oxidant and potassium hydroxide,the hydrogenation reaction of toluene and acetophenone C-C alkylation was achieved.In order to better discuss the catalyst system and its reaction mechanism,a mechanism study was conducted.A new and effective method to obtain symmetric 1,5-dione.(4)A novel F-bridged Mn(?)molecular square complex was designed and synthesized.The crystal structure was determined by single crystal diffraction.In the presence of the catalyst,the hydrogenation reaction of benzyl alcohol and 2-methylquinoline was used.Synthesize the corresponding(E)-2styrylquinoline derivative,the reaction has good substrate applicability for electron-withdrawing or electrondonating substrates,and the good yield proves that the catalytic system has Good catalysis and substrate adaptability...