Theoretical Study On The Reaction Mechanism Of Hydrogen Amination/oxy Amination Of Amine Compounds Catalyzed By Gold And Rhodium

With the development of society,metal organic chemistry has been widely concerned,and research methods are becoming more and more diverse.Quantum chemical calculation is one of them.Quantitative calculations can be used to study molecular structure、properties and reaction mechanism,predict reaction feasibility,etc.The most commonly used in quantum chemical calculations is density functional theory（DFT）.DFT is mainly based on the density function and is used to calculate the structure of multiple electrons.In this thesis,we mainly studied the theoretical mechanism of the following two work through the M06 method of density functional theory.We use theoretical calculations to find a suitable reaction path,explain experimental phenomena,and provide new research directions for future experiments.The specific work is:（1）The 1,5-benzodiazepine derivatives have various biological activities and have received great attention in the fields of medicine and chemistry.Predecessors used different reactants,solvents and catalysts to prepare their derivatives through different routes.It has been proved that 1,5-benzodiazepine is an extremely versatile pharmacophore in metal organic chemistry.We calculated the reaction mechanism of the 1,5-benzodiazepine derivative by the reaction of gold-catalyzed o-phenylenediamine and propargyl alcohol by density functional theory.In this theoretical study,we reasonably explained the infeasibility of the proposed mechanism,and then we proposed a reaction mechanism with reasonable energy.The Au（I）catalyst induces the coupling of o-phenylenediamine and propargyl alcohol to form a C-N bond,which is dehydrated by the reaction of protons and hydroxyl groups on NH₂⁺.Then cyclization is carried out to give a seven-membered ring intermediate.Subsequently,the final product is obtained by 1,3-proton transfer,cleavage of Au-C bond,formation of C-H bond,and deprotonation.（2）In the second system,we also studied the mechanism of the reaction by density functional theory calculation.The unexpected oxyamination reaction of O,?-unsaturated alkoxyamines was found experimentally.The mechanistic issues were studied by DFT calculations.It is suggested that the reaction undergoes[3+2]cyclization addition,O-N bond cleavage,C-N reduction elimination,and the Rh-N unit protonation,generating the produce and regenerating the active catalyst.Through our computational studies,we also proposed a reaction mechanism involving the participation of Rh（V）nitrene in the stable Rh-C bond instead of the Rh-O bond.Why the substrate A with X=O but not X=C undergoes oxyamination reaction was rationalized based on the suggested reaction mechanism,which will help the experiment in this aspect.