Theoretical Mechanistic Study On Transition-Metal Ni Or Cu-catalyzed C-Si/C-N Bond Formation Reaction

As an emerging interdisciplinary subject,the transition-metal organic chemistry has been given the new meaning in the field of chemistry because of its specific properties including high activity,high selectivity and high stability.Up to now,there has been involved in the green environmental protection,new energy sources,new material synthesis and human health medical drugs.However,there are some chemical phenomena that cannot be explained by conventional chemical laws during the experiment.For example,the choice of dominant path and the essential factors affecting the reaction rate or selectivity,which seriously limited the development of the new transition-metal catalytic reaction and the application in metal-organic chemistry.Detailed calculations of the stable intermediates and the meta-stable transition state structures in chemical mechanism by the density functional theory.Therefore,the corresponding information of the energy/the population change/the spatial structure can be obtained,which is the nature of exploring the known experimental phenomena and the development of new reactions has important scientific significance and application prospect.In this paper,we use the density functional theory?DFT?to study the reaction mechanism of the transition-metal Ni or Cu catalyzed C-Si/C-N bond formation.It is divided into four chapters:1.The first chapter is the introduction.It contains the limitations of conventional non-catalytic,the development significance and history of transition metal-organic chemistry.At the same time,it provides the comprehensive expression of the current status of transition metal-organic chemistry and the transition metal-organic chemistry theoretical research.2.The second chapter is the basis and calculation method of theoretical research.These include the detailed description of the basic concepts of the density functional theory,the transition state theory and the natural bond orbital theory.3.The third chapter is the detailed study on the mechanism of silylation reaction of transition-metal Ni catalyzed C-OMe bond cleavage by the density functional theory?DFT?.The in-situ generated silyl anion which act as ligand for the transition-metal nickel center can increase the electron density on nickel and induce the?*_?Ni-Si?orbital to accept C?sp²?-O bond electrons from anisole.orbital to accept C?sp²?-O bond electrons from anisole.This provides the favorable basis for the synthesis and development of the inert C-heteroatom bonds.4.The fourth chapter is the detailed study on the mechanism of the transition metal copper-catalyzed Cope-type hydroamination synthesis asymmetric nitrone reaction of cyclopropene with oxime by the density functional theory.The nature of transition metal catalysis was investigatied in detail and the effects of ligands of different types of scaffolds and ligands with different substituents of the same type on the stereoselectivity,yield and enantiomeric yield ratio?%ee?of the reaction were studied as well.From the electronic effect and the spatial effect,the stereselectivity of the reaction is deeply explored by using the deformation/interaction model and energy decomposition,which provides theoretical support for the design of new,highly active and highly selective ligands.