The Process And Influence Factors Of Rauhut-Currier Reaction Promoted By Organocatalysts

Recently, organocatalyst have attracted extensive attention due to its application in various catalytic reactions. Chemists have made efforts to design novel organocatalysts with high activity for industrial production. Rauhut-Currier (RC) reaction is a significant catalytic reaction which can build carbon-carbon bonds and multiple chiral centers of polycyclic compounds. RC reaction has broad application prospects because its product has functional groups that allow further reactions to produce new materials for applications in the fields of medicine, chemistry, biology and so on. This thesis deals with the microscopic reaction process of RC reaction by density function theory (DFT), and designs more efficient organocatalyst. It provides important theoretical guidance for the experimental study and industrialized production of organocatalyst.This thesis uses density functional theory methods to systematically study two types of RC reaction system respectively. One type is organocatalyst with dual functionality to catalyze intramolecular RC reaction system, and the other type is PPh3 catalyzed intermolecular RC reaction system. At the level of M06-2X/6-31 G(d, p), we used software Gaussian 09 to optimize all structures in the reaction path, and get free energy. We can draw energy curve from the free energy, and determine RC reaction speed-controlling step by reaction energy barrier. We further analyzed the details of the catalytic process in the RC reaction. In addition, we also discussed the impact of the solvent environment on the RC reaction process.We have proposed two possible reaction mechanisms for the intramolecular and intermolecular RC reactions, and drawn the following conclusions:(1) Intramolecular and intermolecular RC reactions have similar reaction mechanism: nucleophilic addition, Michael addition, hydrogen transfer and dissociation.(2) By comparing the free energy barrier of four reactions, we conclude that hydrogen transfer is the rate-controlling step of the reaction owing to its highest free energy barrier. Free energy barrier of intermolecular and intramoleculas RC reactions were 58.99 kcal/mol and 41.12 kcal/mol, respectively.(3) Solvent DCM can promote the reaction to some extent since it can reduce the energy of the rate-controlling step, but the solvent could not change the reaction mechanism.