Theoretical Studies Of Rh(?)-Catalyzed C-H Activation And Ir-Catalyzed Regioselective Of 1,3-Diene Hydroboration

In recent years,the synthesis of various novel organic derivatives with various unsaturated organic compounds such as alkynes,olefins and specific substrates under the transition metal catalysis has become a hot research direction.Such as their cyclization,acyclicization,and selective functionalization reactions have made the synthesis of organic matter has become more abundant and widely used.Among them,the transition metal-catalyzed C-H activation and the functionalization of unsaturated hydrocarbons have been research hotspots in recent years and become the main method for constructing specific molecules.But the mechanism information of this kind of reaction is scarce.In this paper,the reaction mechanism of transition metal Rh-catalyzed C-H activation and Ir-catalyzed 2-substituted 1,3-diene hydroboration reaction was studied using density functional theory(DFT)calculation methods of M06 and B3 LYP.This will provide more guidance for the development of experimental research.In Chapter 3,we chose Rh(?)to catalyze the C-H activation of N-(pivaloyloxy)benzamide as the research system.The reason why the substituent on the alkyne controls the chemical selectivity(cyclization or hydroarylation)was analyzed by density functional theory.The calculated results are consistent with the experimental observations.N-(pivaloyloxy)benzamide without fluorine substituents undergoes cyclization with alkynyl groups,While ?,?-difluoromethylene alkynes undergoes a novel hydroarylation reaction.We found that the inductive effect of a fluorine substituent on the alkyne polarizes the Rh-C bond,and this facilitates the protonation step,thereby forming an unconventional product.Our calculations also explain the experimentally observed regioselectivity,which mainly arises from the interaction energy.In Chapter 4,we mainly studied the mechanism of the selective addition of2-alkyl-substituted 1,3-diene and HBpin catalyzed by transition metal Ir to obtain allylallyl borate.We used the DFT method to calculate the detailed reaction mechanism,regioselectivity,and compared the mechanism energy of multiple selective addition products.We found that the4,3-selective reaction of 1,3-diene was optimal using the iridium complex as a model catalyst.Our calculations show that Ir-catalyzed hydroboration of 2-substituted 1,3-dienes start with4,3-insertion of the double bond of 1,3-dienes to Ir-H bond,followed by addition of Bpin group to C4 atom to give 4,3-selectivity product.