A Computational Study On Reaction Mecha- Nism Of Homogeneous Rhodium-catalyzed Synthesis Of Cyclic Organic Compounds

The reaction of homogeneous rhodium-catalyzed C-H bond functionalization can be easily used to construct new C-C and C-X bond.Because of atom economy,this method has been widely applied to organic synthesis.A computational study on organic reaction mechanism of homogeneous rhodium catalysis containing C-H activation is helpful to understand reaction process and optimize catalytic reactions.In this study,synthesis mechanisms of fused and bridged cycles are investigated by computation.There are eight types to construct cyclic organic compounds through theoretical analysis.But this study only contains reaction mechanisms of three products that involved in the issue.The results of computation show that the reaction mechanism of the fused product 2 contains C-H activation process,insertion reaction,configuration transformation process,conformation transformation process,Diels-Alder reaction process,protonolysis and hydrogen shift process in turn.The reaction mechanism of the bridged product 3 contains C-H activation process,insertion reaction,configuration transformation process,Diels-Alder reaction process,hydrogen shift process and protonolysis in turn.The reaction mechanism of the fused product 4 contains C-H activation process,insertion reaction,configuration transformation process,Diels-Alder reaction process,hydrogen shift process and protonolysis in turn.The C-H activation CMD model is quaternary annular.This reaction is kinetics control.The gibbs free energy change of the fused product 4 transition state is the lowest in insertion reaction process.The gibbs free energy change of the transition state is 9.8 kcal/mol.That is to say,the system prefers to form transition state of the fused product 4 in insertion reaction process.In addition,the gibbs free energy change of reaction between rhodium ion with terminal position is larger than rhodium ion with internal position.In other words,rhodium ion possibly prefers to interact with internal position.