Mechanism Study Of Selection Of Reaction Pathways Between Different Kinds Of Active Methylene Compounds And Azido Triazines

Due to the high conjugation and strong electron affinity of the triazine ring of the azidotriazine molecules(ATs),as a diazonium transfer reagent,it exhibits high activity and excellent thermal stability.Compared to other commonly used diazonium transfer reagents,they have better safety and close diazonium transfer efficiency.In the follow-up study,we found that the reaction path of this kind of molecule and active methylene compounds is related to the aromaticity of the substituent groups on both sides of the active methylene molecules and the property of the solvent.In polar aprotic solvents,ATs and active methylene molecules will undergo a diazo transfer reaction;in protic solvents,ATs and active methylene molecules will undergo a click reaction,which precipitates the triazolyl triazine product in the crystalline state;in the polar aprotic solvent,ATs and active methylene molecules whose ends are replaced by the functional groups with larger steric hindrance will undergo carbon-carbon bond cleavage reaction.We guessed the reaction mechanism and verified the rationality of the guessed mechanism using the quantum chemical density functional theory(DFT)method.The first part of this thesis discusses the DFT calculation methods commonly used in the research of organic chemistry mechanism and the development of DFT methods in recent years.The second part discusses the stable conformation and thermodynamic energy of ATs calculated by the DFT method.Combined with the crystal structure produced by X-ray single-crystal diffraction,these results reflect the reasons for high diazo transfer efficiency and excellent thermal stability of ATs as diazonium transfer reagents.The third part discusses the mechanism of the click reaction between ATs and active methylene molecules and the results of using the DFT method to verify the mechanism.The fourth part discusses the mechanism of the selective carbon-carbon bond cleavage reaction between ATs and active methylene molecules and the results of using the DFT method to verify the mechanism.The fifth part discusses other computer simulations performed by the author at the postgraduate level to explain the reasons for the excellent properties of some materials.