Theoretical Investigation On The Cross-coupling Reaction Mechanism Of The Aromatic Compounds Catalyzed By Cu(Ⅰ)、Pd(0)、Rh(Ⅰ)

The aromatic compounds synthesized by the C-C coupling reaction catalyzed by the transition metals are widely used in many areas of modern industry, for example: the synthetic drugs, liquid crystal, high polymer material and so on. The application of the compounds involves the fragments of the aromatic ether and aromatic amine play an important role in dyestuffs, pharmaceutical, and many materials industries. Nowadays, the main emphasis of this research is to find a method which is more simple and effective to form the C-C bond. Thus, to find a catalyst which has the ability to make the reaction chemo-selective is the key task of this research.At present, transition metals Pd(0), copper salt compounds and Rh metallorganics are testified they are effective catalysts in the C-C coupling reaction of the aromatic compounds. The mechanisms of the cross-coupling reaction of the aromatic compounds are investigated by density functional theory (DFT) with the computing softwares of Gaussion03, AIM2000, GaussView and CHEM2004at the B3LYP/6-31G(d) level. The analysis of the calculated results would make a better understanding of these reactions.1. The reaction mechanism of Arynes with Alkynes catalyzed by CuCl has been investigated by density functional theory (DFT). The geometries and the frequencies of reactants, intermediates, transition states, and products have been calculated at the B3LYP/6-31G(d) level, and the LanL2DZ basis has been used as the extrabasis. The vibration analysis demonstrates the authenticity of transition states, and the reaction processes are confirmed by the changes of charge density at bond-forming critical point which analyzed by the atoms in molecules theory. In addition, the nature bond orbital is used to discuss the bond nature and orbital interactions at the same level. The result of the theory study agrees with the experimental data, it indicates that the CuCl is an effective catalyst in this reaction.2. A palladium-catalyzed multicomponent-coupling reaction has been developed that involves a cross-coupling with organohalides as part of the reaction sequence has been investigated by density functional theory (DFT). The geometries and the frequencies of reactants, intermediates, transition states, and products have been calculated at the B3LYP/6-31G(d) level, and the LanL2DZ basis has been used as the extrabasis. The vibration analysis demonstrates the authenticity of transition states, and the reaction processes are confirmed by the changes of charge density at bond-forming critical point which analyzed by the atoms in molecules theory. In addition, the nature bond orbital is used to discuss the bond nature and orbital interactions at the same level. The result of the theory study agrees with the experimental data, it indicates that the palladium is an effective catalyst in this reaction.3. A rhodium-catalyzed multicomponent-coupling reaction has been developed that involves a cross-coupling with organohalides as part of the reaction sequence has been investigated by density functional theory (DFT). The geometries and the frequencies of reactants, intermediates, transition states, and products have been calculated at the B3LYP/6-31G(d) level, and the LanL2DZ basis has been used as the extrabasis. The vibration analysis demonstrates the authenticity of transition states, and the reaction processes are confirmed by the changes of charge density at bond-forming critical point which analyzed by the atoms in molecules theory. In addition, the nature bond orbital is used to discuss the bond nature and orbital interactions at the same level. The result of the theory study agrees with the experimental data, it indicates that the rhodium is an effective catalyst in this reaction.