An ab initio quantum chemical STUDY OF reaction mechanismS in the С2Н2/CH3OH/KOH/DMSO system
E. Y. Larionova, N. M. Vitkovskaya, V. B. Kobychev, B. A. Trofimov
Keywords: vinyl ethers, vinylation, methoxide ion, mechanism, potassium hydroxide, dimethylsulfoxide, quantum chemical calculations
Pages: 451-458
Abstract
An ab initio quantum chemical study (MP2/6-311++G**//B3LYP/6-31+G*) of a number of possible interactions is performed for the gas phase system of acetylene-potassium hydroxide-dimethylsulfoxide(DMSO)-methanol and with regard to the solvent effect within the continuum model. Key structures in the vinylation reaction are shown to be methoxide ion complexes with the alkali metal hydroxide and acetylene molecules. The formation of these complexes results in the activation of the acetylene molecule and an increase in the nucleophilicity of the methoxide ion. In the С2Н2/CH3OH/KOH/DMSO reaction system, a proton exchange between the acetylene molecule and the anionic nucleophile ([OH]- and [CH3O]-) is freely performed with the formation of systems with ethynide ions, whereas the thermodynamically preferable formation of vinyl alcohol or methyl vinyl ether is determined by a barrier of 20 kcal/mol
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