The mechanism of carbon-nitrogen coupling reaction of 2-iodo-selenophene with 2-oxazolidi-none catalysted by Cul has been investigated at the B3LYP/6-311G * level. The geometries of react-ants, intermediates, transition states and products were calculated. The vibration analysis and energy calculation approve the authenticity of intermediates and transition states. The calculated results indicate that the reaction is very complicated and process through five steps. The Cul catalyst play a bridge role in the coupling reaction, which avoid the high strain four-memebered transition state in the direct coupling without catalyst and result in it proceeds easily. Our calculation results are in good agreement with the experiment, which prove that the transition metal can promote this kind of reaction. Our present works indicate how the catalysts work in the two coupling reactions.%在B3LYP/6-311G*水平下研究了铜催化剂作用下2-唑烷酮与2-碘代硒苯发生C-N偶联的反应机制.优化了反应过程中的反应物、中间体、过渡态和产物,通过能量和振动分析结果证实了中间体和过渡态的真实.计算研究结果显示该反应是一个较为复杂的过程、催化是通过铜与2-唑烷酮上氮配位开始,整个过程中铜催化剂为偶联反应起到了一种桥梁作用,避免了无催化剂作用时直接偶联的四元环高张力的过渡态从而降低了反应的活化能,使反应更易进行.计算结果与实验结果一致,证明了过渡金属催化剂有利于这类反应反应的进行,并揭示了有效催化作用产生的机制.
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