2,3-二甲基-1-对氯苯磺酰基咪唑啉盐与邻氨基苯酚反应的量子化学研究

Quantum Chemical Study on One-Carbon Unit Transfer Reaction of 2,3-Di-methyl-1-p-chlorobenzenesulfonylimidazolinium with 1,2-Aminophenol

用量子化学方法对叶酸辅酶模型化合物 2 ,3 二甲基 1 对氯苯磺酰基咪唑啉盐与邻氨基苯酚的反应进行了理论研究 .结果表明 ,咪唑啉环有两种开环方式 ,反应可以通过两种途径实现 ,得到较稳定的中间体或者实现一碳单元的完全转移 .通过优化计算所有步骤的中间体和过渡态的结构可知 ,各个中间体和过渡态具有不同的构型、构象 ,有些过程的构象变化是进行下一步反应所必需的 ,在所有过程中质子转移步骤过渡态的能量最高 。

One-carbon unit transfer reaction of 2, 3-dimethyl-1-p-chlorobenzenesulfonyl-imidazolinium, a model rotate cofactor, with 1, 2-aminophenol has been studied using theoretical method. The results show that there are two pathways to obtain more stable intermediates or to complete the one carbon transfer because the imidazolinium ring has two different breaking patterns. By optimizing all the intermediates and transition states, it can be found they all have different conformations. Some variation of certain conformation is necessary for the next step. Of all the steps in the two path-ways, the transition state of the proton-migrating that is the rate-limiting step has the highest energy.