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在有机合成反应中常使用甲基磺酰氯与醇反应,将羟基转化为易于离去的甲磺酸酯基。在近期的实验中,我们却发现N-甲基二乙醇胺同甲基磺酰氯反应生成的是羟基被氯取代的产物。我们设计了一系列实验推测生成氯取代产物的关键原因是在反应过程中生成了三元环的氮鎓离子过渡态,而形成这一过渡态必须满足的条件是:氮原子与羟基之间相隔两个碳原子,氮原子有足够的电子云密度,氮原子周围的空间位阻不能太大。
In organic synthesis reactions, methylsulfonyl chloride is often used to react with an alcohol to convert the hydroxyl group to a mesylate group that is readily removable. In a recent experiment, we found that N-methyldiethanolamine reacts with methylsulfonyl chloride to form a product whose hydroxyl group is replaced by chlorine. We have designed a series of experiments to speculate that the key reason for the formation of chlorine-substituted products is the formation of a three-membered ring of nitrogen-ion transition states during the reaction, and the conditions that must be met to form this transition state are that the nitrogen atoms and hydroxyl groups are separated Two carbon atoms, nitrogen atoms have sufficient electron density, nitrogen atoms around the steric hindrance can not be too large.