A convenient method for the selective monocarbamoylation of diols by reaction with alkyl isocyanates, generated in situ from alkyl halides and potassium cyanate under phase-transfer catalysis, is described. Under these conditions the ease of reaction shows the following order cis-diols > trans-diols and diols > monoalcohols. An increase in the number of methylene groups between two hydroxyl groups lead to a decrease in product yields. A plausible mechanism to explain these results is proposed.
一种便捷的方法被描述,用于通过与由烷基卤和
氰酸钾在相转移催化下原位生成的烷基
异氰酸酯反应,实现对二醇的选择性单
氨基甲酸酯化。在这些条件下,反应的容易程度显示以下顺序:顺式二醇 > 反式二醇以及二醇 > 单羟基醇。两个羟基之间甲基链数量的增加会导致产物产量的下降。为了解释这些结果,提出了一个合理的机理。