The Reaction of Carbonyldiimidazole with Alcohols to Form Carbamates and<i>N-</i>Alkylimidazoles
作者:Jonathan L. Vennerstrom、Yuanqing Tang、Yuxiang Dong
DOI:10.1055/s-2004-831215
日期:——
The reactions of non-benzylic primary and secondary aliphatic alcohols with carbonyldiimidazole (CDI) afford the corresponding carbamates but not N-alkylimidazoles. For benzylic primary alcohols, formation of N-alkylimidazoles proceeds reasonably at 170 °C in several different solvents and occurs by way of the initially formed carbamate. However, under these rather forcing conditions, or even at lower
非苄基伯醇和仲脂肪醇与羰基二咪唑 (CDI) 的反应得到相应的氨基甲酸酯,但没有得到 N-烷基咪唑。对于苄基伯醇,N-烷基咪唑的形成合理地在 170 °C 下在几种不同的溶剂中进行,并通过最初形成的氨基甲酸酯发生。然而,在这些相当强制的条件下,甚至在较低的反应温度下,消除对于具有 β-氢原子的苄基仲醇来说是一个重要的副反应。除了一个例外,六种 N,N-二取代的 β-氨基醇与 CDI 形成 N-烷基咪唑的反应在相对温和的条件下进行,并且可能通过氮丙啶中间体发生。