Spontaneous formation of PMB esters using 4-methoxybenzyl-2,2,2-trichloroacetimidate
作者:Jigisha P. Shah、Christopher M. Russo、Kyle T. Howard、John D. Chisholm
DOI:10.1016/j.tetlet.2014.01.097
日期:2014.3
Carboxylic acids are converted to the corresponding 4-methoxybenzyl (PMB) esters with 4-methoxybenzyl-2,2,2-trichloroacetimidate in the absence of an acid catalyst. This operationally simple procedure is a highly effective method for the formation of PMB esters. The reaction is promoted by the carboxylic acids themselves in excellent yields (72–99%). Sterically hindered carboxylic acids, which provide
在不存在酸催化剂的情况下,用4-甲氧基苄基-2,2,2-三氯乙亚氨酸酯将羧酸转化为相应的4-甲氧基苄基(PMB)酯。该操作简单的步骤是形成PMB酯的高效方法。羧酸本身以优异的产率(72–99%)促进了反应。与其他酰亚胺化合物提供较低收率的立体受阻羧酸,与反应性更强的PMB亚氨酸酯以较高的收率进行酯化。在带有α-立体中心的羧酸的情况下未观察到外消旋化,并且对于Z-α,β-不饱和酸未观察到异构化。因此,该方法可用于复杂或敏感底物的酯化反应中,其中更常见的技术会导致分解。