Chemoselective esterification of α-hydroxyacids catalyzed by salicylaldehyde through induced intramolecularity
作者:Shiue-Shien Weng、Hsin-Chun Li、Teng-Mao Yang
DOI:10.1039/c2ra23068b
日期:——
direct and chemoselective esterification of α-hydroxyacids was developed using a reversible covalent-binding strategy. By taking advantage of acetal chemistry, simple aldehydes can be used to efficiently catalyze the esterification of α-hydroxy carboxylic acids in the presence of β-hydroxyacid moieties or other carboxylic acids in amounts equal to or in excess of the alcohols. A diverse array of α-aryl
使用可逆的共价结合策略开发了一种新的,直接的和化学选择性的α-羟基酸酯化方法。通过利用缩醛化学,可以使用简单的醛在等于或超过醇的量的β-羟基酸部分或其他羧酸的存在下有效地催化α-羟基羧酸的酯化。用10 mol%廉价的市售水杨醛催化的1°和2°醇将各种α-芳基,α-烷基,α-杂芳基和官能化的α-羟基酸平稳地酯化,从而在83-在简单的碱性水溶液处理中除去未反应的羟基酸后,产率为95%。此外,水杨醛可通过真空蒸馏或硅胶纯化回收,从而达到绿色化学标准。机理研究证明,共价加合物的形成III在我们建议的催化循环中(方案1A)负责真正的催化作用。