[EN] A HIGHLY EFFICIENT GLYCOSYLATION CHEMISTRY ENABLED BY A DIRECTING-GROUP THAT IS PART OF THE ANOMERIC LEAVING-GROUP<br/>[FR] CHIMIE DE GLYCOSYLATION HAUTEMENT EFFICACE ACTIVÉE PAR UN GROUPE DIRECTEUR FAISANT PARTIE DU GROUPE PARTANT ANOMÉRIQUE
申请人:UNIV CALIFORNIA
公开号:WO2022165224A1
公开(公告)日:2022-08-04
Broadly applicable and stereoselective formation of glycosidic linkage remains challenging yet of critical importance in giycoscience. By developing an SN2 glycosylation, this work advances a general solution to this challenge via stereoinversion at the anomeric position of glycosyl ester donors. This SN2 process is enabled by a basic directing-group in the leaving-group, which is activated by a cationic gold catalyst or any other electrophilic reagent. Unlike all the reported directing group approaches, this strategy is applicable to any glycosyl donors - a long sought-after yet unmet goal in carbohydrate chemistry; moreover, the basic directing-group upon glycosylation is lost as part of the leaving-group and hence traceless in the glycoside products, therefore avoiding potential complications in downstream transformations. Highly selective construction of glycosidic bonds including challenging 1,2-cis glycosidic bonds is achieved in excellent yields. The strategy is applied iteratively to access oligosaccharides and can distinguish alcohols with different steric hindrance.
广泛适用且立体选择性的糖苷键形成仍然具有挑战性,但在糖科学中至关重要。通过开发SN2糖基化,本研究通过糖酯供体的异构反转在糖基位置上推进了对这一挑战的普遍解决方案。此SN2过程由离去基中的碱性定向基启用,该定向基由阳离子金催化剂或任何其他亲电试剂激活。与所有报道的定向基方法不同,该策略适用于任何糖基供体-这是糖化学中一直追求但未能达成的目标;此外,糖基化后的碱性定向基将作为离去基的一部分而丢失,并且在糖苷产物中没有痕迹,因此避免了下游转化中的潜在复杂性。高度选择性的糖苷键构建,包括具有挑战性的1,2-顺式糖苷键,以极高的收率实现。该策略被迭代应用于访问寡糖,并且可以区分不同立体障碍的醇。