Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
Nat Commun. 2017 Oct 27;8(1):1146. doi: 10.1038/s41467-017-01073-7.
Mechanistic study of carbohydrate interactions in biological systems calls for the chemical synthesis of these complex structures. Owing to the specific stereo-configuration at each anomeric linkage and diversity in branching, significant breakthroughs in recent years have focused on either stereoselective glycosylation methods or facile assembly of glycan chains. Here, we introduce the unification approach that offers both stereoselective glycosidic bond formation and removal of protection/deprotection steps required for further elongation. Using dialkylboryl triflate as an in situ masking reagent, a wide array of glycosyl donors carrying one to three unprotected hydroxyl groups reacts with various glycosyl acceptors to furnish the desired products with good control over regioselectivity and stereoselectivity. This approach demonstrates the feasibility of straightforward access to important structural scaffolds for complex glycoconjugate synthesis.
在生物体系中对碳水化合物相互作用的机理研究需要对这些复杂结构进行化学合成。由于每个糖苷键的特定立体构型和支化的多样性，近年来的重大突破主要集中在立体选择性糖基化方法或聚糖链的简便组装上。在这里，我们介绍了一种统一的方法，该方法既可以实现糖苷键的立体选择性形成，又可以去除进一步延伸所需的保护/脱保护步骤。使用二烷基硼酸三氟甲磺酸酯作为原位掩蔽试剂，带有一个到三个未保护羟基的各种糖基供体与各种糖基受体反应，以良好的区域选择性和立体选择性得到所需产物。该方法证明了直接获得复杂糖缀合物合成中重要结构支架的可行性。
