Bi(OTf)3-promoted direct activation of formidable per-O-acetylated ʟ-rhamnose Donor: Stereoselective access to α-ʟ-rhamnopyranosides

IF 2.4 3区化学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Carbohydrate Research Pub Date : 2025-05-17 DOI:10.1016/j.carres.2025.109527

Ankit Yadav, Nitin Kumar, Sudhir Kashyap

引用次数: 0

Abstract

Rare ʟ-hexoses, including deoxy ʟ-hexoses, serve as potential chemical probes for carbohydrate-based drug discovery and vaccine development. 6-Deoxy sugars, particularly ʟ-rhamnose, are essential components of bacterial surface glycans, playing a key role in pathogen-host cell recognition and various physiological functions. Herein, we present an alternative and highly efficient ʟ-rhamnosylation utilizing the milder oxo-philic Bi(OTf)₃ as the promoter, enabling the assembly of biologically significant α-ʟ-rhamnopyranosides in good yields. The Bi-mediated direct anomeric activation of peracetylated ʟ-rhamnose (ʟ-Rha) is amenable to a wide range of acceptors, including sugars, amino acids, natural products, and bioactive scaffolds. The stereocontrolled glycosylation offers significant advantages, utilizing greener catalysts and atom-economical transformations, avoiding expensive ligands/additives, and tolerating the diverse functional groups.

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Bi(OTf)3促进了强大的过o -乙酰化的_ -鼠李糖供体的直接激活：对α- _ -鼠李糖吡喃苷的立体选择性通路

稀有的_ -己糖，包括脱氧_ -己糖，是基于碳水化合物的药物发现和疫苗开发的潜在化学探针。6-脱氧糖，尤其是鼠李糖，是细菌表面聚糖的重要组成部分，在病原体-宿主细胞识别和各种生理功能中发挥关键作用。在此，我们提出了一种替代的、高效的、利用较温和的亲氧Bi(OTf)3作为启动子的_ -鼠李糖基化反应，使具有生物学意义的α- _ -鼠李糖苷的组装具有良好的产量。过乙酰化的鼠李糖（_ -Rha）的双介导的直接端粒活化适用于广泛的受体，包括糖、氨基酸、天然产物和生物活性支架。立体控制糖基化具有明显的优势，使用更环保的催化剂和原子经济的转化，避免昂贵的配体/添加剂，并耐受多种官能团。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Carbohydrate Research 化学-生化与分子生物学

CiteScore

5.00

自引率

3.20%

发文量

183

审稿时长

3.6 weeks

期刊介绍： Carbohydrate Research publishes reports of original research in the following areas of carbohydrate science: action of enzymes, analytical chemistry, biochemistry (biosynthesis, degradation, structural and functional biochemistry, conformation, molecular recognition, enzyme mechanisms, carbohydrate-processing enzymes, including glycosidases and glycosyltransferases), chemical synthesis, isolation of natural products, physicochemical studies, reactions and their mechanisms, the study of structures and stereochemistry, and technological aspects. Papers on polysaccharides should have a "molecular" component; that is a paper on new or modified polysaccharides should include structural information and characterization in addition to the usual studies of rheological properties and the like. A paper on a new, naturally occurring polysaccharide should include structural information, defining monosaccharide components and linkage sequence. Papers devoted wholly or partly to X-ray crystallographic studies, or to computational aspects (molecular mechanics or molecular orbital calculations, simulations via molecular dynamics), will be considered if they meet certain criteria. For computational papers the requirements are that the methods used be specified in sufficient detail to permit replication of the results, and that the conclusions be shown to have relevance to experimental observations - the authors'' own data or data from the literature. Specific directions for the presentation of X-ray data are given below under Results and "discussion".