Methods for site-selective transformations of hydroxyl groups in carbohydrate derivatives are reviewed. The construction of oligosaccharides of defined connectivity hinges on such transformations, which are also needed for the preparation of modified or non-natural sugar derivatives, the installation of naturally occurring postglycosylation modifications, the selective labeling or conjugation of carbohydrate derivatives, and the preparation of therapeutic agents or research tools for glycobiology. The review begins with a discussion of intrinsic factors and processes that can influence selectivity in reactions of unprotected or partially protected carbohydrate derivatives, followed by a description of transformations that engage two OH groups in cyclic adducts (acetals, ketals, boronic esters, and related species). An overview of the various classes of site-selective transformations of OH groups in sugars is then provided: the reactions discussed include esterification, thiocarbonylation, alkylation, glycosylation, arylation, silylation, phosphorylation, sulfonylation, sulfation, and oxidation. Emphasis is placed on recently developed methods that employ reagent or catalyst control to achieve otherwise challenging transformations or site-selectivities.

中文翻译：

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碳水化合物衍生物中羟基的位点选择性官能化

综述了碳水化合物衍生物中羟基的位点选择性转化的方法。定义的连接性寡糖的构建取决于这种转化，制备修饰或非天然糖衍生物，天然糖基化后修饰的安装，碳水化合物衍生物的选择性标记或缀合以及治疗剂的制备也需要这种转化。糖生物学的研究代理或研究工具。该综述首先讨论了可能影响未保护或部分保护的碳水化合物衍生物反应选择性的内在因素和过程，然后描述了与环状加合物（乙缩醛，缩酮，硼酸酯和相关物种）中的两个OH基团结合的转化过程。 ）。然后提供了糖中OH基的各种位置选择性转化的概述：讨论的反应包括酯化，硫代羰基化，烷基化，糖基化，芳基化，甲硅烷基化，磷酸化，磺酰化，硫酸化和氧化。重点放在最近开发的方法上，该方法采用试剂或催化剂控制来实现否则具有挑战性的转化或位点选择性。