Carbohydrates contain numerous hydroxyl groups and sometimes amine functionalities which lead to a variety of complex structures. In order to discriminate each hydroxyl group for the synthesis of complex oligosaccharides, protecting group manipulations are essential. Although the primary role of a protecting group is to temporarily mask a particular hydroxyl/amino group, it plays a greater role in tuning the reactivity of coupling partners as well as regioselectivity and stereoselectivity of glycosylations. Several protecting groups offer anchimeric assistance in glycosylation. They also alter the solubility of substrates and thereby influence the reaction outcome. Since oligosaccharides comprise branched structures, the glycosyl donors and acceptors need to be protected with orthogonal protected groups that can be selectively removed one at a time without affecting other groups. This minireview is therefore intended to provide a discussion on new protecting groups for amino and hydroxyl groups, which have been introduced over last ten years in the field of carbohydrate synthesis. These protecting groups are also useful for synthesizing non-carbohydrate target molecules as well.

中文翻译：

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寡糖合成保护基的研究进展。

碳水化合物包含许多羟基，有时还包含胺官能团，这会导致各种复杂的结构。为了区分每个羟基以合成复杂的寡糖，保护基的操作至关重要。尽管保护基的主要作用是暂时掩盖特定的羟基/氨基，但它在调节偶联伴侣的反应性以及糖基化的区域选择性和立体选择性方面起着更大的作用。几个保护基团在糖基化中提供了嵌合的辅助作用。它们还会改变底物的溶解度，从而影响反应结果。由于寡糖包含分支结构，糖基供体和受体需要用正交保护的基团进行保护，这些基团可以一次选择性地除去而不影响其他基团。因此，本综述旨在提供关于氨基和羟基的新保护基的讨论，该保护基已在最近十年的碳水化合物合成领域中引入。这些保护基团也可用于合成非碳水化合物靶分子。