一种使用由4-O-叔丁基二甲基硅烷基保护基武装的N-乙酰葡糖胺供体进行β-选择性糖基化的直接方法。

Tanaka Hidenori, Hamaya Yu, Kotsuki Hiyoshizo

Oceanography Section, Science Research Center, Kochi University, Otsu, Nankoku-shi, Kochi 783-8502, Japan.

Laboratory of Natural Products Chemistry, Faculty of Science, Kochi University, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan.

Molecules. 2017 Mar 8;22(3):429. doi: 10.3390/molecules22030429.

A new direct method for β-selective glycosylation with an -acetylglucosamine (GlcNAc) donor was developed. This substrate, which can be readily prepared from commercially available GlcNAc in two steps, contains a 4---butyldimethylsilyl (TBDMS) protecting group as a key component. We found that this functionality could have a favorable effect on the reactivity of the GlcNAc donor. Glycosylation with the armed donor using primary alcohols in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf) in 1,2-dichloroethane smoothly gave the desired coupling products in good yields with complete β-selectivity, while sterically hindered acceptors were less efficient.

开发了一种用于以 N-乙酰葡糖胺（GlcNAc）供体进行 β-选择性糖基化的新直接方法。这种底物可通过两步从市售的 GlcNAc 轻松制备，含有叔丁基二甲基甲硅烷基（TBDMS）保护基作为关键成分。我们发现这种官能团对 GlcNAc 供体的反应性可能有有利影响。在 1,2-二氯乙烷中，使用伯醇，在催化量的三甲基甲硅烷基三氟甲磺酸酯（TMSOTf）存在下，用活性供体进行糖基化反应，顺利地以良好的产率和完全的 β-选择性得到所需的偶联产物，而空间位阻较大的受体效率较低。