Wang Liming, Overkleeft Herman S, van der Marel Gijsbert A, Codée Jeroen D C
Leiden Institute of Chemistry Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands.
European J Org Chem. 2019 Mar 14;2019(10):1994-2003. doi: 10.1002/ejoc.201800894. Epub 2018 Oct 4.
Pre-activation based glycosylations have become a very powerful tool in the assembly of oligosaccharides and the use of nucleophilic additives allows for the in situ generation of reactive intermediates with tailored reactivity. We here use a glycosylation strategy that is based on the use of per-benzylated imidate building blocks for the fully stereoselective construction of a spacer equipped α-1,3-octaglucan. We have used the trimethylsilyl iodide (TMSI)-triphenylphosphine oxide (PhP=O) for the stereoselective installation of an azidopropanol spacer and triflic acid (TfOH)-dimethyl formamide (DMF) enabled glycosylations for the coupling reactions with the secondary glucosyl C-3-alcohols. An operationally simple in situ activation coupling procedure is introduced and used for the final glycosylation events towards the octasaccharide.
基于预活化的糖基化反应已成为寡糖组装中一种非常强大的工具，亲核添加剂的使用使得能够原位生成具有定制反应性的反应中间体。我们在此使用一种糖基化策略，该策略基于使用全苄基化亚氨酸酯构建块来完全立体选择性地构建带有间隔基的α-1,3-八葡聚糖。我们使用三甲基硅基碘（TMSI）-三苯基氧化膦（PhP=O）进行叠氮丙醇间隔基的立体选择性安装，并使用三氟甲磺酸（TfOH）-二甲基甲酰胺（DMF）实现与二级葡萄糖基C-3-醇的偶联反应的糖基化。引入了一种操作简单的原位活化偶联程序，并将其用于八糖的最终糖基化反应。
