Gold(I)-Catalyzed Glycosylation with Glycosyl<i>ortho</i>-Alkynylbenzoates as Donors: General Scope and Application in the Synthesis of a Cyclic Triterpene Saponin
作者:Yao Li、Xiaoyu Yang、Yunpeng Liu、Cunsheng Zhu、You Yang、Biao Yu
DOI:10.1002/chem.200902548
日期:2010.2.8
coupling with the poorly nucleophilic amides gives satisfactory yields. Moreover, excellent α‐selective glycosylation with a 2‐deoxy sugar donor and β‐selective sialylation have been realized. Application of the present glycosylation protocol in the efficient synthesis of a cyclic triterpene tetrasaccharide have further demonstrated the versatility and efficacy of this new method, in that a novel chemoselective
糖基邻炔基苯甲酸酯已成为在金(I)配合物如Ph 3 PAuOTf和Ph 3 PAuNTf 2催化下进行糖苷化的新一代供体(Tf =三氟甲磺酸盐)。这些供体种类繁多,包括2-脱氧糖和唾液酸供体,易于制备且易于保存。与醇类的糖苷偶联收率通常非常好;即使与不良亲核酰胺直接偶联也能获得令人满意的收率。此外,已经实现了具有2-脱氧糖供体的出色的α-选择性糖基化和β-选择性唾液酸化。本糖基化方案在环状三萜四糖高效合成中的应用进一步证明了这种新方法的多功能性和有效性,因为已实现了羧酸的新型化学选择性糖基化和新的单锅顺序糖基化序列。