Efficient and First Regio- and Stereoselective Direct<i>C</i>-Glycosylation of a Flavanone Catalysed by Pr(OTf)<sub>3</sub>Under Conventional Heating or Ultrasound Irradiation
作者:Rui G. Santos、Nuno M. Xavier、João C. Bordado、Amélia P. Rauter
DOI:10.1002/ejoc.201201518
日期:2013.3
to other monosaccharidyl donors, such as D-mannose, D-galactose and L-rhamnose, as well as disaccharides, such as lactose and maltose, leading regio- and stereoselectively to 8-C-glycosyl derivatives with equatorial glycosidic bonds in yields ranging from 28 to 38 %. Ultrasound irradiation was used to enhance the reaction outcome and a considerable improvement in reaction time and efficiency was achieved
已经建立了一种用于黄烷酮单 C-糖基化的简单、区域和立体选择性一步方法。通过在乙腈/水中用稀土金属三氟甲磺酸酯催化,柚皮素直接与 D-葡萄糖 C-糖基化。研究了不同的反应条件,即溶剂体系、反应时间、能源和催化剂。市售的镧系元素三氟甲磺酸盐被评估为催化剂,三氟甲磺酸镨被证明是最有效的偶联反应。优化的反应条件应用于其他单糖供体,如 D-甘露糖、D-半乳糖和 L-鼠李糖,以及二糖,如乳糖和麦芽糖,导致区域和立体选择性地产生具有赤道的 8-C-糖基衍生物。糖苷键的产率范围为 28% 至 38%。