已经通过合理的保护基团操作和立体选择性糖基化作用,从市售单糖中完成了与三萜皂苷甜菊苷相关的四糖的简明合成。对于糖基化反应,H 2 SO 4-二氧化硅已成功用作传统路易斯酸(例如TfOH或TMSOTf)的替代物。靶四糖已经以其对-甲氧基苯基糖苷的形式合成,通过对-甲氧基苯基糖苷的选择性脱保护,然后进行三氯乙亚氨酸化学反应,为进一步的糖缀合物形成留有空间。
Organoiridium complexes: efficient catalysts for the formation of sugar acetals and ketals
摘要:
[Cp*IrCl2](2) is used as an efficient promoter for the synthesis of sugar acetals and ketals with good to excellent yields. The catalyst is found to be general for a wide range of sugars. (C) 2011 Elsevier Ltd. All rights reserved.
La(OTf)3: An Efficient Promoter for Thioglycoside Activation in Conjunction with N-Iodosuccinimide
作者:Balaram Mukhopadhyay、Somnath Mukherjee
DOI:10.1055/s-0030-1259016
日期:2010.12
Use of La(OTf)3 as a Lewis acid promoter for N-iodosuccinimide-mediated activation of thioglycosides is reported. The glycosylation reactions proceeded smoothly with good to excellent yields and stereoselectivity.