Stereoretentive Reactions at the Anomeric Position: Synthesis of Selenoglycosides
作者:Feng Zhu、Sloane O'Neill、Jacob Rodriguez、Maciej A. Walczak
DOI:10.1002/anie.201802847
日期:2018.6.11
Reported is the stereospecific cross‐coupling of anomeric stannanes with symmetrical diselenides, resulting in the synthesis of selenoglycosides with exclusive anomeric control. The reaction proceeds without the need for directing groups and is compatible with free hydroxy groups as demonstrated in the preparation of glycoconjugates derived from mono‐, di‐, and trisaccharides and peptides (35 examples)
building blocks, six reaction steps: The recently developed innovative methodology facilitated the convergent synthesis of the complex oligosaccharide core 1 (shown here with protecting groups) for the total synthesis of a glycosylphosphatidylinositol (GPI) anchor. The key factors are the tuning of the reactivity of the building blocks by using 1,2-diacetal protecting groups and the desymmetrization
Addition of Electrophilic Radicals to 2-Benzyloxyglycals: Synthesis and Functionalization of Fluorinated α-<i>C</i>-Glycosides and Derivatives
作者:Sophie Colombel、Nathalie Van Hijfte、Thomas Poisson、Eric Leclerc、Xavier Pannecoucke
DOI:10.1002/chem.201302070
日期:2013.9.16
A new method for the synthesis of fluorinated α‐C‐glycosides is described. The reactions between highly electrophilicradicals (fluorinated or unfluorinated) and a 2‐benzyloxyglucal or galactal provide 2‐keto‐D‐arabino‐ or 2‐keto‐D‐lyxo‐hexopyranosides through an addition/fragmentation process. Sodium borohydride mediated or Meerwein–Ponndorf–Verley (MPV) reduction of these compounds provides α‐C‐glycosides
描述了一种合成氟化α- C-糖苷的新方法。高亲电子基团(氟化或未氟化)与2-苄氧基葡萄糖或半乳糖之间的反应通过加成/分解过程提供了2-酮基-D-阿拉伯糖基或2-酮基-D-己基-吡喃吡喃糖苷。这些化合物的硼氢化钠介导的或Meerwein-Ponndorf-Verley(MPV)还原可提供具有适当锚定基团的α- C-糖苷,以进行进一步的合成修饰。CF 2 CO 2 i Pr或CF 2的存在假异头位置的Br基团可实现有效的还原/烯化或Br / Li交换/亲核加成序列。这些转变为糖缀合物的氟化C糖苷类似物的合成开辟了道路。
Preparation of glycosyl fluorides from phenyl 1-seleno- and phenyl 1-telluroglycosides
作者:Graeme Horne、William Mackie
DOI:10.1016/s0040-4039(99)01846-8
日期:1999.12
1-selenoglycosides and phenyl 1-telluroglycosides with DAST in the presence of halonium ion activators yields the corresponding glycosylfluoride in high yield. The stereoselectivity of the conversion is affected by C-2 substituents, stereochemistry of starting glycoside and reaction solvent.
Iodosylbenzene-Promoted Glycosylation with Selenoglycosides: Application in One-Pot Glycosylation
作者:Ao Sun、Ting Liu、Zipeng Li、Shuai Meng、Xiangbao Meng、Zhongtang Li、Zhongjun Li
DOI:10.1021/acs.orglett.4c00653
日期:2024.3.29
method for the glycosylation of selenoglycosides activated by iodosylbenzene was developed. The glycosylation reaction conditions were mild, fast, and efficient, with a high tolerance to diverse protectinggroups and a wide substrate scope, which is advantageous for synthesizing complex glycosides. In addition, selenoglycosides were shown to be orthogonal to thioglycosides under the promotion of iodosylbenzene