Silver(I) tetrafluoroborate as a potent promoter for chemical glycosylation
作者:Sophon Kaeothip、Papapida Pornsuriyasak、Alexei V. Demchenko
DOI:10.1016/j.tetlet.2007.12.105
日期:2008.2
promoter for the activation of various glycosyldonors including glycosyl halides, trichloroacetimidates, thioimidates, etc. Easy handling and no requirement for azeotropic dehydration prior to application makes AgBF(4) especially beneficial in comparison to the commonly used AgOTf. Selective activation of glycosyl halides or thioimidates over thioglycosides or n-pentenyl glycosides, including simple
Glucosides and disaccharides were prepared in good yields from 2-benzothiazolyl 2,3,4,6-tetra-O-benzyl-1-thio-d-glucopyranoside and alcohols including sterically hindered secondary alcohols in the presence of cupric triflate. α-Glucosides were obtained predominantly by this method.
A Highly Stereoselective Synthesis of α-Glucosides from 1-Thioglucoside Derivative under High Pressure
作者:Yasuo Gama、Masahiko Yasumoto
DOI:10.1246/cl.1993.319
日期:1993.2
High pressure-assisted glycosylation reaction of 2-benzothiazoyl 2,3,4,6-tetra-O-benzyl-1-thio-β-d-glucopyranoside with various alcohols by using methyl iodide as an activator gave α-glucosides in good yield with high selectivity without any use of heavy metal salts.
An Efficient Synthesis of Benzothiazole Derivatives of Thiosugars under Phase-Transfer Conditions
作者:Jadwiga Bogusiak、Wieslaw Szeja
DOI:10.1246/cl.1988.1975
日期:1988.12.5
2-Benzothiazole derivatives of thiosugars can be conveniently prepared by treatment of reducing monosaccharides with tosyl chloride and 2-mercaptobenzothiazole underphase-transferconditions.
Stereoselective Synthesis of 1,2‐
<i>cis</i>
‐Glycosyl Sulfones and Their Application in One‐Pot Julia Olefination for the Synthesis of
<i>exo</i>
‐Glycals
stereoselective synthesis of 1,2-cis-glycosyl sulfones and their application to one-pot Julia olefination are reported. Glycosylation of heteroarylthiols using glycosyl iodides as glycosyl donors afforded heteroaryl 1-thioglycosides in a highly 1,2-cis-selective manner. 1,2-cis-Glycosyl sulfones were obtained by oxidation of the resulting 1-thioglycosides by magnesium monoperphthalate. One-pot Julia olefination
报道了 1,2-顺式糖基砜的立体选择性合成及其在单锅 Julia 烯化中的应用。使用糖基碘作为糖基供体的杂芳基硫醇的糖基化以高度 1,2-顺式选择性方式提供杂芳基 1-硫代糖苷。1,2-顺式-糖基砜通过用单过苯二甲酸镁氧化所得1-硫代糖苷获得。一锅Julia烯使用1,2-顺糖基砜家具外-glycals与é / Z ^达的选择性91:9。