<i>N</i>-Glycosyl Amides as Glycosyl Donors in Stereoselective Glycosylation Reactions
作者:Horst Kunz、Norbert Pleuss
DOI:10.1055/s-2004-834911
日期:——
Due to their high stability, N-glycosyl amides have so far not been considered as glycosyldonors for glycosylation reactions. Two new procedures for the cleavage of the anomeric amide functionality under mild reaction conditions and further stereoselective in situ conversions of the activated glycosyldonors with alcohols and amines to give β-configured O- and N-glycosides are described in this article
The invention relates to compositions for use in animal models of neurodegenerative disease and methods therefor. More particularly, the invention relates to the use of neurotoxic sterol glycosides or neurotoxic glycolipids, or combinations thereof, in animal models of neurodegenerative disease. Neurotoxicity-modulating chromenols can also be used in these animal models in combination with the neurotoxic sterol glycosides or neurotoxic glycolipids, or combinations thereof.
Facile, one-pot synthesis was developed for several β(1→2)-, β(1→3)- or β(1→4)-linked disaccharides from fully unprotected methyl hexopyranosides according to the molecular recognition by arylboronic acids. The methodology was successfully applied to facile, short step assembly of the trisaccharide fragment of type II arabinogalactan.
Stereoselective Synthesis of α-Arylalkylamines by Glycosylation-induced Asymmetric Addition of Organometallic Compounds to Imines
作者:Petra Allef、Horst Kunz
DOI:10.1515/znb-2009-0609
日期:2009.6.1
Activation of imines of aromatic aldehydes by N-glycosylation with O-pivaloyl-galactopyranosyl bromide (pivalobromogalactose) and subsequent addition of organotin, organolithium, Grignard, or organozinc reagents afforded α-arylalkylamines with moderate to high diastereoselectivity. Graphical Abstract Stereoselective Synthesis of α-Arylalkylamines by Glycosylation-induced AsymmetricAddition of Organometallic
Supercritical carbon dioxide (scCO2) is a suitable medium to perform transition metal-free glycosylations in the absence of volatile organic solvents (VOCs) using glycosyl halides as glycosyl donors. The methodology here described can be applied for obtaining O-glycosides in a totally green reaction, as well as orthoesters, depending on the reaction conditions. The process is much more sensitive to
超临界二氧化碳(sc CO 2)是一种合适的介质,可在无挥发性有机溶剂(VOC)的情况下使用糖基卤化物作为糖基供体来进行无过渡金属的糖基化反应。根据反应条件,此处描述的方法可用于在完全绿色反应以及原酸酯中获得O-糖苷。该方法对温度的变化比对压力的改变更为敏感,与糖基溴相比,糖基氯化物需要更高的温度才能被活化。新戊酰基作为良好的CO 2-亲和单元,并被证明是获得良好立体选择性的最佳选择。流体性质和超临界条件的相关性也得到了证明