4291-68-3Relevant articles and documents
Highly regioselective and stereoselective synthesis of C-Aryl glycosidesvianickel-catalyzedortho-C-H glycosylation of 8-aminoquinoline benzamides
Chen, Xi,Ding, Ya-Nan,Gou, Xue-Ya,Liang, Yong-Min,Luan, Yu-Yong,Niu, Zhi-Jie,Shi, Wei-Yu,Zhang, Zhe,Zheng, Nian
, p. 8945 - 8948 (2021/09/10)
C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzedortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C-H activation could be the rate-determining step.
Method for preparing halogenated sugar under mild conditions
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Paragraph 0052-0054, (2020/07/02)
The invention discloses a method for preparing halogenated sugar under mild conditions. The method comprises the following steps that an easily-prepared thioglycoside donor and a halogen simple substance or halogen intercompound undergo a reaction at room temperature to obtain the halogenated sugar (chlorine, bromine and iodine). The halogen simple substance or the halogen intercompound is commercial easily available iodine elementary substance, iodine bromide and iodine chloride. The method is suitable for various pyranoses and furanoses. The method has no limitation on a protecting group ofthe thioglycoside donor, and the protecting group can be an electron withdrawing group such as acetyl, benzoyl and the like, and can also be an electron donating group such as benzyl, silicon base andthe like. Meanwhile, the reaction can occur in various organic solvents such as dichloromethane, acetonitrile and methylbenzene. The preparation method of the halogenated sugar is simple, reaction conditions are mild, raw materials are easy to obtain, the application range is wide, the halogenated sugar is compatible with acid-labile groups such as isopropylidene ketal and silicon groups, and a pure product can be obtained by removing a solvent from the halogenated sugar which is not stable in the separation process.
Solvent-free, under air selective synthesis of α-glycosides adopting glycosyl chlorides as donors
Bedini, Emiliano,Iadonisi, Alfonso,Traboni, Serena,Vessella, Giulia
, p. 5157 - 5163 (2020/07/23)
α-Glycosides are highly relevant synthetic targets due to their abundance in natural oligosaccharides involved in many biological processes. Nevertheless their preparation is hampered by several issues, due to both the strictly anhydrous conditions typically required in glycosylation procedures and the non-trivial achievement of high α-stereoselectivity, one of the major challenges in oligosaccharide synthesis. In this paper we report a novel and efficient approach for the highly stereoselective synthesis of α-glycosides. This is based on the unprecedented solvent-free combination of triethylphosphite, tetrabutylammonium bromide and N,N-diisopropylethylamine for the activation of glycosyl chlorides under air. Despite the relative stability of glycosyl chlorides with respect to more reactive halide donors, the solvent-free procedure allowed a wide set of α-glycosides, including biorelevant fragments, to be obtained in much shorter times compared with similar glycosylation approaches in solution. The presented method features a wide target scope and functional group compatibility, also serving with partially disarmed substrates, and it does not require a high stoichiometric excess of reagents nor the preparation of expensive precursors. The solvent-free glycosylation can be even directly performed from 1-hydroxy sugars without purification of the in situ generated chloride, providing an especially useful opportunity in the case of highly reactive and labile glycosyl donors. This journal is
