Showing papers on "Koenigs–Knorr reaction published in 2007"
TL;DR: Glycosyl triflates, which serve as important intermediates in glycosylation reactions, were generated and accumulated by the low-temperature electrochemical oxidation of thioglycosides such as thioglucosides, thiogalactoside, and thiomannosides in the presence of tetrabutylammonium triflate (Bu(4)NOTf) as a supporting electrolyte.
Abstract: Glycosyl triflates, which serve as important intermediates in glycosylation reactions, were generated and accumulated by the low-temperature electrochemical oxidation of thioglycosides such as thioglucosides, thiogalactosides, and thiomannosides in the presence of tetrabutylammonium triflate (Bu4NOTf) as a supporting electrolyte. Thus-obtained solutions of glycosyl triflates (glycosyl triflate pools) were characterized by low-temperature NMR measurements. The thermal stability of glycosyl triflates and their reactions with glycosyl acceptors were also examined.
102 citations
TL;DR: A series of novel Mahkoside A derivatives was synthesized, and their in vitro cytotoxic activities were evaluated against the human cancer cell line Ec•9706 as discussed by the authors, showing that compounds 7 and 8 have obvious cytotoxicity activities (IC50: 30.0 and 12.5 µg−·mL−1, respectively).
7 citations
01 Jan 2007
TL;DR: Glycosylamines and glycosyl azides are valuable and versatile intermediates in carbohydrate chemistry; furthermore they are easily available in a highly stereoselective fashion.
Abstract: Glycosylamines and glycosyl azides are valuable and versatile intermediates in carbohydrate chemistry; furthermore they are easily available in a highly stereoselective fashion. Glycosylamines and their derivatives glycosyl enamines and glycosyl imines can be transformed into N-glycosyl heterocycles. Glycosyl enamines are also used in the preparation of polyhydroxy pyrrolidines, oxapyrrolizidines, piperidines and azepanes, an intramolecular nucleophilic displacement of a sulfonyloxy group by a stabilized amide anion being the key step. Glycosyl azides can be converted into a plethora of heterocyclic derivatives by different reactions such as the Staudinger reaction, thermolysis and 1,3-dipolar cycloadditions. Much effort has been devoted to the synthesis of glycosyl triazoles by using the Dimroth reaction, ketene aminals, phosphorus ylides, azide–alkyne Huisgen cycloaddition and the especially successful Cu(I)-mediated Huisgen cycloaddition.
5 citations
TL;DR: In this article, a methodology for the synthesis of glycosylenaminoesters from azides under hydrogenation conditions was developed. Yields were moderate to good in all cases.
2 citations