152872-00-9Relevant academic research and scientific papers
Transition state analysis of Vibrio cholerae sialidase-catalyzed hydrolyses of natural substrate analogues
Chan, Jefferson,Lewis, Andrew R.,Indurugalla, Deepani,Schur, Melissa,Wakarchuk, Warren,Bennet, Andrew J.
experimental part, p. 3748 - 3757 (2012/05/04)
A series of isotopically labeled natural substrate analogues (phenyl 5-N-acetyl-α-d-neuraminyl-(2→3)-β-d-galactopyranosyl-(1→4) -1-thio-β-d-glucopyranoside; Neu5Acα2,3LacβSPh, and the corresponding 2→6 isomer) were prepared chemoenzymatically in order to
Efficient acylation and sulfation of carbohydrates using sulfamic acid, a mild, eco-friendly catalyst under organic solvent-free conditions
Santra, Abhishek,Guchhait, Goutam,Misra, Anup Kumar
experimental part, p. 1345 - 1351 (2011/06/26)
A fast and efficient acylation of carbohydrate derivatives and free sugars using a stoichiometric quantity of acylating agents in the presence of sulfamic acid, an environmentally benign catalyst, under organic solvent-free conditions is reported. Excellent yields in the selective acylation and sulfation of carbohydrate derivatives have also been achieved using sulfamic acid as the catalyst. The reaction is fast and the yields were excellent.
Acylation of carbohydrates over Al2O3: Preparation of partially and fully acylated carbohydrate derivatives and acetylated glycosyl chlorides
Tiwari, Pallavi,Misra, Anup Kumar
, p. 339 - 350 (2007/10/03)
Selective and per-O-acylation of carbohydrate derivatives using acyl chlorides and Al2O3, a solid support reagent, is reported. This protocol does not require the addition of any base or activator. This methodology has been further extended to the selective acylation of carbohydrate diols and the one-pot preparation of acetylated glycosyl chlorides direct from free reducing sugars. The yields obtained in most of the cases are excellent.
Efficient acetylation of carbohydrates promoted by imidazole
Tiwari, Pallavi,Kumar, Rishi,Maulik, Prakas R.,Misra, Anup Kumar
, p. 4265 - 4270 (2007/10/03)
An efficient per-O-acetylation of carbohydrate derivatives and unprotected reducing sugars promoted by imidazole is reported. The reaction conditions have been successfully employed to acetylate carbohydrate derivatives containing acid-susceptible functional groups. In most of the cases the yields obtained were excellent. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
SmI2-promoted chemistry at the anomeric center of carbohydrates. Reductive formation and reaction of glycosyl samarium (III) reagents
Pouilly, P. de,Chenede, A.,Mallet, J.-M.,Sinay, P.
, p. 256 - 265 (2007/10/02)
Reaction of 3,4,6-tri-O-benzyl-2-deoxy-α-D-arabino-hexopyranosyl chloride at room temperature with the efficient single electron transfer system of SmI2-THF-HMPA, in the presence of cyclopentanone (Barbier conditions) gave selectively the corresponding α-C-glycoside in 70percent yield.It is postulated that the reactive transient intermediate is a chiral anomeric organosamarium (III) species.Lower yields were obtained in the presence of aldehydes, such as n-butanal or isobutanal.It is also demonstrated that glycosyl phenyl sulfones undergo reductive samariation. 2,3,4,6-Tetra-O-benzyl-β-D-glucopyranosyl phenyl sulfone reacted with cyclopentanone, in the presence of SmI2-THF-HMPA, to give the corresponding β-C-glycoside selectively in 25percent yield, together with the elimination product (40percent).When the protecting group at C-2 was an acetate, a very fast β-elimination of the organosamarium intermediate occurred to give a practically quantitative yield of a substituted glycal.This work constitutes the first application of samarium(II) iodide to the reductive metallation of the anomeric center of carbohydrates.Key words: samarium diiodide / sulfones / carbohydrates / glycals / C-glycosides
