6983-35-3Relevant academic research and scientific papers
Photoinitiated glycosylation at 350 nm
Cumpstey, Ian,Crich, David
experimental part, p. 469 - 485 (2012/06/15)
A method for photochemical activation of glycosyl donors is presented. Selenoglycosides were activated by single-electron transfer using a photooxidant, N-methylquinolinium hexafluorophosphate, as photosensitizer and a toluene cosolvent as cosensitizer under irradiation at 350 nm. In this way we were able to synthesize glycosides including (1→6)-linked disaccharides. Benzyl ethers and benzoate esters were compatible with these conditions, allowing potentially synthetically useful transformations. The major by-products were due to hydrolysis; the reactions required the presence of oxygen and were run in air.
Traceless Staudinger ligation of glycosyl azides with triaryl phosphines: Stereoselective synthesis of glycosyl amides
Bianchi, Aldo,Bernardi, Anna
, p. 4565 - 4577 (2007/10/03)
α-Glycosyl amides can be synthesized from the corresponding O-benzyl-α-glycosyl azides using a traceless Staudinger ligation with diphenylphosphanyl-phenyl esters 4. All the phosphines employed and their phenol precursors are stable to air at 4 °C for months. Fast intramolecular trapping of the reduction intermediates results in the direct formation of the amide link, which, in turn, prevents epimerisation and allows retention of configuration at the anomeric carbon. Yields and α-selectivity are high when the reaction is performed in polar aprotic solvents. Removal of the benzyl ether protecting groups is achieved by catalytic hydrogenation. α-Glycosyl amides represent a class of virtually unexplored nonhydrolyzable monosaccharide derivatives that may find a useful application as sugar mimics. Conformational studies by NMR spectroscopy confirm that deprotected α-glycosyl amides in the gluco, galacto, and fuco series retain the normal pyranose conformation of the monosaccharide. The reaction of phosphines 4 with tetra-O-acetyl-glycosyl azides is nonstereoconservative, and β-glycosyl amides are obtained in good yields and with complete stereoselectivity starting from both α and β azides.
β-Galactosidase catalysed transglycosylation in aqueous organic media using glycosylasparagine mimics as novel acceptors
Priya, Kuttikode,Loganathan, Duraikkannu
, p. 1119 - 1128 (2007/10/03)
β-1-N-acetamido-D-glucopyranose (2), a model of N-glycoprotein linkage region, and its benzamido analogue were explored as novel acceptors in transglycosylation catalysed by β-galactosidase from Bacillus circulans. Acceptor ability of 2 was shown to be as good as or better than several O- glycosides employed earlier. Systematic variation of reaction conditions led to improvement of yield from 5 % to 41 %. Interestingly, use of aqueous organic media has led to increased yield of transglycosylation and the 1,3- linked disaccharide was formed in considerable amounts under all the conditions examined.
