608124-97-6Relevant academic research and scientific papers
A highly stereoselective construction of 1,2-trans-β-glycosidic linkages capitalizing on 2-azido-2-deoxy-D-glycosyl diphenyl phosphates as glycosyl donors
Tsuda, Toshifumi,Nakamura, Seiichi,Hashimoto, Shunichi
, p. 10711 - 10737 (2004)
The scope of TMSOTf-promoted glycosidation of 2-azido-2-deoxyglycopyranosyl diphenyl phosphates is investigated. The 3,4,6-tri-O-benzyl-protected glucosyl and galactosyl donors and the 4,6-O-benzylidene-protected galactosyl donor each react with a range of acceptor alcohols in the presence of a stoichiometric amount of TMSOTf in propionitrile at -78°C to afford 1,2-trans-β-linked disaccharides in high yields with α:β ratios ranging from 9:91 to 1:>99, regardless of the anomeric composition of the donor used. The use of propionitrile as a solvent at -78°C has proven to be among the best choice for the highest levels of β-selectivity reported to date for this type of glycosidation. A plausible reaction mechanism, which features a large equilibrium preference for α-glycosyl-nitrilium ions over β-nitrilium ions, is proposed based on byproducts formed through their intermediacy and accounts for the observed excellent β-selectivities. Graphical Abstract.
A stereocontrolled construction of 2-azido-2-deoxy-1,2-trans-β-glycosidic linkages utilizing 2-azido-2-deoxyglycopyranosyl diphenyl phosphates
Tsuda, Toshifumi,Nakamura, Seiichi,Hashimoto, Shunichi
, p. 6453 - 6457 (2003)
A high-yielding and stereocontrolled construction of 2-azido-2-deoxy-1,2-trans-β-glycosidic linkages has been achieved by exploiting TMSOTf-promoted 1,2-trans-glycosidation of 2-azido-2-deoxyglycopyranosyl diphenyl phosphates with various glycoside alcohols in propionitrile at -78°C. The present method exhibits the highest levels of 1,2-trans-β-selectivity reported to date for this type of glycosidation.
