Indium salts-catalyzed O and S-glycosylation of bromo sugar with benzyl glycolate: an unprecedented hydrogenolysis

Novel Glycosylation of Aromatic Amines Through 1, 2-Anhydrosugars

“…Glycosylation of β-lactam alcohols and other alcohols were studied by our group [1][2][3][4][5][6][7][8][9][10][11][12]. This was performed with iodine-catalyzed and indium metal-catalyzed reactions of alcohols and glycal or bromo sugar derivatives.…”

“…Acid-catalyzed glycosylation of alcohols and thiols is an attractive field of research. The nucleophilicity of alcohols and thiols is high enough to react with an anomeric center of a sugar system that has an alkene, hydroxy or halogen group [1][2][3][4][5][6][7][8][9][10][11][12]. It is necessary to activate the reactants by acidic catalysts.…”

Synthesis and Glycosidation of Anomeric Halides: Evolution from Early Studies to Modern Methods of the 21st Century

“…Indium chloride-catalyzed C -glycosylations of pyrrole and indoles were also described . In addition, various O - and S -glycosyl esters were synthesized by activation of glycosyl bromides with catalytic InCl 3 …”

Catalytic Glycosylations in Oligosaccharide Synthesis

“…Nishizawa and co-workers reported that the addition of an acid scavenger in a model reaction would increase the yield but lower the stereoselectivity. The Nishizawa group has done some in-depth work on thermal activation of glycosyl chlorides, which has also enabled glycosylations in the absence of a catalyst; however, there is still a need for an acid scavenger or molecular sieves. − Later, a modified version of the glycosylation was developed, but this relied on 22 equiv of an acid scavenger present, during glycosylations at rt. , Another possible way of keeping the reaction mixture somewhat neutral is by evaporating off the HCl or HBr formed during the reaction, since both are highly volatile gases …”

“…358,359 Another possible way of keeping the reaction mixture somewhat neutral is by evaporating off the HCl or HBr formed during the reaction, since both are highly volatile gases. 360 Recently, the use of thiourea-and urea-derived catalysts to activate glycosyl chlorides and glycosyl bromides has been reported. 361,362 Although these procedures still rely on the addition of an acid scavenger, these catalysts are good alternatives to the traditional use of metal salts and provide excellent stereoselectivity in glycosylations.…”