62771-95-3

Upstream product

• 104-81-4 4-Methylbenzyl bromide 
• 352310-78-2 3,4,5,7,-tetra-O-acetyl-2,6-anhydro-D-glycero-L-manno-heptose tosylhydrazone 
• 706784-62-5 5-(2',3',4',6'-tetra-O-benzoyl-β-D-glucopyranosyl)tetrazole 
• 18039-42-4 5-phenyl-2H-1,2,3,4-tetrazole 
• 104-92-7 1-bromo-4-methoxy-benzene 
• 108-86-1 bromobenzene 

Relevant academic research and scientific papers

Coupling ofN-tosylhydrazones with tetrazoles: synthesis of 2-β-d-glycopyranosylmethyl-5-substituted-2H-tetrazole type glycomimetics

Coupling reactions ofO-peracylated 2,6-anhydro-aldose tosylhydrazones (C-(β-d-glycopyranosyl)formaldehyde tosylhydrazones) with tetrazoles were studied under metal-free conditions using thermic or microwave activation in the presence of different bases. The reactions proved highly regioselective and gave the corresponding, up-to-now unknown 2-β-d-glycopyranosylmethyl-2H-tetrazoles in 7-67% yields. The method can be applied to get new types of disaccharide mimetics, 5-glycosyl-2-glycopyranosylmethyl-2H-tetrazoles, as well. Galectin binding studies withC-(β-d-galactopyranosyl)formaldehyde tosylhydrazone and 2-(β-d-galactopyranosylmethyl)-5-phenyl-2H-tetrazole revealed no significant inhibition of any of these lectins.

C-Glycosyl Styrene Type Compounds by Pd-Catalyzed Cross-Coupling Reactions of Anhydro-Aldose Tosylhydrazones with Benzyl Bromides

C-Glycopyranosyl styrene type compounds are valuable synthetic intermediates whose syntheses are known in rather lengthy procedures. Herein palladium-catalyzed cross-couplings of O-peracylated 2,6-anhydro-aldose tosylhydrazones with benzyl bromides were studied under thermic conditions in the presence of LiOtBu. The reactions gave the corresponding C-glycopyranosyl styrenes in up to 59% yields. The transformations represent a new, short synthetic sequence to get this type of glycomimetic compounds in 4–5 steps from a free aldose. (Figure presented.).

Pd-catalyzed coupling reactions of anhydro-aldose tosylhydrazones with aryl bromides to produce substituted exo-glycals

Palladium-catalyzed cross-couplings of O-peracylated and O-permethylated 2,6-anhydro-aldose tosylhydrazones with aryl halides were studied under thermic conditions in the presence of LiOtBu and phosphine ligands. The reactions gave the corresponding aryl substituted exo-glycals as mixtures of diastereomers in 11–75% yields. The transformations represent a new access to these types of glycomimetic compounds. The double bond of some aryl substituted exo-glycals was saturated to give good yields of benzylic C-glycosyl derivatives.

C-Glycosylmethylene carbenes: Synthesis of anhydro-aldose tosylhydrazones as precursors; generation and a new synthetic route to exo-glycals

Acylated anhydro-aldononitriles (glycosyl cyanides) were transformed into anhydro-aldose tosylhydrazones by Raney-nickel reduction in the presence of tosylhydrazine in a one-pot reaction. The configuration of the C=N double bond in these hydrazones was E as proven by 15N-1H coupling constants as well as X-ray crystallography. Thermolysis in refluxing 1,4-dioxane of the sodium salts of the tosylhydrazones obtained by sodium hydride (generally 10 eq.) resulted in the formation of anhydro-1-deoxy-ald-1-enitols (exo-glycals). "Dimeric" N-glycosyl-methyl anhydro-aldose tosylhydrazones could also be isolated when the use of less base caused incomplete deprotonation of the starting compounds. This two-step procedure constitutes a novel, reasonably short synthetic pathway to acylated exo-glycals from the readily available glycosyl cyanides.