77667-56-2

Upstream product

• 126786-18-3 1-azi-2,3,4,6-tetra-O-benzyl-1-deoxy-D-mannopyranose 
• 108-95-2 phenol 
• 3262-89-3 triphenylboroxine 
• 4132-28-9 2,3,4,6-tetra-O-benzyl-D-mannopyranose 
• 92470-93-4 (2R,3R,4S,5S,6R)-3,4,5-tris(benzyloxy)-2-((benzyloxy)methyl)-6-chlorotetrahydro-2H-pyran 
• 139212-74-1 N-sodio-N'-(2,3,4,6-tetra-O-benzyl-D-glucopyranosylidene)-4-toluenesulfonohydrazidate 
• 100-39-0 benzyl bromide 
• 4630-62-0 phenyl-α-D-glucopyranoside 
• 6564-72-3 2,3,4,6-tetra-O-benzyl-D-glucopyranose 
• 89025-46-7 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl fluoride 
• 126709-14-6 1-Azi-2,3,4,6-tetra-O-benzyl-1-deoxy-D-glucopyranose 
• 126709-11-3 1,5-anhydro-2,3,4,6-tetra-O-benzyl-1-hydrazi-D-glucitol 
• 4291-69-4 2,3,4,6-Tetra-O-benzyl-D-glucopyranose 
• 80300-30-7 1-O-acetyl-2,3,4,6-tetra-O-benzyl-D-glucopyranose 

Relevant academic research and scientific papers

Stereoselective O-Glycosylations by Pyrylium Salt Organocatalysis**

Despite many years of invention, the field of carbohydrate chemistry remains rather inaccessible to non-specialists, which limits the scientific impact and reach of the discoveries made in the field. Aiming to increase the availability of stereoselective

Metal-free glycosylation with glycosyl fluorides in liquid SO2

Liquid SO2 is a polar solvent that dissolves both covalent and ionic compounds. Sulfur dioxide possesses also Lewis acid properties, including the ability to covalently bind Lewis basic fluoride ions in a relatively stable fluorosulfite anion (FSO2?). Herein we report the application of liquid SO2 as a promoting solvent for glycosylation with glycosyl fluorides without any external additive. By using various temperature regimes, the method is applied for both armed and disarmed glucose and mannose-derived glycosyl fluorides in moderate to excellent yields. A series of pivaloyl-protected O- and S-mannosides, as well as one example of a C-mannoside, are synthesized to demonstrate the scope of the glycosyl acceptors. The formation of the fluorosulfite species during the glycosylation with glycosyl fluorides in liquid SO2 is proved by 19F NMR spectroscopy. A sulfur dioxide-assisted glycosylation mechanism that proceeds via solvent separated ion pairs is proposed, whereas the observed α,β-selectivity is substrate-controlled and depends on the thermodynamic equilibrium.

Stereoselective β-mannosylations and β-rhamnosylations from glycosyl hemiacetals mediated by lithium iodide

Stereoselective β-mannosylation is one of the most challenging problems in the synthesis of oligosaccharides. Herein, a highly selective synthesis of β-mannosides and β-rhamnosides from glycosyl hemi-acetals is reported, following a one-pot chlorination,

Copper-mediated anomeric: O -arylation with organoboron reagents

Copper-mediated couplings of arylboroxines with glycosyl hemiacetals furnish O-aryl glycosides via Csp2-O bond formation. The method enables the anomeric O-arylation of protected pyranose and furanose derivatives, and is tolerant of functionalized arylboroxine partners. Whereas mixtures of anomers are formed from glucopyranose, galactopyranose and arabinofuranose hemiacetals, the α-anomer is generated selectively from mannopyranose and mannofuranose-derived substrates.

Copper-Catalyzed Anomeric O-Arylation of Carbohydrate Derivatives at Room Temperature

Direct and practical anomeric O-arylation of sugar lactols with substituted arylboronic acids has been established. Using copper catalysis at room temperature under an air atmosphere, the protocol proved to be general, and a variety of aryl O-glycosides have been prepared in good to excellent yields. Furthermore, this approach was extended successfully to unprotected carbohydrates, including α-mannose, and it was demonstrated here how the interaction between carbohydrates and boronic acids can be combined with copper catalysis to achieve selective anomeric O-arylation.

Reengineering Chemical Glycosylation: Direct, Metal-Free Anomeric O-Arylation of Unactivated Carbohydrates

To sustain innovation in glycobiology, effective routes to well-defined carbohydrate probes must be developed. For over a century, glycosylation has been dominated by the formation of the anomeric Csp3?O acetal junction in glycostructures. A dissociative mechanistic spectrum spanning SN1 and SN2 is frequently operational thereby reducing the efficiency. By reengineering this fundamental process, an orthogonal disconnection allows the acetal to be formed directly from the reducing sugar without the need for substrate pre-functionalisation. The use of stable aryliodonium salts facilitates a formal O?H functionalisation reaction. This allows lactols to undergo mild, metal-free O-arylation at ambient temperature. The efficiency of the transformation has been validated using a variety of pyranoside and furanoside monosaccharides in addition to biologically relevant di- and trisaccharides (up to 85 %). Fluorinated mechanistic probes that augment the anomeric effect were employed. It is envisaged that this strategy will prove expansive for the construction of complex acetals under substrate-based stereocontrol.

Synthesis of Phenolic Glycosides: Glycosylation of Sugar Lactols with Aryl Bromides via Dual Photoredox/Ni Catalysis

Multifarious sugar lactols were efficiently transformed into the corresponding phenolic glycosides by treating with aryl bromides in acetonitrile with Ir[dF(CF3)ppy]2(dtbbpy)(PF6) as a photocatalyst under visible light irr

Dehydrative glycosylation with cyclic phosphonium anhydrides

Cyclic phosphonium anhydrides generated from bis-phosphine oxides and trifluoromethanesulfonic anhydride are shown as general coupling reagents in a dehydrative glycosylation reaction of C1-hemiacetals. This reaction protocol is characterized by a broad substrate scope and high yields, including reactions of O-, C-, N-, and S-based nucleophiles with furanose, pyranose, and deoxysugar donors.

Gold(III) Chloride and Phenylacetylene: A Catalyst System for the Ferrier Rearrangement, and O-Glycosylation of 1-O-Acetyl Sugars as Glycosyl Donors

We have developed a new catalyst system comprising AuCl3 and phenylacetylene that promotes the Ferrier rearrangement of glycals and 2-acetoxymethylglycals with different nucleophiles, and also the O-glycosylation of 1-O-acetyl sugars to obtain a variety of useful glycosides at room temperature through relay catalysis. Good anomeric selectivity was observed for the Ferrier rearrangements, whereas the O-glycosylation of 1-O-acetyl sugars gave mixtures of diastereomers with moderate to excellent selectivity.

Formation of O-glycosidic linkages from 1-hydroxy sugars by bismuth(III) triflate-catalyzed dehydrative glycosidation

This paper describes the direct formation of various O-glycosidic linkages from 1-hydroxy sugars by bismuth(III) triflate-catalyzed dehydrative glycosidation. The condensation reactions of 1 -hydroxy sugars with some primary alcohols in the presence of on