74256-83-0

Upstream product

• 100-02-7 4-nitro-phenol 
• 6564-72-3 2,3,4,6-tetra-O-benzyl-D-glucopyranose 
• 126709-14-6 1-Azi-2,3,4,6-tetra-O-benzyl-1-deoxy-D-glucopyranose 
• 90357-89-4 2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl trichloroacetimidate 
• 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 
• 47005-14-1 4.4'-Dinitro-diphenyliodoniumhydroxid 
• 74808-09-6 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl trichloroacetimidate 
• 24067-17-2 4-nitrophenylboronic acid 
• 905718-45-8 [(4-nitrophenyl)(phenyl)iodonium trifluoromethanesulfonate] 
• 636-98-6 p-nitrobenzene iodide 
• 4196-35-4 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl bromide 

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

Copper-mediated O-arylation of lactols with aryl boronic acids

An efficient and novel methodology to access phenolic glycosides has been established by using copper-mediated coupling reaction of aryl boronic acids with hemiacetals. The reaction takes place normally in the presence of Cu(OAc)2 (1.0 equiv.) and pyridine (2.0 equiv.) at 40 °C. This protocol distinguishes itself by wide substrate scope, operational simplicity and giving rise to a myriad of phenolic glycosides in good to excellent yields.

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.

Efficient O-Functionalization of Carbohydrates with Electrophilic Reagents

Novel methodology for O-functionalization of carbohydrate derivatives has been established using bench-stable and easily prepared iodonium(III) reagents. Both electron-withdrawing and electron-donating aryl groups were introduced under ambient conditions and without precautions to exclude air or moisture. Furthermore, the approach was extended both to full arylation of cyclodextrin, and to trifluoroethylation of carbohydrate derivatives. This is the first general approach to introduce traditionally non-electrophilic groups into any of the OH groups around the sugar backbone. The methodology will be useful both in synthetic organic chemistry and biochemistry, as important functional groups can be incorporated under simple and robust reaction conditions in a fast and efficient manner.

Application of silver N-heterocyclic carbene complexes in O-glycosidation reactions

We report the efficient O-glycosidation of glycosyl bromides with therapeutically relevant acceptors facilitated by silver N-heterocyclic carbene (Ag-NHC) complexes. A set of four Ag-NHC complexes was synthesized and evaluated as promoters for glycosidation reactions. Two new bis-Ag-NHC complexes derived from ionic liquids 1-benzyl-3-methyl-1H-imidazolium chloride and 1-(2-methoxyethyl)-3-methylimidazolium chloride were found to efficiently promote glycosidation, whereas known mono-Ag complexes of 1,3-bis(2,4,6- trimethylphenyl)imidazolium chloride and 1,3-bis(2,6-di-isopropylphenyl) imidazolium chloride failed to facilitate the reaction. The structures of the promoters were established by X-ray crystallography and these complexes were employed in the glycosidation of different glycosyl bromide donors with biologically valuable acceptors, such as estrone, estradiol, and various flavones. The products were obtained in yields considered good to excellent, and all reactions were highly selective for the β isomer regardless of neighboring group effects.

O-Glycoside Synthesis under Neutral Conditions in Concentrated Solutions of LiClO4 in Organic Solvents Employing Benzyl-Protected Glycosyl Donors

The benzyl-protectd glucosyl trichloroacetimidates, phosphates, and halides 1 are activated under neutral conditions and without the addition of any further promoter in 1 M solutions of LiCl4 in ether, CH2Cl2, CHCl3, or CH3CN and react under these conditi

159. Glycosylidene Carbenes - Part 2 - Synthesis of O-Aryl Glycosides

Phenol, 4-methoxyphenol, 4-nitrophenol, methyl orsellinate (1), and 2,6-di(tert-butyl)-4-methylphenol (BHT; 2) have been glycosylated by thermal reaction (20-60 deg C) with various glycosylidene-derived diazirines. 4-Methoxyphenol reacted with the D-gluco

α-Glucosylation of Phenols with Tetra-O-benzyl-α-D-glucose

An α-glucosylation of phenols with 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose is described.This uses a mixture of p-nitobenzenesulfonyl chloride, silver trifluoromethanesulfonate and triethylamine in dichloromethane in a two-stage treatment.