203740-95-8

Upstream product

• 74666-83-4 1-deoxy-1-(S-ethyl)-2,3,4,6-tetra-O-benzyl-β-D-glucopyranoside 
• 76375-66-1 methyl 2-O-benzyl-4,6-O-benzylidene-α-D-glucopyranoside 
• 810670-73-6 benzoxazol-2-yl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside 
• 38184-10-0 phenyl 2,3,4,5-tetra-O-benzyl-1-thio-β-D-glucopyranoside 
• 90357-89-4 2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl trichloroacetimidate 
• 83-87-4 D-glucose pentaacetate 
• 28244-94-2 p-tolyl-2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranoside 
• 78153-79-4 2,3,4,6-tetra-O-benzyl-D-glucopyranosyl fluoride 
• 3162-96-7 4,6-O-benzylidene-1-O-methyl-α-D-glucopyranoside 
• 100-39-0 benzyl bromide 
• 28244-94-2 4-methylphenyl 2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside 
• 1152-39-2 p-methylphenyl 1-thio-β-D-glucopyranoside 
• 4291-69-4 2,3,4,6-Tetra-O-benzyl-D-glucopyranose 
• 74666-83-4 ethyl 2-O-benzoyl-3,4,6-tri-O-benzyl-1-thio-α-D-glucopyranoside 

Relevant academic research and scientific papers

Ferrocenium complex aided: O-glycosylation of glycosyl halides

A new strategy for the activation of glycosyl halide donors to be utilized in glycosylation reactions is presented, utilizing the ferrocenium (Fc) complexes [FcB(OH)2]SbF6 and FcBF4 as promoters. The scope of the new system has been investigated using glycosyl chloride and glycosyl fluoride donors in combination with common glycosyl acceptors, such as protected glucose. The corresponding glycosylation products were formed in 95 to 10% isolated yields with α/β ratios ranging from 1/1 to β only (2 to 14 h reaction time at room temperature, 40 to 100% ferrocenium promoter load). This journal is

Automated Quantification of Hydroxyl Reactivities: Prediction of Glycosylation Reactions

The stereoselectivity and yield in glycosylation reactions are paramount but unpredictable. We have developed a database of acceptor nucleophilic constants (Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure high reproducibility and accuracy. A diverse range of glycosylation donors and acceptors with well-defined reactivity and promoters were organized and processed by the designed software program “GlycoComputer” for prediction of glycosylation reactions without involving sophisticated computational processing. The importance of Aka was further verified by random forest algorithm, and the applicability was tested by the synthesis of a Lewis A skeleton to show that the stereoselectivity and yield can be accurately estimated.

Photo-induced glycosylation using a diaryldisulfide as an organo-Lewis photoacid catalyst

Photo-induced glycosylations of several acceptors with trichloroacetimidate donors using bis(2-naphthyl)disulfide as an organo-Lewis photoacid (LPA) catalyst proceeded effectively to give the corresponding glycosides in good to high yields. In addition, t

Establishment of Guidelines for the Control of Glycosylation Reactions and Intermediates by Quantitative Assessment of Reactivity

Stereocontrolled chemical glycosylation remains a major challenge despite vast efforts reported over many decades and so far still mainly relies on trial and error. Now it is shown that the relative reactivity value (RRV) of thioglycosides is an indicator for revealing stereoselectivities according to four types of acceptors. Mechanistic studies show that the reaction is dominated by two distinct intermediates: glycosyl triflates and glycosyl halides from N-halosuccinimide (NXS)/TfOH. The formation of glycosyl halide is highly correlated with the production of α-glycoside. These findings enable glycosylation reactions to be foreseen by using RRVs as an α/β-selectivity indicator and guidelines and rules to be developed for stereocontrolled glycosylation.

Matching Glycosyl Donor Reactivity to Sulfonate Leaving Group Ability Permits SN2 Glycosylations

Here we demonstrate that highly β-selective glycosylation reactions can be achieved when the electronics of a sulfonyl chloride activator and the reactivity of a glycosyl donor hemiacetal are matched. While these reactions are compatible with the acid- and base-sensitive protecting groups that are commonly used in oligosaccharide synthesis, these protecting groups are not relied upon to control selectivity. Instead, β-selectivity arises from the stereoinversion of an α-glycosyl arylsulfonate in an SN2-like mechanism. Our mechanistic proposal is supported by NMR studies, kinetic isotope effect (KIE) measurements, and DFT calculations.

N-Trifluoromethylthiosaccharin/TMSOTf: A New Mild Promoter System for Thioglycoside Activation

For the first time, N-trifluoromethylthiosaccharin was used to activate thioglycosides in the presence of catalytic amounts of TMSOTf. The results show that the activated thioglycosides undergo glycosidation reactions with various glycosyl acceptors to gi

Glycosylation with 3,5-Dimethyl-4-(2′-phenylethynylphenyl)phenyl (EPP) Glycosides via a Dearomative Activation Mechanism

A highly effective and versatile glycosylation method is developed, which uses 3,5-dimethyl-4-(2′-phenylethynylphenyl)phenyl (EPP) glycosides as donors and NIS/TMSOTf as promoter and proceeds via an unprecedented dearomative activation mechanism.

A versatile glycosylation strategy: Via Au(III) catalyzed activation of thioglycoside donors

Among various methods of chemical glycosylations, glycosylation by activation of thioglycoside donors using a thiophilic promoter is an important strategy. Many promoters have been developed for the activation of thioglycosides. However, incompatibility w

Aryl(trifluoroethyl)iodonium Triflimide and Nitrile Solvent Systems: A? Combination for the Stereoselective Synthesis of Armed 1,2-trans-β-Glycosides at Noncryogenic Temperatures

Armed thioglycosides can be activated with aryl(trifluoroethyl)iodonium triflimide in 2:1 CH2Cl2/pivalonitrile or a solvent combination of CH2Cl2, acetonitrile, isobutyronitrile, and pivalonitrile (6:1:1:1) at 0

Polyvinyl trisulfonate ethylamine based solid acid catalyst for the efficient glycosylation of sugars under solvent free conditions

Heterogeneous Bronsted solid acid catalysts have the potential to decrease the environmental impact related to chemical production. Herein, we have synthesized polyvinyl bound trisulfonate ethylamine chloride (PV-THEAC) and polyvinyl bound disulfonate ethylamine (PV-DSEA) as Bronsted solid acid catalysts which exhibited effective catalytic activity for acid catalyzed glycosylation reactions with sugar derivatives. In particular, 0.3 equiv. of the PV-THEAC catalyst was found to be the most efficient and a reusable catalyst for glycosylation reactions. A high density of the trisulfonic group (-OSO3H) contributed to the excellent catalytic activity during glycosylation. Moreover, glycosylation reactions with d-mannose, d-xylose and d-glucose have been studied with alcohol. Remarkable acceleration of the glycosylation reaction using a glycosyltrichloroacetimidate donor was obtained with the selective production of β-glycoside.