82805-17-2

Upstream product

• 19488-48-3 methyl O-2,3,6-tri-O-benzyl-α-D-glucopyranoside 
• 212119-72-7 Thiophosphoric acid O,O'-dimethyl ester O''-((2R,3S,4S,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-tetrahydro-pyran-2-yl) ester 
• 920749-10-6 tetrabenzyl mannosyl pentenoate 
• 38184-10-0 phenyl 2,3,4,6-tetra-O-benzyl-1-thio-α-D-mannopyranoside 
• 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 
• 100-39-0 benzyl bromide 
• 4291-68-3 1-chloro-2,3,4,6-tetra-O-benzyl-D-glucopyranoside 
• 19488-49-4 methyl 2,3,6-tri-O-benzyl-β-D-glucopyranoside 
• 6564-72-3 2,3,4,6-tetra-O-benzyl-D-glucopyranose 
• 68-12-2 N,N-dimethyl-formamide 
• 67-56-1 methanol 
• 100-44-7 benzyl chloride 
• 14227-66-8 acetobromocellobiose 

Relevant academic research and scientific papers

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.

α-Selective glycosylations using glycosyl: N-(ortho-methoxyphenyl)trifluoroacetimidates

Six N-(o-methoxyphenyl)trifluoroacetimidate glycosyl donors have been synthesized and their role as glycosyl donors has been investigated. The donors were synthesized with complete -selectivity, except in one case, and were found to be stable. When Bi(OTf

Catalytic and Atom-Economic Glycosylation using Glycosyl Formates and Cheap Metal Salts

Benzylated glycosyl formates have been synthesized in one step from the corresponding hemiacetal or orthoester with formic acid as the sole reagent. The glycosyl formates are used as glycosyl donors under catalytic conditions with cheap metal catalysts ba

A Highly Efficient Glycosidation of Glycosyl Chlorides by Using Cooperative Silver(I) Oxide–Triflic Acid Catalysis

Following our discovery that silver(I) oxide-promoted glycosylation with glycosyl bromides can be greatly accelerated in the presence of catalytic TMSOTf or TfOH, we report herein a new discovery that glycosyl chlorides are even more effective glycosyl do

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.

Iron(iii) chloride-catalyzed activation of glycosyl chlorides

Glycosyl chlorides have historically been activated using harsh conditions and/or toxic stoichiometric promoters. More recently, the Ye and the Jacobsen groups showed that glycosyl chlorides can be activated under organocatalytic conditions. However, thos

Nucleofuge Generating Glycosidations by the Remote Activation of Hydroxybenzotriazolyl Glycosides

Hydroxybenzotriazole is routinely used in peptide chemistry for reducing racemization due to the increased reactivity. In this article, very stable hydroxybenzotriazolyl glucosides were identified to undergo glycosidation. The reaction was hypothesized to go through the remote activation by the Tf2O at the N3-site of HOBt followed by the extrusion of the oxocarbenium ion that was attacked by the glycosyl acceptor. Further, equilibration of the zwitterionic benzotriazolyl species makes the leaving group noncompetitive and generates the nucleofuge that has been reconverted to the glycosyl donor. The reaction is mild, high yielding, fast and suitable for donors containing both C2-ethers and C2-esters as well. The regenerative-donor glycosidation strategy is promising as it enables us to regenerate the glycosyl donor for further utilization. The utility of the methodology for the oligosaccharide synthesis was demonstrated by the successful synthesis of the branched pentamannan core of the HIV1-gp120 complex.

Iron(iii) chloride modulated selective 1,2-trans glycosylation based on glycosyl trichloroacetimidate donors and its application in orthogonal glycosylation

The development of a new glycosylation method for efficient stereoselective synthesis of β-gluco- and galactosides from their corresponding armed trichloroacetimidate donors mediated by 10 mole% of FeCl3 has been focused. FeCl3 has a

Stereoselective Koenigs–Knorr Glycosylation Catalyzed by Urea

A stereoselective Koenigs–Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).

Stable Alkynyl Glycosyl Carbonates: Catalytic Anomeric Activation and Synthesis of a Tridecasaccharide Reminiscent of Mycobacterium tuberculosis Cell Wall Lipoarabinomannan

Oligosaccharide synthesis is still a challenging task despite the advent of modern glycosidation techniques. Herein, alkynyl glycosyl carbonates are shown to be stable glycosyl donors that can be activated catalytically by gold and silver salts at 25 °C in just 15 min to produce glycosides in excellent yields. Benzoyl glycosyl carbonate donors are solid compounds with a long shelf life. This operationally simple protocol was found to be highly efficient for the synthesis of nucleosides, amino acids, and phenolic and azido glycoconjugates. Repeated use of the carbonate glycosidation method enabled the highly convergent synthesis of tridecaarabinomannan in a rapid manner.