128503-40-2

Upstream product

• 14218-11-2 2,3,4,6-Tetra-O-benzoyl-α-D-mannopyranosyl bromide 
• 19488-48-3 methyl O-2,3,6-tri-O-benzyl-α-D-glucopyranoside 
• 627466-98-2 2,3,4,6-tetra-O-benzoyl-α,β-D-mannospyranose 
• 166241-68-5 ethyl 2,3,4,6-tetra-O-benzoyl-1-thio-α-D-mannopyranoside 
• 1521271-28-2 3,3-difluoro-3H-indol-2-yl 2,3,4,6-tetra-O-benzoyl-α-D-mannopyranoside 
• 934492-05-4 2,3,4,6-tetra-O-benzoyl-α,b-D-mannopyranosyl trichloroacetimidate 
• 14262-87-4 2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl chloride 
• 439-01-0 2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl fluoride 
• 920749-11-7 tetrabenzoyl mannosyl pentenate 
• 125367-09-1 n-pent-4-enyl 2,3,4,6-tetra-O-benzoyl-α-D-mannopyranoside 

Relevant academic research and scientific papers

Revisiting Glycosylations Using Glycosyl Fluoride by BF3·Et2O: Activation of Disarmed Glycosyl Fluorides with High Catalytic Turnover

Catalytic glycosylations with glycosyl fluorides using BF3·Et2O are presented. Glycosylations with both armed and disarmed donors were efficiently catalyzed by 1 mol% of BF3·Et2O in a nitrogen-filled glovebox without the use of dehydrating agents. Our finding is in sharp contrast with conventional BF3·Et2O-mediated glycosylations, where excess Lewis acid and additives are required. Mechanistic studies indicated that the chemical species formed by the reaction of in situ generated HF and glass vessels are involved in the catalytic cycle.

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

Koenigs–Knorr Glycosylation Reaction Catalyzed by Trimethylsilyl Trifluoromethanesulfonate

The discovery that traditional silver(I)-oxide-promoted glycosidations of glycosyl bromides (Koenigs–Knorr reaction) can be greatly accelerated in the presence of catalytic trimethylsilyl trifluoromethanesulfonate (TMSOTf) is reported. The reaction conditions are very mild that allowed for maintaining a practically neutral pH and, at the same time, providing high rates and excellent glycosylation yields. In addition, unusual reactivity trends among a series of differentially protected glycosyl bromides were documented. In particular, benzoylated α-bromides were much more reactive than their benzylated counterparts under these conditions.

Gold(I)-Catalyzed Glycosylation with Glycosyl Ynenoates as Donors

A simple and versatile glycosylation method with both armed and disarmed glycosyl ynenoates as donors is developed. Employing a gold(I) complex as catalyst with or without the assistance of TfOH, the scope of the present glycosylation protocol is very wid

Regenerative Glycosylation

Previously, we communicated 3,3-difluoroxindole (HOFox)-mediated glycosylations wherein 3,3-difluoro-3H-indol-2-yl (OFox) imidates were found to be key intermediates. Both the in situ synthesis from the corresponding glycosyl bromides and activation of the OFox imidates could be conducted in a regenerative fashion. Herein, we extend this study to the synthesis of various glycosidic linkages using different sugar series. The main outcome of this study relates to enhanced yields and/or reduced reaction times of glycosylations. The effect of HOFox-mediated reactions is particularly pronounced in case of unreactive glycosyl donors and/or glycosyl acceptors. A multistep regenerative synthesis of oligosaccharides is also reported.

Investigation of Glycosyl Nitrates as Building Blocks for Chemical Glycosylation

Glycosyl nitrates are important synthetic intermediates in the synthesis of 2-amino sugars, 1,2-orthoesters or, more recently, 2-OH glucose. However, glycosyl nitrates have never been glycosidated. Presented herein is our first attempt to use glycosyl nitrates as glycosyl donors for O-glycosylation. Lanthanide triflates showed good affinity to activate the nitrate leaving group.

O-Glycosylation Enabled by N-(Glycosyloxy)acetamides

A novel glycosylation protocol has been established by using N-(glycosyloxy)acetamides as glycosyl donors. The N-oxyacetamide leaving group in donors could be rapidly activated in the presence of Cu(OTf)2 or SnCl4 under microwave irr

Radical halogenation-mediated latent-active glycosylations of allyl glycosides

Radical halogenation-mediated glycosylation using allyl glycosides as donors and as acceptors emerges to be an efficient and hither-to unknown glycosylation method, adhering to the concept of the latent-active methodology. Several di- and trisaccharides that possess the allyl moiety at their reducing end are prepared through this new glycosylation methodology.

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.

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.