950664-79-6

Upstream product

• 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 
• 358-23-6 trifluoromethylsulfonic anhydride 
• 2923-28-6 silver trifluoromethanesulfonate 
• 1493-13-6 trifluorormethanesulfonic acid 
• 942043-17-6 4-methylphenyl 2,3,4,6-tetrakis-O-trimethylsilyl-1-thio-β-D-glucopyranoside 

Downstream Products

• 1393742-44-3 2-propyl 4,6-O-benzylidene-2,3-di-O-methyl-β-D-glucopyranoside 
• 1393742-43-2 2-propyl 4,6-O-benzylidene-2,3-di-O-methyl-α-D-glucopyranoside 

Relevant academic research and scientific papers

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.

Dissecting the mechanisms of a class of chemical glycosylation using primary 13C kinetic isotope effects

Although arguably the most important reaction in glycoscience, chemical glycosylations are among the least well understood of organic chemical reactions, resulting in an unnecessarily high degree of empiricism and a brake on rational development in this critical area. To address this problem, primary 13C kinetic isotope effects have now been determined for the formation of β- and α-manno- and glucopyranosides using a natural abundance NMR method. In contrast to the common current assumption, for three of the four cases studied the experimental and computed values are indicative of associative displacement of the intermediate covalent glycosyl trifluoromethanesulfonates. For the formation of the α-mannopyranosides, the experimentally determined KIE differs significantly from that computed for an associative displacement, which is strongly suggestive of a dissociative mechanism that approaches the intermediacy of a glycosyl oxocarbenium ion. The application of analogous experiments to other glycosylation systems should shed further light on their mechanisms and thus assist in the design of better reactions conditions with improved stereoselectivity.