190515-39-0

Upstream product

• 34234-44-1 methyl 2,3,4-tri-O-benzoylglucopyranoside 
• 125411-99-6 ethyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside 
• 74801-29-9 phenyl-2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside 
• 6386-24-9 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 101966-50-1 2,3,4,6-tetrakis-O-(phenylmethyl)-β-D-galactopyranosyl fluoride 
• 139903-48-3 phenyl-2,3,4,6-tetra-O-benzyl-1-seleno-β-D-galactopyrannoside 
• 100-39-0 benzyl bromide 
• 4163-60-4 β-D-galactose peracetate 
• 101973-60-8 n-propyl-2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside 
• 69534-66-3 (5R)-5-acetoxy-1,2,3,4-tetra-O-acetyl-β-D-xylopyranose 
• 117307-18-3 phenyl (2,3,4,6-tetra-O-benzyl)-1-thio-β-D-galactopyranoside S-oxide 
• 358-23-6 trifluoromethylsulfonic anhydride 

Relevant academic research and scientific papers

Catalytic stereoselective synthesis of α-D-galactopyranosides from 2,3,4,6-tetra-O-benzyl-D-galactopyranose and several alcoholic nucleophiles

The glycosylation reaction of several alcoholic nucleophiles with 2,3,4,6-tetra-O-benzyl-D-galactopyranose (1-hydroxy sugar) is successfully carried out by the combined use of Sn(OTf)2-Me3SiCl catalyst system and lithium perchlorate, an effecti

Synthesis of the hyper-branched core tetrasaccharide motif of chloroviruses

Chemical synthesis of complex oligosaccharides, especially those possessing hyper-branched structures with one or multiple 1,2-cisglycosidic bonds, is a challenging task. Complementary reactivity of glycosyl donors and acceptors and proper tuning of the s

OFox imidates as versatile glycosyl donors for chemical 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

AuCl3-AgOTf promoted O-glycosylation using anomeric sulfoxides as glycosyl donors at room temperature

Activation of sulfoxide as glycosyl donors using AuCl3/AgOTf reagent system has been described. Under optimal reaction conditions, both armed and disarmed glycosyl sulfoxide donors were found to react with a range of primary, secondary, and tertiary alcohol acceptors, and sugar derived glycosyl acceptors to afford the corresponding glycosides in moderate to good yields with predictable selectivity. The reactions are quick (20–60 min), facile at room temperature and the reactions conditions tolerate acid sensitive groups.

Directing effect by remote electron-withdrawing protecting groups at O-3 or O-4 position of donors in glucosylations and galactosylations

Glucosylations and galactosylations of various acceptors with donors possessing an electron-withdrawing benzylsulfonyl, benzoyl, or acetyl group at the O-3 or O-4 position were performed. A β-directing effect by the benzylsulfonyl group at O-3 of the glucosyl donors and by the benzylsulfonyl and acyl groups at O-4 of the glucosyl donors was observed. In contrast, acyl groups at O-3 of the glucosyl donors and acyl groups at O-3 and O-4 of the galactosyl donors exhibited an α-directing effect. The α-directing effect is partly considered to remote participation of the acyl groups, whereas the β-directing effect is somewhat attributed to the SN2-like reaction of the acceptor with the glycosyl triflate or the contact ion pair, which is stabilized by remote electron-withdrawing groups. Further evidence for the stability of the α-glycosyl triflates was determined by a low-temperature NMR study.

Bismuth(V)-mediated thioglycoside activation

A straightforward method utilizing a bismuth(V) compound was developed for the activation of thiopropylglycosides for coupling to various acceptors; good to excellent yields were obtained without applying additional additives/co-promoters. The method does

Studies of S -But-3-ynyl and gem -dimethyl S -But-3-ynyl thioglycoside donors in gold-catalyzed glycosylations

Gold-catalyzed glycosylation using S-but-3-ynyl and gem-dimethyl S-but-3-ynyl thioglycoside donors has been investigated for the synthesis of various types of complex oligosaccharides. It was found that 2,2-dimethyl S-but-3-ynyl thioglycoside donors are m

Photoinitiated glycosylation at 350 nm

A method for photochemical activation of glycosyl donors is presented. Selenoglycosides were activated by single-electron transfer using a photooxidant, N-methylquinolinium hexafluorophosphate, as photosensitizer and a toluene cosolvent as cosensitizer under irradiation at 350 nm. In this way we were able to synthesize glycosides including (1→6)-linked disaccharides. Benzyl ethers and benzoate esters were compatible with these conditions, allowing potentially synthetically useful transformations. The major by-products were due to hydrolysis; the reactions required the presence of oxygen and were run in air.

Improved catalytic and stereoselective glycosylation with glycosyl N-trichloroacetylcarbamate: application to various 1-hydroxy sugars

Efficient catalytic and stereoselective glycosylation was achieved by activating a glycosyl N-trichloroacetylcarbamate with a catalytic amount of Lewis acid in the presence of a glycosyl acceptor and 5 ? molecular sieves. Catalytic one-pot dehydrative glycosylation of a 1-hydroxy carbohydrate was achieved stereoselectively by reaction with trichloroacetyl isocyanate, followed by activation with a catalytic amount of activators.

A catalytic and stereoselective glycosylation with β-glycosyl fluorides

A catalytic and stereoselective glycosylation of several glycosyl acceptors with β-D-glycosyl fluoride was successfully performed in the presence of a catalytic amount of trityl tetrakis(pentafluorophenyl)borate (TrB(C6F5)4/sub