64495-82-5

Upstream product

• 7559-62-8 S-benzyl methanethiosulfonate 
• 572-09-8 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide 
• 16601-02-8 S-benzyl 4-methylbenzenethiosulfonate 
• 16601-01-7 benzenethiosulfonic acid S-benzyl ester 
• 1394124-53-8 S-benzyl 4-fluorobenzenesulfonothioate 
• 14204-26-3 N-(benzylthio)phthalimide 
• 100-53-8 phenylmethanethiol 
• 3366-47-0 2,3,4,6-tetra-O-acetyl-1,5-anhydro-D-arabinohex-1-enopyranose 
• 604-68-2 α-D-glucopyranose peracetylate 

Relevant academic research and scientific papers

Direct, stereoselective thioglycosylation enabled by an organophotoredox radical strategy

While strategies involving a 2e- transfer pathway have dictated glycosylation development, the direct glycosylation of readily accessible glycosyl donors as radical precursors is particularly appealing because of high radical anomeric selectivity and atom- and step-economy. However, the development of the radical process has been challenging owing to notorious competing reduction, elimination and/or SN side reactions of commonly used, labile glycosyl donors. Here we introduce an organophotocatalytic strategy through which glycosyl bromides can be efficiently converted into corresponding anomeric radicals by photoredox mediated HAT catalysis without a transition metal or a directing group and achieve highly anomeric selectivity. The power of this platform has been demonstrated by the mild reaction conditions enabling the synthesis of challenging α-1,2-cis-thioglycosides, the tolerance of various functional groups and the broad substrate scope for both common pentoses and hexoses. Furthermore, this general approach is compatible with both sp2 and sp3 sulfur electrophiles and late-stage glycodiversification for a total of 50 substrates probed.

Systematic study on free radical hydrothiolation of unsaturated monosaccharide derivatives with exo- and endocyclic double bonds

Exo- and endocyclic double bonds of glycals and terminal double bonds of enoses were reacted with various thiols by irradiation with UV light in the presence of a cleavable photoinitiator. The photoinduced radical-mediated hydrothiolation reactions showed highly varying overall conversions depending not only on the substitution pattern and electron-density of the double bond but also on the nature and substitution pattern of the thiol partner. Out of the applied thiols thiophenol, producing the highly stabilized thiyl radical, exhibited the lowest reactivity toward each type of alkene. In most cases, the hydrothiolations took place with full regio- and stereoselectivities. Successful addition of 1,2:3,4-di-O-isopropylidene-6-thio-α-d-galactopyranose to a 2,3-unsaturated N-acetylneuraminic acid derivative, providing a (3 → 6)-S-linked pseudodisaccharide, demonstrated that the endocyclic double bond of Neu5Ac-2-ene, bearing an electron-withdrawing substituent, shows sufficient reactivity in the photoinduced thiol-ene coupling reaction.

A new route to exo-glycals using the Ramberg-Baecklund rearrangement

A new route to exo-glycals 4 is described in which glycosyl sulfones 3 are subjected to the Meyers variant of the Ramberg-Baecklund rearrangement. The conversion of sulfones derived from glucose, galactose, mannose, cellobiose, and ribose into di-, tri-, and tetra-substituted alkenes is reported. Preliminary mechanistic studies of this process are also described. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.