ChemInform Abstract: One‐Step Conversion of Unprotected Sugars to β‐Glycosyl Azides Using 2‐Chloroimidazolinium Salt in Aqueous Solution.

Tanaka, Tomonari; Nagai, Hikaru; Noguchi, Masato; Kobayashi, Atsushi; Shoda, Shin Ichiro

doi:10.1002/chin.200942190

Cited by 6 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…32 lower than those of the alcohol groups. 33 Selective anomeric Oalkylations, 34,35 O-acylations, 36 and nucleophilic displacement reactions 37,38 have been developed to take advantage of this property (e.g., 15 → 16, Scheme 4). Monosaccharides lacking a free anomeric hemiacetal, as well as nucleosides, have been shown to undergo selective reactions at the 2-position in the presence of a strong base (e.g., α-9 → 17a).…”

Section: Trends In the Relative Reactivity Of Hydroxyl Groups In Carb...mentioning

confidence: 99%

Site-Selective Functionalization of Hydroxyl Groups in Carbohydrate Derivatives

2018

View full text Add to dashboard Cite

Methods for site-selective transformations of hydroxyl groups in carbohydrate derivatives are reviewed. The construction of oligosaccharides of defined connectivity hinges on such transformations, which are also needed for the preparation of modified or non-natural sugar derivatives, the installation of naturally occurring postglycosylation modifications, the selective labeling or conjugation of carbohydrate derivatives, and the preparation of therapeutic agents or research tools for glycobiology. The review begins with a discussion of intrinsic factors and processes that can influence selectivity in reactions of unprotected or partially protected carbohydrate derivatives, followed by a description of transformations that engage two OH groups in cyclic adducts (acetals, ketals, boronic esters, and related species). An overview of the various classes of site-selective transformations of OH groups in sugars is then provided: the reactions discussed include esterification, thiocarbonylation, alkylation, glycosylation, arylation, silylation, phosphorylation, sulfonylation, sulfation, and oxidation. Emphasis is placed on recently developed methods that employ reagent or catalyst control to achieve otherwise challenging transformations or site-selectivities.

show abstract

Section: Trends In the Relative Reactivity Of Hydroxyl Groups In Carb...mentioning

confidence: 99%

Site-Selective Functionalization of Hydroxyl Groups in Carbohydrate Derivatives

2018

View full text Add to dashboard Cite

show abstract

“…We note that this process is complementary to the direct thioglycosylation of anomeric alcohols under the Shoda conditions which produces the 1,2trans anomers. 78,79 However, the new protocol is highly αselective, complementing the established β-selectivity with the imidazolium salts. These results support the notion that the photochemical thioglycosylation can be applied in a late-stage glycodiversification of complex molecules.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Catalytic and Photochemical Strategies to Stabilized Radicals Based on Anomeric Nucleophiles

et al. 2020

View full text Add to dashboard Cite

Carbohydrates, one of the three primary macromolecules of living organisms, play significant roles in various biological processes such as intercellular communication, cell recognition, and immune activity. While the majority of established methods for the installation of carbohydrates through the anomeric carbon rely on nucleophilic displacement, anomeric radicals represent an attractive alternative because of their functional group compatibility and high anomeric selectivities. Herein, we demonstrate that anomeric nucleophiles such as C1 stannanes can be converted into anomeric radicals by merging Cu(I) catalysis with blue light irradiation to achieve highly stereoselective C(sp3)–S cross-coupling reactions. Mechanistic studies and DFT calculations revealed that the C–S bond-forming step occurs via the transfer of the anomeric radical directly to a sulfur electrophile bound to Cu(II) species. This pathway complements a radical chain observed for photochemical metal-free conditions where a disulfide initiator can be activated by a Lewis base additive. Both strategies utilize anomeric nucleophiles as efficient radical donors and achieve a switch from an ionic to a radical pathway. Taken together, the stability of glycosyl nucleophiles, a broad substrate scope, and high anomeric selectivities observed for the thermal and photochemical protocols make this novel C–S cross coupling a practical tool for late-stage glycodiversification of bioactive natural products and drug candidates.

show abstract

“…4-Trimethylsilyl-3-butynyl acrylamide (TMS BtnAAm), 6′-sialyllactose azide (6′-SALac azide), 3′-sialyllactose azide (3′-SALac azide), tris(benzyltriazolylmethyl) amine (TBTA), and 2-azidoethanol were prepared according to the previous paper. 29,30 Characterization. Proton nuclear resonance ( 1 H NMR) spectra were recorded on a JEOL-ECP400 spectrometer (JEOL, Tokyo, Japan) using CDCl 3 , MeOD, DMSO-d 6 , or D 2 O as a solvent.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Design of Glycopolymers Carrying Sialyl Oligosaccharides for Controlling the Interaction with the Influenza Virus

et al. 2017

View full text Add to dashboard Cite

We designed glycopolymers carrying sialyl oligosaccharides by "post-click" chemistry and evaluated the interaction with the influenza virus. The glycopolymer structures were synthesized in a well-controlled manner by reversible addition-fragmentation chain transfer polymerization and the Huisgen reaction. Acrylamide-type monomers were copolymerized to give hydrophilicity to the polymer backbones, and the hydrophilicity enabled the successful introduction of the oligosaccharides into the polymer backbones. The glycopolymers with different sugar densities and polymer lengths were designed for the interaction with hemagglutinin on the virus surface. The synthesized glycopolymers showed the specific molecular recognition against different types of influenza viruses depending on the sugar units (6'- or 3'-sialyllactose). The sugar density and the polymer length of the glycopolymers affected the interaction with the influenza virus. Inhibitory activity of the glycopolymer against virus infection was demonstrated.

show abstract

ChemInform Abstract: One‐Step Conversion of Unprotected Sugars to β‐Glycosyl Azides Using 2‐Chloroimidazolinium Salt in Aqueous Solution.

Cited by 6 publications

References 1 publication

Site-Selective Functionalization of Hydroxyl Groups in Carbohydrate Derivatives

Site-Selective Functionalization of Hydroxyl Groups in Carbohydrate Derivatives

Catalytic and Photochemical Strategies to Stabilized Radicals Based on Anomeric Nucleophiles

Design of Glycopolymers Carrying Sialyl Oligosaccharides for Controlling the Interaction with the Influenza Virus

Contact Info

Product

Resources

About