ChemInform Abstract: A New Glycosylation Reaction Based on a “Remote Activation Concept”: Glycosyl 2-Pyridinecarboxylate as a Novel Glycosyl Donor.

AbstractGenerally, glycosylation reactions activate an anomeric substituent in a glycosyl donor to generate an oxocarbenium ion intermediate. Here we report a novel glycosylation reaction triggered by the activation of a 2-O-substituted propargyl group in a 3,6-O-1,1′-[(ethane-1,2-diyl)bibenzene-2,2′-bis(methylene)]-β-thioglucoside. This reaction proceeds through a cationic Au(I)-mediated intramolecular migration of the anomeric substituent onto the alkyne moiety of the propargyl group, followed by α-attack by the hydroxy group in the glycosyl acceptor on the oxocarbenium ion. The migration of the anomeric group occurs selectively through a 6-exo-dig pathway. The 2-(phenylsulfanyl)prop-2-en-1-yl group produced during the glycosylation is removable under conditions similar to those used for removing an allyl group. This reaction will be developed for further applications in orthogonal oligosaccharide synthesis.

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A new glycosylation reaction based on a “remote activation concept”: glycosyl 2-pyridinecarboxylate as a novel glycosyl donor

Tetrahedron Letters ◽

10.1016/0040-4039(91)85041-3 ◽

1991 ◽

Vol 32 (48) ◽

pp. 7065-7068 ◽

Cited By ~ 26

Author(s):

Kazunori Koide ◽

Masaji Ohno ◽

Susumu Kobayashi

Keyword(s):

Glycosyl Donor ◽

Glycosylation Reaction

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Reversing Reactivity: Stereoselective Desulfurative β-O-Glycosylation of Anomeric Thiosugars with Carboxylic Acids Under Copper or Cobalt Catalysis

10.26434/chemrxiv.11421576.v1 ◽

2019 ◽

Author(s):

Samir Messaoudi ◽

Nedjwa Bennai ◽

Amelie Chabrier ◽

Maha Fatthalla ◽

Expédite Yen-Pon ◽

...

Keyword(s):

Carboxylic Acids ◽

Late Stage ◽

Catalytic Amount ◽

Broad Scope ◽

Wide Range ◽

Glycosylation Reaction

We have discovered a new mode of reactivity of 1-thiosugars in the presence of Cu(II) or Co(II) for a stereoselective <i>O</i>-glycosylation reaction. The process involves the use of a catalytic amount of Cu(acac)2 or Co(acac)2 and Ag2CO3 as an oxidant in α,α,α-trifluorotoluene (TFT). Moreover, this protocol turned out to have a broad scope, allowing to prepare a wide range of com-plex substituted <i>O</i>-glycoside esters in good to excellent yields with an exclusive β-selectivity. The late-stage modification of phar-maceuticals by this method was also demonstrated.

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The influence of acceptor nucleophilicity on the glycosylation reaction mechanism

Chemical Science ◽

10.1039/c6sc04638j ◽

2017 ◽

Vol 8 (3) ◽

pp. 1867-1875 ◽

Cited By ~ 65

Author(s):

S. van der Vorm ◽

T. Hansen ◽

H. S. Overkleeft ◽

G. A. van der Marel ◽

J. D. C. Codée

Keyword(s):

Reaction Mechanism ◽

Systematic Study ◽

Glycosylation Reaction

The acceptor dependence on the glycosylation stereoselectivity is revealed by a systematic study employing model acceptors of gradually changing nucleophilicity.

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A One-Pot Approach to Novel Pyridazine C-Nucleosides

Molecules ◽

10.3390/molecules26082341 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2341

Author(s):

Flavio Cermola ◽

Serena Vella ◽

Marina DellaGreca ◽

Angela Tuzi ◽

Maria Rosaria Iesce

Keyword(s):

Organic Chemistry ◽

Research Field ◽

Modified Nucleosides ◽

Protecting Groups ◽

Coupling Reactions ◽

One Pot ◽

Pharmacological Interest ◽

Classical Methodology ◽

Glycosyl Donor ◽

Neutral Conditions

The synthesis of glycosides and modified nucleosides represents a wide research field in organic chemistry. The classical methodology is based on coupling reactions between a glycosyl donor and an acceptor. An alternative strategy for new C-nucleosides is used in this approach, which consists of modifying a pre-existent furyl aglycone. This approach is applied to obtain novel pyridazine C-nucleosides starting with 2- and 3-(ribofuranosyl)furans. It is based on singlet oxygen [4+2] cycloaddition followed by reduction and hydrazine cyclization under neutral conditions. The mild three-step one-pot procedure leads stereoselectively to novel pyridazine C-nucleosides of pharmacological interest. The use of acetyls as protecting groups provides an elegant direct route to a deprotected new pyridazine C-nucleoside.

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Highly regioselective and stereoselective synthesis of C-Aryl glycosides via Nickel-catalyzed ortho-C-H glycosylation of 8-aminoquinoline benzamides

Chemical Communications ◽

10.1039/d1cc03589d ◽

2021 ◽

Author(s):

Wei-Yu Shi ◽

Ya-Nan Ding ◽

Nian Zheng ◽

Xue-Ya Gou ◽

Zhe Zhang ◽

...

Keyword(s):

Stereoselective Synthesis ◽

Cost Effective ◽

Drug Candidates ◽

Aryl Glycosides ◽

Glycosylation Reaction

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows...

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Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽

10.3390/md19010043 ◽

2021 ◽

Vol 19 (1) ◽

pp. 43

Author(s):

Marco Mangiagalli ◽

Marina Lotti

Keyword(s):

Low Temperature ◽

Molecular Mechanisms ◽

Building Blocks ◽

Cold Active ◽

Cold Adaption ◽

Glycosyl Donor ◽

Pharmaceutical Industries ◽

Biotechnological Processes ◽

Hydrolysis Of ◽

Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

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