'Click' Preparation of Carbohydrate 1-Benzotriazoles, 1,4-Disubstituted, and 1,4,5-Trisubstituted Triazoles and their Utility as Glycosyl Donors

2008 ◽  
Vol 61 (11) ◽  
pp. 837 ◽  
Author(s):  
Jacinta A. Watt ◽  
Carlie T. Gannon ◽  
Karen J. Loft ◽  
Zoran Dinev ◽  
Spencer J. Williams
Keyword(s):  
Lewis Acids ◽  
Terminal Alkynes ◽  
Cuaac Reaction ◽  
Anthranilic Acids ◽  
Glycosyl Donor ◽  
Dimethyl Acetylene Dicarboxylate ◽  
Electron Withdrawing Substituents ◽  
Glycosyl Donors

Glycosyl triazoles can be prepared from readily available anomeric azides through various ‘click’ methodologies: thermal Huisgen cycloaddition with alkynes, strain-promoted Huisgen cycloaddition of benzynes, and CuI-catalyzed azide-alkyne cycloaddition of terminal alkynes (CuAAC reaction). Here we investigate the formation of glycosyl 1-benzotriazoles from anomeric and non-anomeric carbohydrate azides using benzynes derived from substituted anthranilic acids. The reactivity of the resulting anomeric 1-benzotriazoles as glycosyl donors was investigated and compared with 1,4-disubstituted glycosyl triazoles (from the CuAAC reaction) and 1,4,5-trisubstituted glycosyl triazoles (prepared by Huisgen cycloaddition of glycosyl azides and dimethyl acetylene dicarboxylate). The 1,4,5-trisubstituted glycosyl triazoles were activated by Lewis acids and could be converted to O-glycosides, S-glycosides, glycosyl chlorides, and glycosyl azides. By contrast, under all conditions investigated, the 1,4-disubstituted glycosyl triazoles were unreactive as glycosyl donors. Glycosyl 1-benzotriazoles were generally inert as glycosyl donors; however, a tetrafluorobenzotriazole derivative, which bears electron-withdrawing substituents on the benzotriazole group, was a moderate glycosyl donor and could be converted to an S-glycoside by treatment with thiocresol and tin(iv) chloride.

Synthesis of the tetrasaccharide repeat unit of the O-antigen polysaccharide from Escherichia coli O77 employing the 2′-carboxybenzyl glycoside

2006 ◽  
Vol 84 (4) ◽  
pp. 506-515 ◽  
Author(s):  
Bo Ram Lee ◽  
Joo Mi Jeon ◽  
Jae Hyuk Jung ◽  
Heung Bae Jeon ◽  
Kwan Soo Kim
Keyword(s):  
Escherichia Coli ◽  
Repeat Unit ◽  
O Antigen ◽  
Glycosyl Donor ◽  
Glycosyl Donors

The synthesis of the suitably protected form (1) of the tetrasaccharide repeat unit, →2)-α-D-Manp-(1→2)-β-D-Manp-(1→3)-α-D-GlcpNAc-(1→6)-α-D-Manp-(1→ (A), of the O-antigen polysaccharide of the lipopolysaccharide from Escherichia coli O77 has been accomplished by latent–active glycosylation employing the 2′-carboxybenzyl (CB) gly coside method. In addition to previously used latent glycosyl donors, 2′-(benzyloxycarbonyl)benzyl (BCB) glycosides, new latent glycosyl donors, 2'-(allyloxycarbonyl)benzyl (ACB) glycosides, have been introduced as a direct precursor for the active CB glycosides. We also demonstrate that 4,6-O-benzylidene-2-azido-2-deoxy-α-D-mannopyranoside (7) has been readily prepared from D-glucosamine in good yield.Key words: Escherichia coli O77, glycosylation, 2′-carboxybenzyl (CB) glycosides, 2′-(allyloxycarbonyl)benzyl (ACB) glycosides, glycosyl donor.

Coil-rod-coil triblock copolymers synthesized by macromolecular clicking and their compatibilizer effects in all-polymer solar cells

2021 ◽  
Author(s):  
Sultan Otep ◽  
Yu-Cheng Tseng ◽  
Naomasa Yomogita ◽  
Jia-Fu Chang ◽  
Chu-Chen Chueh ◽  
...  
Keyword(s):  
Solar Cells ◽  
Triblock Copolymers ◽  
Polymer Solar Cells ◽  
Terminal Alkynes ◽  
Cuaac Reaction

Poly(diethynylthiophene) (PDET) synthesized via Hay coupling polycondensation retains terminal alkynes for tethering polystyrene (PS) blocks by a simple Cu-catalyzed azide-alkyne click (CuAAC) reaction. Successful syntheses of triblock copolymers were confirmed...

C-Glycosylation of Oxygenated Naphthols with 3-Dimethylamino-2,3,6-trideoxy-L-arabino-hexopyranose and 3-Azido-2,3,6-trideoxy-D-arabino-hexopyranose

2003 ◽  
Vol 56 (8) ◽  
pp. 787 ◽  
Author(s):  
Margaret A. Brimble ◽  
Roger M. Davey ◽  
Malcolm D. McLeod ◽  
Maureen Murphy
Keyword(s):  
Lewis Acid ◽  
Boron Trifluoride ◽  
Electronic Effects ◽  
Effective Coupling ◽  
Boron Trifluoride Diethyl Etherate ◽  
Glycosyl Donor ◽  
Aryl Glycosides ◽  
Coupling Partner ◽  
Fine Tune ◽  
Glycosyl Donors

In connection with studies directed towards the synthesis of the pyranonaphthoquinone antibiotic medermycin, C-aryl glycosides were prepared by C-glycosylation of naphthols with glycosyl donors. Boron trifluoride diethyl etherate proved to be a suitable Lewis acid to promote the C-glycosylation, and use of the azido glycosyl donor proved more successful than using the dimethylamino glycosyl donor. 5-Hydroxy-1,4-dimethoxynaphthalene underwent facile C-glycosylation with two particular glycosyl donors, whereas 3-bromo-5-hydroxy-1,4-dimethoxynaphthalene was not an effective coupling partner with the same glycosyl donors. These studies indicate that subtle steric and electronic effects need to be considered in order to fine-tune C-glycosylations when using highly functionalized glycosyl donors.

Zinc mediated activation of terminal alkynes: stereoselective synthesis of alkynyl glycosides

2014 ◽  
Vol 12 (40) ◽  
pp. 7900-7903 ◽  
Author(s):  
Madhu Babu Tatina ◽  
Anil Kumar Kusunuru ◽  
Syed Khalid Yousuf ◽  
Debaraj Mukherjee
Keyword(s):  
Stereoselective Synthesis ◽  
Zinc Dust ◽  
Terminal Alkynes ◽  
Ethyl Bromoacetate ◽  
Glycosyl Donors

Zinc mediated alkynylation reaction was studied for the preparation of C-glycosides from unactivated aromatic and aliphatic acetylenes. Different glycosyl donors such as glycals and anomeric acetates were tested towards in situ generated alkynyl zinc reagent using zinc dust and ethyl bromoacetate. The method provides a simple, mild and stereoselective access of alkynyl glycosides.

Synthesis of 2-Amino-2-deoxy-β-D-galactopyranosyl-(1→4)-2-amino-2-deoxy-β-D-galactopyranosides: Using Various 2-Deoxy-2-phthalimido-D-galactopyranosyl Donors and Acceptors

2004 ◽  
Vol 69 (10) ◽  
pp. 1914-1938 ◽  
Author(s):  
Jan Veselý ◽  
Miroslav Ledvina ◽  
Jindřich Jindřich ◽  
Tomáš Trnka ◽  
David Šaman
Keyword(s):  
Systematic Study ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Glycosyl Donors

A systematic study is presented of the efficiency of the most common glycosylation methods using standard 2-deoxy-2-phthalimidogalactopyranosyl donors ethyl 4-O-acetyl-3,6-di-O- benzyl-2-deoxy-2-phthalimido-1-thio-β-D-galactopyranoside (3a), 4-O-Acetyl-3,6-di-O-benzyl- 2-deoxy-2-phthalimido-β-D-galactopyranosyl bromide (4), 4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranosyl fluoride (5b), O-(4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranosyl) trichloroacetimidate (7) and ethyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-galactopyranoside (8), pent-4-enyl 3,6-di-O-benzyl- and 3-O-allyl-6-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranoside (10a) and (10b) and pent-4-enyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-4-O-(trimethylsilyl)-β-D-galactopyranoside (11) as glycosyl acceptors in the synthesis of 2-amino-2-deoxy-β-D-galactopyranosyl-(1→4)-2-amino-2-deoxy-β-D-galactopyranosides 12, 16a and 17a. It was found that due to a low reactivity of the axial OH(4) group of glycosyl acceptors, disaccharides 16b and 17b with α(1→4) bond were also formed. The unexpected intermolecular migration of ethylsufanyl group from the reducing end of glycosyl acceptor 8 the reducing end of the activated form of glycosyl donor 4 in the glycosylation step to give ethylsulfanyl derivative 3a was proved. For preparation of the glycosyl donors and glycosyl acceptors with galacto configuration an approach based on epimerization of 4-O-mesyl derivatives of appropriate synthons with gluco configuration 2a and 2b was employed.

scholarly journals Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

2018 ◽  
Vol 14 ◽  
pp. 2916-2922 ◽  
Author(s):  
Muhammad Israr ◽  
Changqing Ye ◽  
Munira Taj Muhammad ◽  
Yajun Li ◽  
Hongli Bao
Keyword(s):  
Carboxylic Acids ◽  
Tandem Reaction ◽  
Reaction Synthesis ◽  
Terminal Alkynes ◽  
Alkyl Azides ◽  
Organic Azides ◽  
Cuaac Reaction ◽  
First Time

A copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction for the synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and terminal alkynes is reported. The alkyl carboxylic acids is for the first time being used as the alkyl azide precursors in the form of alkyl diacyl peroxides. This method avoids the necessity to handle organic azides, as they are generated in situ, making this protocol operationally simple. The Cu(I) catalyst not only participates in the alkyl diacyl peroxides decomposition to afford alkyl azides but also catalyzes the subsequent CuAAC reaction to produce the 1,2,3-triazoles.

Towards an unprotected self-activating glycosyl donor system: Bromobutyl glycosides

2002 ◽  
Vol 80 (6) ◽  
pp. 555-558 ◽  
Author(s):  
Benjamin G Davis ◽  
Steven D Wood ◽  
Michael AT Maughan
Keyword(s):  
Glycosyl Donor ◽  
Donor System ◽  
Glycosyl Donors

Bromobutyl mannopyranosides have been successfully used as both protected and unprotected glycosyl donors both with and without the use of an external activator.Key words: glycosylation, unprotected glycosyl donors, oligosaccharides.

Synthesis of the Nephritogenoside Trisaccharide Unit Using Phenyl 1-Thioglycopyranoside Sulfoxides as a Glycosyl Donor

1993 ◽  
Vol 48 (8) ◽  
pp. 1143-1145 ◽  
Author(s):  
Yali Wang ◽  
Hong Zhang ◽  
Wolfgang Voelter
Keyword(s):  
Protecting Groups ◽  
Coupling Process ◽  
Mild Conditions ◽  
Glycosyl Donor ◽  
Glycosyl Donors

The nephritogenoside trisaccharide unit was synthesized under mild conditions using phenyl 1-thioglycopyranoside sulfoxides as glycosyl donors. In the coupling process neither thiophenyl nor trityl protecting groups are cleaved from the carbohydrate moieties demonstrating the utility of this method also for oligosaccharide block syntheses.

Synthesis of N-substituted Five and Six-membered Iminocyclitols-bearing Sugar Moiety: Strategy Toward the Synthesis of Pseudodisaccharide

2018 ◽  
Vol 15 (6) ◽  
pp. 853-862
Author(s):  
Nader Al Bujuq ◽  
Manuel Angulo
Keyword(s):  
Molecular Modeling ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Efficient Synthesis ◽  
Active Compounds ◽  
Sugar Moiety ◽  
Stereoselective Method ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Glycosyl Donors

Aim and Objective: The efficient synthesis of disaccharide containing iminosugar moiety has a considerable interest in the field of glycoscience. In the present work, we describe a novel and applicable method for synthesis of five and six-membered N-substituted iminosugars attached with sugar moiety (pseudodisaccharides). Materials and Methods: The method of the glycosylation was based on the coupling of iminosugar thioglycoside (glycosyl donors) with partially protected sugars (glycosyl acceptors) in the presence of DMTST as a promoter. 2D COSY, HMQC, HMBC experiments were carried out to assist in NMR signal assignments. The pseudoanomeric configuration was established through NOE experiments and molecular modeling calculations. Results: Two classes of pseudodisaccharides were successfully obtained, five and six-membered N-substituted iminosugars glycosides. The six-membered pseudodisaccharides compounds were produced selectively with only β anomer. The corresponding five-membered pseudodisaccharides were achieved with moderate stereoselectivity. The yields obtained were good. These derivatives of iminocyclitols are thought to be precedents to develop various pseudodisaccharides, novel biologically active compounds, and new functional molecules. Conclusion: According to the results, utilizing iminosugar thioglycosides (1 and 2) as a glycosyl donor in glycosylation reactions is an efficient and highly stereoselective method to prepare (five- and six-membered) iminocyclitols (iminosugars) that bear a sugar moiety. The results will add to the synthesis of the iminosugars derivatives and contribute to make our approach among the few methods able to synthesize iminosugar glycosides.

Hydrogen transfer from formic acid to alkynes catalyzed by a diruthenium complex

2001 ◽  
Vol 79 (5-6) ◽  
pp. 915-921 ◽  
Author(s):  
Yuan Gao ◽  
Michael C Jennings ◽  
Richard J Puddephatt
Keyword(s):  
Carbon Dioxide ◽  
Formic Acid ◽  
Hydrogen Transfer ◽  
Hydrogen Donor ◽  
Transfer Hydrogenation ◽  
Stable Complex ◽  
Terminal Alkynes ◽  
Hydrogenation Catalysis ◽  
Diruthenium Complex ◽  
Electron Withdrawing Substituents

The diruthenium(0) complex [Ru2(µ-CO)(CO)4(µ-dppm)2] (1) (dppm = Ph2PCH2PPh2), is a catalyst for the transfer hydrogenation, using formic acid as hydrogen donor, of the alkynes PhCºCPh, PhCºCMe, EtCºCEt, and PrCºCPr but not of the terminal alkynes HCºCH, PhCºCH, BuCºCH, or the alkynes containing one or two electron-withdrawing substituents PhCºCCO2Me and MeO2CCtriple bondCCO2Me. In the successful reactions, the formic acid is first decomposed to carbon dioxide and hydrogen, which then hydrogenates the alkynes in a slower reaction. In the unsuccessful reactions, the decomposition of formic acid is strongly retarded by the alkyne. In the case with the alkyne PhCºCH, it is shown that the alkyne reacts with protonated 1 to give first [Ru2(µ-CPh=CH2)(CO)4(µ-dppm)2][HCO2], which then isomerizes to give the catalytically inactive, stable complex [Ru2(µ-CH=CHPh)(CO)4(µ-dppm)2][HCO2]. This complex has been structurally characterized and both of the µ-styrenyl complexes are shown to be fluxional in solution.Key words: ruthenium, hydrogenation, catalysis, binuclear..

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