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Robert A Field - One of the best experts on this subject based on the ideXlab platform.
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recent applications of the cui catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of CuI-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
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recent applications of the cu i catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of Cu(I)-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
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Iodine: A versatile reagent in Carbohydrate Chemistry IV. Per-O-acetylation, regioselective acylation and acetolysis
Tetrahedron, 1997Co-Authors: K. P. Ravindranathan Kartha, Robert A FieldAbstract:Abstract Iodine has been found to be an effective Lewis acid for promoting the per-O-acetylation of unprotected sugars. Under controlled conditions it can bring about regioselective acylation of Carbohydrate derivatives. At higher concentration and with longer reaction times, iodine can effect the selective acetolysis of benzyl ether-protected primary hydroxyl groups. All of these reactions proceed in high yield, are easy to carry out and make use of readily available iodine, which is both cheap and easy to handle.
Simone Dedola - One of the best experts on this subject based on the ideXlab platform.
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recent applications of the cui catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of CuI-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
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recent applications of the cu i catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of Cu(I)-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
Sergey A Nepogodiev - One of the best experts on this subject based on the ideXlab platform.
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recent applications of the cui catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of CuI-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
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recent applications of the cu i catalysed huisgen azide alkyne 1 3 dipolar cycloaddition reaction in Carbohydrate Chemistry
Organic and Biomolecular Chemistry, 2007Co-Authors: Simone Dedola, Sergey A Nepogodiev, Robert A FieldAbstract:This article surveys recent applications of Cu(I)-catalysed 1,3-dipolar cycloaddition of azides and alkynes in Carbohydrate Chemistry, highlighting developments in the preparation of simple glycoside and oligosaccharide mimetics, glyco-macrocycles, glycopeptides, glyco-clusters and Carbohydrate arrays.
Nikolay E Nifantiev - One of the best experts on this subject based on the ideXlab platform.
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1 3 syn diaxial repulsion of typical protecting groups used in Carbohydrate Chemistry in 3 o substituted derivatives of isopropyl d idopyranosides
Journal of Organic Chemistry, 2017Co-Authors: Bozhena S Komarova, Alexey G Gerbst, Andrey S Dmitrenok, Anastasiia M Finogenova, Yury E Tsvetkov, Nikolay E NifantievAbstract:The strength of 1,3-syn-diaxial repulsion was evaluated for main types of protecting groups (alkyl, silyl, and acyl) usually used in Carbohydrate Chemistry. As molecular probes for this study, derivatives of isopropyl 2-O-benzyl-4,6-O-benzylidene-α-d-idopyranoside bearing allyl, acetyl, and tert-butyldiphenylsilyl (TBDPS) protecting groups at O-3 were prepared from p-methoxyphenyl d-galactopyranoside. The equilibrium between OS2 and 4C1 conformations in these compounds was investigated using 3JH,H and 3JC,H coupling constants that were determined from 1D 1H NMR and 2D J-resolved HMBC spectra in various solvents. The analysis of the corresponding coupling constants calculated using DFT/B3LYP/pcJ-1 approximation applied to conformations optimized at DFT/B3LYP/6-311++G** level supported the investigation. Proportions of conformers in the equilibrium revealed the highest repulsion between the 3-allyloxy group and the isopropoxy aglycon and its dependence on the solvent polarity. Differences in the conformatio...
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1,3-syn-Diaxial Repulsion of Typical Protecting Groups Used in Carbohydrate Chemistry in 3‑O‑Substituted Derivatives of Isopropyl d‑Idopyranosides
2017Co-Authors: Bozhena S. Komarova, Alexey G Gerbst, Andrey S Dmitrenok, Anastasiia M Finogenova, Yury E Tsvetkov, Nikolay E NifantievAbstract:The strength of 1,3-syn-diaxial repulsion was evaluated for main types of protecting groups (alkyl, silyl, and acyl) usually used in Carbohydrate Chemistry. As molecular probes for this study, derivatives of isopropyl 2-O-benzyl-4,6-O-benzylidene-α-d-idopyranoside bearing allyl, acetyl, and tert-butyldiphenylsilyl (TBDPS) protecting groups at O-3 were prepared from p-methoxyphenyl d-galactopyranoside. The equilibrium between OS2 and 4C1 conformations in these compounds was investigated using 3JH,H and 3JC,H coupling constants that were determined from 1D 1H NMR and 2D J-resolved HMBC spectra in various solvents. The analysis of the corresponding coupling constants calculated using DFT/B3LYP/pcJ-1 approximation applied to conformations optimized at DFT/B3LYP/6-311++G** level supported the investigation. Proportions of conformers in the equilibrium revealed the highest repulsion between the 3-allyloxy group and the isopropoxy aglycon and its dependence on the solvent polarity. Differences in the conformational behavior of 3-O-allyl and 3-O-acetyl-α-d-idopyranoside derivatives complied with the notion that higher electron density on O-3 increased 1,3-syn-diaxial repulsion. 3-O-TBDPS derivative existed mainly in 4C1 conformation. The attenuation of the 1,3-syn-diaxial repulsive interaction indicates that TBDPS has stereoelectronic properties that may have significance in context of fixing unnatural pyranoside conformation with the help of silyl groups but have been disregarded until now
Andrey S Dmitrenok - One of the best experts on this subject based on the ideXlab platform.
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1 3 syn diaxial repulsion of typical protecting groups used in Carbohydrate Chemistry in 3 o substituted derivatives of isopropyl d idopyranosides
Journal of Organic Chemistry, 2017Co-Authors: Bozhena S Komarova, Alexey G Gerbst, Andrey S Dmitrenok, Anastasiia M Finogenova, Yury E Tsvetkov, Nikolay E NifantievAbstract:The strength of 1,3-syn-diaxial repulsion was evaluated for main types of protecting groups (alkyl, silyl, and acyl) usually used in Carbohydrate Chemistry. As molecular probes for this study, derivatives of isopropyl 2-O-benzyl-4,6-O-benzylidene-α-d-idopyranoside bearing allyl, acetyl, and tert-butyldiphenylsilyl (TBDPS) protecting groups at O-3 were prepared from p-methoxyphenyl d-galactopyranoside. The equilibrium between OS2 and 4C1 conformations in these compounds was investigated using 3JH,H and 3JC,H coupling constants that were determined from 1D 1H NMR and 2D J-resolved HMBC spectra in various solvents. The analysis of the corresponding coupling constants calculated using DFT/B3LYP/pcJ-1 approximation applied to conformations optimized at DFT/B3LYP/6-311++G** level supported the investigation. Proportions of conformers in the equilibrium revealed the highest repulsion between the 3-allyloxy group and the isopropoxy aglycon and its dependence on the solvent polarity. Differences in the conformatio...
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1,3-syn-Diaxial Repulsion of Typical Protecting Groups Used in Carbohydrate Chemistry in 3‑O‑Substituted Derivatives of Isopropyl d‑Idopyranosides
2017Co-Authors: Bozhena S. Komarova, Alexey G Gerbst, Andrey S Dmitrenok, Anastasiia M Finogenova, Yury E Tsvetkov, Nikolay E NifantievAbstract:The strength of 1,3-syn-diaxial repulsion was evaluated for main types of protecting groups (alkyl, silyl, and acyl) usually used in Carbohydrate Chemistry. As molecular probes for this study, derivatives of isopropyl 2-O-benzyl-4,6-O-benzylidene-α-d-idopyranoside bearing allyl, acetyl, and tert-butyldiphenylsilyl (TBDPS) protecting groups at O-3 were prepared from p-methoxyphenyl d-galactopyranoside. The equilibrium between OS2 and 4C1 conformations in these compounds was investigated using 3JH,H and 3JC,H coupling constants that were determined from 1D 1H NMR and 2D J-resolved HMBC spectra in various solvents. The analysis of the corresponding coupling constants calculated using DFT/B3LYP/pcJ-1 approximation applied to conformations optimized at DFT/B3LYP/6-311++G** level supported the investigation. Proportions of conformers in the equilibrium revealed the highest repulsion between the 3-allyloxy group and the isopropoxy aglycon and its dependence on the solvent polarity. Differences in the conformational behavior of 3-O-allyl and 3-O-acetyl-α-d-idopyranoside derivatives complied with the notion that higher electron density on O-3 increased 1,3-syn-diaxial repulsion. 3-O-TBDPS derivative existed mainly in 4C1 conformation. The attenuation of the 1,3-syn-diaxial repulsive interaction indicates that TBDPS has stereoelectronic properties that may have significance in context of fixing unnatural pyranoside conformation with the help of silyl groups but have been disregarded until now
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pyranoside into furanoside rearrangement new reaction in Carbohydrate Chemistry and its application in oligosaccharide synthesis
Chemistry: A European Journal, 2014Co-Authors: Vadim B Krylov, Dmitry A Argunov, Dmitry Z Vinnitskiy, Stella A Verkhnyatskaya, Alexey G Gerbst, Nadezhda E Ustyuzhanina, Andrey S Dmitrenok, Johannes Huebner, Otto Holst, Hanschristian SiebertAbstract:Great interest in natural furanoside-containing compounds has challenged the development of preparative methods for their synthesis. Herein a novel reaction in car- bohydrate Chemistry, namely a pyranoside-into-furanoside (PIF) rearrangement permitting the transformation of selec- tively O-substituted pyranosides into the corresponding fur- anosides is reported. The discovered process includes acid- promoted sulfation accompanied by rearrangement of the pyranoside ring into a furanoside ring followed by solvolytic O-desulfation. This process, which has no analogy in organic Chemistry, was shown to be a very useful tool for the synthe- sis of furanoside-containing complex oligosaccharides, which was demonstrated by synthesizing disaccharide derivatives a-d-Galp-(1!3)-b-d-Galf-OPr, 3-O-s-lactyl-b-d-Galf-(1!3)-b- d-Glcp-OPr, and a-l-Fucf-(1!4)-b-d-GlcpA-OPr related to polysaccharides from the bacteria Klebsiella pneumoniae and Enterococcus faecalis and the brown seaweed Chordaria flagelliformis.