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Joanne E Harvey - One of the best experts on this subject based on the ideXlab platform.
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divergent synthesis of 2 c branched Pyranosides and oxepines from 1 2 gem dibromocyclopropyl carbohydrates
ChemInform, 2015Co-Authors: Peter Moore, Russell J Hewitt, Julia K Schuster, Rhia M L Stone, Paul H Teesdalespittle, Joanne E HarveyAbstract:The use of a base affords Pyranosides, whereas silver salts gives the corresponding bromooxepines.
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divergent synthesis of 2 c branched Pyranosides and oxepines from 1 2 gem dibromocyclopropyl carbohydrates
Tetrahedron, 2014Co-Authors: Peter Moore, Russell J Hewitt, Julia K Schuster, Rhia M L Stone, Paul H Teesdalespittle, Joanne E HarveyAbstract:Abstract The ring opening of 1,2-(gem-dibromo)cyclopropyl carbohydrates by two different modes leads to either 2-C-(bromomethylene)Pyranosides (using base) or 2-bromooxepines (using silver salts), as shown previously by us for a d -glucal-derived cyclopropane. The base-promoted ring opening is extended to encompass additional alcohol, thiol and amine nucleophiles, and diastereoisomeric cyclopropane precursors. Cross-coupling of the 2-C-(bromomethylene)Pyranosides leads to extended 2-C-branched Pyranosides. Silver-promoted ring expansion of the cyclopropyl carbohydrates in the presence of various alcohols is described. Cross-coupling of the resulting benzyl 2-bromooxepines affords 2-C-substituted oxepines.
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synthesis of oxepines and 2 branched Pyranosides from a d glucal derived gem dibromo 1 2 cyclopropanated sugar
Journal of Organic Chemistry, 2010Co-Authors: Russell J Hewitt, Joanne E HarveyAbstract:The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics. 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar. In contrast, cyclopropane ring cleavage under basic conditions leads to 2-C-branched Pyranosides, not the 2-bromooxepine structures assigned in an earlier report.
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a versatile and stereocontrolled route to pyranose and furanose c glycosides
Organic Letters, 2004Co-Authors: Joanne E Harvey, Steven A Raw, Richard J K TaylorAbstract:The α,β-unsaturated-γ,δ-epoxyester 1 is a novel and versatile precursor to a wide variety of C-glycosides. For instance, treatment of Z-1 or E-1 with palladium(0) affords, stereospecifically, β- or α-C-furanosides, respectively. In contrast, reaction of Z-1 or E-1 with base gives, stereoselectively, the β- or α-C-Pyranosides, respectively.
Nikolay E. Nifantiev - One of the best experts on this subject based on the ideXlab platform.
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Driving Force of the Pyranoside-into-Furanoside Rearrangement
2019Co-Authors: Alexey G Gerbst, Dmitry A Argunov, Vadim B Krylov, Andrey S Dmitrenok, Nikolay E. NifantievAbstract:Ab initio calculations of fully O-sulfated model monosaccharides, including common hexoses (glucose, galactose, fucose, and mannose) and pentoses (arabinose and xylose), were performed to study the energetic properties of the recently discovered Pyranoside-into-furanoside (PIF) rearrangement. It was shown that the per-O-sulfated derivatives of furanoside isomers generally had lower energies than the corresponding per-O-sulfated Pyranosides, while nonsulfated furanosides were always less favored than nonsulfated Pyranosides. Mannose, which is known to be unreactive in PIF rearrangement, was the only exception. The results of the theoretical calculations were confirmed by experimental studies of monosaccharide models and explained the driving force of such unusual ring contraction process as PIF rearrangement. The conclusions of performed investigation can be used for prediction of new substrates applicability for PIF rearrangement
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Pyranoside into furanoside rearrangement of 4 pentenyl glycosides in the synthesis of a tetrasaccharide related to galactan i of klebsiella pneumoniae
European Journal of Organic Chemistry, 2017Co-Authors: Stella A Verkhnyatskaya, Vadim B Krylov, Nikolay E. NifantievAbstract:An efficient strategy for synthesis of spacer-armed tetrasaccharide related to galactan I of Klebsiella pneumoniae was reported employing newly developed acid-free conditions for Pyranoside-into-furanoside (PIF) rearrangement of a digalactoside bearing 4-pentenyl group at anomeric position. The 4-pentenyl aglycon was successfully used both as a leaving group in glycosylation of 3-trifluoroacetamidopropanol, and as a temporary anomeric protection, permitting its conversion into the imidate donor. Regioselective coupling of the disaccharide blocks afforded the desired tetrasaccharide sequence required for investigation of interaction of galactan I with immune system proteins.
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Pyranoside into furanoside rearrangement of d glucuronoPyranoside derivatives
Mendeleev Communications, 2016Co-Authors: Vadim B Krylov, Dmitry A Argunov, Nikolay E. NifantievAbstract:The Pyranoside- into -furanoside (PIF) rearrangement of α and β- d -glucuronoPyranosides under acid-promoted sulfation proceeded significantly faster than similar isomerization of β- d -glucoPyranosides.
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the use of Pyranoside into furanoside rearrangement and controlled o 5 o 6 benzoyl migration as the basis of a synthetic strategy to assemble 1 5 and 1 6 linked galactofuranosyl chains
Organic Letters, 2016Co-Authors: Dmitry A Argunov, Vadim B Krylov, Nikolay E. NifantievAbstract:A new Pyranoside-into-furanoside (PIF) rearrangement of selectively protected galactoPyranosides, followed by controlled O(5) → O(6) benzoate migration, gives either 5-OH or 6-OH products. It has been applied for the synthesis of four oligosaccharides related to the galactomannan from Aspergillus fumigatus. The assembly of target oligosaccharides containing both (1→5) and (1→6) linkages between galactofuranosyl residues was performed by applying terminal mannoside and digalactofuranoside blocks, forming a versatile approach toward fungal and bacterial carbohydrate antigens containing both 5-O- and 6-O-substituted galactofuranoside residues.
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The Use of Pyranoside-into-Furanoside Rearrangement and Controlled O(5) → O(6) Benzoyl Migration as the Basis of a Synthetic Strategy To Assemble (1→5)- and (1→6)-Linked Galactofuranosyl Chains
2016Co-Authors: Dmitry A Argunov, Vadim B Krylov, Nikolay E. NifantievAbstract:A new Pyranoside-into-furanoside (PIF) rearrangement of selectively protected galactoPyranosides, followed by controlled O(5) → O(6) benzoate migration, gives either 5-OH or 6-OH products. It has been applied for the synthesis of four oligosaccharides related to the galactomannan from Aspergillus fumigatus. The assembly of target oligosaccharides containing both (1→5) and (1→6) linkages between galactofuranosyl residues was performed by applying terminal mannoside and digalactofuranoside blocks, forming a versatile approach toward fungal and bacterial carbohydrate antigens containing both 5-O- and 6-O-substituted galactofuranoside residues
Andrea Turkson - One of the best experts on this subject based on the ideXlab platform.
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Regioselective Beckmann rearrangements of furanoside and Pyranoside-derived oximes
Tetrahedron: Asymmetry, 2011Co-Authors: R. K. Benning, Helen M I Osborn, Andrea TurksonAbstract:The Beckmann rearrangement is a useful reaction employed to provide access to amides from oxime substrates. Applied to cyclic structures, the Beckmann rearrangement leads to ring expansion and allows access to cyclic lactams. Our investigations focused upon the synthesis of glycoside-derived lactams from oxime precursors. In probing a range of conditions, we observed that 2,4,6-trichloro[1,3,5]triazine (TCT) was an effective and mild promoter of the rearrangement affording pyrano- and heptanoside lactam products with excellent regioselectivities.
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synthesis and nmr spectroscopic analysis of 3 nitro Pyranoside 3 nitro septanoside and 4 nitro septanoside derivatives by condensation of the anion of nitromethane with glycoside dialdehydes
Tetrahedron-asymmetry, 2009Co-Authors: Helen M I Osborn, Andrea TurksonAbstract:Abstract The utility of the nitroaldol reaction for accessing 3-nitro-Pyranoside, 3-nitro-septanoside or 4-nitro-septanoside derivatives, by reaction of the anion of nitromethane with glycoside dialdehydes is demonstrated. Initially, the feasibility of using unprotected glucoside dialdehydes was probed for the synthesis of the septanoside products, but this afforded Pyranoside rather than septanoside targets. Subsequent studies utilised protected glycoside dialdehydes within the methodology, which allowed entry into a range of 3-nitro or 4-nitro-septanosides in good yield. NMR spectroscopic analysis allowed determination of the stereochemistry of each of the products thus afforded.
Vadim B Krylov - One of the best experts on this subject based on the ideXlab platform.
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Driving Force of the Pyranoside-into-Furanoside Rearrangement
2019Co-Authors: Alexey G Gerbst, Dmitry A Argunov, Vadim B Krylov, Andrey S Dmitrenok, Nikolay E. NifantievAbstract:Ab initio calculations of fully O-sulfated model monosaccharides, including common hexoses (glucose, galactose, fucose, and mannose) and pentoses (arabinose and xylose), were performed to study the energetic properties of the recently discovered Pyranoside-into-furanoside (PIF) rearrangement. It was shown that the per-O-sulfated derivatives of furanoside isomers generally had lower energies than the corresponding per-O-sulfated Pyranosides, while nonsulfated furanosides were always less favored than nonsulfated Pyranosides. Mannose, which is known to be unreactive in PIF rearrangement, was the only exception. The results of the theoretical calculations were confirmed by experimental studies of monosaccharide models and explained the driving force of such unusual ring contraction process as PIF rearrangement. The conclusions of performed investigation can be used for prediction of new substrates applicability for PIF rearrangement
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Pyranoside into furanoside rearrangement of 4 pentenyl glycosides in the synthesis of a tetrasaccharide related to galactan i of klebsiella pneumoniae
European Journal of Organic Chemistry, 2017Co-Authors: Stella A Verkhnyatskaya, Vadim B Krylov, Nikolay E. NifantievAbstract:An efficient strategy for synthesis of spacer-armed tetrasaccharide related to galactan I of Klebsiella pneumoniae was reported employing newly developed acid-free conditions for Pyranoside-into-furanoside (PIF) rearrangement of a digalactoside bearing 4-pentenyl group at anomeric position. The 4-pentenyl aglycon was successfully used both as a leaving group in glycosylation of 3-trifluoroacetamidopropanol, and as a temporary anomeric protection, permitting its conversion into the imidate donor. Regioselective coupling of the disaccharide blocks afforded the desired tetrasaccharide sequence required for investigation of interaction of galactan I with immune system proteins.
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Pyranoside into furanoside rearrangement of d glucuronoPyranoside derivatives
Mendeleev Communications, 2016Co-Authors: Vadim B Krylov, Dmitry A Argunov, Nikolay E. NifantievAbstract:The Pyranoside- into -furanoside (PIF) rearrangement of α and β- d -glucuronoPyranosides under acid-promoted sulfation proceeded significantly faster than similar isomerization of β- d -glucoPyranosides.
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the use of Pyranoside into furanoside rearrangement and controlled o 5 o 6 benzoyl migration as the basis of a synthetic strategy to assemble 1 5 and 1 6 linked galactofuranosyl chains
Organic Letters, 2016Co-Authors: Dmitry A Argunov, Vadim B Krylov, Nikolay E. NifantievAbstract:A new Pyranoside-into-furanoside (PIF) rearrangement of selectively protected galactoPyranosides, followed by controlled O(5) → O(6) benzoate migration, gives either 5-OH or 6-OH products. It has been applied for the synthesis of four oligosaccharides related to the galactomannan from Aspergillus fumigatus. The assembly of target oligosaccharides containing both (1→5) and (1→6) linkages between galactofuranosyl residues was performed by applying terminal mannoside and digalactofuranoside blocks, forming a versatile approach toward fungal and bacterial carbohydrate antigens containing both 5-O- and 6-O-substituted galactofuranoside residues.
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The Use of Pyranoside-into-Furanoside Rearrangement and Controlled O(5) → O(6) Benzoyl Migration as the Basis of a Synthetic Strategy To Assemble (1→5)- and (1→6)-Linked Galactofuranosyl Chains
2016Co-Authors: Dmitry A Argunov, Vadim B Krylov, Nikolay E. NifantievAbstract:A new Pyranoside-into-furanoside (PIF) rearrangement of selectively protected galactoPyranosides, followed by controlled O(5) → O(6) benzoate migration, gives either 5-OH or 6-OH products. It has been applied for the synthesis of four oligosaccharides related to the galactomannan from Aspergillus fumigatus. The assembly of target oligosaccharides containing both (1→5) and (1→6) linkages between galactofuranosyl residues was performed by applying terminal mannoside and digalactofuranoside blocks, forming a versatile approach toward fungal and bacterial carbohydrate antigens containing both 5-O- and 6-O-substituted galactofuranoside residues
Montserrat Dieguez - One of the best experts on this subject based on the ideXlab platform.
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enantioselective ir catalyzed hydrogenation of minimally functionalized olefins using Pyranoside phosphinite oxazoline ligands
ChemInform, 2014Co-Authors: Javier Mazuela, Oscar Pamies, Montserrat DieguezAbstract:A novel iridium complex containing a Pyranoside phosphinite-oxazoline ligand is prepared and successfully applied as catalyst for the asymmetric hydrogenation of different di- and trisubstituted alkenes.
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enantioselective ir catalyzed hydrogenation of minimally functionalized olefins using Pyranoside phosphinite oxazoline ligands
European Journal of Inorganic Chemistry, 2013Co-Authors: Javier Mazuela, Oscar Pamies, Montserrat DieguezAbstract:Pyranoside phosphinite-oxazoline ligands prepared from readily available (+)-D-glucosamine were applied to the Ir-catalyzed asymmetric hydrogenation of minimally functionalized olefins. Our results show that the enantioselectivity is dependent on the ozaxoline and the phosphinite moieties and the substrate structure. By carefully selecting the ligand components, enantioselectivities up to 99 % were obtained in the asymmetric reduction of several (E)- and (Z)-trisubstituted and 1,1-disubstituted olefins. The asymmetric hydrogenation was also performed using propylene carbonate as solvent, which allowed the iridium catalysts to be reused and maintained the high enantioselectivities.
