- Copper-Catalyzed Anomeric O-Arylation of Carbohydrate Derivatives at Room Temperature
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Direct and practical anomeric O-arylation of sugar lactols with substituted arylboronic acids has been established. Using copper catalysis at room temperature under an air atmosphere, the protocol proved to be general, and a variety of aryl O-glycosides have been prepared in good to excellent yields. Furthermore, this approach was extended successfully to unprotected carbohydrates, including α-mannose, and it was demonstrated here how the interaction between carbohydrates and boronic acids can be combined with copper catalysis to achieve selective anomeric O-arylation.
- Verdelet, Tristan,Benmahdjoub, Sara,Benmerad, Belkacem,Alami, Mouad,Messaoudi, Samir
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p. 9226 - 9238
(2019/08/12)
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- A simple synthesis of 3-deoxyanthocyanidins and their O-glucosides
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This work deals with the chemical synthesis of simple analogs of anthocyanins, the main class of water-soluble natural pigments. Flavylium ions with hydroxyl, methoxyl and β-D-glucopyranosyloxyl substituents at positions 4′ and 7 have been prepared by straightforward chemical procedures. Moreover, the two 3-deoxyanthocyanidins of red sorghum apigeninidin (4′,5,7-trihydroxyflavylium) and luteolinidin (3′,4′,5,7-tetrahydroxyflavylium) were synthesized in a one-step protocol. Attempts to synthesize luteolinidin O-β-D-glucosides resulted in a mixture of the 5-O- and 7-O-regioisomers in low yield. A preliminary study of the 4′-β-D-glucopyranosyloxy-7-hydroxyflavylium and 7-β-D-glucopyranosyloxy-4′-hydroxy-flavylium ions shows that simply changing the glucosidation site can profoundly affect the color intensity and stability.
- Al Bittar, Sheiraz,Mora, Nathalie,Loonis, Michèle,Dangles, Olivier
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p. 4294 - 4302
(2016/07/06)
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- Effective friedel-crafts acylations of O- and C-arylglycosides with triflic acid
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Triflic acid is well known not only as a Friedel-Crafts promoter, but also as a deglycosidation reagent. In this study, we promote effective Friedel-Crafts acylations for O- or C-arylglucosides without deglycosidation and check their inhibitory activities for β-glucosidase.
- Hashimoto, Makoto,Takahashi, Miho
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body text
p. 227 - 231
(2009/09/06)
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- Structure and reactivity of glycosides: IV. Koenigs-Knorr synthesis of aryl β-D-glucopyranosides using phase-transfer catalysts
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A series of acetylated aryl β-D-glucopyranosides were prepared in 12-63% yields from tetra-O-acetyl-α-D-glycopyranosyl bromide and phenols containing acyl, formyl, and hydroxy substituents, and also from sterically hindered phenols in the two-phase system chloroform-aqueous alkali in the presence of triethylbenzylammonium chloride. Hydroxyethylated sucrose and dibenzo-18-crown-6 do not behave as phase-transfer catalysts in glycosylation of phenols. 2001 MAIK "Nauka/Interperiodica".
- Pavlov,Sokolov,Zakharov
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p. 1811 - 1814
(2007/10/03)
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- Phenolic and triterpenoid glycosides from Aster batangensis
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A new phenolic glycoside, asterbatanoside A [p-hydroxyacetophenone-4-O-β-D-xylopyranosyl-(1 → 6)-β-D-glucopyranoside], and two new triterpenoid saponins, asterbatanoside B [2α,3β,23-trihydroxyolean-12-en-28-oic acid-28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside] and asterbatanoside C [3-O-β-D-glucopyranosyl-2β,3β,23-trihydroxyolean-12-en-28- oicacid-28-O-β-D-glucopyranoside] were isolated from the roots of Aster batangensis. Their structures were determined by spectroscopic methods and chemical evidence. The total synthesis of asterbatanoside A is also reported. Copyright
- Shao, Yu,Li, Yun Long,Zhou, Bing Nan
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p. 1593 - 1598
(2007/10/03)
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- Novel Synthesis of Aryl 2,3,4,6-Tetra-O-acetyl-D-glucopyranosides
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The glucosidation of phenols with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl fluoride in the presence of BF3*OEt2 to give, predominantly, α-anomers has been studied.In the presence of an amine base, 1,1,3,3-tetramethylguanidine, however, enhanced β-selectivity was achieved.The former reaction provides a novel and useful synthesis of aryl 2,3,4,6-tetra-O-acetyl-α-D-glucopyranoside whilst the latter is effective for the glycosidation of relatively hindered phenols.
- Yamaguchi, Masahiko,Horiguchi, Akira,Fukuda, Akira,Minami, Toru
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p. 1079 - 1082
(2007/10/02)
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