- Sulfoxide Covalent Catalysis: Application to Glycosidic Bond Formation
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A versatile glycosylation reaction is used to establish the process of sulfoxide covalent catalysis. Hemiacetals are activated by benzenesulfonic anhydride and a dialkyl sulfoxide catalyst, nBu2SO, for coupling with various nucleophiles (Nu; se
- Boebel, Timothy A.,Gin, David Y.
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- Direct dehydrative glycosylation catalyzed by diphenylammonium triflate
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Methods for direct dehydrative glycosylations of carbohydrate hemiacetals catalyzed by diphenylammonium triflate under microwave irradiation are described. Both armed and disarmed glycosyl-C1-hemiacetal donors were efficiently glycosylated in moderate to excellent yields without the need for any drying agents and stoichiometric additives. This method has been successfully applied to a solid-phase glycosylation.
- Hsu, Mei-Yuan,Lam, Sarah,Lin, Mei-Huei,Lin, Su-Ching,Wang, Cheng-Chung,Wu, Chia-Hui
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supporting information
(2020/03/13)
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- AuCl3- and AuCl3-Phenylacetylene-Catalyzed Glycosylations by Using Glycosyl Trichloroacetimidates
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Glycosylations of armed and disarmed trichloroacetimidate-based glycosyl donors were carried out by using the AuCl3-phenylacetylene relay catalyst system. The effectiveness of this catalytic system was also compared with that of using AuCl3 alone as a catalyst. Glycosylations with these catalysts proceeded efficiently at room temperature within 5-45 min. Excellent diastereoselectivity was obtained for the glycosylation of 2-O-acetyl-protected disarmed glycosyl donors, whereas armed glycosyl trichloroacetimidates gave rise to a mixture of anomeric glycosides. Acid-sensitive nucleophiles such as Fmoc-serine tert-butyl ester or Fmoc-threonine tert-butyl ester successfully underwent the glycosylations, albeit in moderate yields, under mild conditions at room temperature. We have reported a convenient room temperature protocol that employs AuCl3 and phenylacetylene as a catalyst system to carry out the glycosylation of glycosyl trichloroacetimidates. The effectiveness of this relay catalyst system was also compared with that of using AuCl3 alone to catalyze the glycosylations.
- Roy, Rashmi,Palanivel, Ashok Kumar,Mallick, Asadulla,Vankar, Yashwant D.
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p. 4000 - 4005
(2015/06/30)
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- Improved catalytic and stereoselective glycosylation with glycosyl N-trichloroacetylcarbamate: application to various 1-hydroxy sugars
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Efficient catalytic and stereoselective glycosylation was achieved by activating a glycosyl N-trichloroacetylcarbamate with a catalytic amount of Lewis acid in the presence of a glycosyl acceptor and 5 ? molecular sieves. Catalytic one-pot dehydrative glycosylation of a 1-hydroxy carbohydrate was achieved stereoselectively by reaction with trichloroacetyl isocyanate, followed by activation with a catalytic amount of activators.
- Shirahata, Tatsuya,Matsuo, Jun-ichi,Teruya, Satoko,Hirata, Nozomu,Kurimoto, Taku,Akimoto, Nanao,Sunazuka, Toshiaki,Kaji, Eisuke,Omura, Satoshi
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experimental part
p. 740 - 749
(2010/06/21)
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- Glycosyl disulfides: Novel glycosylating reagents with flexible aglycon alteration
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Glycosyl disulfides have been shown for the first time to be effective glycosyl donors. Glucosylation and galactosylation of a panel of representative alcohol acceptors allowed the formation of 28 simple glycosides, disaccharides, and glycoamino acids in yields of up to 90%. As well as providing a novel class of effective glycosyl donors, the ability to easily alter the nature of the aglycon and the ability to differently activate donors that differ only in their aglycon simply through altering conditions lends glycosyl disulfide donors to their use in latent-active reactivity tuning strategies.
- Grayson, Elizabeth J.,Ward, Sarah J.,Hall, Alison L.,Rendle, Phillip M.,Gamblin, David P.,Batsanov, Andrei S.,Davis, Benjamin G.
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p. 9740 - 9754
(2007/10/03)
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- Stereoselective O-glycosylation reactions using glycosyl donors with diphenylphosphinate and propane-1,3-diyl phosphate leaving groups
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Glycosyl donors having a diphenylphosphinate and a propane-1,3-diyl phosphate leaving group were easily prepared by the addition of the anomeric hydroxyl group of 2,3,4,6-tetra-O-benzyl-α,β-D-glucopyranose to diphenylphosphinic and propane-1,3- diyldioxyphosphoryl chlorides. These glycosyl donors were selectively glycosylated with a number of primary and secondary oxygen nucleophiles in the presence of trimethylsilyl triflate (TMSOTf). The use of 1,3-diyl phosphate resulted in the stereoselective formation of β-O-linked glycosides.
- Vankayalapati, Hariprasad,Singh, Gurdial,Tranoy, Isabelle
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p. 1373 - 1381
(2007/10/03)
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- Glycosyldisulfides: A new class of solution and solid phase glycosyl donors
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Mixed glycosyl disulfides are not only glycomimetics but also glycosyl donors that may be readily constructed in either armed ether-protected or disarmed ester-protected and in soluble or solid-supported forms from corresponding glycosyl methanethiosulfonates and used in the glycosylation of a variety of representative acceptors.
- Davis,Ward,Rendle
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p. 189 - 190
(2007/10/03)
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- Stereoselective O-glycosylation reactions employing diphenylphosphinate and propane-1,3-diyl phosphate as anomeric leaving groups
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Glycosidation of tetra-O-benzyl-D-glucose using diphenylphosphinate as the leaving group afforded β-O-linked glycosides as the major products, whilst the use of propane-1,3-diyl phosphate as the leaving group resulted in the exclusive formation of β-O-lin
- Hariprasad, Vankayalapati,Singh, Gurdial,Tranoy, Isabelle
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p. 2129 - 2130
(2007/10/03)
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- O-Glycoside Synthesis under Neutral Conditions in Concentrated Solutions of LiClO4 in Organic Solvents Employing Benzyl-Protected Glycosyl Donors
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The benzyl-protectd glucosyl trichloroacetimidates, phosphates, and halides 1 are activated under neutral conditions and without the addition of any further promoter in 1 M solutions of LiCl4 in ether, CH2Cl2, CHCl3, or CH3CN and react under these conditi
- Boehm, Gerd,Waldmann, Herbert
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p. 613 - 620
(2007/10/03)
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- New Synthetic Methods and Reagents for Complex Carbohydrates. VII. Syntheses and Glycosylation Reactions of Glycopyranosyl Dimethylphosphinothioate Series Having a Nonparticipating Group at the C-2 Position
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Several glycopyranosyl dimethylphosphinothioates having a nonparticipating group at the C-2 position could be easily prepared by reactions of the corresponding glycopyranose and dimethylphosphinothioyl chloride using butyllithium as a base in tetrahydrofu
- Yamanoi, Takashi,Nakamura, Kazumi,Sada, Shuji,Goto, Masahiro,Furusawa, Yoji,et al.
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p. 2617 - 2622
(2007/10/02)
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- A Highly Stereoselective Synthesis of α-Glucosides from 1-O-Acetyl Glucose by Use of Tin(IV) Chloride - Silver Perchlorate Catalyst System
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In the presence of a catalytic amount of tin(IV) species generated from tin(IV) chloride and silver perchlorate, 1-O-acetyl-D-glucose stereoselectively reacts with silyl alkoxides to give the corresponding α-glucosides in high yields.
- Mukaiyama, Teruaki,Takashima, Tohru,Katsurada, Manabu,Aizawa, Hiroyuki
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p. 533 - 536
(2007/10/02)
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- GLUCOSYLATION USING GLUCOPYRANOSYL DIMETHYLPHOSPHINOTHIOATE
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Several glucosides were prepared in good yields from 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl dimethylphosphinothioate and alcohols in the presence of silver perchlorate.By this method α-glucosides were predominantly obtained.
- Inazu, Toshiyuki,Hosokawa, Hideaki,Satoh, Yuzuru
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p. 297 - 300
(2007/10/02)
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- Un nouvel agent de glycosylation: l'anhydride trifluoromethanesulfonique. Synthese des α et β O-glycosyl-L-serine, -L-threonine et -L-hydroxyproline
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When 2,3,4,6-tetra-O-benzyl-D-glucopyranose, -D-galactopyranose and 2,3,4-tri-O-benzyl-D-xylopyranose were allowed to react in the cold in dichloromethane or acetonitrile as solvent in the presence of trifluoromethanesulfonic (triflic) anhydride, with methyl or benzyl esters of the N-(benzyloxycarbonyl)-L-serine, -L-threonine, and -L-hydroxyproline, an anomeric mixture of the corresponding O-glycosylaminoacids was obtained (55 to 90percent overall yield), with the α-anomer being predominant.The same experimental procedure was successfully applied to the condensation of the benzyl ester of the N-(benzyloxycarbonyl)-L-hydroxyproline with 2,3,4-tri-O-benzyl-L-arabinopyranose and 2,3,5-tri-O-benzyl-L-arabinofuranose affording the corresponding condensation products with similar yield.Pure α and β anomers were obtained after column chromatography or crystallization with 30 to 65percent yield.Hydrogenolysis of benzyl derivatives afforded the unprotected compounds.Optical rotation, (1)H and (13)C nmr were the main methods used to assess structure and stereochemistry.
- Lacombe, J. M.,Pavia A. A.,Rocheville, J. M.
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p. 473 - 481
(2007/10/02)
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