- Automated Quantification of Hydroxyl Reactivities: Prediction of Glycosylation Reactions
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The stereoselectivity and yield in glycosylation reactions are paramount but unpredictable. We have developed a database of acceptor nucleophilic constants (Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure high reproducibility and accuracy. A diverse range of glycosylation donors and acceptors with well-defined reactivity and promoters were organized and processed by the designed software program “GlycoComputer” for prediction of glycosylation reactions without involving sophisticated computational processing. The importance of Aka was further verified by random forest algorithm, and the applicability was tested by the synthesis of a Lewis A skeleton to show that the stereoselectivity and yield can be accurately estimated.
- Chang, Chun-Wei,Lin, Mei-Huei,Chan, Chieh-Kai,Su, Kuan-Yu,Wu, Chia-Hui,Lo, Wei-Chih,Lam, Sarah,Cheng, Yu-Ting,Liao, Pin-Hsuan,Wong, Chi-Huey,Wang, Cheng-Chung
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supporting information
p. 12413 - 12423
(2021/05/03)
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- Catalytic and Atom-Economic Glycosylation using Glycosyl Formates and Cheap Metal Salts
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Benzylated glycosyl formates have been synthesized in one step from the corresponding hemiacetal or orthoester with formic acid as the sole reagent. The glycosyl formates are used as glycosyl donors under catalytic conditions with cheap metal catalysts ba
- Hammelev, Christian H.,Pedersen, Christian M.,Yang, Liang
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- α-Selective glycosylations using glycosyl: N-(ortho-methoxyphenyl)trifluoroacetimidates
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Six N-(o-methoxyphenyl)trifluoroacetimidate glycosyl donors have been synthesized and their role as glycosyl donors has been investigated. The donors were synthesized with complete -selectivity, except in one case, and were found to be stable. When Bi(OTf
- Kowalska, Karolina,Pedersen, Christian Marcus
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supporting information
p. 1918 - 1925
(2020/03/23)
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- A Highly Efficient Glycosidation of Glycosyl Chlorides by Using Cooperative Silver(I) Oxide–Triflic Acid Catalysis
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Following our discovery that silver(I) oxide-promoted glycosylation with glycosyl bromides can be greatly accelerated in the presence of catalytic TMSOTf or TfOH, we report herein a new discovery that glycosyl chlorides are even more effective glycosyl do
- Geringer, Scott A.,Singh, Yashapal,Hoard, Daniel J.,Demchenko, Alexei V.
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p. 8053 - 8063
(2020/06/05)
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- Establishment of Guidelines for the Control of Glycosylation Reactions and Intermediates by Quantitative Assessment of Reactivity
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Stereocontrolled chemical glycosylation remains a major challenge despite vast efforts reported over many decades and so far still mainly relies on trial and error. Now it is shown that the relative reactivity value (RRV) of thioglycosides is an indicator for revealing stereoselectivities according to four types of acceptors. Mechanistic studies show that the reaction is dominated by two distinct intermediates: glycosyl triflates and glycosyl halides from N-halosuccinimide (NXS)/TfOH. The formation of glycosyl halide is highly correlated with the production of α-glycoside. These findings enable glycosylation reactions to be foreseen by using RRVs as an α/β-selectivity indicator and guidelines and rules to be developed for stereocontrolled glycosylation.
- Chang, Chun-Wei,Wu, Chia-Hui,Lin, Mei-Huei,Liao, Pin-Hsuan,Chang, Chun-Chi,Chuang, Hsiao-Han,Lin, Su-Ching,Lam, Sarah,Verma, Ved Prakash,Hsu, Chao-Ping,Wang, Cheng-Chung
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p. 16775 - 16779
(2019/11/03)
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- Iron(iii) chloride-catalyzed activation of glycosyl chlorides
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Glycosyl chlorides have historically been activated using harsh conditions and/or toxic stoichiometric promoters. More recently, the Ye and the Jacobsen groups showed that glycosyl chlorides can be activated under organocatalytic conditions. However, thos
- Geringer, Scott A.,Demchenko, Alexei V.
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p. 9133 - 9137
(2019/01/03)
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- Nucleofuge Generating Glycosidations by the Remote Activation of Hydroxybenzotriazolyl Glycosides
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Hydroxybenzotriazole is routinely used in peptide chemistry for reducing racemization due to the increased reactivity. In this article, very stable hydroxybenzotriazolyl glucosides were identified to undergo glycosidation. The reaction was hypothesized to go through the remote activation by the Tf2O at the N3-site of HOBt followed by the extrusion of the oxocarbenium ion that was attacked by the glycosyl acceptor. Further, equilibration of the zwitterionic benzotriazolyl species makes the leaving group noncompetitive and generates the nucleofuge that has been reconverted to the glycosyl donor. The reaction is mild, high yielding, fast and suitable for donors containing both C2-ethers and C2-esters as well. The regenerative-donor glycosidation strategy is promising as it enables us to regenerate the glycosyl donor for further utilization. The utility of the methodology for the oligosaccharide synthesis was demonstrated by the successful synthesis of the branched pentamannan core of the HIV1-gp120 complex.
- Neralkar, Mahesh,Mishra, Bijoyananda,Hotha, Srinivas
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p. 11494 - 11504
(2017/11/10)
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- Iron(iii) chloride modulated selective 1,2-trans glycosylation based on glycosyl trichloroacetimidate donors and its application in orthogonal glycosylation
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The development of a new glycosylation method for efficient stereoselective synthesis of β-gluco- and galactosides from their corresponding armed trichloroacetimidate donors mediated by 10 mole% of FeCl3 has been focused. FeCl3 has a
- Mukherjee, Mana Mohan,Basu, Nabamita,Ghosh, Rina
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p. 105589 - 105606
(2016/11/18)
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- Stereoselective Koenigs–Knorr Glycosylation Catalyzed by Urea
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A stereoselective Koenigs–Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
- Sun, Lifeng,Wu, Xiaowei,Xiong, De-Cai,Ye, Xin-Shan
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supporting information
p. 8041 - 8044
(2016/09/13)
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- Stable Alkynyl Glycosyl Carbonates: Catalytic Anomeric Activation and Synthesis of a Tridecasaccharide Reminiscent of Mycobacterium tuberculosis Cell Wall Lipoarabinomannan
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Oligosaccharide synthesis is still a challenging task despite the advent of modern glycosidation techniques. Herein, alkynyl glycosyl carbonates are shown to be stable glycosyl donors that can be activated catalytically by gold and silver salts at 25 °C in just 15 min to produce glycosides in excellent yields. Benzoyl glycosyl carbonate donors are solid compounds with a long shelf life. This operationally simple protocol was found to be highly efficient for the synthesis of nucleosides, amino acids, and phenolic and azido glycoconjugates. Repeated use of the carbonate glycosidation method enabled the highly convergent synthesis of tridecaarabinomannan in a rapid manner.
- Mishra, Bijoyananda,Neralkar, Mahesh,Hotha, Srinivas
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supporting information
p. 7786 - 7791
(2016/07/07)
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- Synthesis of thioglycosides from propargyl glycosides exploiting alkynophilic gold catalyst
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Various thioglycosides were synthesized from stable propargyl glycosides using catalytic quantity of AuBr3 and various thiol aglycons. The current protocol enables preparation of thioglycosides from propargyl glycosides in an efficient and simp
- Vidadala, Srinivasa Rao,Thadke, Shivaji A.,Hotha, Srinivas,Kashyap, Sudhir
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p. 241 - 251
(2012/07/27)
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- 2-Allylphenyl glycosides as glycosyl donors for sugar coupling
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Glycosylations employing 2-allylphenyl glycoside, a new type of stable glycosyl donor, were optimized and explored with a variety of acceptors promoted by ICl/AgOTf. The utility of the protocol was further demonstrated with an efficient synthesis of the disaccharide fragment of bleomycins.
- Luo, Shun-Yuan,Tripathi, Ashish,Zulueta, Medel Manuel L.,Hung, Shang-Cheng
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p. 197 - 201
(2012/06/30)
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- Stereoselective direct glycosylation with anomeric hydroxy sugars by activation with phthalic anhydride and trifluoromethanesulfonic anhydride involving glycosyl phthalate intermediates
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An efficient direct one-pot glycosylation method with anomeric hydroxy sugars as glycosyl donors employing phthalic anhydride and triflic anhydride as activating agents has been developed. Thus, highly stereoselective β-mannopyranosylations were achieved
- Kwan, Soo Kim,Fulse, Dinanath Baburao,Ju, Yuel Baek,Lee, Bo-Young,Heung, Bae Jeon
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supporting information; experimental part
p. 8537 - 8547
(2009/02/02)
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- IPy2BF4-mediated glycosylation and glycosyl fluoride formation
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A facile method to convert thioglycosides to glycosyl fluorides with Ipy2BF4 (py = pyridine) is presented. Alternatively, activation of thioglycosides with Ipy2BF4 in the presence of acids and glycosyl acceptors
- Huang, Kuo-Ting,Winssinger, Nicolas
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p. 1887 - 1890
(2008/02/06)
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- A new efficient glycosylation method employing glycosyl pentenoates and PhSeOTf
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The PhSeOTf promoted glycosylations of various glycosyl acceptors with mannosyl pentenoates and glucosyl pentenoates as glycosyl donors afforded corresponding disaccharides in high yields. And the present glycosyl pentenoates/PhSeOTf method showed that th
- Choi, Tae Jin,Baek, Ju Yuel,Jeon, Heung Bae,Kim, Kwan Soo
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p. 9191 - 9194
(2007/10/03)
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- Glycosyl trichloroacetylcarbamate: A new glycosyl donor for O-glycosylation
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Glycosyl trichloroacetylcarbamates, readily obtained by reacting 1-hydroxy sugars with trichloroacetylisocyanate, have been found as excellent glycosyl donors, and the corresponding O-glycosides are formed in good to excellent yields with a fairly good degree of selectivity.
- Jayakanthan,Vankar, Yashwant D.
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p. 2688 - 2692
(2007/10/03)
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- Potent, versatile, and stable: Thiazolyl thioglycosides as glycosyl donors
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Donating with a difference: Thiazolyl (Taz) substituted thioglycosides have been successfully used in the synthesis of both 1,2-trans- and 1,2-cis-glycosides and also have found application in convergent oligosaccharide synthesis. In addition, this study
- Demchenko, Alexei V.,Pornsuriyasak, Papapida,De Meo, Cristina,Malysheva, Nelli N.
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p. 3069 - 3072
(2007/10/03)
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- 6-Nitro-2-benzothiazolyl α-Glucoside and α-Mannoside in β-Selective Glycosylations
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Highly β-selective glucosylations of glycosyl acceptors having α primary hydroxy group with a 6-nitro-2-benzothia-zolyl α-glucoside donor 3α proceeded smoothly in the presence of a catalytic amount of trifluoromethanesulfonic acid (TfOH) in CH 2Cl2 at -78 °C to afford the corresponding glycosides in high yields. With the use of 3α, β-saccharides could be obtained more dominantly than other α-glucosyl donors such as thioform- and trichloroacet-imidates or fluoride in the glucosylation under the same conditions. Similarly, highly β-selective mannosylations of glycosyl acceptors with a 6-nitro-2-benzothiazolyl α-mannoside donor 18α were carried out smoothly in the presence of a catalytic amount of tetrakis(pentafluorophenyl)boric acid H[B(C6F5) 4] to afford the corresponding disaccharides in good to high yields; 18α apparently behaved as a potent donor here for the construction of β-mannoside linkage. Interestingly, in situ anomerization from 18β to 18α was observed when β-mannosyl donor 18β was treated with a catalytic amount of H[B(C6F5)4] in CH 2Cl2.
- Hashihayata, Takashi,Mandai, Hiroki,Mukaiyama, Teruaki
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p. 169 - 178
(2007/10/03)
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- Stereocontrolled glycosidations using a heterogeneous solid acid, sulfated zirconia, for the direct syntheses of α- and β-manno- and 2-deoxyglucopyranosides
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Novel α- and β-stereocontrolled glycosidations using a heterogeneous solid acid, sulfated zirconia (SO4/ZrO2), as an activator have been developed. The glycosidations of manno- and 2-deoxyglucopyranosyl α-fluorides with several alcoh
- Toshima, Kazunobu,Nagai, Hideyuki,Kasumi, Ken-Ichi,Kawahara, Kanako,Matsumura, Shuichi
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p. 5331 - 5339
(2007/10/03)
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- Glycosylation with 2′-carboxybenzyl glycosides as glycosyl donors: Scope and application to the synthesis of a tetrasaccharide
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Glycosylation of 2′-carboxybenzyl (CB) 2,3,4,6-tetra-O-benzyl-α-D-mannopyranoside (3), CB 2,3,4,6-tetra-O-benzyl-β-D-glucopyranoside (4), and CB 2,3-di-O-benzyl-4,6-O-benzylidene-β-D-glucopyranoside (5) as glycosyl donors with various glycosyl acceptors p
- Kim, Kwan Soo,Kang, Sung Soo,Seo, Yong Sung,Kim, Hyo Jin,Lee, Yong Joo,Jeong, Kyu-Sung
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p. 1311 - 1314
(2007/10/03)
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- Catalytic and β-stereoselective mannosylation of several glycosyl acceptors with mannosyl 6-nitro-2-benzothiazoate
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Mannosylation of several glycosyl acceptors with a novel mannosyl donor having the 6-nitro-2-benzothiazoate function at an anomeric position proceeded smoothly in the presence of a catalytic amount of tetrakis(pentafluorophenyl)boric acid [HB(C6/sub
- Hashihayata, Takashi,Mandai, Hiroki,Mukaiyama, Teruaki
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p. 442 - 443
(2007/10/03)
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- Glycosyl 2-pyridinecarboxylate as an effective glycosyl donor: Glycosidation of mannose, 2-azidosugar, and 2-deoxysugar into disaccharides
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Glycosylation reactions using a glycosyl 2-pyridinecarboxylate as a glycosyl donor were performed. Glycosyl 2-pyridinecarboxylate was designed based on a variation of the Remote Activation Concept and is activated through bidentate coordination to mild Le
- Furukawa, Hironori,Koide, Kazunori,Takao, Ken-Ichi,Kobayashi, Susumu
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p. 1244 - 1247
(2007/10/03)
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- Preparation of glycosyl dimethylthiophosphates and their application as glycosyl donors
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Benzyl- and acetyl-protected glycosyl dimethylthiophosphates were readily prepared from corresponding 1-hydroxyl sugars in good yield, and acted as very stable and efficient glycosyl donors in the construction of glycosidic bonds in the presence of variou
- Zhang, Guangtao,Yu, Biao,Deng, Shaojiang,Hui, Yongzheng
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p. 547 - 556
(2007/10/03)
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- Novel stereocontrolled glycosidations using a solid acid, SO4/ZrO2, for direct syntheses of α- and β-mannopyranosides
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Novel stereocontrolled glycosidations using an environmentally friendly solid acid, sulfated zirconia (SO4/ZrO2), for direct syntheses of α- and β-mannopyranosides have been developed. The glycosidations of the totally benzylated mannopyranosyl fluoride 1 and various alcohols using SO4/ZrO2 in CH3CN at 40°C for 15 h exclusively gave the corresponding α-mannopyranosides. On the other hand, the corresponding β-mannopyranosides were selectively obtained by the glycosidations of 1 and various alcohols employing SO4/ZrO2 in the presence of molecular sieves 5A? in Et2O at 25°C for 15 h.
- Toshima, Kazunobu,Kasumi, Ken-Ichi,Matsumura, Shuichi
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p. 643 - 645
(2007/10/03)
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- Dehydrative glycosylation by diethylaminosulfur trifluoride (DAST) - tin(II) trifluoromethanesulfonate-tetrabutylammonium perchlorate - triethylamine system
-
Dehydrative glycosylation using 2,3,4,6-tetra-O-benzyl-D-glucopyranose was carried out by the use of a condensing reagent system composed of diethylaminosulfur trifluoride (DAST), tin(II) triflate, tetrabutylammonium perchlorate, and triethylamine. Using this system, two tetrasaccharides, O- a-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→3)-Oα-D-glucopyranosyl- (1→4)-D-glucopyranose and O-a-D-glucopyranosyl-(1→3)-O-α-D- glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→4)-D-glucopyranose, were synthesized.
- Hirooka, Motoko,Koto, Shinkiti
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p. 2893 - 2902
(2007/10/03)
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- The synthesis of some epoxyalkyl β-C-glycosides as potential inhibitors of β-glucan hydrolases
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The treatment of tetra-O-benzyl-D-glucono-1,5-lactone with various alkenylmagnesium halides gave the intermediate lactols which, upon reduction (Et3SiH/BF3) and protecting group manipulation, yielded alkenyl tetra-O-acetyl-β-D-C-gluc
- Best, Wayne M.,Ferro, Vito,Harle, Julia,Stick, Robert V.,Tilbrook, D. Mathew G.
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p. 463 - 472
(2007/10/03)
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- GLYCOSYLATION USING GLYCOSYL PHOSPHITE AS A GLYCOSYL DONOR
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Glycosylation using glycosyl phosphites as glycosyl donors in the presence of a Lewis acid such as ZnCl2 or ZnCl2-AgClO4 has afforded the glycosides including sialoglycosides in good yields.
- Watanabe, Yutaka,Nakamoto, Chikara,Yamamoto, Takashi,Ozaki, Shoichiro
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p. 6523 - 6536
(2007/10/02)
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- 'Dibutyltin diperchlorate' for activation of glycosyl fluoride
-
The Bu2SnCl2-2AgClO4 combination shows promise as an activator for glycosyl fluorides, as revealed by experiments with 2,3,4,6-tetra-O-benzyl-α-D-mannosyl fluoride as a model glycosyl donor in comparison with activators prepared in situ from five types of organotin chlorides (Bu2SnCl2, Me2SnCl2, Bu3SnCl, Me3SnCl, and Ph3SnCl) in combination with silver perchlorate. The Bu2SnCl2-2AgClO4 combination shows promise as an activator for glycosyl fluorides, as revealed by experiments with 2, 3,4,6-tetra-O-benzyl-α-D-mannosyl fluoride as a model glycosyl donor in comparison with activators prepared in situ from five types of organotin chlorides (Bu2SnCl2, Me2SnCl2, Bu3 SnCl, Me3SnCl, and Ph3SnCl) in combination with silver perchlorate.
- Maeta,Matsumoto,Suzuki
-
-
- Cp2ZrCl2-AgBF4 IN BENZENE: A NEW REAGENT SYSTEM FOR RAPID AND HIGHLY SELECTIVE Α-MANNOSIDE SYNTHESIS FROM TETRA-O-BENZYL-D-MANNOSYL FLUORIDE
-
Combination of Cp2ZrCl2-AgBF4 (molar ratio= 0.5:1) is highly effective in promoting rapid and high-yield glycosidation of tetra-O-benzyl-D-mannopyranosyl fluoride.Yields are excellent in all cases examined and high α-selectivity is achievable by the reaction in benzene at room temperature.
- Suzuki, Keisuke,Maeta, Hideki,Suzuki, Toshiyuki,Matsumoto, Takashi
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p. 6879 - 6882
(2007/10/02)
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- Direct Elaboration of Pent-4-enyl Glycosides Into Disaccharides
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Pent-4-enyl glycosides, on treatment with halonium ions, become chemospecifically activated so that coupling with partially protected monosaccharides can be effected, leading to the in situ formation of disaccharides.
- Fraser-Reid, Bert,Konradsson, Peter,Mootoo, David R.,Udodong, Uko
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p. 823 - 825
(2007/10/02)
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- α-D-glucosylation by 6-O-Acetyl-2,3,4-tri-O-benzyl-D-glucopyranose Using Trimethylsilyl Triflate and Pyridine. Synthesis of α-Maltosyl and α-isomaltosyl α-D-Glucosides
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The D-glucosylation of methyl 2,3,4-tri-O-benzyl-α-D-glucopyranoside and methyl 2,3,6-tri-O-benzyl-β-D-glucupyranoside by 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose using pyridine and excess trimethylsilyl triflate was carried out in dichloromethane, 1,2 dimethoxyethane, and acetonitrile.In a given solvent, the selectivity of the reaction varied depending on the type of hydroxyl group of the glucosyl acceptors.The D-glucosylation of these acceptors with 6-O-acetyl-2,3,4-tri-O-benzyl-D-glucopyranose employing this reagent system in dichloromethane proceeded with good α-selectivity irrespective of the type of the hydroxyl group.This α-D-glucosylation was applied for the synthesis of O-α-D-glucopyranosyl-(1->4)- and -(1->6)-α-D-glucopyranosyl α-D-glucopyranosides from α,α-trehalose.
- Koto, Shintiki,Yago, Kazuo,Zen, Shonosuke,Tomonaga, Fumiya,Shimada, Shigehiko
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p. 411 - 414
(2007/10/02)
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- A STEREOSELECTIVE α-GLUCOSYLATION BY USE OF A MIXTURE OF 4-NITROBENZENESULFONYL CHLORIDE, SILVER TRIFLUOROMETHANESULFONATE, N,N-DIMETHYLACETAMIDE, AND TRIETHYLAMINE
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Stereoselective α-glucosylation of partially protected carbohydrates with 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose in dichloromethane, in the presence of a quaternary mixture of 4-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, N,N-dimethylacetamide, and triethylamine gave O-α-D-glucopyranosyl-(1->4)- and -(1->6)-2-acetamido-2-deoxy-D-glucopyranose (N-acetylmaltosamine and N-acetylisomaltosamine).A step-by-step synthesis of O-α-D-glucopyranosyl-(1->4)-O-6)>-D-glucopyranose is described.
- Koto, Shinkiti,Morishima, Naohiko,Owa, Miho,Zen, Shonosuke
-
-
- DEHYDRATIVE α-GLUCOSYLATION USING A MIXTURE OF p-NITROBENZENESULFONYL CHLORIDE, SILVER TRIFLUOROMETHANESULFONATE, N,N-DIMETHYLACETAMIDE, AND TRIETHYLAMINE
-
Stereoselective synthesis of α-linked di- and trisaccharides is performed by the one-stage glucosylation using 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose and a mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, N,N-dimethylacetami
- Morishima, Naohiko,Koto, Shinkiti,Zen, Shonosuke
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p. 1039 - 1040
(2007/10/02)
-