81389-84-6Relevant academic research and scientific papers
ZnCl2-catalyzed Ferrier reaction; Synthesis of 2,3-unsaturated 1-O-glucopyranosides of allylic, benzylic and tertiary alcohols
Bettadaiah,Srinivas
, p. 7257 - 7259 (2003)
Tertiary, allylic and benzylic alcohols react with 3,4,6-tri-O-acetyl-D-glucal in dichloromethane at 25°C in the presence of ZnCl2 to afford the corresponding 2, 3-unsaturated-1-O-glucopyranoside acetates in 65-91% yields, with selective format
Diastereoselective Synthesis of Thioglycosides via Pd-Catalyzed Allylic Rearrangement
Jiang, Xuefeng,Li, Jiagen,Wang, Ming
supporting information, p. 9053 - 9057 (2021/11/30)
Stereoselective glycosylation is challenging in carbohydrate chemistry. Herein, stereoselective thioglycosylation of glycals via palladium-catalyzed allylic rearrangement yields various substituents on α-isomer thioglycosides. Two comprehensive series of aryl and benzyl thioglycosides were obtained via a combination of thiosulfates with glycals derived from glucose, arabinose, galactose, and rhamnose. Furthermore, diosgenyl α-l-rhamnoside and isoquercitrin achieved selectivity via stereospecific [2,3]-sigma rearrangements of α-sulfoxide-rhamnoside and α-sulfoxide-glucoside, respectively.
Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton-Coupled Electron Transfer
Knowles, Robert R.,Metrano, Anthony J.,Tsuchiya, Yuto,Tsui, Elaine
supporting information, p. 11845 - 11849 (2020/05/22)
We report a catalytic, light-driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible-light irradiation in the presence of an IrIII-based photoredox catalyst, a Br?nsted base catalyst, and a hydrogen-atom transfer (HAT) co-catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O?H bonds through a proton-coupled electron-transfer mechanism. This method exhibits a broad substrate scope and high functional-group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented.
Copper(ii)-catalyzed stereoselective 1,2-addition: Vs. Ferrier glycosylation of "armed" and "disarmed" glycal donors
Gurawa, Aakanksha,Kashyap, Sudhir,Kumar, Manoj,Reddy, Thurpu Raghavender
, p. 4848 - 4862 (2020/07/13)
Selective activation of "armed' and "disarmed"glycal donors enabling the stereo-controlled glycosylations by employing Cu(ii)-catalyst as the promoter has been realized. The distinctive stereochemical outcome in the process is mainly influenced by the presence of diverse protecting groups on the donor and the solvent system employed. The protocol is compatible with a variety of aglycones including carbohydrates, amino acids, and natural products to access deoxy-glycosides and glycoconjugates with high α-anomeric selectivity. Notably, the synthetic practicality of the method is amply verified for the stereoselective assembling of trisaccharides comprising 2-deoxy components. Mechanistic studies involving deuterated experiments validate the syn-diastereoselective 1,2-addition of acceptors on the double bond of armed donors.
Robust perfluorophenylboronic acid-catalyzed stereoselective synthesis of 2,3-unsaturated O-, C-, N- And S-linked glycosides
Tatina, Madhu Babu,Mengxin, Xia,Peilin, Rao,Judeh, Zaher M. A.
supporting information, p. 1275 - 1280 (2019/07/08)
A convenient protocol was developed for the synthesis of 2,3-unsaturated C-, O-, N- and S-linked glycosides (enosides) using 20 mol % perflurophenylboronic acid catalyst via Ferrier rearrangement. Using this protocol, D-glucals and L-rhamnals reacted with various C-, O-, N- and S-nucleophiles to give a wide range of glycosides in up to 98% yields with mainly α-anomeric selectivity. The perflurophenylboronic acid successfully catalyzed a wide range of substrates (both glucals and nucleophiles) under very mild reaction conditions.
A Highly Efficient Magnetic Iron(III) Nanocatalyst for Ferrier Rearrangements
Chen, Heshan,Ding, Zekun,Dong, Youxian,Guo, Hong,Jiang, Nan,Qiu, Saifeng,Xu, Xiaoxia,Zhang, Jianbo,Zhou, Le
supporting information, p. 1419 - 1426 (2019/07/15)
A novel and highly efficient magnetic Fe 3 O 4 &at;C&at;Fe(III) core-shell catalyst, in which the carbon shell was prepared from lotus leaf, was fabricated. This nanocatalyst was successfully applied in the synthesis of a series of 2,3-unsaturated O- glycosides in excellent yields and with high selectivity, especially in the case of 2-halo O- glycosides, which differ in reactivity from nonsubstituted O- glycosides, but which have scarcely been explored before. Moreover, the catalyst could be easily separated from the reaction by the application of an external magnetic force and reused a minimum of five times without any significant decrease in the yields of the products. In addition, the reaction proceeded readily on a gram scale, which provides a bright prospect for future applications.
Substrate-Controlled Direct α-Stereoselective Synthesis of Deoxyglycosides from Glycals Using B(C6F5)3 as Catalyst
Sau, Abhijit,Palo-Nieto, Carlos,Galan, M. Carmen
, p. 2415 - 2424 (2019/02/26)
B(C6F5)3 enables the metal-free unprecedented substrate-controlled direct α-stereoselective synthesis of deoxyglycosides from glycals. 2,3-Unsaturated α-O-glycoside products are obtained with deactivated glycals at 75 °C in the presence of the catalyst, while 2-deoxyglycosides are formed using activated glycals that bear no leaving group at C-3 at lower temperatures. The reaction proceeds in good to excellent yields via concomitant borane activation of glycal donor and nucleophile acceptor. The method is exemplified with the synthesis of a series of rare and biologically relevant glycoside analogues.
Montmorillonite-catalyzed glysosylation of alcohols with glycals derived from galactose and glucose under microwave-induced reactions
Yadav, Ram Naresh,Banik, Indrani,Banik, Bimal Krishna
, p. 1385 - 1387 (2020/06/27)
Montmorillonite K10-catalyzed glycosylation of alcohols with glycals obtained from galactose and glucose is performed efficiently using microwave irradiation with good anomeric selectivity.
Synthesis of anti-inflammatory 2,3-unsaturated O-glycosides using conventional and microwave heating techniques
De Melo, Adriana Cristina N.,De Oliveira, Ronaldo N.,De Freitas Filho, Joao R.,Da Silva, Teresinha G.,Srivastava, Rajendra M.
, p. 205 - 211 (2017/07/22)
The preparation of eight 2,3-unsaturated O-glycosides from D-glycals and alcohols, using montmorillonite K-10 as an acid catalyst, is described. The Ferrier rearrangement products were obtained in good yields using conventional heating and microwave irradiation but the reaction time was substantially reduced employing the latter procedure. The yields were slightly lower under microwave exposure. Five of the di-O-acetylated products were deacetylated to the glycosides in excellent yields. The acetylated products possess good antiinflammatory property suggesting that the acetyl group plays an important role in reducing the inflammation. Among the compounds tested, glycosides containing thiophene as an aglycone present much better inflammation reducing characteristics than the analogues without this function.
Hafinium (IV) promoted synthesis of 2,3-unsaturated N- and C-pseudoglycosides via Type I Ferrier Rearrangement
Chen, Peiran,Zhang, Xiaoying
, p. 309 - 312 (2017/01/03)
By using Hf(OTf)4as the catalyst, a series of 2,3-N- and C-unsaturated-glucosides have been synthesized from 3,4,6-tri-O-acetyl-D-glucal, 2,4,6-tri-O-benzyl-D-glucal and ((2R,3S)-3-acetoxy-2,3-dihydrofuran-2-yl)methyl acetate under mild reaction conditions in good yields with high anomeric selectivities.
