- Triflic Imide-Catalyzed Glycosylation of Disarmed Glycosyl ortho-Isopropenylphenylacetates and ortho-Isopropenylbenzyl Thioglycosides
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Glycosylation reaction involving the coupling of a glycosyl donor with a glycosyl acceptor is one of the cornerstones of chemical preparation of pure glycans and glycoconjugates of biological relevance. Catalytic glycosylation of glycosyl ester donors and thioglycosides is an attractive but underexplored topic in carbohydrate chemistry. Herein, triflic imide (Tf2NH)-catalyzed glycosylation of various O-, S-, and C-nucleophiles has been achieved using disarmed glycosyl ortho-isopropenylphenylacetates (GIPPAs) and ortho-isopropenylbenzyl thioglycosides as glycosylating agents. The reactions proceed under mild conditions to give the desired glycosides in good-to-excellent yields. Of particular note, the comparable reactivity for the α-isomers and the β-ones of GIPPAs is observed. The mechanistic investigation demonstrates that the isopropenyl group is essential for the reaction and its preferential protonation triggers the reaction. This work provides another member to the arsenals of glycosyl ester and thioglycoside donors suitable for acid-catalyzed glycosylation to create various glycosidic bonds.
- Qiao, Zhi,Wang, Peng,Ni, Jingxuan,Li, Dongwei,Sun, Yao,Li, Tiantian,Li, Ming
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- C- ARYL GLYCOSID DERIVATIVES, PHARMACEUTICAL COMPOSITION, PREPARATION PROCESS AND USES THEREOF
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This invention relates to a kind of C-aryl glycoside derivatives, its pharmaceutical compositions, preparation methods, and uses thereof. The preparation method comprises: method 1: in a solvent, deprotecting the acetyl protecting groups of compound 1-f in the presence of a base; method 2: 1) compound 2-g reacts with via Mitsunobu reaction; 2) deprotecting the acetyl protecting groups of compound 2-f obtained from step 1; method 3: 1) compound 2-g reacts with via nucleophilic substitution reaction; 2) deprotecting the acetyl protecting groups of compound 3-f obtained from step 1. The pharmaceutical composition comprises a kind of C-aryl glycoside derivatives; it's pharmaceutically acceptable salts and/or prodrugs thereof and excipient thereof. This invention further relates to a kind of C-aryl glycoside derivatives, it's pharmaceutically acceptable salts or pharmaceutical compositions thereof for the use in preparation of a SGLT inhibitor. The C-aryl glycoside derivatives of this invention provides a new direction for the study of SGLT inhibitors.
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- Synthesis of isothiochromenes and 1,3-dihydrobenzo[c]thiophenes by iodine- and hydrobromic acid-mediated cyclizations of o-[(tert-butylsulfanyl)methyl)]styrenes
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Methods for the syntheses of 4-substituted isothiochromenes and 1,1-disubstituted 1,3-dihydrobenzo[c]thiophenes have been developed. Thus, treatment of α-substituted o-[(tert-butylsulfanyl)methyl]styrenes, derived from α-substituted o-bromostyrenes using
- Kobayashi, Kazuhiro,Ueyama, Takuma,Horiuchi, Mai
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p. 2065 - 2079
(2017/11/21)
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- Preparation of conformationally constrained α2 antagonists: The bicyclo[3.1.0]hexane approach
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The aim of the research was to discover antagonists at α2 receptor subtypes potentially more selective than known compounds. We focused on new, conformationally restricted analogues of atipamezole. The key step in the synthetic sequences leading to target compounds relied on a rhodium-catalyzed intramolecular cyclopropanation reaction, the outcome of which varied with the nature of the diazo styrene precursor. Thus, depending on the substitution pattern of the double bond and the electronic properties of the diazo precursors, the cyclopropanes 2 or 7, naphtalenes 8, or pyrazolines 17 were formed. The byproducts 8 and 17 originated from different, nonoverlapping mechanisms. Among the racemates synthesized, three compounds (1a, 22a, and 22b) showed increased selectivity for α2A vs. α2B and α2C receptor subtypes, and consequently were prepared in enantiomerically pure form. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Bonnaud, Bernard,Funes, Philippe,Jubault, Nathalie,Vacher, Bernard
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p. 3360 - 3369
(2007/10/03)
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