- Ionic liquid-promoted three-component domino reaction of propargyl alcohols, carbon dioxide and 2-aminoethanols: A thermodynamically favorable synthesis of 2-oxazolidinones
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To circumvent the thermodynamic limitation of the synthesis of oxazolidinones starting from 2-aminoethanols and CO2 and realize incorporation CO2 under atmospheric pressure, a protic ionic liquid-facilitated three-component reaction of propargyl alcohols, CO2 and 2-aminoethanols was developed to produce 2-oxazolidinones along with equal amount of α-hydroxyl ketones. The ionic liquid structure, reaction temperature and reaction time were in detail investigated. And 15 mol% 1,5,7-triazabicylo[4.4.0]dec-5-ene ([TBDH][TFE]) trifluoroethanol was found to be able to synergistically activate the substrate and CO2, thus catalyzing this cascade reaction under atmospheric CO2 pressure. By employing this task-specific ionic liquid as sustainable catalyst, 2-aminoethanols with different substituents were successfully transformed to 2-oxazolidinones with moderate to excellent yield after 12 h at 80 °C.
- Xia, Shumei,Song, Yu,Li, Xuedong,Li, Hongru,He, Liang-Nian
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- AgI/TMG-Promoted Cascade Reaction of Propargyl Alcohols, Carbon Dioxide, and 2-Aminoethanols to 2-Oxazolidinones
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Chemical valorization of CO2 to access various value-added compounds has been a long-term and challenging objective from the viewpoint of sustainable chemistry. Herein, a one-pot three-component reaction of terminal propargyl alcohols, CO2, and 2-aminoethanols was developed for the synthesis of 2-oxazolidinones and an equal amount of α-hydroxyl ketones promoted by Ag2O/TMG (1,1,3,3-tetramethylguanidine) with a TON (turnover number) of up to 1260. By addition of terminal propargyl alcohol, the thermodynamic disadvantage of the conventional 2-aminoethanol/CO2 coupling was ameliorated. Mechanistic investigations including control experiments, DFT calculation, kinetic and NMR studies suggest that the reaction proceeds through a cascade pathway and TMG could activate propargyl alcohol and 2-aminoethanol through the formation of hydrogen bonds and also activate CO2.
- Li, Xue-Dong,Song, Qing-Wen,Lang, Xian-Dong,Chang, Yao,He, Liang-Nian
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p. 3182 - 3188
(2017/10/03)
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- Triazole Derivatives, Process for Preparing the Same and Pharmaceutical Composition Comprising the Same
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The present invention refers to view body prostaglandin E 2 synthase -1 (mPGES-1) inhibitors having excellent effects of triazole derivatives, including as an active ingredient and manufacturing method thereof pharmaceutical composition is disc
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Paragraph 0079; 0080
(2016/11/24)
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- Structural studies on bioactive compounds. 34.1 Design, synthesis, and biological evaluation of triazenyl-substituted pyrimethamine inhibitors of Pneumocystis carinii dihydrofolate reductase
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The triazenyl-pyrimethamine derivative 3a (TAB), a potent and selective inhibitor of Pneumocystis carinii DHFR, was selected as the starting point for a lead optimization study. Molecular modeling studies, corroborated by a recent crystal structure determination of the ternary complex of P. carinii DHFR-NADPH bound to TAB, predicted that modifications to the acetoxy residue of the lead inhibitor could exploit binding opportunities in the vicinity of an active site pocket bounded by residues Ile33, Lys37, and Leu72. Substitutions in the benzyl moiety with electron-donating and electron-withdrawing groups were predicted to probe face-edge interactions with amino acid Phe69 unique to the P. carinii enzyme. New triazenes 10a-v and 12a-f were prepared by coupling the diazonium tetrafluoroborate salt 6b of aminopyrimethamine with substituted benzylamines or phenethylamines. The most potent of the new inhibitors against P. carinii DHFR was the naphthylmethyl-substituted triazene 10t (IC50: 0.053 μM), but a more substantial increase in potency against the rat liver DHFR led to a reduction in selectivity (ratio rat liver DHFR IC50/P. carinii DHFR IC50: 5.36) compared to the original lead structure 3a (ratio rat liver DHFR IC50/P. carinii DHFR IC50: 114).
- Chan,Laughton,Queener,Stevens
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p. 2555 - 2564
(2007/10/03)
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