- Electronically Induced Proton Transfer Reactions in Salicylic Acid Esters and Salicyloyl Chloride
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The multiple fluorescence emission spectra, excitation spectra, and lifetime of isopropyl salicylate, tert-butyl salycilate, and salicyloyl chloride have been analyzed in the gas phase and in cyclohexane and N,N-dimethylformamide solutions.Study of the electronic emission and IR absorption spectra of both esters and methyl salicylate gives further support to the hypothesis of a ground-state equilibrium between two intramolecular H-bonded conformers.The efficiency of the excited-state proton transfer reaction was determined from fluorescence and lifetime data of the 450-nm emission and found to be ca. 40percent lower in tert-butyl than in methyl salicylate.On the other hand, the characteristic fast electronic energy relaxation of these compounds was not sensitive to the carboxyl substituent.Finally, the effect of solvent polarity on the radiationless rate was discussed in terms of the interaction between (?,?*) and (n,?*) states of the zwitterionic structures.
- Catalan, F.,Toribio, J.,Amat, F.,Acuna, A. U.
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- Enantioselective degradation of the organophosphorus insecticide isocarbophos in Cupriavidus nantongensis X1T: Characteristics, enantioselective regulation, degradation pathways, and toxicity assessment
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The chiral pesticide enantiomers often show selective efficacy and non-target toxicity. In this study, the enantioselective degradation characteristics of the chiral organophosphorus insecticide isocarbophos (ICP) by Cupriavidus nantongensis X1T were investigated systematically. Strain X1T preferentially degraded the ICP R isomer (R-ICP) over the S isomer (S-ICP). The degradation rate constant of R-ICP was 42-fold greater than S-ICP, while the former is less bioactive against pest insects but more toxic to humans than the latter. The concentration ratio of S-ICP to R-ICP determines whether S-ICP can be degraded by strain X1T. S-ICP started to degrade only when the ratio (CS-ICP/CR-ICP) was greater than 62. Divalent metal cations could improve the degradation ability of strain X1T. The detected metabolites that were identified suggested a novel hydrolysis pathway, while the hydrolytic metabolites were less toxic to fish and green algae than those from P-O bond breakage. The crude enzyme degraded both R-ICP and S-ICP in a similar rate, indicating that enantioselective degradation was due to the transportation of strain X1T. The strain X1T also enantioselectively degraded the chiral organophosphorus insecticides isofenphos-methyl and profenofos. The enantioselective degradation characteristics of strain X1T make it suitable for remediation of chiral organophosphorus insecticide contaminated soil and water.
- Fang, Liancheng,Xu, Luyuan,Zhang, Nan,Shi, Qiongying,Shi, Taozhong,Ma, Xin,Wu, Xiangwei,Li, Qing X.,Hua, Rimao
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- Isocarbophos semiantigen, and preparation method and application thereof
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A disclosed isocarbophos semiantigen possesses a structural formula shown in the specification. In the formula, -R is -(CH2)5COOH or -PhCOOH. The isocarbophos semiantigen is designed aiming at isocarbophos and is applicable to prepare an isocarbophos antibody. Experiments prove that the prepared isocarbophos antibody is capable of specifically identifying isocarbophos with both relatively good accuracy and sensitivity. The invention also discloses a preparation method and application of the above isocarbophos semiantigen.
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Paragraph 0075
(2017/03/18)
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- Direct Hydroxylation and Amination of Arenes via Deprotonative Cupration
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Deprotonative directed ortho cupration of aromatic/heteroaromatic C-H bond and subsequent oxidation with t-BuOOH furnished functionalized phenols in high yields with high regio- and chemoselectivity. DFT calculations revealed that this hydroxylation reaction proceeds via a copper (I → III → I) redox mechanism. Application of this reaction to aromatic C-H amination using BnONH2 efficiently afforded the corresponding primary anilines. These reactions show broad scope and good functional group compatibility. Catalytic versions of these transformations are also demonstrated.
- Tezuka, Noriyuki,Shimojo, Kohei,Hirano, Keiichi,Komagawa, Shinsuke,Yoshida, Kengo,Wang, Chao,Miyamoto, Kazunori,Saito, Tatsuo,Takita, Ryo,Uchiyama, Masanobu
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supporting information
p. 9166 - 9171
(2016/08/05)
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- Efficient microwave-assisted esterification reaction employing methanesulfonic acid supported on alumina as catalyst
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A rapid and efficient protocol assisted by microwave irradiation for the synthesis of esters using methanesulfonic acid (CH3SO3H) supported on Al2O3 (AMA) as catalyst and free of solvent is described. The products were obtained in good yields and purity, with reduced reaction time, and the process is simple and environmentally benign. Copyright
- Fabian, Lucas,Gomez, Matias,Kuran, Juan A. Caturelli,Moltrasio, Graciela,Moglioni, Albertina
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p. 2386 - 2392
(2014/07/22)
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- SO3H-functionalized Bronsted acidic ionic liquids as efficient catalysts for the synthesis of isoamyl salicylate
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Six Bronsted acidic ionic liquids (BAILs) composed of [HSO 4] were prepared, characterized, and used as catalysts of low dosage in the synthesis of isoamyl salicylate. The effects of various parameters such as the kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of salicylic acid were also examined in detail. The results suggested that the catalytic performances of BAILs were of close relevance to their Hammett acidities. The SO3H-functionalized BAILs 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate ([BSmim][HSO 4]) and N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate ([BSEt3N][HSO4]) of strong acidities exhibited excellently catalytic activities and selectivities in the esterification of salicylic acid with isoamyl alcohol. The fully optimized geometries of [BSmim][HSO4] and [BSEt3N][HSO4] further manifest that their strong acidities are derived from the strong interactions between the anion with the sulfonic acid group. In addition, it was found that [BSmim][HSO4] could be also recovered easily and used repetitively at least six times without obvious decline in activity and quantity.
- Tao, Duan-Jian,Wu, Jing,Wang, Zhen-Zhen,Lu, Zhang-Hui,Yang, Zhen,Chen, Xiang-Shu
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- Esterification of salicylic acid using Br?nsted acidic ionic liquid based on Keggin heteropoly acid
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For the first time, a newwater stable Br?nsted acidic ionic liquid based on Keggin heteroployacid (HPA) was used as environmentally benign catalytic medium in the esterfication of salicylic acid with aliphatic alcohols, CnH2n+1OH (n = 1-5) and benzylic alcohols, RC6H4CH2OH (R = H, NO2, OCH3). This ionic liquid (IL) afforded excellent yield in both thermal conditions and microwave irradiation. Maximum yields were observed under microwave irradiation. Different reaction runs were conducted by varying the reaction parameters such as molar ratio of reactants, weight of the IL, and reaction period in order to optimize the reaction. The IL was easily recovered and reused many times. No significant loss in catalytic activity was observed on recycling.
- Bamoharram, Fatemeh F.,Heravi, Majid M.,Ebrahimi, Javad,Tavakoli-Hoseini, Nilofar
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- PHARMACEUTICAL COMBINATIONS INCLUDING ANTI-INFLAMMATORY AND ANTIOXIDANT CONJUGATES USEFUL FOR TREATING METABOLIC DISORDERS
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One aspect of the present invention is a pharmaceutical combination comprising (a) an anti-inflammatory agent/anti-oxidant agent conjugate; and (b) an insulin secretogogue, an insulin sensitizer, an alpha-glucosidase inhibitor, a peptide analog, or a combination thereof. Another aspect of the invention relates to methods of treating metabolic disorders with such conjugates.
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Page/Page column 89
(2013/03/28)
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- Thiocarbonates as Anti-Inflammatory and Antioxidant Compounds Useful For Treating Metabolic Disorders
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The invention is directed to thiocarbonate compounds of Formula (I)-(III) and methods of treating atherosclerosis, neuropathy, nephropathy, retinopathy, inflammatory disorders, COPD, cardiovascular diseases, metabolic disorders, type I diabetes mellitus, type II diabetes mellitus, LADA, Wolfram Syndrome 1, Wolcott-Rallison syndrome, metabolic syndrome, dyslipidemia, hyperglycemia, or insulin resistance. The compounds of the invention are also useful for protecting pancreatic beta-cells and for reducing free fatty acids, triglycerides, advanced glycated end products, ROS, lipid peroxidation, tissue and plasma TNFalpha and IL6 levels, or for delaying or preventing cardiovascular complications associated with atherosclerosis.
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Page/Page column 26
(2012/06/18)
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- Catalytic performance of nano-SiO2-supported Preyssler heteropolyacid in esterification of salicylic acid with aliphatic and benzylic alcohols
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An efficient and environmentally benign procedure for the catalytic esterification of salicylic acid with aliphatic alcohols, CnH 2n+1OH (n = 1-5) and benzylic alcohols, RC6H 4CH2OH (R = H, NO2, OCH3, Br, Cl, Me) was developed using nano-SiO2-supported Preyssler heteropolyacid both under thermal conditions and microwave irradiation. Silica nanostructures were obtained through a sol-gel method and were characterized by transmission electron microscopy and powder X-ray diffraction. The effects of various parameters such as solvent type, molar ratio of substrates, Preyssler heteropolyacid loading on silica, catalyst amount, temperature, and reaction time were studied and the optimum conditions were obtained. It has been found that the catalyst with 30 wt loading is highly active and shows high yields in esterification reactions. The use of nano-SiO2-supported Preyssler heteropolyacid coupled with microwave irradiation allows a solvent-free, rapid (3 min), and high-yielding reaction. This catalyst can be easily recovered and reused for many times without a significant loss in its activity.
- Bamoharram, Fatemeh F.,Heravi, Majid M.,Ebrahimi, Javad,Ahmadpour, Ali,Zebarjad, Mojtaba
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experimental part
p. 782 - 788
(2012/05/04)
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- Microwave-accelerated esterification of salicylic acid using Br?nsted acidic ionic liquids as catalysts
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A variety of Br?nsted acidic ionic liquids were screened as catalysts for the esterification of salicylic acid. The experimental results indicated that SO3H-functionalized ionic liquids with HSO4- performed high catalytic activity under microwave irradiation, and the yields can reach 91.9-93.6%. Furthermore, ionic liquids can be easily separated by simple decantation and have a fair reusability. The Br?nsted acidity-catalytic activity relationships were also investigated and the results showed that the activity of the acidic ionic liquids is in excellent agreement with their acidity order. Crown Copyright
- Shi, Hua,Zhu, Wenshuai,Li, Huaming,Liu, Hua,Zhang, Ming,Yan, Yongsheng,Wang, Zhigao
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experimental part
p. 588 - 591
(2010/11/05)
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- Potassium phosphate / benzyltriethylammonium chloride as efficient catalytic system for transesterification
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Potassium phosphate (K3PO4) in the presence of benzyltriethylammonium chloride have been found to catalyses the transesterifications of a wide variety of aliphatic and aromatic esters with primary and secondary alcohols affording the corresponding esters in good-to-excellent yields.
- Cepanec, Ivica,Zivkovic, Andreja,Bartolincic, Anamarija,Mikuldas, Hrvoje,Litvic, Mladen,Merkas, Sonja
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experimental part
p. 519 - 523
(2010/01/07)
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- A facile, catalytic and environmentally benign method for esterification of carboxylic acids and transesterification of carboxylic esters with nearly equimolar amounts of alcohols
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A practical and green chemical process for the esterification of carboxylic acids with alcohols and transesterification of carboxylic esters in good to excellent yields by using K5CoW12O14· 3H2O (0.1 mol%) as catalyst is reported. The catalyst exhibited remarkable reusable activity. Georg Thieme Verlag Stuttgart.
- Bose, D. Subhas,Satyender, Apuri,Das, A. P. Rudra,Mereyala, Hari Babu
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p. 2392 - 2396
(2008/02/08)
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- Na2CO3/SOCl2: A mild and convenient reagent for the preparation of isopropyl carboxylates
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Na2CO3/SOCl2 has been used for esterification of aliphatic and aromatic acids with isopropanol. This esterification method is compatible with a wide assortment of functional groups.
- Kazemi, Foad,Kiasat, Ali Reza,Mombaini, Began
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p. 1187 - 1191
(2007/10/03)
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- A mild and effective method for the transesterification of carboxylic acid esters
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An extraordinarily versatile transesterification of simple or highly functionalized esters of aliphatic and aromatic carboxylic acids in high yields is catalyzed by dibutyltin oxide [Eq. (1)]. The reaction is compatible with several functional groups, for example, acetals, ketals, aliphatic bromides, enol ethers, urethanes, as well as free hydroxy, phenolic, and amino groups, and even with water.
- Baumhof, Patrick,Mazitschek, Ralph,Giannis, Athanassios
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p. 3672 - 3674
(2007/10/03)
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- Cobalt schiff base complex promoted retro-claisen reaction of 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanediones and flavone formation
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Co(salpr) promotes the conversion of 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanediones to retro-Claisen reaction products and flavones in methanol under oxygen. Base catalysis by Co(salpr)(OH) produced in situ is responsible for the reaction.
- Nishinaga, Akira,Maruyama, Kazushige,Ando, Hiroyuki,Sato, Ryoji,Mashino, Takahiro,Inada, Akira,Nakanishi, Tsutomu
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p. 3171 - 3174
(2007/10/02)
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