- Synthesis of isophthalates from methyl coumalate
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Methyl coumalate reacts with enol ethers to form stable adducts which can be converted into isophthalates in good to excellent yields. Alkyl vinyl ethers afford higher yields of isophthalates than enol silyl ethers. The adduct of the enol silyl ether of acetophenone with methyl coumalate reacted with PTSA to produce a styryl coumalate.
- Kraus, George A.,Wang, Shuai
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- Surface-enhanced infrared absorption of DMIP on gold-germanium substrates coated by self-assembled monolayers
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Gold islands coated with self-assembled monolayers of three enough different thiols - thiophenol, propanethiol and octadecanethiol - are shown to enable the detection of molecules without polar groups, such as dimehylisophthalate (DMIP), using Surface enhanced infrared absorption (SEIRA). Binding of thiols was studied using SERS and SEIRA. The careful comparison of the transmission and p-polarized external reflection SEIRA spectra of DMIP taken using the modified substrates, with the corresponding spectra taken on the uncoated gold-Ge and bare Ge and CaF2 surfaces, has allowed to elucidate the role played by the underlayer substrate and the different thiols in the total observed enhancement effect. Furthermore, the DMIP orientation with respect to the gold surface for each thiol-coating has also been deduced, confirming that the surface selection rule in our case applies both to reflection and transmission SEIRA spectra. No SERS spectra of DMIP, either on the modified or on the uncoated gold substrates, were revealed.
- Domingo,García-Ramos,Sánchez-Cortés,Aznarez
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- A supramolecular porous material comprising Fe(ii) mesocates
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The dinuclear mesocate [Fe2L3](BF4)4, 1, is a supramolecular building block for a microporous material. Structural analysis reveals that extensive noncovalent interactions in the solid state generate a 3D framework with microporous channels. These channels are permanently accessible to incoming guest molecules and adsorption isotherms demonstrate that the material has a high selectivity for CO2 over N2
- Wilson, Benjamin H.,Scott, Hayley S.,Qazvini, Omid T.,Telfer, Shane G.,Mathonière, Corine,Clérac, Rodolphe,Kruger, Paul E.
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- Electrochemical Reduction of Pyridine- and Benzene-Substituted n-Alkyl Esters and Thioic S-Esters in Acetomtrile
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Bulk controlled potential electrolysis experiments have been performed on a wide range of n-alkyl- substituted esters and thioic S-esters of pyridine and benzene in dry acetonitrile with tetraalkylammonium salts as the supporting electrolyte. In most cases, the bulk one-electron reduction of oxygen esters results in unstable or semistable radicals being formed that decompose via loss of the alkyl radical to leave the carboxylate anion in high yield (ca. 70-100%). Benzoate and dinicotinate esters are the exception to this where the final decomposition products are numerous and complicated. For the thioic S-esters, two types of decomposition mechanism have been identified as operating depending on the stability of their anion radicals. Thioic S-ester radical anions that are very unstable (lifetimes in the order of several milliseconds) decompose with loss of the thiolate ion to leave a neutral acyl radical that undergoes aromatic substitution reactions with other acyl radicals to form, among other products, γ-lactones. Thioic S-esters radical anions that are stable for many minutes to hours ultimately decompose via reaction with molecular oxygen to form carboxylate anions.
- Webster, Richard D.,Bond, Alan M.
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- Novel Isophthalohydrazide-cDB24C8 cryptand derivative for the selective recognition of fluoride ion: An experimental and DFT study
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A highly selective and sensitive novel Isophthalohydrazide-cDB24C8 cryptand derivative was developed for fluoride recognition at a very low concentration of 2.31 × 10?10 M. The binding was established by UV–Vis, fluorescence and 1H NMR titration. The receptor formed very strong H-bonded complex with fluoride, furnished a sharp new UV–Vis absorption peak at 280 nm which was also supported by the DFT-study. The fluorescence emission spectra showed large quenching up to 79.13% upon addition of fluoride.
- Bora, Sankar Jyoti,Dutta, Rakesh,Kalita, Dhruba Jyoti,Chetia, Bolin
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- Carboxyl Methyltransferase Catalysed Formation of Mono- and Dimethyl Esters under Aqueous Conditions: Application in Cascade Biocatalysis
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Carboxyl methyltransferase (CMT) enzymes catalyse the biomethylation of carboxylic acids under aqueous conditions and have potential for use in synthetic enzyme cascades. Herein we report that the enzyme FtpM from Aspergillus fumigatus can methylate a broad range of aromatic mono- and dicarboxylic acids in good to excellent conversions. The enzyme shows high regioselectivity on its natural substrate fumaryl-l-tyrosine, trans, trans-muconic acid and a number of the dicarboxylic acids tested. Dicarboxylic acids are generally better substrates than monocarboxylic acids, although some substituents are able to compensate for the absence of a second acid group. For dicarboxylic acids, the second methylation shows strong pH dependency with an optimum at pH 5.5–6. Potential for application in industrial biotechnology was demonstrated in a cascade for the production of a bioplastics precursor (FDME) from bioderived 5-hydroxymethylfurfural (HMF).
- Ashbrook, Chloe,Carnell, Andrew J.,Goulding, Ellie,Hatton, Harry,Johnson, James R.,Kershaw, Neil M.,McCue, Hannah V.,Rigden, Daniel J.,Ward, Lucy C.
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supporting information
(2022/02/21)
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- Br?nsted acid-catalyzed chlorination of aromatic carboxylic acids
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The chlorination of aromatic carboxylic acids with SOCl2 has been effectively performed by reacting with a Br?nsted acid as the catalyst. Based on this discovery, an efficient catalytic method that is cheaper than traditional catalytic methods was developed. 20 substrates were chlorinated offering excellent yields in a short reaction time. And the SOCl2/Br?nsted acid system has been used in a larger scale preparative reaction. A dual activation mechanism was proposed to prove the irreplaceable system of SOCl2/Br?nsted acid.
- Yu, Zhiqun,Yao, Hongmiao,Xu, Qilin,Liu, Jiming,Le, Xingmao,Ren, Minna
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supporting information
p. 685 - 689
(2021/04/09)
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- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
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Paragraph 0175; 0250-0252
(2021/06/22)
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- Mild Copper-Catalyzed Addition of Arylboronic Esters to Di- tert -butyl Dicarbonate: An Easy Access to Methyl Arylcarboxylates
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An efficient copper-catalyzed addition of arylboronic esters to (Boc) 2O was developed. The reaction can be conducted under exceedingly mild conditions and is compatible with a variety of synthetically relevant functional groups. It therefore represents a useful alternative route for the synthesis of methyl arylcarboxylates. A preliminary mechanistic study indicated the involvement of an addition-elimination mechanism.
- Xu, Jin-Di,Su, Xiao-Bo,Wang, Cai,Yao, Li-Wei,Liu, Jing-Hui,Hu, Guo-Qin
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supporting information
p. 833 - 837
(2021/02/26)
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- Method for coproducing methyl benzoic acid Process for the production of methyl benzoates and diesters of phthalic acids
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The invention discloses a coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester. The method comprises the following steps: (1) continuously introducing xylene, a catalyst and oxygen-containing gas into an oxidation reactor for a reaction, and controlling oxygenic concentration in the tail gas to not exceed 5% by controlling introduction amount of the oxygen-containing gas to obtain an oxidation reaction liquid; (2) feeding the obtained oxidation reaction liquid into a predistillation tower for distillation separation to obtain a low-boiling-point component and a predistillation tower bottom liquid; (3) feeding the predistillation tower bottom liquid into a distillation tower for distillation to obtain a methylbenzoic acid product and a distillationtower bottom liquid; (4) mixing the distillation tower bottom liquid and alcohol for an esterification reaction, and controlling the reaction endpoint to be lower than 0.5wt% of the content of methylbenzoic acid to obtain an esterification reaction liquid; (5) performing distillation separation on the obtained esterification reaction liquid to obtain methyl benzoate and benzenedicarboxylic acid diester products. The method has the advantages that the process is simple, equipment investment is low, and the method is environmentally friendly and has good comprehensive economic benefits.
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Paragraph 0125-0175
(2021/02/09)
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- Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
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The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.
- Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
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supporting information
p. 3370 - 3378
(2020/10/02)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- Reducing dehalogenating method of organic halogenated compound
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The invention discloses a reducing dehalogenating method of an organic halogenated compound. The reducing dehalogenating method comprises: mixing an organic halogenated compound R-X, a non-noble metalpromoter, a sulfide and an alkali, and carrying out a reducing dehalogenating reaction to obtain a reducing product R-H, wherein R is at least one selected from alkyl and aryl, and X is at least oneselected from iodine, bromine and chlorine. According to the present invention, the types and the ratio (especially the specific type of the promoter) of various raw materials used in the reducing dehalogenating reaction, the corresponding reaction conditions and the like are researched and improved, such that the problems of use of highly-toxic or expensive reagent, poor tolerance of the group, narrow application range of the substrate and the like in the prior art can be effectively solved.
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Paragraph 0111; 0112; 0113
(2019/02/10)
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- Multi-targeted dihydrazones as potent biotherapeutics
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Hydrazone compounds were considered as a useful moiety in drug design development. Therefore, these studies were aimed at the synthesis of new dihydrazones and were screened for their in vitro H+/K+-ATPase and anti-inflammatory activities. The results revealed that compounds 9 (22 ± 0.62 μg/mL), 10 (26 ± 0.91 μg/mL), 15 (24 ± 0.44 μg/mL), 16 (28 ± 0.63 μg/mL), 17 (12 ± 0.38 μg/mL), 18 (14 ± 0.47 μg/mL), 19 (26 ± 0.54 μg/mL), 20 (16 ± 0.41 μg/mL), 25 (06 ± 0.68 μg/mL) and 26 (08 ± 0.43 μg/mL) showed excellent H+/K+-ATPase activity and their IC50 value were lower than the standard drug Omerazole (48 ± 0.12 μg/mL). Compounds 5 (28 ± 0.65 μg/mL), 6 (24 ± 0.61 μg/mL), 7 (28 ± 0.64 μg/mL), 8 (26 ± 0.45 μg/mL), 11 (30 ± 0.74 μg/mL), 12 (28 ± 0.40 μg/mL), 13 (32 ± 0.24 μg/mL), 14 (30 ± 0.55 μg/mL) and 21 (08 ± 0.47 μg/mL), 22 (12 ± 0.47 μg/mL), 23 (10 ± 0.51 μg/mL) and 24 (14 ± 0.84 μg/mL) showed better anti-inflammatory activity compared to standard indomethacin (44 ± 0.15 μg/mL). The structure activity relationship (SAR) showed that, electron donating groups (OH, OCH3) favored the H+/K+-ATPase and antioxidants activity, whereas, electron withdrawing groups (F, Cl, Br and NO2) favored the anti-inflammatory activity. Furthermore, molecular docking study was performed to investigate the binding interactions of the most active analogs with the active site of H+/K+-ATPase enzyme. Compounds 25 (G-score = ?9.063) and 26 (G-score = ?8.977) showed the highest docking G-scores for H+/K+-ATPase inhibition activity.
- Li, Chen,Sridhara,Rakesh,Vivek,Manukumar,Shantharam,Qin, Hua-Li
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supporting information
p. 389 - 395
(2018/09/13)
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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- Promising bactericidal approach of dihydrazone analogues against bio-film forming Gram-negative bacteria and molecular mechanistic studies
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Gram-negative members of the ESCAPE family are more difficult to treat, due to the presence of an additional barrier in the form of a lipopolysaccharide layer and the efficiency of efflux pumps to pump out the drugs from the cytoplasm. The development of alternative therapeutic strategies to tackle ESCAPE Gram-negative members is of extreme necessity to provide a solution to the cause of life-threatening infections. The present investigations demonstrated that compounds 17, 20, 25 and 26 possessing the presence of electron donating (OH and OCH3) groups on the phenyl rings are highly potent; whereas compounds 9, 10, 15, 16, 18, 33 and 36 showed moderate activity against Gram-negative bacteria. An excellent dose-dependent antibacterial activity was established compared to that of the standard antibiotic ampicillin. Significant anti-biofilm properties were measured quantitatively, showing optical density (O.D) values of 0.51 ± 015, 0.63 ± 0.20, 0.38 ± 0.07 and 0.62 ± 0.11 at 492 nm and the leakage of cellular components by the compounds, such as 17, 20, 25 and 26, increased the O.D. of respective treated samples compared to the control. In addition, the implication of experimental results is discussed in the light of the lack of survivability of planktonic bacteria and biofilm destruction in vitro. These results revealed the great significance of the development of a new generation of synthetic materials with greater efficacy in anti-biofilm properties by targeting to lock the bio-film associated protein Bap in Gram-negative bacteria.
- Rakesh,Vivek,Manukumar,Shantharam,Bukhari,Qin, Hua-Li,Sridhara
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p. 5473 - 5483
(2018/04/30)
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- Protection of COOH and OH groups in acid, base and salt free reactions
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We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
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- Methylation of Aliphatic and Aromatic Carboxylic Acids with Dimethyl Carbonate under the Influence of Manganese and Iron Carbonyls
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The synthesis of methyl esters has been carried out via the reaction of aliphatic and aromatic carboxylic acids with dimethyl carbonate in the presence of manganese and iron carbonyls. The optimal ratio of catalyst and reagents and other conditions for the synthesis of methyl esters of carboxylic acids with high yield have been found.
- Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.
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- Oxalic acid as the: In situ carbon monoxide generator in palladium-catalyzed hydroxycarbonylation of arylhalides
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An efficient palladium-catalyzed hydroxycarbonylation reaction of arylhalides using oxalic acid as a CO source has been developed. The reaction features high safety, low catalyst loading, and a broad substrate scope, and provides a safe and tractable approach to access a variety of aromatic carboxylic acid compounds. Mechanistic studies revealed the decomposition pattern of oxalic acid.
- Shao, Changdong,Lu, Ailan,Wang, Xiaoling,Zhou, Bo,Guan, Xiaohong,Zhang, Yanghui
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supporting information
p. 5033 - 5040
(2017/07/10)
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- Visible-Light-Driven Carboxylation of Aryl Halides by the Combined Use of Palladium and Photoredox Catalysts
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A highly useful, visible-light-driven carboxylation of aryl bromides and chlorides with CO2 was realized using a combination of Pd(OAc)2 as a carboxylation catalyst and Ir(ppy)2(dtbpy)(PF6) as a photoredox catalyst. This carboxylation reaction proceeded in high yields under 1 atm of CO2 with a variety of functionalized aryl bromides and chlorides without the necessity of using stoichiometric metallic reductants.
- Shimomaki, Katsuya,Murata, Kei,Martin, Ruben,Iwasawa, Nobuharu
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supporting information
p. 9467 - 9470
(2017/07/24)
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- A containing double (2-substituted-sulfonyl -1, 3, 4-oxadiazol-5-yl) heterocyclic compound and use thereof
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The invention belongs to the field of chemical engineering and pesticides, and particularly relates to a heterocyclic compound containing bis(2-substituted sulfonyl-1,3,4-oxadiazole-5-radical) and application thereof. The structure of the heterocyclic compound is shown in the specification. In a general formula, R is hydrogen, C1-C5 alkyl radicals, C1-C5 halogenated alkyl radicals, C2-C5 alkenyl, and ester, benzyl or substituted benzyl of C2-C5, and Z is hydrocarbyl or substituted hydrocarbon thereof, phenyl, substituted phenyl, biphenylyl, substituted biphenylyl, naphthyl, substituted naphthyl, diphenyl hydrocarbyl, substituted diphenyl hydrocarbyl, and diphenyl ether or substituted diphenyl ether. The heterocyclic compound has very good inhibitory activity on rhizoctonia solani, fusarium asiaticum, borrytis cinerea, physalospora piricala, helminthossporium oryzae, tobacco bacterial wilt and rice brown blotches, can be applied to prevention and control of plant diseases and has wide application prospect.
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Paragraph 0056-0059
(2017/01/19)
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- Oxygen-Controlled Catalysis by Vitamin B12-TiO2: Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation
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An oxygen switch in catalysis of the cobalamin derivative (B12)-TiO2 hybrid catalyst for the dechlorination of trichlorinated organic compounds has been developed. The covalently bound B12 on the TiO2 surface transformed trichlorinated organic compounds into an ester and amide by UV light irradiation under mild conditions (in air at room temperature), while dichlorostilbenes (E and Z forms) were formed in nitrogen from benzotrichloride. A benzoyl chloride was formed as an intermediate of the ester and amide, which was detected by GC-MS. The substrate scope of the synthetic strategy is demonstrated with a range of various trichlorinated organic compounds. A photo-duet reaction utilizing the hole and conduction band electron of TiO2 in B12-TiO2 for the amide formation was also developed.
- Shimakoshi, Hisashi,Hisaeda, Yoshio
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supporting information
p. 15439 - 15443
(2016/01/26)
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- A highly reducing metal-free photoredox catalyst: Design and application in radical dehalogenations
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Here we report the use of 10-phenylphenothiazine (PTH) as an inexpensive, highly reducing metal-free photocatalyst for the reduction of carbon-halogen bonds via the trapping of carbon-centered radical intermediates with a mild hydrogen atom donor. Dehalogenations were carried out on various substrates with excellent yields at room temperature in the presence of air.
- Discekici, Emre H.,Treat, Nicolas J.,Poelma, Saemi O.,Mattson, Kaila M.,Hudson, Zachary M.,Luo, Yingdong,Hawker, Craig J.,De Alaniz, Javier Read
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supporting information
p. 11705 - 11708
(2015/07/15)
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- Efficient synthesis of amides and esters from alcohols under aerobic ambient conditions catalyzed by a Au/mesoporous Al2O3 nanocatalyst
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An efficient heterogeneous Au/mesoporous alumina nanocatalyst has been successfully developed for the synthesis of amides and esters from simple building blocks of readily available alcohols and amines. The processes were simple and were performed at room temperature and atmospheric pressure of O2 to form the desired products with up to 97% isolated yield. The ability of Au/mesoporous alumina to catalyze these reactions under ambient conditions further enhances the sustainability of these chemical processes. Furthermore, the nanocatalyst was stable to air and water and could be recovered and reused easily. The enhanced catalytic activity of Au/mesoporous alumina might be attributed to the presence of negatively charged Au nanoparticles that could promote oxidation processes as well as the stability of the mesoporous alumina support calcined at a high temperature of 800°C. Gold for green: Gold nanoparticles supported on mesoporous alumina catalyze the efficient synthesis of amides and esters from simple building blocks of readily available alcohols and amines under ambient aerobic reaction conditions (R1=aryl, alkyl, and R2=H, alkyl).
- Chng, Leng Leng,Yang, Jinhua,Ying, Jackie Y.
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p. 1916 - 1925
(2015/06/16)
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- Iron oxalate capped iron-copper nanomaterial for oxidative transformation of aldehydes
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An efficient, sustainable and green procedure for the synthesis of selective orthorhombic iron(oxalate) capped Fe-Cu bimetallic oxide nanomaterial [Fe(ox)Fe-CuOx] was developed using a sodium borohydride reduction of iron(ii) salt in the presence of oxalic acid at room temperature followed by addition of copper sulfate in water. The reported method is a cost-effective chemical route for producing [Fe(ox)Fe-CuOx] nano material at the gram level with a surface area of 78.4 m2 g-1 and a pore volume of 0.141 cm3 g-1. The [Fe(ox)Fe-CuOx] nanomaterials were found to be useful as a recoverable catalyst for the oxidative transformation of an aldehyde to its corresponding ester and acid in presence of hydrogen peroxide.
- Kashyap, Rajarshi,Talukdar, Dhruba Joyti,Pratihar, Sanjay
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p. 1430 - 1437
(2015/02/19)
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- Ultrasound assisted direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone
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A sonochemical procedure for direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone in an alcoholic solvent is described. Mild reaction conditions, short reaction times, cost-effectiveness, and facile isolation of the products make the present system as a practical method.
- Mirza-Aghayan, Maryam,Zonoubi, Somayeh,Molaee Tavana, Mahdieh,Boukherroub, Rabah
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p. 359 - 364
(2014/10/16)
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- Nanomolar fluorogenic detection of Al(iii) by a series of Schiff bases in an aqueous system and their application in cell imaging
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Three positional isomers of a Schiff base containing -OH as end groups have been synthesized and evaluated for selective Al(iii) detection due to inhibition of ESIPT, PET and activation of CHEF in 70% aqueous medium. Devoid of any conventional fluorophore, these sensors have nanomolar detection limits with high quantum yields and naked eye sensing of Al(iii). Moreover, these probes have been demonstrated to enable the Al(iii) detection in live human HeLa cells and rat C6 glioma cells using a confocal microscope. the Partner Organisations 2014.
- Sharma, Sanyog,Hundal, Maninder Singh,Walia, Amandeep,Vanita, Vanita,Hundal, Geeta
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supporting information
p. 4445 - 4453
(2014/06/23)
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- One-pot formal synthesis of biorenewable terephthalic acid from methyl coumalate and methyl pyruvate
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Diverse functionalized aromatic compounds are constructed from captodative dienophiles with exclusive regioselectivity. 100% biorenewable dimethyl terephthalate (DMT) from methyl coumalate and methyl pyruvate is achieved in a one-pot, Diels-Alder/decarboxylation/elimination sequence in nearly quantitative yield. The DMT system is solvent-free and purification is accomplished through recrystallization. DMT hydrolysis reveals the co-monomer terephthalic acid (TPA) as a bio-based drop-in replacement for the polymer industry, avoiding harsh oxidation and petrochemicals. the Partner Organisations 2014.
- Lee, Jennifer J.,Kraus, George A.
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supporting information
p. 2111 - 2116
(2014/04/17)
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- Oxidative cyclizations, the synthesis of aryl-substituted c-glycosides, and the role of the second electron transfer step
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Anodic oxidation reactions have been used to synthesize aryl- and biaryl-substituted C-glycosides. The reactions take advantage of the tendency for alcohol nucleophiles to trap nonpolar radical cations. The addition of the alcohol to the radical cation appears to be reversible, and the success of the cyclizations is dependent on the ease with which the resulting benzylic radical is oxidized.
- Smith, Jake A.,Moeller, Kevin D.
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supporting information
p. 5818 - 5821
(2013/12/04)
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- Selective oxidation of alcohols to esters using heterogeneous Co 3O4-N@C catalysts under mild conditions
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Novel cobalt-based heterogeneous catalysts have been developed for the direct oxidative esterification of alcohols using molecular oxygen as benign oxidant. Pyrolysis of nitrogen-ligated cobalt(II) acetate supported on commercial carbon transforms typical homogeneous complexes to highly active and selective heterogeneous Co3O4-N@C materials. By applying these catalysts in the presence of oxygen, the cross and self-esterification of alcohols to esters proceeds in good to excellent yields.
- Jagadeesh, Rajenahally V.,Junge, Henrik,Pohl, Marga-Martina,Radnik, Joerg,Brueckner, Angelika,Beller, Matthias
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supporting information
p. 10776 - 10782
(2013/08/23)
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- Aromatics from pyrones: Esters of terephthalic acid and isophthalic acid from methyl coumalate
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The Diels-Alder reaction of methyl coumalate with alkenes bearing electron-withdrawing groups provides terephthalates or isophthalates in good yields, with the regioselectivity depending on the electron-withdrawing group. The reaction of methyl coumalate with the salt of acrylic acid gave only the monoester of isophthalic acid. Density functional theory (B3LYP/6-31 + G(d,p)) computations of the energies of the competing transition states of the para-selective Diels-Alder reactions are in good agreement with experiment. The surprising regioselectivity of methyl coumalate with activated alkenes is attributed to a secondary orbital interaction between the pyrone oxygen and the dienophile LUMO, which switches the regiochemistry expected from simple frontier molecular orbital theory arguments. The Royal Society of Chemistry 2013.
- Kraus, George A.,Pollock III, Gerald R.,Beck, Christie L.,Palmer, Kyle,Winter, Arthur H.
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p. 12721 - 12725
(2013/08/23)
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- The effect of indium(III) triflate in oxone-mediated oxidative methyl esterification of aldehydes
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An oxidative methyl esterification of aldehydes was effectively achieved. The trivalent indium reagent, indium(III) triflate, was revealed to accelerate the reactions in many cases. Aromatic aldehydes with various substituents were subjected to this method, and each produced the corresponding methyl esters in good to excellent yields within a relatively short reaction time.
- Mineno, Tomoko,Sakai, Mai,Ubukata, Akira,Nakahara, Kazuhide,Yoshimitsu, Hitoshi,Kansui, Hisao
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p. 870 - 872
(2013/09/12)
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- 3-Mercapto-1,2,4-triazoles and N-acylated thiosemicarbazides as metallo-β-lactamase inhibitors
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The production of β-lactamases is an effective strategy by which pathogenic bacteria can develop resistance against β-lactam antibiotics. While inhibitors of serine-β-lactamases are widely used in combination therapy with β-lactam antibiotics, there are no clinically available inhibitors of metallo-β-lactamases (MBLs), and so there is a need for the development of such inhibitors. This work describes the optimisation of a lead inhibitor previously identified by fragment screening of a compound library. We also report that thiosemicarbazide intermediates in the syntheses of these compounds are also moderately potent inhibitors of the IMP-1 MBL from Pseudomonas aeruginosa. The interactions of these inhibitors with the active site of IMP-1 were examined using in silico methods.
- Faridoon,Hussein, Waleed M.,Vella, Peter,Islam, Nazar Ul,Ollis, David L.,Schenk, Gerhard,McGeary, Ross P.
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supporting information; experimental part
p. 380 - 386
(2012/02/04)
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- Oxidative esterification of benzaldehyde and deactivated aromatic aldehydes with N-bromosuccinimide-pyridine
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(Chemical Equation Presented) Whereas the oxidative esterification of benzaldehyde to methyl benzoate with N-bromosuccinimide (NBS)-pyridine requires dark conditions and 5 equivalents each of NBS and K2CO3 and gave only moderate yield (52%) of the product (McDonald et al. J. Org. Chem. 1989, 54, 1213), simple change of base to pyridine gave the desired product in 83% gas chromatographic yield with only 1 equivalent each of NBS and pyridine. Moreover, the reaction could be conducted without exclusion of light. Aromatic aldehydes bearing electron-withdrawing substituents at meta/para position yielded the corresponding methyl esters in still better yields. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Agrawal, Manoj K.,Adimurthy, Subbarayappa,Ghosh, Pushpito K.
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experimental part
p. 2931 - 2936
(2012/07/16)
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- NOVEL FXR (NR1H4 ) BINDING AND ACTIVITY MODULATING COMPOUNDS
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The present invention relates to compounds which bind to the NR1 H4 receptor (FXR) and act as agonists of the NR1 H4 receptor (FXR). The invention further relates to the use of the compounds for the preparation of a medicament for the treatment of diseases and/or conditions through binding of said nuclear receptor by said compounds, and to a process for the synthesis of said compounds.
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Page/Page column 45; 46
(2011/04/13)
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- Novel FXR (NR1H4) binding and activity modulating compounds
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The present invention relates to compounds which bind to the NR1H4 receptor (FXR) and act as agonists of the NR1H4 receptor (FXR). The invention further relates to the use of the compounds for the preparation of a medicament for the treatment of diseases and/or conditions through binding of said nuclear receptor by said compounds, and to a process for the synthesis of said compounds.
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Page/Page column 17
(2011/04/14)
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- Nickel-catalyzed reductive cleavage of aryl-oxygen bonds in alkoxy- and pivaloxyarenes using hydrosilanes as a mild reducing agent
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A nickel-catalyzed reductive deoxygenation of aryl alkyl ethers and aryl pivalates has been developed. Hydrosilanes serve as a mild reducing agent. The present protocol allows the use of a pivalate group as a robust and traceless steering group in arene functionalization reactions. The Royal Society of Chemistry.
- Tobisu, Mamoru,Yamakawa, Ken,Shimasaki, Toshiaki,Chatani, Naoto
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p. 2946 - 2948
(2011/04/24)
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- Layered double hydroxide-supported l-methionine-catalyzed chemoselective o-methylation of phenols and esterification of carboxylic acids with dimethyl carbonate: A "green" protocol
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" Chemical equation presented" Simple methodology: A layered double hydroxide-supported L-methionine (LDH-Met) catalyst is designed in a simple methodology to explore its synthetic utility in biologically relevant reactions. The organocatalyst is characterized by FT-IR, TGA/DTA, powder XRD, and EDX spectroscopic techniques. This material has been successfully utilized for the preparation of aryl methyl ethers and esters from the corresponding phenols and carboxylic acids, respectively, in moderate to high yields (see scheme).
- Dhakshinamoorthy, Amarajothi,Sharmila, Alagarsamy,Pitchumani, Kasi
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supporting information; experimental part
p. 1128 - 1132
(2010/06/13)
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- Cu(II) complex of an abiotic receptor as highly selective fluorescent sensor for acetate
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A copper complex having quinoline moiety as fluorophore has been synthesized. The anion recognition behavior of the receptor and its copper complex has been studied in acetonitrile and in acetonitrile: H2O (95:5 v/v). The copper complex shows high selectivity toward acetate over other anions studied such as F-, Cl-, Br-, I-, OAc-, dl-malate, l-mandelate, benzoate, isophthalate, H2 PO4-, NO3- and HSO4-.
- Goswami, Shyamaprosad,Chakrabarty, Rinku
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supporting information; experimental part
p. 5994 - 5997
(2010/03/01)
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- Selective oxidation of acetophenones bearing various functional groups to benzoic acid derivatives with molecular oxygen
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Acetophenones substituted by alkyl, alkoxy, acetoxy, and halogen groups were selectively oxidized with molecular oxygen to the corresponding benzoic acids by using the N,N',N"-trihydroxyisocyanuric acid (THICA)/cobalt(II) acetate [Co(OAc)2] and THICA/Co(OAc)2/manganese(II) acetate.
- Nakamura, Ryota,Obora, Yasushi,Ishii, Yasutaka
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experimental part
p. 1677 - 1684
(2011/02/25)
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- Norstatines from Aldehydes by sequential organocatalytic α-amination and passerini reaction
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The combination of the enantioselective, organocatalytic α-amination of aldehydes by diazodicarboxylates and the Passerini reaction provides rapid access to norstatine-based peptidomimetics. These intermediates were elaborated further by deprotection and cleavage of the N-N bond to provide useful building blocks for aspartic protease inhibitors. Coupling of the compounds 76-86 with the mono-isophthalamide 91 provided moderate inhibitors of human β-secretase (BACE) 92-102. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Umbreen, Sumaira,Brockhaus, Manfred,Ehrenberg, Helmut,Schmidt, Boris
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p. 4585 - 4595
(2007/10/03)
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- Carboxylation and esterification of functionalized arylcopper reagents
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Functionalized arylcopper reagents have been produced in good yields at 25 °C from activated copper and the corresponding functionalized aryl iodides without the need of traditional organolithium or Grignard precursors. These organocopper compounds will undergo carboxylation with CO2 to form the corresponding copper benzoates. In turn, these salts can be acidified to produce the functionalized aryl acids or treated with appropriate alkyl halides in the presence of a dipolar aprotic solvent to generate the corresponding aryl esters. This methodology permits the formation of functionalized organic acids and esters that could not be generated by the carboxylation of organomagnesium compounds.
- Ebert, Greg W.,Juda, Wayne L.,Kosakowski, Robert H.,Ma, Bing,Dong, Liming,Cummings, Keith E.,Phelps, Mwita V. B.,Mostafa, Adel E.,Luo, Jianyuan
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p. 4314 - 4317
(2007/10/03)
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- Identification and quantification of aerosol polar oxygenated compounds bearing carboxylic or hydroxyl groups. 1. Method development
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In this study, a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group, or both. This technique is based on derivatizing first the carboxylic group(s) of the multifunctional compound using an alcohol (e.g., methanol, 1-butanol) in the presence of a relatively strong Lewis acid (BF3) as a catalyst. This esterification reaction quicldy and quantitatively converts carboxylic acids to their ester forms. The second step is based on silylation of the ester compounds using bis(trimethylsilyl) trifluoroacetamide (BSTFA) as the derivatizing agent. For compounds bearing ketone groups in addition to carboxylic and hydroxyl groups, a third step was used based on PFBHA derivatization of the carbonyls. Different parameters including temperature, reaction time, and effect due to artifacts were optimized. A GC/MS in EI and in methane-CI mode was used for the analysis of these compounds. The new approach was tested on a number of multifunctional compounds. The interpretation of their EI (70 eV) and CI mass spectra shows that critical information is gained leading to unambiguous identification of unknown compounds. For example, when derivatized only with BF3-methanol, their mass spectra comprise primary ions at m/z M .+ + 1, M.+ + 29, and M.- - 31 for compounds bearing only carboxylic groups and M.- + 1, M.+ + 29, M.+ - 31, and M+. - 17 for those bearing hydroxyl and carboxylic groups. However, when a second derivatization (BSTFA) was used, compounds bearing hydroxyl and carboxylic groups simultaneously show, in addition to the ions observed before, ions at m/z M.+ + 73, M .+ - 15, M.+ - 59, M.+ - 75, M.+ - 89, and 73. To the best of our knowledge, this technique describes systematically for the first time a method for identifying multifunctional oxygenated compounds containing simultaneously one or more hydroxyl and carboxylic acid groups.
- Jaoui,Kleindienst,Lewandowski,Edney
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p. 4765 - 4778
(2007/10/03)
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- TRICYCLIC DERIVATIVES OR PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF, THEIR PREPARATIONS AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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The present invention relates to tricyclic derivatives or pharmaceutically acceptable salts thereof, their preparations and pharmaceutical compositions containing them. More precisely, the present invention relates to tricyclic derivatives as colchicine derivatives, pharmaceutically acceptable salts thereof, their preparations and pharmaceutical compositions containing them. Tricyclic derivatives of the present invention show very powerful cytotoxicity to cancer cell lines but were much less toxic than colchicine or taxol, confirmed through animal toxicity test. Tricyclic derivatives of the invention also decrease the volume and weight of a tumor and have a strong angiogenesis inhibiting activity in HUVEC cells. Thus, tricyclic derivatives of the present invention can effectively be used as an anticancer agent, anti-proliferation agent and an angiogenesis inhibitor.
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- Aspartyl protease inhibitors
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The present invention provides compounds having the formula: wherein R1, R′, R2, R3, R3′, R4, X1, X2 and X3 are as defined herein, and pharmaceutical compositions thereof. The present invention also provides methods of inhibiting proteases, more specifically aspartyl proteases. In certain embodiments, compounds inhibit BACE (β-site APP-cleaving enzyme), and thus are useful in the treatment or prevention of a disease characterized by β-amyloid deposits in the brain (including, but not limited to, Alzheimer's Disease). The present invention also provides methods for preparing compounds of the invention.
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- Process for the preparation of bromoisophthalic acid compounds
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The present invention relates to a process for preparing bromoisophthalic acid compounds, particularly 5-bromoisophthalic acid compounds and 4,5-dibromoisophthalic acid compounds comprising brominating an isophthalic acid compound of the general formula (1) wherein R1 and R2 independently of one another are hydrogen atom or C1-6 alkyl, with bromine in a solvent containing sulfur trioxide. The object of the invention is to provide a process for preparing bromoisophthalic acid compounds, particularly 5-bromoisophthalic acid compounds and 4,5-dibromoisophthalic acid compounds in a highly selective manner by using bromine that is industrially inexpensive.
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- Matrix metalloproteinase inhibitors
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Compounds are provided that bind allosterically to the catalytic domain of MMP-13 and comprise a hydrophobic group, first and second hydrogen bond acceptors and at least one, and preferably both, of a third hydrogen bond acceptor and a second hydrophobic group. Cartesian coordinates for centroids of the above features are defined in the specification. When the ligand binds to MMP-13, the first, second and third (when present) hydrogen bond acceptors bond respectively with Thr245, Thr 247 and Met 253, the first hydrophobic group locates within the S1' channel of MMP-13 and the second hydrophobic group (when present) is relatively open to solvent. The compounds specifically inhibit the matrix metalloproteinase-13 enzyme and thus are useful for treating diseases resulting from tissue breakdown, such as heart disease, multiple sclerosis, arthritis, atherosclerosis, and osteoporosis.
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- METHOD FOR STORING QUATERNARY AMMONIUM SALT
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A method of improving the stability of a quaternary ammonium salt and a method of efficiently preparing the quaternary ammonium salt having improved stability.
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- Refinement and evaluation of a pharmacophore model for flavone derivatives binding to the benzodiazepine site of the GABAA receptor
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To further develop and evaluate a pharmacophore model previously proposed by Cook and co-workers (Drug Des. Discovery 1995, 12, 193-248) for ligands binding to the benzodiazepine site of the GABAA receptor, 40 new flavone derivatives have been synthesized and their affinities for the benzodiazepine site have been determined. Two new regions of steric repulsive interactions between ligand and receptor have been characterized, and the receptor region in the vicinity of 6- and 3′-substituents has been mapped out. 2′-Hydroxy substitution is shown to give a significant increase in affinity, which is interpreted in terms of a novel hydrogen bond interaction with the previously proposed hydrogen bond-accepting site A2. On the basis of the results of these studies and the refined pharmacophore model, 5′-bromo-2′-hydroxy-6-methylflavone, the highest affinity flavone derivative reported so far (Ki = 0.9 nM), was successfully designed. A comparison of the pharmacophore model with a recently proposed alternative model (Marder; et al. Bioorg. Med. Chem., 2001, 9, 323-335) has been made.
- Kahnberg, Pia,Lager, Erik,Rosenberg, Celia,Schougaard, Jette,Camet, Linda,Sterner, Olov,Nielsen, Elsebet ?stergaard,Nielsen, Mogens,Liljefors, Tommy
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p. 4188 - 4201
(2007/10/03)
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