- Synthesis of 3-bromo-5-(2-ethylimidazo[1, 2-a]pyridine-3-carbonyl)-2-hydroxybenzonitrile
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The invention discloses a synthetic method of 3-bromo-5-(2-ethylimidazo[1,2-a]pyridine-3-carbonyl)-2-hydroxybenzonitrile, particularly relates to a synthetic method of a compound shown as a formula (III), and particularly relates to a step A or a step B;
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Paragraph 0068; 0071; 0078; 0081
(2020/07/24)
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- Toward a treatment of diabesity: In vitro and in vivo evaluation of uncharged bromophenol derivatives as a new series of PTP1B inhibitors
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Protein tyrosine phosphatase 1B (PTP1B) has been considered as a validated biological target for type 2 diabetes treatment, but past endeavors to develop inhibitors of PTP1B into drugs have been unsuccessful. Two challenging aspects are selective inhibition and cell permeability. A structure-based strategy was employed to develop uncharged bromophenols as a new series of PTP1B inhibitors. The most potent compound 22 (LXQ46) inhibited PTP1B with an IC50 value of 0.190 μM, and showed remarkable selectivity over other protein tyrosine phosphatases (PTPs, 20–200 folds). In the SPR study, increasing concentrations of compound 22 led to concentration-dependent increases in binding responses, indicating that compound 22 could bind to the surface of PTP1B via noncovalent means. By treating insulin-resistant C2C12 myotubes with compound 22, enhanced insulin and leptin signaling pathways were observed. Long-term oral administration of compound 22 reduced the blood glucose level of diabetic BKS db mice. The glucose tolerance tests (OGTT) and insulin tolerance tests (ITT) in BKS db mice showed that oral administration of compound 22 could increase insulin sensitivity. In addition, long-term oral administration of compound 22 could protect mice from obesity, which was not the result of toxicity. Our pharmacokinetics results from the rat-based assays showed that orally administered compound 22 was absorbed rapidly from the gastrointestinal tract, extensively distributed to the tissues, and rapidly eliminated from the body. All these results indicate that compound 22 could serve as a qualified agent to treat type II diabetes.
- Li, Xiangqian,Xu, Qi,Li, Chao,Luo, Jiao,Li, Xiuxue,Wang, Lijun,Jiang, Bo,Shi, Dayong
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supporting information
p. 178 - 185
(2019/02/05)
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- Aromatic Halogenation Using N-Halosuccinimide and PhSSiMe3 or PhSSPh
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We developed a mild aromatic halogenation reaction using a combination of N-halosuccinimide and PhSSiMe3 or PhSSPh. Less reactive aromatic compounds, such as methyl 4-methoxybenzoate, were brominated with PhSSiMe3 or PhSSPh and N-bromosuccinimide in high yields. No reaction was observed in the absence of PhSSiMe3 or PhSSPh. This method is also applicable to chlorination reactions using N-chlorosuccinimide and PhSSPh.
- Hirose, Yuuka,Yamazaki, Mirai,Nogata, Misa,Nakamura, Akira,Maegawa, Tomohiro
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p. 7405 - 7410
(2019/06/14)
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- Synthesis method for aromatic ring bromination of acetophenones derivative
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The invention relates to a synthesis method for aromatic ring bromination of an acetophenones derivative, and belongs to the technical field of organic synthesis. The synthesis method consists of twokinds of synthesis methods: method A, adding the acetophenone derivative into a first oxidizing agent and stirring to form a suspension system, controlling the temperature of the suspension system tobe 10-50 DEG C, adding a first reducing agent or a second reducing agent, stirring and reacting for 2-20 h, and performing aftertreatment after the reaction is completed to obtain the aromatic ring brominated acetophenone derivative; method B, adding the acetophenone derivative into the second reducing agent and stirring to form a suspension system, controlling the temperature of the suspension system to be 10-50 DEG C, then adding a second oxidizing agent or the first oxidizing agent, stirring and reacting for 2-20 h, and performing aftertreatment after the reaction is completed to obtain thearomatic ring brominated acetophenone derivative. According to the synthesis method provided by the invention, an inorganic and non-toxic bromination reagent is used, water is used as a reaction solvent, the prepared product is mutually incompatible with water, so that separation and the aftertreatment are convenient to perform, therefore, the synthesis method of the invention is applicable to large-scale industrial production of intermediate products for aromatic ring bromination of the acetophenones derivative.
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Paragraph 0059-0062
(2019/06/11)
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- SUBSTITUTED AMINOTHIAZOLES AS INHIBITORS OF NUCLEASES
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The invention provides compounds represented by the structural formula (1): wherein R1, R2, R3, R4, R5, R6 are as defined in the claims. The compounds are inhibitors of nucleases, and are useful in particular in a method of treatment and/or prevention of proliferative diseases, neurodegenerative diseases, and other genomic instability associated diseases.
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Page/Page column 14; 19
(2019/11/12)
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- Synthesis and catalytic reactivity in Friedel–Crafts acylations of monobridged bis(cyclopentadienyl)molybdenum(I) carbonyl complexes
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When the monobridged biscyclopentadienes (C5H5)R(C5H5) [R = C(CH3)2 (1), Si(CH3)2 (2), C(CH2)5 (3)] reacted with Mo(CO)6 in refluxing xylene, the corresponding complexes [(η5-C5H4)2R][Mo(CO)3]2 [R = C(CH3)2 (4), Si(CH3)2 (5), C(CH2)5 (6)] were obtained. These complexes were separated by chromatography and characterized by elemental analysis, IR, and 1H NMR spectroscopy. The molecular structures of 4 and 5 were determined by X-ray diffraction analysis. Friedel–Crafts acylation reactions of anisole derivatives with aromatic or aliphatic acyl chlorides catalyzed by complexes 4–6 showed that all of these monobridged bis(cyclopentadienyl)molybdenum carbonyl complexes have catalytic activity.
- Yan, Xin Long,Zhang, Ning,Hao, Zhi Qiang,Ma, Zhi Hong,Han, Zhan Gang,Zheng, Xue Zhong,Lin, Jin
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- Mechanistic study on iodine-catalyzed aromatic bromination of aryl ethers by N-Bromosuccinimide
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Although iodine-catalyzed reaction has rapid advances in recent years, examples on iodine-catalyzed bromination are rare and the mechanism of these reactions remains unclear. Herein, we reported an I2-catalyzed aromatic bromination of aryl ethers by NBS and presented the details of the mechanistic study including kinetic study and the study of kinetic isotope effects. The study revealed that the reaction was actually catalyzed by IBr formed in the induction period, and the rate-determining step was the HBr-elimination of the Wheland intermediate assisted by IBr.
- Pramanick, Pranab Kumar,Hou, Zhen-Lin,Yao, Bo
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p. 7105 - 7114
(2017/11/27)
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- Direct Transformation of Ethylarenes into Primary Aromatic Amides with N -Bromosuccinimide and I2-Aqueous NH3
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A variety of ethylarenes were converted into the corresponding primary aromatic amides in good yields via treatment with N-bromosuccinimide in the presence of a catalytic amount of 2,2′-azobis(isobutyronitrile) in a mixture of ethyl acetate and water, acetonitrile and water, or chloroform and water, followed by reaction with molecular iodine and aq NH3 in one pot. It was found that aryl α-bromomethyl ketones and/or aryl methyl ketones were formed at the first reaction step and their iodoform-type reaction occurred at the second reaction step to provide primary aromatic amides. The present reaction is a useful and practical transition-metal-free method for the preparation of primary aromatic amides from ethylarenes. (Chemical Equation Presented).
- Shimokawa, Shohei,Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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supporting information
p. 784 - 787
(2016/03/01)
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- Synthesis, biological evaluation and molecular modeling studies of psammaplin A and its analogs as potent histone deacetylases inhibitors and cytotoxic agents
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In this study, a concise synthetic method of psammaplin A was achieved from 3-bromo-4-hydroxybenzaldahyde and hydantoin through a four-step synthesis via Knoevenagel condensation, hydrolysis, oximation and amidation in 37% overall yield. A collection of novel psammaplin A analogs focused on the variations of substituents at the benzene ring and modifications at the oxime moiety were synthesized. Among all the synthesized compounds, 5d and 5e showed better HDAC inhibition than psammaplin A and comparable cytotoxicity against four cancer cell lines (PC-3, MCF-7, A549 and HL-60). Molecular docking and dynamics simulation revealed that (i) hydrogen atom of the oxime group interacts with Asp99 of HDAC1 through a water bridged hydrogen bond and (ii) a hydroxyl group is optimal attached on the para-position of benzene, interacting with Glu203 at the entrance to the active site tunnel.
- Wen, Jiachen,Bao, Yu,Niu, Qun,Liu, Jiang,Yang, Jinyu,Wang, Wanqiao,Jiang, Tao,Fan, Yinbo,Li, Kun,Wang, Jian,Zhao, Linxiang,Liu, Dan
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supporting information
p. 4372 - 4376
(2016/08/18)
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- Aggregation-induced emission enhancement in halochalcones
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A family of push-pull fluorophores, consisting of a chalcone core decorated with electron-donating substituents and halogen atoms, was designed and synthesized. Luminescence studies were performed in solution, aggregate form and in the solid state. Although some compounds are only weakly fluorescent in solution, all are emissive in the solid state showing aggregation-induced emission enhancement. In the crystalline state, the halogen atoms are not involved in halogen bonds but their presence strongly influences the aggregation-induced emission properties of the fluorophores.
- Vaz, Patricia A. A. M.,Rocha, Jo?o,Silva, Artur M.S.,Guieu, Samuel
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supporting information
p. 8198 - 8201
(2016/10/11)
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- Synthesis and antibacterial activities of cadiolides A, B and C and analogues
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The one-pot multicomponent synthesis of natural butenolides named cadiolides A, B, C and analogues has been realized. The antibacterial structure activity relationship shows that the presence of phenolic hydroxyl groups and the number and position of bromine atoms on the different aromatic rings are important features for antibacterial activity, besides it was demonstrated the tolerance of both benzene and furan ring at position 3 of the butenolide nucleus. Furthermore, none of the most relevant antibacterial compounds showed any cytotoxicity in freshly isolated human neutrophils.
- Boulangé, Agathe,Parraga, Javier,Galán, Abraham,Cabedo, Nuria,Leleu, Stéphane,Sanz, Maria Jesus,Cortes, Diego,Franck, Xavier
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p. 3618 - 3628
(2015/07/27)
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- Strong Lewis acid air-stable cationic titanocene perfluoroalkyl(aryl) sulfonate complexes as highly efficient and recyclable catalysts for C-C bond forming reactions
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A series of strong Lewis acid air-stable titanocene perfluoroalkyl(aryl) sulfonate complexes Cp2Ti(OH2)2(OSO 2X)2·THF (X = C8F17, 1·THF; X = C4F9, 2·H2O· THF; X = C6F5, 3) were successfully synthesized by the treatment of Cp2TiCl2 with C8F 17SO3Ag, C4F9SO3Ag and C6F5SO3Ag, respectively. In contrast to well-known titanocene bis(triflate), these complexes showed no change in open air over three months. TG-DSC analysis showed that 1·THF, 2·H 2O·THF and 3 were thermally stable at 230 °C, 220°C and 280°C, respectively. Conductivity measurements showed that these complexes underwent ionic dissociation in CH3CN solution. X-ray analysis results confirmed that 2·H2O·THF and 3 were cationic. ESR spectra showed that the Lewis acidity of 1·THF (1.06 eV) was higher than that of Sc3+ (1.00 eV) and Y3+ (0.85 eV). UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2·H2O·THF. Fluorescence spectra showed that the Lewis acidity of 2 (λem = 477 nm) was higher than that of Sc3+ (λem = 474 nm). These complexes showed high catalytic ability in various carbon-carbon bond forming reactions. Moreover, they show good reusability. Compared with 1·THF, 2·H2O·THF and 3 exhibit higher solubility and better catalytic activity, and will find broad applications in organic synthesis. This journal is the Partner Organisations 2014.
- Li, Ningbo,Wang, Jinying,Zhang, Xiaohong,Qiu, Renhua,Wang, Xie,Chen, Jinyang,Yin, Shuang-Feng,Xu, Xinhua
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supporting information
p. 11696 - 11708
(2014/07/22)
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- Bromination of arenes using I2O5-KBr in water
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An efficient and environmentally benign bromination of various aromatic compounds using aN aqueous I2O5-KBr system at room temperature has been developed in this work. A series of aromatic compounds such as acetophenones, benzaldehydes, benzoic acids, anilines, amides, and aminopyridine have been successfully brominated in excellent regioselectivities and good yields under the typical reaction conditions. The features of KBr as brominating reagent, water as solvent, and mild conditions make this system an attractive synthetic procedure. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Hou, Jieping,Li, Zejiang,Jia, Xiao-Dong,Liu, Zhong-Quan
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supporting information
p. 181 - 187
(2013/12/04)
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- Practical and metal-free electrophilic aromatic halogenation by interhalogen compounds generated in situ from N-halosuccinimide and catalytic TMSCL
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Halomonochloride compounds (ClCl, BrCl, ICl) generated in situ from N-halosuccinimide and catalytic chlorotrimethylsilane (TMSCl, 0.1 equiv) can efficiently halogenate aromatic compounds to give halogenated products in good to excellent yields and selectivities. The reaction can be carried out at room temperature or at lower temperatures, requires only one hour, is practical to apply to a wide range of substrates, and provides a simple access to a variety of haloarene compounds. Georg Thieme Verlag Stuttgart New York.
- Maibunkaew, Tapanee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Bunrit, Anon,Ruchirawat, Somsak
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supporting information
p. 1769 - 1775
(2014/08/05)
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- Total synthesis and biological activity of marine alkaloid eudistomins Y1-Y7 and their analogues
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Eudistomin Y class compounds are a series of β-carbolines which was originally isolated from a marine turnicate or ascidian near the South Korea Sea. These compounds contain bromo-substituted groups, which is one of the typical characters of marine natural products. We report herein the chemical synthesis and biological evaluation of seven new β-carboline-based metabolites, Eudistomins Y1-Y7, and their hydroxyl-methylated phenyl derivatives. Using bromo-substituted tryptamines and bromo-substituted phenylglyoxals as the key intermediates, Eudistomins Y 1-Y7 and their derivatives were synthesized via the acid-catalyzed Pictet-Spengler reaction and fully characterized by 1H- and 13C-NMR and mass spectroscopy. Biological studies revealed that all of the compounds showed moderate growth inhibitory activity against breast carcinoma cell line MDA-231 with IC50 of 15-63 μM and the inhibitory activities of hydroxyl-methylated phenyl products were higher than that of the corresponding natural products Eudistomins Y 1-Y7.
- Jin, Huijuan,Zhang, Puyong,Bijian, Krikor,Ren, Sumei,Wan, Shengbiao,Alaoui-Jamali, Moulay A.,Jiang, Tao
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p. 1427 - 1439
(2013/07/11)
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- Metal and H2O2 free aerobic oxidative aromatic halogenation with [RNH3+] [NO3-]/HX and [BMIM(SO3H)][NO3)x(X)y] (X = Br, Cl) as multifunctional ionic liquids
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Novel multifunctional ionic liquids (ILs) are generated by addition of HBr or HCl to alkylammonium nitrates ([RNH3+] [NO 3-]) and to 3-methyl-1-(butyl-4-sulfonyl)imidazolium nitrate ([BMIM(SO3H)][NO3]). The resulting [RNH 3+] [NO3-]/HX and mono (3-methyl-1-(butyl-4-sulfonyl)imidazolium) monohalogenide mononitrate ([BMIM(SO3H)][NO3)x(X)y] (X = Br, Cl)) systems act as solvent and promoter for aerobic oxidative halogenation of arenes under mild conditions in high yields that can be repeated over several cycles.
- Prebil, Rok,Laali, Kenneth K.,Stavber, Stojan
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supporting information
p. 2108 - 2111
(2013/06/05)
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- Direct and selective benzylic oxidation of alkylarenes via C-H abstraction using alkali metal bromides
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A direct benzylic oxidation of alkylarenes via C-H bond abstraction was developed using alkali metal bromides and oxidants under mild conditions. This reaction proceeded with excellent selectivity by thermal oxidation or photooxidation to provide a broad range of carbonyl compounds containing electron-deficient aryl carbonyl compounds in high yields.
- Moriyama, Katsuhiko,Takemura, Misato,Togo, Hideo
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supporting information; experimental part
p. 2414 - 2417
(2012/06/18)
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- A boronic acid chalcone analog of combretastatin A-4 as a potent anti-proliferation agent
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Chalcones represent a class of natural products that inhibits tubulin assembly. In this study we designed and synthesized boronic acid analogs of chalcones in an effort to compare biological activities with combretastatin A-4, a potent inhibitor of tubuli
- Kong, Yali,Wang, Kan,Edler, Michael C.,Hamel, Ernest,Mooberry, Susan L.,Paige, Mikell A.,Brown, Milton L.
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experimental part
p. 971 - 977
(2010/05/02)
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- Electrooxidation of alcohols in N-oxyl-immobilized silica gel/water disperse system: Approach to totally closed system
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Electrooxidation of alcohols in a disperse system with N-oxyl-immobilized silica gel as a disperse phase and an aqueous NaBr/NaHCO3 solution as a disperse medium proceeded smoothly to give the corresponding carbonyl compounds. The N-oxyl-immobilized silica gel 1 was prepared by silane-coupling method. Recycling of both the aqueous solution and the N-oxyl-immobilized silica gel 1 was performed successfully. Georg Thieme Verlag Stuttgart.
- Kuroboshi, Manabu,Goto, Kentaro,Tanaka, Hideo
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scheme or table
p. 903 - 908
(2009/10/14)
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- Testing the validity of microwave-interfaced, in situ Raman spectroscopy as a tool for kinetic studies
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(Chemical Equation Presented) (Graph Presented) Raman spectroscopy in conjunction with microwave heating is a convenient and robust tool for monitoring organic reactions from a qualitative perspective. Its validity as a method for obtaining quantitative d
- Schmink, Jason R.,Holcomb, Jennifer L.,Leadbeater, Nicholas E.
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supporting information; experimental part
p. 365 - 368
(2009/07/11)
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- Friedel-Crafts acylation reaction using carboxylic acids as acylating agents
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Dehydrative Friedel-Crafts acylation reaction of aromatic compounds with carboxylic acids as acylating agents was investigated in the presence of Lewis acid- or Br?nsted acid-catalyst. Various metal triflates and bis(trifluoromethanesulfonyl)amides showed catalytic activity at high temperature, among which Eu(NTf2)3 proved to be the most effective and efficiently catalyzed the acylation reaction of alkyl- and alkoxybenzenes with aliphatic and aromatic carboxylic acids at 250 °C. Bi(NTf2)3 was more effective than Eu(NTf2)3 at lower temperature, but proved to be hydrolyzed in the presence of a small amount of water to give HNTf2 and [Bi6O4(OH)4(H2O)6](NTf2)6. The structure of the latter compound was confirmed by a single crystal X-ray analysis. Among five Br?nsted acids, HOTf, HNTf2, HCTf3, TsOH, and Nafion SAC-13, HNTf2 has proved to be the most efficient catalyst and more effective than Eu(NTf2)3 for the acylation of p-xylene with heptanoic acid at 220 °C or lower temperature. HNTf2 catalyzed the acylation of anisole with carboxylic acids in high yields in refluxing toluene with azeotropic removal of water.
- Kawamura, Masato,Cui, Dong-Mei,Shimada, Shigeru
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p. 9201 - 9209
(2007/10/03)
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- An efficient, rapid and regioselective nuclear bromination of aromatics and heteroaromatics with NBS using sulfonic-acid-functionalized silica as a heterogeneous recyclable catalyst
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A simple, efficient and rapid method has been developed for high-yielding regioselective nuclear monobromination of aromatic and heteroaromatic compounds using NBS in the presence of sulfonic-acid-functionalized silica at room temperature. The catalyst works under heterogeneous conditions and can be recycled.
- Das, Biswanath,Venkateswarlu, Katta,Krishnaiah, Maddeboina,Holla, Harish
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p. 8693 - 8697
(2007/10/03)
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- Directed regioselectivity of bromination of ketones with NBS: solvent-free conditions versus water
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The reaction conditions employed directed the site of functionalisation of ketones with NBS: under solvent-free conditions α-bromination was the exclusive process, while in water, ring functionalisation occurred in the case of methoxy substituted aromatic ketones.
- Pravst, Igor,Zupan, Marko,Stavber, Stojan
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p. 4707 - 4710
(2007/10/03)
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- Water-soluble N-oxyl compounds-mediated electrooxidation of alcohols in water: A prominent access to a totally closed system
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Electrooxidation of alcohols in water involving water-soluble N-oxyl compounds (WS-TEMPOs) proceeded smoothly to afford the corresponding ketones and aldehydes in good yields. Notably, most of WS-TEMPOs in water remained intact after the electrolysis. The aqueous solution containing WS-TEMPOs was recovered easily and repeatedly used for the electrooxidation of alcohols, offering a totally closed system.
- Kubota, Jun,Shimizu, Yusuke,Mitsudo, Koichi,Tanaka, Hideo
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p. 8975 - 8979
(2007/10/03)
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- Electrooxidation of alcohols in an N-Oxyl-immobilized poly(ethylene-co- acrylic acid)/water disperse system
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The electrooxidation of alcohols in a disperse system with N-oxyl-immobilized polymer particles (PE-co-AA-N-Oxyl), prepared from poly(ethylene-co-acrylic acid) (PE-co-AA-CO2H), as a disperse phase and an aqueous saturated NaHCO3 containing 20 wt % NaBr as a disperse medium was successfully performed in a simple beaker-type undivided cell under constant-current conditions. The electrooxidation of alcohols proceeded in a similar manner by the use of PE-co-AA-CO2H as a disperse phase, though the current efficiency decreased in some extent. Protection of most of the carboxylic acid moieties on the surface of PE-co-AA-CO2H by esterification or amidation resulted in significant decrease of the product yields, suggesting that the carboxylic acid moieties on the surface of PE-co-AA-CO2H would also act as a mediator for the electrooxidation of alcohols. Both the recovered PE-co-AA-W-Oxyl and the aqueous solution were used repeatedly for the electrooxidation of alcohols, thereby offering a formally closed system for the electrooxidation of alcohols.
- Tanaka, Hideo,Kubota, Jun,Miyahara, Seiji,Kuroboshi, Manabu
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p. 1677 - 1684
(2007/10/03)
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- Electrooxidation of alcohols in a disperse system with N-oxyl-immobilized polyethylene particles as disperse phase and aqueous NaHCO3/NaBr as disperse media: A totally closed electrolysis system
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Electrooxidation of alcohols was performed successfully in a disperse system with N-oxyl immobilized polyethylene particles as disperse phase and an aqueous saturated NaHCO3 solution involving 20 wt% NaBr as disperse media. The N-oxyl immobilized polyethylene particles were prepared by heating a suspension of polyethylene particles (3 x 3 x 0.02 mm3) in fuming nitric acid at 80°C for 1 h followed by treatment with 4-amino-2,2,6,6-tetramethylpyperidine-1-oxyl in chlorobenzene in the presence of DCC. Recycle use of the N-oxyl-immobilized polyethylene particles and the aqueous media was performed successfully without significant change of the yields of the products and current efficiency, thereby offering a totally closed electrolysis system.
- Tanaka, Hideo,Kubota, Jun,Itogawa, Shin-Ji,Ido, Toru,Kuroboshi, Manabu,Shimamura, Kaoru,Uchida, Tetsuya
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p. 951 - 954
(2007/10/03)
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- Inorganic ion receptor active compounds
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The present invention features compounds able to modulate one or more activities of an inorganic ion receptor and methods for treating diseases or disorders using such compounds. Preferred compounds can mimic or block the effect of extracellular calcium on a cell surface calcium receptor.
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Page column 20
(2008/06/13)
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- Novel process for generating useful electrophiles from common anions using Selectfluor fluorination agent
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In the present work, the electrophile equivalents C1+, Br+, SCN+, and NO2+ are generated from their respective sodium, potassium, and in some cases ammonium salts (M+X-) by reaction with Selectfluor electrophilic fluorination agent in acetonitrile solution at room temperature. These generated electrophilic species subsequently react in situ with a variety of aromatic substrates containing one or more substituent groups including H, F, C1, CH3, COOH, C(O)CH3, NO2, and OR′ and NR′R″ where R′ and R″ are H or CH3. The resulting substitution products are, in most cases, isolable as pure compounds in high yield. Variations in the process include the use of other anions, electrophilic fluorination agents, and solvents.
- Syvret, Robert G.,Butt, Kathleen M.,Nguyen, Tung P.,Bulleck, Victoria L.,Rieth, Ryan D.
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p. 4487 - 4493
(2007/10/03)
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- LiClO4-acyl anhydrides complexes as powerful acylating reagents of aromatic compounds in solvent free conditions
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The Friedel-Crafts acylation of various activated benzenes is smoothly carried out with acyl anhydrides in the presence of 2 equiv. of LiClO4, as reaction promoter, under solventless conditions.
- Bartoli, Giuseppe,Bosco, Marcella,Marcantoni, Enrico,Massaccesi, Massimo,Rinaldi, Samuele,Sambri, Letizia
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p. 6331 - 6333
(2007/10/03)
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- An aqueous silica gel disperse electrolysis system. N-Oxyl-mediated electrooxidation of alcohols
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N-Oxyl-mediated electrooxidation of alcohols was performed in an aqueous silica gel disperse system. The newly devised electrolysis system offers an organic solvent-free and operationally simple procedure for oxidation of alcohols and could be successfully applied to kinetic resolution of sec-alcohol as well as enantioselective oxidation of meso-1,4-diol affording optically active γ-lactone.
- Tanaka, Hideo,Kawakami, Yusuke,Goto, Kentaro,Kuroboshi, Manabu
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p. 445 - 448
(2007/10/03)
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- Substituted benzylaminopiperidine compounds
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The invention provides a substituted benzylaminopiperidine compounds that are useful in the treatment of gastrointestinal disorders; central nervous system (CNS) disorders; inflammatory disease; emesis; urinary incontinence; pain; migraine; sunburn; diseases, disorders and adverse conditions caused byHeliobacter pylori;or angiogenesis, especially CNS disorders in a mammalian subject, especially in humans.
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- Substituent Control of Intramolecular Hydrogen Bonding in Formyl-Protonated o-Anisaldehydes: A Stable Ion and Semiempirical MO Investigation
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o-Anisaldehyde and its 5-Br, 5-F, 5-CF3, 5-CN, 5-NO2, and 5-COMe derivatives are protonated at the formyl group in 1 : 1 SbF5-FSO3H/SO2 (or SO2ClF) to give persistent carboxonium ions as mixtures of Z and E geometrical isomers.The cyano, nitro, and acetyl substituents are also protonated, leading to dications and additional geometrical isomers in the nitro and acetyl cases.The carboxonium ions are predominantly in the Z,syn configuration, but with increased amounts of the E,anti configuration with increased electron withdrawal by the substituents.With 5-NO2H(+), Eisomers become more abundant than Z.The formyl protonated 2-(trifluoromethoxy)benzaldehyde shows a strong preference for the E configuration.The preference for the Z,syn form is attributed to intramolecular hydrogen bonding that becomes less favorable as electron density is withdrawn from the methoxyl oxygen.The log Z/E values correlate with differences in energy content of the isomers predicted in AM1 calculations, and the chemical shift of the hydroxyl proton of the carboxonium group correlates well with predicted charge on the proton.
- Laali, Kenneth K.,Koser, Gerald F.,Subramanyam, Sundar,Forsyth, David A.
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p. 1385 - 1392
(2007/10/02)
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- Optically active liquid crystal compound having cyano group
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An optically liquid crystalline compound having an extremely large spontaneous polarization value and a chiral smectic liquid crystal composition containing the compound are provided, the compound being expressed by the formula STR1 wherein m represents an integer of 2 to 18; l represents an integer of 0 to 12; n represents 0 or 1; R represents an alkyl group or an alkoxy group each of 2 to 20 carbon atoms, a halogen atom or cyano group; and A and B each represent a single bond, STR2 wherein X represents hydrogen atom, a halogen atom or cyano group, and a chiral smectic liquid crystal composition containing at least one kind of the above compound.
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- Formation and Stability of Ring-Substituted 1-Phenylethyl Carbocations
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The solvolysis of 1-phenylethyl derivatives with electron-donating 4-substituents in 50:50 trifluoroethanol:water(v:v) occurs at a rate that is independent of azide concentration but gives yields of the corresponding azide adducts of up to 98percent by trapping a carbocation intermediate.Rate constants for reactions of the cations with solvent range from 2 x 103 s-1 (4-Me2N) to 4 x 109 s-1 (4-Me), assuming a diffusion-controlled rate constant of 5 x 109 M-1 s-1 for their reactions with azide and thiol anions.Correlation of the rate constants following the Yukawa-Tsuno treatment gives ρn = 2.5, ρr = 5.2, and r+ = 2.1 for the reaction with trifluoroethanol, and ρn = 2.7, ρr = 4.9, and r+ = 1.8 for the reaction with water.The reverse reaction, acid-catalyzed cleavage of substituted 1-phenylethyl alcohols to give the corresponding carbocation, follows ρn = -4.9, ρr = -4.4, and r+ = 0.9.This gives values of ρn = -7.6, ρr = -9.3, and r+ = 1.2 for formation of the cations at equilibrium.There is an imbalance in the development of resonance delocalization, analogous to the "nitroalkane anomaly", that is consistent with a dependence of the fraction of maximal resonance delocalization on the fraction of rehybridization or C-X bond cleavage.Solvent effects on carbocation stability in aqueous-organic mixtures are relatively small.They depend mainly on the nucleophilicity of the solvent components and a specific solvent effect of trifluoroethanol on the reactivity of hydroxylic nucleophiles, including trifluoroethanol itself.The "ionizing power" of the solvent has only a small effect on cation stability, and there is little effect of the concentration or nature of added salts.
- Richard, John P.,Rothenberg, Marc E.,Jencks, William P.
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p. 1361 - 1372
(2007/10/02)
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