- Hydrazine Hydrate Accelerates Neocuproine–Copper Complex Generation and Utilization in Alkyne Reduction, a Significant Supplement Method for Catalytic Hydrogenation
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Diimine (HN═NH) is a strong reducing agent, but the efficiency of diimine oxidized from hydrazine hydrate or its derivatives is still not good enough. Herein, we report an in situ neocuproine–copper complex formation method. The redox potential of this complex enable it can serve as an ideal redox catalyst in the synthesis of diimine by oxidation of hydrazine hydrate, and we successfully applied this technique in the reduction of alkynes. This reduction method displays a broad functional group tolerance and substrate adaptability as well as the advantages of safety and high efficiency. Especially, nitro, benzyl, boc, and sulfur containing alkynes can be reduced to the corresponding alkanes directly, which provides a useful complementary method to traditional catalytic hydrogenation. Besides, we applied this method in the preparation of the Alzheimer’s disease drug CT-1812 and studied the mechanism.
- Chen, Guoliang,He, Xiaoyan,Huang, Gang,Lu, Xiuhong,Wang, Jincheng,Yang, Zhenjiao,Zhang, Yongsheng,Zhang, Zeng
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p. 17696 - 17709
(2021/12/09)
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- Design, synthesis, docking studies and monoamine oxidase inhibition of a small library of 1-acetyl- and 1-thiocarbamoyl-3,5-diphenyl-4,5-dihydro-(1h)-pyrazoles
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New N-acetyl/N-thiocarbamoylpyrazoline derivatives were designed and synthesized in high yields to assess their inhibitory activity and selectivity against human monoamine oxidase A and B. The most important chiral compounds were separated into their single enantiomers and tested. The impact of the substituents at N1, C3 and C5 positions as well the influence of the configuration of the C5 on the biological activity were analyzed. Bulky aromatic groups at C5 were not tolerated. p-Prenyloxyaryl moiety at C3 oriented the selectivity toward the B isoform. The results were also corroborated by molecular modelling studies providing new suggestions for the synthesis of privileged structures to serve as lead compounds for the treatment of mood disorders and neurodegenerative diseases.
- Guglielmi, Paolo,Carradori, Simone,Poli, Giulio,Secci, Daniela,Cirilli, Roberto,Rotondi, Giulia,Chimenti, Paola,Petzer, Anél,Petzer, Jacobus P.
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- Design, synthesis and structure-based optimization of novel isoxazole-containing benzamide derivatives as FtsZ modulators
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Antibiotic resistance among clinically significant bacterial pathogens is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. Utilizing computational docking method and structure-based optimization strategy, we rationally designed and synthesized two series of isoxazol-3-yl- and isoxazol-5-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compounds B14 and B16 that possessed the isoxazol-5-yl group showed strong antibacterial activity against various testing strains, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. aureus. Further molecular biological studies and docking analyses proved that the compound functioned as an effective inhibitor to alter the dynamics of FtsZ self-polymerization via a stimulatory mechanism, which finally terminated the cell division and caused cell death. Taken together, these results could suggest a promising chemotype for development of new FtsZ-targeting bactericidal agent.
- Bi, Fangchao,Song, Di,Zhang, Nan,Liu, Zhiyang,Gu, Xinjie,Hu, Chaoyu,Cai, Xiaokang,Venter, Henrietta,Ma, Shutao
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- Mechanochromic luminescent difluoroboron beta-diketonates
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The invention provides luminescent solid-state compositions comprising difluoroboron beta-diketonates wherein the compositions can exhibit mechanochromic luminescence. The mechanochromic effect on the luminescence can be reversible, such as thermally reversible. Various solid-state forms of the invention can have emission spectra that differ from the properties of the respective difluoroboron beta-diketonate in solution. The mechanochromic effect can be stimulated by pressure such as handwriting, and can be reversed over a period of minutes to hours at room temperature. The invention also provides methods of making and methods of using the solid-state compositions, such as for sensors and for information displays for use in biological sensing, and in art, design, and consumer products. Compositions of the invention, such as compositions in nanoparticulate form, or contained within a matrix material, can be used in conjunction with fluorescence microscopy to provide information concerning pressures and tensions within and external to living cells, tissues, or organisms.
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Page/Page column
(2015/07/15)
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- Alkyl chain length effects on solid-state difluoroboron β-diketonate mechanochromic luminescence
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Solid-state difluoroboron β-diketonate dyes display reversible mechanochromic luminescence (ML). To test the effects of alkyl chain length on solid state photoluminescence and ML, a series of dyes, BF2dbmOR, with dibenzoylmethane (dbm) ligands and alkoxyl substituents (-OR) were prepared, where R = CnH2n+1 and n = 1, 2, 3, 5, 6, 12, 14, 16, 18. Emission properties were investigated in solution and in the solid state. Fluorescence spectra and lifetimes were nearly identical for dyes in CH2Cl2 solution; whereas, in the solid state, as powders, thin films or spin cast films, emission maxima, and lifetimes were different among the samples. Solid-state ML emission spectra were monitored at room temperature as a function of time for smeared powders on quartz surfaces. The recovery time generally increased with alkyl chain length, ranging from minutes (n = 3) to days (n = 18). Longer chain analogues (n = 6, 12, 14, 16, 18) did not fully return to the original annealed emissive state even after months on quartz, though the dynamics are substrate dependent. Solid-state dyes were also investigated by XRD and DSC (powders), and by AFM (spin cast films).
- Nguyen, Nguyen D.,Zhang, Guoqing,Lu, Jiwei,Sherman, Arianna E.,Fraser, Cassandra L.
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supporting information
p. 8409 - 8415
(2013/01/11)
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- Triton B-mediated efficient and convenient alkoxylation of activated aryl and heteroaryl halides
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A simple and convenient one-pot synthesis of aryl alkyl ethers by the alkoxylation of aryl halides with alcohol in the presence of Triton B as a base is described. The procedure is applicable for a variety of aryl and heteroaryl halides, and yields are very good. The use of a nonmetallic base and solvent-free conditions are important features of the reaction. Copyright Taylor & Francis Group, LLC.
- Meshram,Goud, P. Ramesh,Reddy, B. Chennakesava,Kumar, D. Aravind
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experimental part
p. 2122 - 2129
(2010/08/13)
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- Ionic and organometallic reductions with N-Heterocyclic carbene boranes
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Surgical reduction: N-Heterocyclic carbene-borane complexes such as depicted are neutral, organic soluble analogues of borohydride anions with a weak hydridic character, compatible with organometallic catalysis. They are applicable for surgical reductions in complex, multifunctional molecules.
- Chu, Qianli,Brahmi, Malika Makhlouf,Solovyev, Andrey,Ueng, Shau-Hua,Curran, Dennis P.,Malacria, Max,Fensterbank, Louis,Lacote, Emmanuel
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supporting information; experimental part
p. 12937 - 12940
(2010/05/19)
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- Palladium-catalysed synthesis of aryl-alkyl ethers using alkoxysilanes as nucleophiles
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Changing the activator from tetrabutyl ammonium fluoride (TBAF) to sodium hydroxide unexpectedly switches the catalytic pathway of the Hiyama coupling reaction of vinyl trialkoxysilanes with aryl bromides into a Pd catalysed C-O bond forming reaction; if
- Milton, Edward J.,Fuentes, Jose A.,Clarke, Matthew L.
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experimental part
p. 2645 - 2648
(2009/10/30)
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- Regioselective hydroperoxygenation of aralkanes and α,β- unsaturated carbonyl compounds catalyzed by N-hydroxyphthalimide and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile)
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Aerobic oxidation of aralkanes and α,β-unsaturated carbonyl compounds in the presence of a catalytic amount of N-hydroxyphthalimide (NHPI) and 2,2′-Azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) under 1 atmos. of oxygen at 30°C gave α-hydroperoxyaralkanes and γ-hydroperoxy-α,β-unsaturated carbonyl compounds, respectively. Copyright Taylor & Francis, Inc.
- Sugamoto, Kazuhiro,Matsushita, Yoh-Ichi,Yamamoto, Takashi,Matsui, Takanao
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p. 1865 - 1874
(2007/10/03)
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- The methoxycarbonylation of aryl chlorides catalysed by palladium complexes of bis(di-tert-butylphosphinomethyl)benzene
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A catalyst system based on palladium-1,2-bis-(di-tert-butylphosphinomethyl) benzene (BDTBPMB) shows good activity for the methoxycarbonylation of strongly activated aryl chlorides, like 4-chloromethylbenzoate or 4-chlorocyanobenzene. Surprisingly, the use of less activated aryl chlorides, like 4-chloroacetophenone, leads to the formation of dimethyl terephthalate amongst other products arising from organic reactions of methoxide ion and/or CO. Less nucleophilic alcohols such as 2,2,2-trifluoroethanol promote the formation of carbonylation products even from 4-chloroacetophenone and chlorobenzene. Labelling studies involving CD3OH, CD3OD or 13CO give information on the origin of many of the products. The Royal Society of Chemistry 2005.
- Jimenez-Rodriguez, Cristina,Eastham, Graham R.,Cole-Hamilton, David J.
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p. 1826 - 1830
(2007/10/03)
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- Precursors for fragrant ketones and fragrant aldehydes
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The present invention refers to fragrance precursors of formula I for a fragrant ketone of formula II and one or more fragrant aldehydes or ketones of formula III and IV, These fragrance precursors are useful in perfumery, especially in the fine and functional perfumery.
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- N-aryl-3-aryl-4-substituted-2,3,4,5-tetrahydro-1H-pyrazole-1-carboxamides
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This invention relates to novel N-aryl-3-aryl-4-substituted-2,3,4,5-tetrahydro-1H-pyrazole-1-carboxamide compounds which are useful as pesticides, compositions containing those compounds, methods of controlling pests and processes for preparing these compounds.
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- Method of treating diabetes mellitus using arylglyoxals
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A method of treating diabetes mellitus using arylglyoxals which are known compounds.
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