- Photosensitive self-assembled monolayers on gold: Photochemistry of surface-confined aryl azide and cyclopentadienylmanganese tricarbonyl
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Photosensitive self-assembled monolayers (SAMs) are prepared by the spontaneous reaction of di-11-(4-azidobenzoate)-1-undecyl disulfide, I, or 11-mercaptoundecylcyclopentadienylmanganese tricarbonyl, II, with polycrystalline Au. SAMs of I are photosensitive by virtue of a pendant aryl azide moiety (λmax = 270 nm, log ε = 4.2) which undergoes photoreaction with secondary amines to form Au-confined derivatives of 3-H azepine and hydrazine, while Au-II SAMs undergo photosubstitution of phosphine for CO. Au-I SAMs irradiated in the presence of various secondary amines were characterized by reflection absorption infrared spectroscopy (RAIRS), XPS, and cyclic voltammetry, and showed persistent attachment of approximately one monolayer of amine. Infrared spectroscopy was used to establish that primary photoproducts obtained upon irradiation of Au-I SAMs in diethylamine are nearly identical to primary photoproducts obtained upon irradiating an analog of I, methyl 4-azidobenzoate, in diethylamine solution. XPS analysis of Au-I SAMs before and after irradiation in the presence of secondary amines confirms loss of N2 from the Au-I SAM and incorporation of one nitrogen atom per surface-confined molecule. Most definitively, cyclic voltammetry of Au-I after irradiation in the presence of 2-ferrocenylethyl-2′,2′,2′-trifluoroethylamine, III, showed 3.3 × 10-10 mol cm-2 of surface-confined ferrocene. Positive ion SIMS spectra of Au-II irradiated in the presence of PPh2Et, PPh2(n-Pr), PPh2(CH2)11Fc, X, Fc = ferrocenyl, or PPh2(CH2)2(CF2)5CF 3, XI, show that introduction of the phosphine onto the surface occurs upon near-UV irradiation. Importantly, the surface photochemistry of I and II allows the high lateral resolution patterning of Au surfaces and Au microstructures with a variety of molecular reagents. SIMS maps for vinyl ferrocenium (m/z 212) or F- (m/z 19) of flat Au-II substrates irradiated through a Cr-on-glass mask in the presence of X or XI demonstrate photochemical patterning at a lateral resolution of 2H5OH)2NH.
- Wollman, Eric W.,Kang, Doris,Frisbie, C. Daniel,Lorkovic, Ivan M.,Wrighton, Mark S.
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- Hypersensitive azobenzenes: Facile synthesis of clickable and cleavable azo linkers with tunable and high reducibility
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The aim of this work is to show that by increasing the number of donor substituents in a donor/acceptor system, the sensitivity of the azobenzene linkage towards a reductive cleavage reaction can be enhanced to unprecedented high levels. For instance, in a triple-donor system, less than a second constitutes the half-life of the azo (NN) bond. Synthetic access to such redox active scaffolds is highly practical and requires only 1-2 synthetic steps. The fundamental molecular design is also adaptable. This is demonstrated through scaffold functionalization by azide, tetraethylene glycol, and biotin groups. The availability of the azide group is shown in a copper-free 'click' reaction suitable in context with protein conjugation and proteomics application. Finally, the clean nature of the scission process is demonstrated with the help of liquid chromatography coupled with mass analysis. This work, therefore, describes development of cleavable azobenzene linkers that can be accessed with synthetic ease, can be multiply functionalized, and show a clean and rapid response to mild reducing conditions.
- Eom, Taejun,Khan, Anzar
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- A new monoclinic polymorph of methyl p-aminobenzoate
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The crystal structure of methyl-p-aminobenzoate (MAB) was analyzed. A P21/c polymorph of MAB was found and the intra and intermolecular geometries were compared with those of the previously known C2/c structure. It was found that in the C2/c polymorph, two hydrogen bonds formed infinite chains along the [110] and [110] directions. The molecule was also found to be almost flat, and the largest deviations from the least square plane through the aromatic rings were 0.300 (3) and 0.180 (2) A for the atoms C8 and O2 respectively.
- Doriguetto, Antonio C.,De Paula Silva, Carlos H.T.,Rando, Daniela G.,Ferreira, Elizabeth I.,Ellena, Javier
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- A “universal” catalyst for aerobic oxidations to synthesize (hetero)aromatic aldehydes, ketones, esters, acids, nitriles, and amides
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Functionalized (hetero)aromatic compounds are indispensable chemicals widely used in basic and applied sciences. Among these, especially aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides represent valuable fine and bulk chemicals, which are used in chemical, pharmaceutical, agrochemical, and material industries. For their synthesis, catalytic aerobic oxidation of alcohols constitutes a green, sustainable, and cost-effective process, which should ideally make use of active and selective 3D metals. Here, we report the preparation of graphitic layers encapsulated in Co-nanoparticles by pyrolysis of cobalt-piperazine-tartaric acid complex on carbon as a most general oxidation catalyst. This unique material allows for the synthesis of simple, functionalized, and structurally diverse (hetero)aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides from alcohols in excellent yields in the presence of air.
- Bartling, Stephan,Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Rabeah, Jabor,Rockstroh, Nils,Senthamarai, Thirusangumurugan
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supporting information
p. 508 - 531
(2022/02/11)
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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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- Selective Reduction of Nitroarenes to Arylamines by the Cooperative Action of Methylhydrazine and a Tris(N-heterocyclic thioamidate) Cobalt(III) Complex
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We report an efficient catalytic protocol that chemoselectively reduces nitroarenes to arylamines, by using methylhydrazine as a reducing agent in combination with the easily synthesized and robust catalyst tris(N-heterocyclic thioamidate) Co(III) complex [Co(κS,N-tfmp2S)3], tfmp2S = 4-(trifluoromethyl)-pyrimidine-2-thiolate. A series of arylamines and heterocyclic amines were formed in excellent yields and chemoselectivity. High conversion yields of nitroarenes into the corresponding amines were observed by using polar protic solvents, such as MeOH and iPrOH. Among several hydrogen donors that were examined, methylhydrazine demonstrated the best performance. Preliminary mechanistic investigations, supported by UV-vis and NMR spectroscopy, cyclic voltammetry, and high-resolution mass spectrometry, suggest a cooperative action of methylhydrazine and [Co(κS,N-tfmp2S)3] via a coordination activation pathway that leads to the formation of a reduced cobalt species, responsible for the catalytic transformation. In general, the corresponding N-arylhydroxylamines were identified as the sole intermediates. Nevertheless, the corresponding nitrosoarenes can also be formed as intermediates, which, however, are rapidly transformed into the desired arylamines in the presence of methylhydrazine through a noncatalytic path. On the basis of the observed high chemoselectivity and yields, and the fast and clean reaction processes, the present catalytic system [Co(κS,N-tfmp2S)3]/MeNHNH2 shows promise for the efficient synthesis of aromatic amines that could find various industrial applications.
- Ioannou, Dimitris I.,Gioftsidou, Dimitra K.,Tsina, Vasiliki E.,Kallitsakis, Michael G.,Hatzidimitriou, Antonios G.,Terzidis, Michael A.,Angaridis, Panagiotis A.,Lykakis, Ioannis N.
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supporting information
p. 2895 - 2906
(2021/02/27)
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- METHOD OF PREPARING(3R,5R)-7-(2-(4-FLUOROPHENYL)-5-ISOPROPYL-3-PHENYL-4-((4-HYDROXYMETHYLPHENYLAMINO)CARBONYL)-PYRROL-1-YL)-3,5-DIHYDROXY-HEPTANOIC ACID HEMI CALCIUM SALT, AND METHOD OF PREPARING INTERMEDIATES USED THEREIN
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The present invention provides a method for preparing (3R,5R)-7-(2-(4-flurophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrole-1-yl)-3,5-dihydroxy heptanoic acid hemicalcium salt. The preparation method of the present invention is performed in a convergent synthesis manner in which main structural moieties of a (3R,5R)-7-(2-(4-flurophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrole-1-yl)-3,5-dihydroxy heptanoic acid hemicalcium salt are independently synthesized, and then coupled. Accordingly, related substances can be easily controlled and preparing time can be reduced, thus improving the productivity of a compound, and the yield of a final compound can also be increased.
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Paragraph 0079-0082
(2021/02/05)
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- Optimizing the structure of (salicylideneamino)benzoic acids: Towards selective antifungal and anti-staphylococcal agents
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An increasing resistance of human pathogenic bacteria and fungi has become a global health problem. Based on previous reports of 4-(salicylideneamino)benzoic acids, we designed, synthesised and evaluated their me-too analogues as potential antimicrobial agents. Forty imines derived from substituted salicylaldehydes and aminobenzoic acids, 4-aminobenzoic acid esters and 4-amino-N-phenylbenzamide were designed using molecular hybridization and prodrug strategies. The target compounds were synthesized with high yields and characterized by spectral methods. They were investigated against a panel of Gram-positive and Gram-negative bacteria, mycobacteria, yeasts and moulds. The most active imines were tested to determine their cytotoxicity and selectivity in HepG2 cells. Dihalogenosalicylaldehydes-based derivatives showed potent broad-spectrum antimicrobial properties, particularly against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (minimum inhibitory concentrations, MIC, from 7.81 μM) and Enterococcus faecalis (MIC of ≥15.62 μM), yeasts (MIC from 7.81 μM) and Trichophyton interdigitale mould (MIC of ≥3.90 μM). Methyl 4-[(2-hydroxy-3,5-diiodobenzylidene)amino]benzoate 4h exhibited excellent in vitro activity along with low toxicity to mammalian cells. This compound is selective for staphylococci, Candida spp. and Trichophyton interdigitale. In addition, this imine was evaluated as a potential inhibitor of Gram-positive biofilms. The successful approach used provided some promising derivatives with more advantageous properties than the parent 4-(salicylideneamino)benzoic acids.
- Krátky, Martin,Kone?ná, Klára,Broke?ová, Kate?ina,Maixnerová, Jana,Trejtnar, Franti?ek,Vin?ová, Jarmila
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- An amino-functionalized three-dimensional cadmium metal–organic framework: Synthesis, characterization and excellent fluorescence sensing of Fe3+
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An amino-functionalized three-dimensional cadmium metal–organic framework, [Cd1.5(L)(DMF)]·2H2O (complex 1) L = H3TTCA-NH2 = 2′-amino-[1,1′:3′,1″-terphenyl]-4,4″,5′-tricarboxylic acid), is successfully synthesized under solvothermal conditions and structurally characterized. Interestingly, as a transition metal organic framework, the cadmium metal–organic framework exhibits favorable luminescence properties. In addition, the cadmium metal–organic framework reveals excellent selective and sensitive fluorescence sensing for the recognition of Fe3+ with high quenching efficiency (Ksv = 3.340 × 103 M?1), demonstrating that the cadmium metal–organic framework can be used as a potential sensor for Fe3+.
- Han, Youjie,Tian, Ye,Yin, Jifa,Zhu, Hongmei
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p. 845 - 849
(2021/06/06)
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- Biobased Spiroimides from Itaconic Acid and Formamides: Molecular Targets for a Novel Synthetic Application of Renewable Chemicals
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Spiroimides exhibit a wide range of biological activities, such as anticonvulsant, antiarrhythmic, and antihyperglycemic activities. Herein, a novel synthetic application of renewable chemicals, itaconic acid and formamides, is described. Proper exploitation of the reactivity of itaconic acid and formamide allows for the development of an efficient synthetic approach for the production of several new biobased spiroimides, spiro[dihydroquinolin-2-one-succinimides] and spiro[indolin-2-one-glutarimides], in excellent overall yields (up to 98%).
- Hornink, Milene Macedo,Lopes, Alice Uva,Andrade, Leandro Helgueira
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supporting information
p. 296 - 308
(2020/11/09)
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- Isoxazole FXR receptor agonist as well as preparation method and medical application thereof
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The invention belongs to the field of medicinal chemistry, and particularly relates to an isoxazole FXR receptor agonist and a preparation method and medical application thereof. The invention relates to a compound as shown in a formula (I), and pharmaceutically acceptable salts and isotope markers thereof. The compound as shown in the formula (I), the pharmaceutically acceptable salts and the isotope markers thereof have FXR receptor agonist activity and can be applied to preparation of drugs for treating or preventing hyperlipidemia, atherosclerosis, non-alcoholic steatohepatitis and type II diabetes mellitus.
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Paragraph 0057-0059
(2021/07/14)
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- Synthesis, characterization and computational study of N-acylhydrazone derivatives
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The N-Acylhydrazone of benzoic acid and their derivatives are important intermediates in organic synthesis and have widespread applications in the medicinal industry. The N-Acylhydrazone was prepared through the condensing the phenyl hydrazide derivatives which prepared from phenylmethyl ester, with benzaldehyde and then identified by physicochemical properties and spectral analysis; FT-IR and 1HNMR. Computation calculations studies by using Semi-empirical-PM3 method through a molecular structure with optimized geometry showed that there is a high correlation between dipole moment, Electron affinity (EA), ionization potential (IP), electronegativity, ClogP and hardness. To Proof, the stability of N-Acylhydrazone derivatives by using Molecular orbital calculations supported a full description of the orbitals and the contributions of individual atoms. Highest occupied molecular orbital/lowest unoccupied molecular orbital energies and structures are demonstrated, calculation atomic charge and molecular electrostatic potential. Through the data obtained from the computational chemistry program, Hyper Chem 8, we were able to demonstrate that the N-acylhydrazone derivatives have a close values and within the limits of stability.
- Alrubaie, Leaqaa A. Raheem
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p. 5067 - 5075
(2021/08/31)
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- Efficient reduction of nitro compounds and domino preparation of 1-substituted-1H-1,2,3,4-tetrazoles by Pd(ii)-polysalophen coated magnetite NPs as a robust versatile nanocomposite
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A new, versatile, and green methodology has been developed for the efficient NaBH4-reduction of nitroarenes as well as the domino/reduction MCR preparation of 1-substituted-1H-1,2,3,4-tetrazoles using Pd(ii)-polysalophen coated magnetite NPs as an efficient heterogeneous magnetically recyclable nanocatalyst. Polysalophen was firstly prepared based on a triazine framework with a high degree of polymerization, then coordinated to Pd ions and, finally, the resulting hybrid was immobilized on magnetite NPs. The catalyst was characterized by various instrumental and analytical methods, including GPC, DLS, N2adsorption-desorption, TGA, VSM, TEM, HRTEM, EDX, XPS, XRD, and ICP analyses. The catalyst possesses dual-functionality including the reduction of nitroarenes and the construction of tetrazole rings all in one stepviaa domino protocol. High to excellent yields were obtained for both nitro reduction and the direct preparation of 1-substituted-1H-1,2,3,4-tetrazoles from nitro compounds. Insight into the mechanism was conducted by XPSin situas well as DLSin situalong with several control experiments. Recyclability of the catalyst was studied for 6 consecutive runs along with metal leaching measurements in each cycle.
- Xu, DaPeng,Xiong, Meilu,Kazemnejadi, Milad
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p. 12484 - 12499
(2021/04/14)
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- Biorenewable carbon-supported Ru catalyst for: N -alkylation of amines with alcohols and selective hydrogenation of nitroarenes
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Herein, we developed a renewable carbon-supported Ru catalyst (Ru/PNC-700), which was facilely prepared via simple impregnation followed by the pyrolysis process. The prepared Ru/PNC-700 catalyst demonstrated remarkable catalytic activity in terms of conversion and selectivity towards N-alkylation of anilines with benzyl alcohol and chemoselective hydrogenation of aromatic nitro compounds. In addition, local anesthetic pharmaceutical agents (e.g., butamben and benzocaine), including key drug intermediates, were synthesized in excellent yields under mild conditions and in the presence of water as a green solvent. Moreover, the prepared Ru/PNC-700 catalyst could be easily recovered and reused up to five times without any apparent loss in activity and selectivity.
- Goyal, Vishakha,Narani, Anand,Natte, Kishore,Poddar, Mukesh Kumar,Ray, Anjan,Sarki, Naina,Tripathi, Deependra
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p. 14687 - 14694
(2021/08/23)
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- Development and Application of Efficient Ag-based Hydrogenation Catalysts Prepared from Rice Husk Waste
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The development of strategies for the sustainable management and valorization of agricultural waste is of outmost importance. With this in mind, we report the use of rice husk (RH) as feedstock for the preparation of heterogeneous catalysts for hydrogenation reactions. The catalysts were prepared by impregnating the milled RH with a silver nitrate solution followed by carbothermal reduction. The composition and morphology of the prepared catalysts were fully assessed by IR, AAS, ICP-MS, XPS, XRD and STEM techniques. This novel bio-genic silver-based catalysts showed excellent activity and remarkable selectivity in the hydrogenation of nitro groups in both aromatic and aliphatic substrates, even in the presence of reactive functionalities like halogens, carbonyls, borate esters or nitriles. Recycling experiments showed that the catalysts can be easily recovered and reused multiple times without significant drop in performance and without requiring re-activation.
- Unglaube, Felix,Kreyenschulte, Carsten Robert,Mejía, Esteban
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p. 2583 - 2591
(2021/04/09)
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- A Concise Route to Cyclic Amines from Nitroarenes and Ketoacids under Iron-Catalyzed Hydrosilylation Conditions
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Starting from nitroarenes, under hydrosilylation conditions, using a well-defined N-heterocyclic carbene iron(0) catalyst, (IMes)Fe(CO)4, the corresponding aniline derivatives were produced in 61–92% isolated yields. More impressively, a selective synthesis of cyclic amines such as pyrrolidines, piperidines and azepanes were conducted from levulinic acid, 1,5- and 1,6-keto acids, respectively. The sequential procedure proceeded under both visible light irradiation and thermal conditions with 20 examples in isolated yields up to 69%. (Figure presented.).
- Ammaiyappan, Yuvaraj,Darcel, Christophe,Tongdee, Satawat,Wu, Jiajun
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p. 3859 - 3865
(2021/07/12)
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- A highly effective green catalyst Ni/Cu bimetallic nanoparticles supported by dendritic ligand for chemoselective oxidation and reduction reaction
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The highly active Ni/Cu bimetallic nanoparticles (NPs) of the different molar ratios of Ni and Cu (1:1, 1:3, 3:1) assisted by dendritic ligand 2,4,6-Tris (di-4-chlorobenzamido)-1,3-diazine were synthesized successfully confirmed by Scanning Electron Microscopy (SEM), Electron Diffraction X-ray (EDX), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM) analysis. These NPs were studied as a heterogeneous catalyst for the chemoselective oxidation of alcohol to the corresponding aldehyde at 30?min and chemoselective reduction of aromatic nitro substituents to the corresponding amino substituents at 20?min, while the Ni/Cu (3:1) NPs were found to be the most effective among other Ni/Cu?(1:1)?and Ni/Cu?(1:3)?NPs at room temperature under mild conditions. The Ni/Cu (3:1) NPs can be recycled for at least five successive runs with no perceptible decrease in catalytic activity. Graphic abstract: [Figure not available: see fulltext.]
- Islam, Md. Sayedul,Khan, Md. Wahab
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p. 2353 - 2369
(2021/01/07)
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- Synthesis, Structure, and Catalytic Hydrogenation Activity of [NO]-Chelate Half-Sandwich Iridium Complexes with Schiff Base Ligands
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A series of N,O-coordinate iridium(III) complexes with a half-sandwich motif bearing Schiff base ligands for catalytic hydrogenation of nitro and carbonyl substrates have been synthesized. All iridium complexes showed efficient catalytic activity for the hydrogenation of ketones, aldehydes, and nitro-containing compounds using clean H2 as reducing reagent. The iridium catalyst displayed the highest TON values of 960 and 950 in the hydrogenation of carbonyl and nitro substrates, respectively. Various types of substrates with different substituted groups afforded corresponding products in excellent yields. All N,O-coordinate iridium(III) complexes 1-4 were well characterized by IR, NMR, HRMS, and elemental analysis. The molecular structure of complex 1 was further characterized by single-crystal X-ray determination.
- Lv, Wen-Rui,Li, Rong-Jian,Liu, Zhen-Jiang,Jin, Yan,Yao, Zi-Jian
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p. 8181 - 8188
(2021/05/26)
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- Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
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The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.
- Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
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supporting information
p. 2742 - 2747
(2021/05/05)
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- Light-Promoted C–N Coupling of Aryl Halides with Nitroarenes
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A photochemical C–N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a NiII complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald–Hartwig C–N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a NiI/NiIII cycle, to a nitrosoarene intermediate.
- Li, Gang,Yang, Liu,Liu, Jian-Jun,Zhang, Wei,Cao, Rui,Wang, Chao,Zhang, Zunting,Xiao, Jianliang,Xue, Dong
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supporting information
p. 5230 - 5234
(2021/02/05)
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- Fe-Catalyzed Anaerobic Mukaiyama-Type Hydration of Alkenes using Nitroarenes
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Hydration of alkenes using first row transition metals (Fe, Co, Mn) under oxygen atmosphere (Mukaiyama-type hydration) is highly practical for alkene functionalization in complex synthesis. Different hydration protocols have been developed, however, control of the stereoselectivity remains a challenge. Herein, highly diastereoselective Fe-catalyzed anaerobic Markovnikov-selective hydration of alkenes using nitroarenes as oxygenation reagents is reported. The nitro moiety is not well explored in radical chemistry and nitroarenes are known to suppress free radical processes. Our findings show the potential of cheap nitroarenes as oxygen donors in radical transformations. Secondary and tertiary alcohols were prepared with excellent Markovnikov-selectivity. The method features large functional group tolerance and is also applicable for late-stage chemical functionalization. The anaerobic protocol outperforms existing hydration methodology in terms of reaction efficiency and selectivity.
- Bhunia, Anup,Bergander, Klaus,Daniliuc, Constantin Gabriel,Studer, Armido
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supporting information
p. 8313 - 8320
(2021/03/08)
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- Retro-Aza-Piancatelli Rearrangement Triggered Cascade Reaction of Methyl Furylacrylates with Anilines to Access Cyclopenta[b]pyrrolidinones
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A novel aza-Piancatelli rearrangement triggered cascade reaction has been developed by utilizing methyl furylacrylates as a new type of functionalized furanoxonium ion precursor, permitting rapid and flexible construction of diverse cyclopenta[b]pyrrolidinone derivatives. The unprecedented and highly efficient bicyclic γ-lactam product formation is originated from an unusual retro-aza-Piancatelli rearrangement of the major cis-fused multifunctionalized cyclopentenone to the minor trans-fused one followed by a lactamization reaction.
- Cai, Yunfei,Li, Hongxiang,Tang, Yurong,Xing, Liuzhuang,Xu, Lei,Yang, Qian
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supporting information
(2021/12/27)
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- Cu-Catalyzed Cross-Coupling of Nitroarenes with Aryl Boronic Acids to Construct Diarylamines
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The development and study of a simple copper-catalyzed reaction of nitroarenes with aryl boronic acids to form diarylamines that uses phenyl silane as the stoichiometric terminal reductant is described. This cross-coupling reaction requires as little as 2 mol % of CuX and 4 mol % of diphosphine for success and tolerates a broad range of functional groups on either the nitroarene or the aryl boronic acid to afford the amine in good yield. Mechanistic investigations established that the cross-coupling reaction proceeds via a nitrosoarene intermediate and that copper is required to catalyze both the deoxygenation of the nitroarene to afford the nitrosoarene and C-NAr bond formation of the nitrosoarene with the aryl boronic acid.
- Guan, Xinyu,Zhu, Haoran,Driver, Tom G.
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p. 12417 - 12422
(2021/10/12)
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- A Metal-Free Direct Arene C?H Amination
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The synthesis of aryl amines via the formation of a C?N bond is an essential tool for the preparation of functional materials, active pharmaceutical ingredients and bioactive products. Usually, this chemical connection is only possible by transition metal-catalyzed reactions, photochemistry or electrochemistry. Here, we report a metal-free arene C?H amination using hydroxylamine derivatives under benign conditions. A charge transfer interaction between the aminating reagents TsONHR and the arene substrates enables the chemoselective amination of the arene, even in the presence of various functional groups. Oxygen was crucial for an effective conversion and its accelerating role for the electron transfer step was proven experimentally. In addition, this was rationalized by a theoretical study which indicated the involvement of a dioxygen-bridged complex with a “Sandwich-like” arrangement of the aromatic starting materials and the aminating agents at the dioxygen molecule. (Figure presented.).
- Wang, Tao,Hoffmann, Marvin,Dreuw, Andreas,Hasagi?, Edina,Hu, Chao,Stein, Philipp M.,Witzel, Sina,Shi, Hongwei,Yang, Yangyang,Rudolph, Matthias,Stuck, Fabian,Rominger, Frank,Kerscher, Marion,Comba, Peter,Hashmi, A. Stephen K.
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supporting information
p. 2783 - 2795
(2021/04/05)
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- Method for synthesizing heteroatom- substituted aromatic compound from styrene compound
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The invention discloses a method for synthesizing a heteroatom-substituted aromatic compound from a styrene compound, which comprises the following steps of: mixing a styrene compound with a general formula (I) and a heteroatom-containing compound with a general formula (II), and reacting in the presence of an acid additive and an organic solvent to obtain a heteroatom-substituted compound with ageneral formula (III). According to the synthesis method disclosed by the invention, a large amount of styrene compounds are used as raw materials and react to generate aromatic amine or phenol compounds under the action of no metal catalysis; and compared with the traditional aromatic amine and phenol synthesis method, the method has the advantages of high yield, simple conditions, low waste discharge amount, no metal participation, simple reaction equipment, easiness in industrial production and the like.
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Paragraph 0166-0168
(2021/02/06)
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- Alkali-modified heterogeneous Pd-catalyzed synthesis of acids, amides and esters from aryl halides using formic acid as the CO precursor
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To establish an environmentally friendly green chemical process, we minimized and resolved a significant proportion of waste and hazards associated with conventional organic acids and molecular gases, such as carbon monoxide (CO). Herein, we report a facile and milder reaction procedure, using low temperatures/pressures and shorter reaction time for the carboxyl- and carbonylation of diverse arrays of aryl halides over a newly developed cationic Lewis-acid promoted Pd/Co3O4catalyst. Furthermore, the reaction proceeded in the absence of acid co-catalysts, and anhydrides for CO release. Catalyst reusability was achievedviascalable, safer, and practical reactions that provided moderate to high yields, paving the way for developing a novel environmentally benign method for synthesizing carboxylic acids, amides, and esters.
- Fapojuwo, Dele Peter,Maqunga, Nomathamsanqa Prudence,Meijboom, Reinout,Mogudi, Batsile M.,Molokoane, Pule Petrus,Onisuru, Oluwatayo Racheal,Oseghale, Charles O.
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p. 26937 - 26948
(2021/08/17)
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- Copper catalyzed reduction of azides with diboron under mild conditions
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We report herein the first Cu catalyzed reduction of azides with B2pin2 (pin = pinacolato) as the reductant under very mild conditions. A series of primary amines and amides were obtained in moderate to excellent yields with high chemoselectivity and good functional group tolerance. This reaction can be performed with a cheap copper salt, a simple NHC ligand and a diboron reagent.
- Chen, Yang,Deng, Shengqi,Gao, Yihua,Liu, Liwen,Liu, Yu,Lu, Da,Wang, Qianwen,Zhang, Xiao
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supporting information
(2020/02/27)
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- Selective Photoinduced Reduction of Nitroarenes to N-Arylhydroxylamines
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We report the selective photoinduced reduction of nitroarenes to N-arylhydroxylamines. The present methodology facilitates this transformation in the absence of catalyst or additives and uses only light and methylhydrazine. This noncatalytic photoinduced transformation proceeds with a broad scope, excellent functional-group tolerance, and high yields. The potential of this protocol reflects on the selective and straightforward conversion of two general antibiotics, azomycin and chloramphenicol, to the bioactive hydroxylamine species.
- Kallitsakis, Michael G.,Ioannou, Dimitris I.,Terzidis, Michael A.,Kostakis, George E.,Lykakis, Ioannis N.
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supporting information
p. 4339 - 4343
(2020/06/08)
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- A more sustainable and highly practicable synthesis of aliphatic isocyanides
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Synthesis protocols to convert N-formamides into isocyanides using three different dehydration reagents (i.e. p-toluenesulfonyl chloride (p-TsCl), phosphoryl trichloride (POCl3) and the combination of triphenylphosphane (PPh3) and iodine) were investigated and optimized, while considering the principles of green chemistry. Comparison of the yield and the E-factors of the different synthesis procedures revealed that, in contrast to the typically applied POCl3 or phosgene derivatives, p-TsCl was the reagent of choice for non sterically demanding aliphatic mono- or di-N-formamides (yields up to 98% and lowest E-factor 6.45). Apart from a significantly reduced E-factor, p-TsCl is cheap, offers a simplified reaction protocol and work-up, and is less toxic compared to other dehydration reagents. Thus, this procedure offers easier and greener access to aliphatic isocyanide functionalities.
- Waibel,Nickisch,M?hl,Seim,Meier
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supporting information
p. 933 - 941
(2020/02/21)
-
- A synthetic 2,3-diarylindole induces microtubule destabilization and G2/M cell cycle arrest in lung cancer cells
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The anticancer potential of a synthetic 2,3-diarylindole (PCNT13) has been demonstrated in A549 lung cancer cells by inducing both apoptosis and autophagic cell death. In this report, we designed to connect a fluorophore to the compound via a hydrophilic linker for monitoring intracellular localization. The best position for linker attachment was identified from cytotoxicity and effect on cell morphology of newly synthesized PCNT13 derivatives bearing hydrophilic linker. Cytotoxicity and effect on cell morphology related to the parental compound were used to identify the optimum position for linker attachment in the PCNT13 chemical structure. The fluorophore-PCNT13 conjugate was found to localize in the cytoplasm. Microtubules were found to be one of the cytosolic target proteins of PCNT13, as the compound could inhibit tubulin polymerization in vitro. A molecular docking study revealed that PCNT13 binds at the colchicine binding site on the α/β-tubulin heterodimer. The effect of PCNT13 on microtubule dynamics caused cell cycle arrest in the G2/M phase as analyzed by flow cytometric analysis.
- Thanaussavadate, Bongkotrat,Ngiwsara, Lukana,Lirdprapamongkol, Kriengsak,Svasti, Jisnuson,Chuawong, Pitak
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supporting information
(2019/11/14)
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- Synthesis and Biological Evaluation of Novel Carbazole Hybrids as Promising Antimicrobial Agents
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Two series of carbazole analogs of 8-methoxy-N-substituted-9H-carbazole-3-carboxamides (series 1) and carbazolyl substituted rhodanines (series 2) were synthesized through facile synthetic routes. All the final compounds from these two series were evaluated for their preliminary in vitro antifungal and antibacterial activity against four fungal (Candida albicans, Cryptococcus neoformans, Cryptococcus tropicalis and Aspergillus niger) and four bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) strains, respectively. Among the tested compounds, three compounds of series 1 displayed promising antifungal and antibacterial activity, especially against C. neoformans and S. aureus. In addition, one compound of series 1 displayed notable antimicrobial activity (MIC: 6.25 μg/mL) against clinical isolates of C. albicans and C. neoformans (MIC: 12.5 μg/mL). From the second series, four compounds exhibited significant antifungal and antibacterial activity, especially against C. neoformans and S. aureus. The most active compound of series 2 displayed a prominent antimicrobial activity against C. neoformans (MIC: 3.125 μg/mL) and S. aureus (MIC: 1.56 μg/mL), respectively.
- Shaikh, Mahamadhanif S.,Chandrasekaran, Balakumar,Palkar, Mahesh B.,Kanhed, Ashish M.,Kajee, Afsana,Mlisana, Koleka P.,Singh, Parvesh,Ghai, Meenu,Cleopus Mahlalela, Mavela,Karpoormath, Rajshekhar
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- 2-Arylamino-6-ethynylpurines are cysteine-targeting irreversible inhibitors of Nek2 kinase
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Renewed interest in covalent inhibitors of enzymes implicated in disease states has afforded several agents targeted at protein kinases of relevance to cancers. We now report the design, synthesis and biological evaluation of 6-ethynylpurines that act as covalent inhibitors of Nek2 by capturing a cysteine residue (Cys22) close to the catalytic domain of this protein kinase. Examination of the crystal structure of the non-covalent inhibitor 3-((6-cyclohexylmethoxy-7H-purin-2-yl)amino)benzamide in complex with Nek2 indicated that replacing the alkoxy with an ethynyl group places the terminus of the alkyne close to Cys22 and in a position compatible with the stereoelectronic requirements of a Michael addition. A series of 6-ethynylpurines was prepared and a structure activity relationship (SAR) established for inhibition of Nek2. 6-Ethynyl-N-phenyl-7H-purin-2-amine [IC50 0.15 μM (Nek2)] and 4-((6-ethynyl-7H-purin-2-yl)amino)benzenesulfonamide (IC50 0.14 μM) were selected for determination of the mode of inhibition of Nek2, which was shown to be time-dependent, not reversed by addition of ATP and negated by site directed mutagenesis of Cys22 to alanine. Replacement of the ethynyl group by ethyl or cyano abrogated activity. Variation of substituents on the N-phenyl moiety for 6-ethynylpurines gave further SAR data for Nek2 inhibition. The data showed little correlation of activity with the nature of the substituent, indicating that after sufficient initial competitive binding to Nek2 subsequent covalent modification of Cys22 occurs in all cases. A typical activity profile was that for 2-(3-((6-ethynyl-9H-purin-2-yl)amino)phenyl)acetamide [IC50 0.06 μM (Nek2); GI50 (SKBR3) 2.2 μM] which exhibited >5-10-fold selectivity for Nek2 over other kinases; it also showed > 50% growth inhibition at 10 μM concentration against selected breast and leukaemia cell lines. X-ray crystallographic analysis confirmed that binding of the compound to the Nek2 ATP-binding site resulted in covalent modification of Cys22. Further studies confirmed that 2-(3-((6-ethynyl-9H-purin-2-yl)amino)phenyl)acetamide has the attributes of a drug-like compound with good aqueous solubility, no inhibition of hERG at 25 μM and a good stability profile in human liver microsomes. It is concluded that 6-ethynylpurines are promising agents for cancer treatment by virtue of their selective inhibition of Nek2. This journal is
- Bayliss, Richard,Boxall, Kathy,Carbain, Benoit,Coxon, Christopher R.,Fry, Andrew M.,Golding, Bernard T.,Griffin, Roger J.,Hardcastle, Ian R.,Harnor, Suzannah J.,Mas-Droux, Corine,Matheson, Christopher J.,Newell, David R.,Richards, Mark W.,Sivaprakasam, Mangaleswaran,Turner, David,Cano, Céline
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supporting information
p. 707 - 731
(2020/08/24)
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- Design, synthesis, and biological evaluation of new challenging thalidomide analogs as potential anticancer immunomodulatory agents
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Thalidomide and its analogs are immunomodulatory drugs that inhibit the production of certain inflammatory mediators associated with cancer. In the present work, a new series of thalidomide analogs was designed and synthesized to obtain new effective antitumor immunomodulatory agents. The synthesized compounds were evaluated for their cytotoxic activities against a panel of four cancer cell lines (HepG-2, HCT-116, PC3 and MCF-7). Compounds 33h, 33i, 42f and 42h showed strong potencies against all tested cell lines with IC50 values ranging from 14.63 to 49.90 μM comparable to that of thalidomide (IC50 values ranging from 32.12 to 76.91 μM). The most active compounds were further evaluated for their in vitro immunomodulatory activities via estimation of human tumor necrosis factor alpha (TNF-α), human caspase-8 (CASP8), human vascular endothelial growth factor (VEGF), and nuclear factor kappa-B P65 (NF-κB P65) in HCT-116 cells. Thalidomide was used as a positive control. Compounds 33h and 42f showed a significant reduction in TNF-α. Furthermore, compounds 33i and 42f exhibited significant elevation in CASP8 levels. Compounds 33i and 42f inhibited VEGF. In addition, compound 42f showed significant decrease in levels of NF-κB p65. Moreover, apoptosis and cell cycle tests of the most active compound 42f, were performed. The results indicated that compound 42f significantly induce apoptosis in HCT-116 cells and arrest cell cycle at the G2/M phase.
- El-Zahabi, Mohamed Ayman,Sakr, Helmy,El-Adl, Khaled.,Zayed, Mohamed,Abdelraheem, Adel S.,Eissa, Sally I.,Elkady, Hazem,Eissa, Ibrahim H.
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- Optimizing Multivariate Metal-Organic Frameworks for Efficient C2H2/CO2Separation
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Adsorptive separation of acetylene (C2H2) from carbon dioxide (CO2) promises a practical way to produce high-purity C2H2 required for industrial applications. However, challenges exist in the pore environment engineering of porous materials to recognize two molecules due to their similar molecular sizes and physical properties. Herein, we report a strategy to optimize pore environments of multivariate metal-organic frameworks (MOFs) for efficient C2H2/CO2 separation by tuning metal components, functionalized linkers, and terminal ligands. The optimized material UPC-200(Al)-F-BIM, constructed from Al3+ clusters, fluorine-functionalized organic linkers, and benzimidazole terminal ligands, demonstrated the highest separation efficiency (C2H2/CO2 uptake ratio of 2.6) and highest C2H2 productivity among UPC-200 systems. Experimental and computational studies revealed the contribution of small pore size and polar functional groups on the C2H2/CO2 selectivity and indicated the practical C2H2/CO2 separation of UPC-200(Al)-F-BIM.
- Fan, Weidong,Yuan, Shuai,Wang, Wenjing,Feng, Liang,Liu, Xiuping,Zhang, Xiurong,Wang, Xia,Kang, Zixi,Dai, Fangna,Yuan, Daqiang,Sun, Daofeng,Zhou, Hong-Cai
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supporting information
p. 8728 - 8737
(2020/12/25)
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- Gold(I)-Thiolate Oligomers for Catalytic Hydrogenation of Nitroaromatics in Aqueous and Organic Medium
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Thiolated gold nanoclusters (AuNCs) have been introduced to efficiently and selectively catalyze the hydrogenation of nitroaromatics due to the strong interaction of their S?Au-S staple motifs with the nitro groups of nitroaromatics. However, without a gold core, gold(I)-thiolate oligomers (AuSOs) with S?Au-S staple motifs are rarely explored as catalysts for nitroaromatics. Here, we report a straightforward strategy for the synthesis of AuSOs through hydroxyl radical-induced leaching of glutathione-capped gold nanoparticles (GSH-AuNPs). Raman spectroscopy and matrix-assisted laser desorption/ionization-time of flight mass spectrometry demonstrated that hydroxyl radical-triggered etching of the GSH-AuNPs resulted in the production of AuSOs, including Au4(GSH)7 and Au7(GSH)9. The AuSOs were found to catalyze NaBH4-mediated hydrogenation of 4-nitrophenol to 4-aminophenol with a chemoselectivity of ~100 percent and a normalized rate constant (Knor) of 4.8×105 s? g?1. In addition to the high affinity of the S?Au?S staple motifs for 4-nitrophenol, the unusual catalytic activity of the AuSOs was attributable to the fact that they efficiently catalyzed the production of H2 from NaBH4 and the reaction of dissolved oxygen and NaBH4. The chemoselectivity and applicability of the AuSOs were further verified by performing the catalytic reaction of methyl 2-(2-nitrophenyl) acetate or methyl 4-nitrobenzoate with NaBH4.
- You, Jyun-Guo,Jin, Dun-Yuan,Tseng, Wei-Bin,Tseng, Wei-Lung,Lin, Po-Chiao
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p. 4558 - 4567
(2020/08/19)
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- Palladium supported on metal–organic framework as a catalyst for the hydrogenation of nitroarenes under mild conditions
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Sustainable development demands an environmentally friendly and efficient method for the hydrogenation of organic molecules, including the hydrogenation of functionalized nitroarenes. In this study, a highly active and selective metal–organic framework-supported palladium catalyst was prepared for the catalytic hydrogenation of nitroarenes. High selectivity (>99%) and excellent yield (98%) of aniline were realized after 2 hours in ethanol under hydrogen (1 atm) at room temperature. The reductions were successfully carried out in the presence of a wide range of other reducible functional groups. More importantly, the catalyst was very stable without the loss of its catalytic activity after five cycles.
- Bao, Lingxiang,Fei, Teng,Li, Jiazhe,Pang, Siping,Sun, Chenghui,Yan, Zhiyuan,Yu, Zongbao
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- Commercially Available CuO Catalyzed Hydrogenation of Nitroarenes Using Ammonia Borane as a Hydrogen Source
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Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high-cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support-free, excellent chemoselectivity, low-cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction.
- Du, Jialei,Chen, Jie,Xia, Hehuan,Zhao, Yiwei,Wang, Fang,Liu, Hong,Zhou, Weijia,Wang, Bin
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p. 2426 - 2430
(2020/03/30)
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- General and selective synthesis of primary amines using Ni-based homogeneous catalysts
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The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
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p. 4332 - 4339
(2020/05/18)
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- Tandem selective reduction of nitroarenes catalyzed by palladium nanoclusters
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We report a catalytic tandem reduction of nitroarenes by sodium borohydride (NaBH4) in aqueous solution under ambient conditions, which can selectively produce five categories of nitrogen-containing compounds: anilines, N-aryl hydroxylamines, azoxy-, azo- and hydrazo-compounds. The catalyst is in situ-generated ultrasmall palladium nanoclusters (Pd NCs, diameter of 1.3 ± 0.3 nm) from the reduction of Pd(OAc)2 by NaBH4. These highly active Pd NCs are stabilized by surface-coordinated nitroarenes, which inhibit the further growth and aggregation of Pd NCs. By controlling the concentration of Pd(OAc)2 (0.1-0.5 mol% of nitroarene) and NaBH4, the water/ethanol solvent ratio and the tandem reaction sequence, each of the five categories of N-containing compounds can be obtained with excellent yields (up to 98%) in less than 30 min at room temperature. This tunable catalytic tandem reaction works efficiently with a broad range of nitroarene substrates and offers a green and sustainable method for the rapid and large-scale production of valuable N-containing chemicals.
- Yan, Ziqiang,Xie, Xiaoyu,Song, Qun,Ma, Fulei,Sui, Xinyu,Huo, Ziyu,Ma, Mingming
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supporting information
p. 1301 - 1307
(2020/03/11)
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- Synthesis and characterization of go-chit-ni nanocomposite as a recoverable nanocatalyst for reducing nitroarenes in water
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In the present study, nickel nanoparticles (Ni-NPs) immobilized on graphene oxide-chitosan (GO-Chit-Ni) have been synthesized and characterized as a catalyst for reduction of nitroarenes in water. For this purpose, GO has been functionalized with chitosan (GO-Chit). Then, Ni-NPs were immobilized on the surface of GO-Chit using a simple method. The GO-Chi-Ni nanocomposites were characterized using Fourier Transforms Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-Ray Diffraction Measurements (XRD), and Atomic Adsorption Spectrometry (AAS). The GO-Chi-Ni nanoparticles demonstrated appropriate catalytic activity in reducing nitroarenes to aryl amines in the existence of sodium borohydride (NaBH4) aqueous solution as a hydrogen source at 80oC. This catalytic system applies environmentally benign water as a solvent that is cheap, easily accessible, non-toxic, non-volatile, non-flammable and thermally stable. This type of catalyst can be applied several times with no considerable change in its performance.
- Azadi, Roya,Sarvestani, Mosayeb
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p. 523 - 531
(2020/07/17)
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- Tin(ii) chloride dihydrate/choline chloride deep eutectic solvent: Redox properties in the fast synthesis of: N -arylacetamides and indolo(pyrrolo)[1,2- a] quinoxalines
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In this contribution a physicochemical, IR and Raman characterization for the tin(ii) chloride dihydrate/choline chloride eutectic mixture is reported. The redox properties of this solvent were also studied by cyclic voltammetry finding that it can be successfully used as an electrochemical solvent for electrosynthesis and electroanalytical processes and does not require negative potentials as verified by the reduction of nitrobenzene. The potential use of this eutectic mixture as a redox solvent was further explored in obtaining aromatic amines and N-arylacetamides starting from a wide variety of nitroaromatic compounds. In addition, a fast synthetic strategy for the construction of a series of indolo(pyrrolo)[1,2-a]quinoxalines was developed by reacting 1-(2-nitrophenyl)-1H-indole(pyrrole) with aldehydes. This simple protocol offers a straightforward method for the construction of the target quinoxalines in short reaction times and high yields where the key step involves a tandem one-pot reductive cyclization-oxidation.
- Bejarano, Oscar Rodríguez,Ochoa-Puentes, Cristian,Pe?a-Solórzano, Diana,Trujillo, Sergio Alfonso
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p. 40552 - 40561
(2020/11/18)
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- NEW CLASS OF DNA GYRASE AND/OR TOPOISOMERASE IV INHIBITORS WITH ACTIVITY AGAINST GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA
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The present invention relates to compounds having a structure of general formula (I), processes for their preparation, pharmaceutical compositions containing them as the active ingredient, to their use as medicaments and to their use in the manufacture of medicaments for use in the treatment of bacterial infections in humans and warm-blooded animals.
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Page/Page column 56-57; 101-102
(2020/03/29)
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- EffectiveN-methylation of nitroarenes with methanol catalyzed by a functionalized NHC-based iridium catalyst: a green approach toN-methyl amines
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Compound [IrBr(CO)2(κC-tBuImCH2PyCH2OMe)] featuring a flexible pyridine/OMe functionalized NHC ligand κ1C coordinated efficiently catalyzes the selectiveN-monomethylation of nitroarenes using methanol as both the reducing agent and the C1 source. A range of functionalized nitroarenes including heterocyclic or sterically hindered derivatives have been efficiently converted to the correspondingN-monomethyl amines in good yields at low catalyst loadings using sub-stoichiometric amounts of Cs2CO3as a base. Mechanistic investigations support a borrowing-hydrogen mechanism in which methanol acts as the hydrogen source and methylating agent. Further, the hydrogen transfer reduction of nitrobenzene to aniline under optimized reaction conditions should proceed through a direct mechanism involving nitrosobenzene andN-phenylhydroxylamine intermediates.
- González-Lainez, Miguel,Jiménez, M. Victoria,Passarelli, Vincenzo,Pérez-Torrente, Jesús J.
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p. 3458 - 3467
(2020/06/17)
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- Synthesis of azido-substituted benzaldehydes via SNAr chemistry
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Conditions for the formation of azidobenzaldehydes and azidobenzonitriles using sodium azide in DMSO under typical SNAr conditions are described. This simplifies access to these valuable building blocks compared to the more common sequences reported in the literature. Interestingly, fluorosubstituted aryl ketones and esters do not afford azides, but instead amine products.
- Kafle, Arjun,Yossef, Sandy,Handy, Scott T.
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supporting information
(2020/04/21)
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- Ruthenium(II)-cored supramolecular organic framework-mediated recyclable visible light photoreduction of azides to amines and cascade formation of lactams
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Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reduction of phenyl, benzyl, 2-phenylethyl and 3-phenylpropyl azides in acetonitrile to produce the corresponding amines in good to high yields. For the last two kinds of azides that bear a CO2Me group at the para-position of the benzene ring, cascade reactions take place to generate the corresponding lactams in high yields. Compared with homogeneous control [Ru(bpy)3]Cl2, SMOF-1 exhibits remarkably increased photocatalysis activity as a result of synergistic effect of the [Ru(bpy)3]2+ units that form cubic cages to host the azide molecules and related intermediates. Moreover, SMOF-1 displays high recyclability and considerable photocatalysis activity after 3 to 12 runs.
- Wu, Yi-Peng,Yan, Meng,Gao, Zhong-Zheng,Hou, Jun-Li,Wang, Hui,Zhang, Dan-Wei,Zhang, Junliang,Li, Zhan-Ting
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p. 1383 - 1386
(2019/05/06)
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- Novel multitarget-directed ligands targeting acetylcholinesterase and σ1 receptors as lead compounds for treatment of Alzheimer's disease: Synthesis, evaluation, and structural characterization of their complexes with acetylcholinesterase
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Pleiotropic intervention may be a requirement for effective limitation of the progression of multifactorial diseases such as Alzheimer's Disease. One approach to such intervention is to design a single chemical entity capable of acting on two or more targets of interest, which are accordingly known as Multi-Target Directed Ligands (MTDLs). We recently described donecopride, the first MTDL able to simultaneously inhibit acetylcholinesterase and act as an agonist of the 5-HT4 receptor, which displays promising activities in vivo. Pharmacomodulation of donecopride allowed us to develop a novel series of indole derivatives possessing interesting in vitro activities toward AChE and the σ1 receptor. The crystal structures of complexes of the most promising compounds with Torpedo californica AChE were solved in order to further understand their mode of inhibition.
- Lalut, Julien,Santoni, Gianluca,Karila, Delphine,Lecoutey, Cédric,Davis, Audrey,Nachon, Florian,Silman, Israel,Sussman, Joel,Weik, Martin,Maurice, Tangui,Dallemagne, Patrick,Rochais, Christophe
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supporting information
p. 234 - 248
(2018/11/24)
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- Design, synthesis and biological evaluation of curcumin analogues as novel LSD1 inhibitors
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Histone lysine-specific demethylase 1 (LSD1) was the first discovered histone demethylase. Inactivating LSD1 or downregulating its expression inhibits cancer-cell development, and thus, it is an attractive molecular target for the development of novel cancer therapeutics. In this study, we worked on the structural optimization of natural products and identified 30 novel LSD1 inhibitors. Utilizing a structure-based drug design strategy, we designed and synthesized a series of curcumin analogues that were shown to be potent LSD1 inhibitors in the enzyme assay. Compound WB07 displayed the most potent LSD1 inhibitory activity, with an IC50 value of 0.8 μM. Moreover, WA20 showed an anticlonogenic effect on A549 cells with an IC50 value of 4.4 μM. Molecular docking simulations were also carried out, and the results indicated that the inhibitors bound to the protein active site located around the key residues of Asp555 and Asp556. These findings suggested that compounds WA20 and WB07 are the first curcumin analogue-based LSD1 inhibitors with remarkable A549 suppressive activity, providing a novel scaffold for the development of LSD1 inhibitors.
- Wang, Jiming,Zhang, Xiangyu,Yan, Jiangkun,Li, Wei,Jiang, Qinwen,Wang, Xinran,Zhao, Dongmei,Cheng, Maosheng
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supporting information
(2019/10/22)
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- Halogen-substituted anthranilic acid derivatives provide a novel chemical platform for androgen receptor antagonists
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Androgen receptor (AR) antagonists are used for hormone therapy of prostate cancer (PCa). However resistance to the treatment occurs eventually. One possible reason is the occurrence of AR mutations that prevent inhibition of AR-mediated transactivation by antagonists. To offer in future more options to inhibit AR signaling, novel chemical lead structures for new AR antagonists would be beneficial. Here we analyzed structure-activity relationships of a battery of 36 non-steroidal structural variants of methyl anthranilate including 23 synthesized compounds. We identified structural requirements that lead to more potent AR antagonists. Specific compounds inhibit the transactivation of wild-type AR as well as AR mutants that render treatment resistance to hydroxyflutamide, bicalutamide and the second-generation AR antagonist enzalutamide. This suggests a distinct mode of inhibiting the AR compared to the clinically used compounds. Competition assays suggest binding of these compounds to the AR ligand binding domain and inhibit PCa cell proliferation. Moreover, active compounds induce cellular senescence despite inhibition of AR-mediated transactivation indicating a transactivation-independent AR-pathway. In line with this, fluorescence resonance after photobleaching (FRAP) - assays reveal higher mobility of the AR in the cell nuclei. Mechanistically, fluorescence resonance energy transfer (FRET) - assays indicate that the amino-carboxy (N/C)-interaction of the AR is not affected, which is in contrast to known AR-antagonists. This suggests a mechanistically novel mode of AR-antagonism. Together, these findings indicate the identification of a novel chemical platform as a new lead structure that extends the diversity of known AR antagonists and possesses a distinct mode of antagonizing AR-function.
- Roell, Daniela,R?sler, Thomas W.,Hessenkemper, Wiebke,Kraft, Florian,Hauschild, Monique,Bartsch, Sophie,Abraham, Tsion E.,Houtsmuller, Adriaan B.,Matusch, Rudolf,van Royen, Martin E.,Baniahmad, Aria
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- Atomically dispersed Ni as the active site towards selective hydrogenation of nitroarenes
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Rational design of heterogeneous non-noble metal catalysts as highly efficient and selective catalysts for hydrogenation of nitroarenes with hydrogen as the reducing agent is currently a great challenge, which has attracted a great deal of attention. Herein, a new strategy for achieving atomic dispersion of Ni atoms on nitrogen-doped porous carbon (Ni-N-C) with a specific surface area of up to 810 m2 g-1 and nickel loading as high as 4.4 wt% is developed, yielding high activity, chemoselectivity, and reusability of catalysts in the hydrogenation of nitroarenes using hydrogen as the reductant with a turnover of number (TON) value of 84 and a turnover of frequency (TOF) value of 8.4 h-1 for the first time. The Ni single atoms anchored on N-doped porous carbon by binding with nitrogen/carbon have been proved to be the active sites. Importantly, the Ni-N3 active species is found to contribute more activity compared with Ni-N2 and Ni-N4. Density functional theory (DFT) calculations also reveal that the Ni-N3 structure exhibits the highest activity according to the lowest adsorption energy and the longest elongation N-O bonds of nitrobenzene, which originated from the induced charge transfer. This work opens a new route for rational design and accurate modulation of nanostructured organic molecular transformation catalysts at the atomic scale.
- Yang, Fan,Wang, Minjian,Liu, Wei,Yang, Bin,Wang, Ying,Luo, Jun,Tang, Yushu,Hou, Liqiang,Li, Yun,Li, Zihui,Zhang, Bing,Yang, Wang,Li, Yongfeng
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supporting information
p. 704 - 711
(2019/02/14)
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- Superfine CoNi alloy embedded in Al2O3 nanosheets for efficient tandem catalytic reduction of nitroaromatic compounds by ammonia borane
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Aromatic amino compounds are important and universally used chemical intermediates in a wide range of industrial fields. Thus, their production with high efficiency and selectivity under ambient conditions is expected and demanded in modern industry. Herein, a series of superfine CoNi alloy nanoparticles embedded in Al2O3 nanosheet (CoxNi1-x/Al2O3, where x represents the content of Co in the precursor) catalysts was fabricated from CoNiAl-LDH and used to catalyze the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of nitroaromatics to the corresponding amines. Systematic experiments indicate that the composition, size, morphology and catalytic performance of the CoxNi1-x/Al2O3 catalysts can be easily controlled by changing the content of Ni in the CoNiAl-LDH precursor. Particularly, Co0.67Ni0.33/Al2O3 exhibited the best tandem catalytic performance among the six samples. This as-prepared catalyst not only showed a moderate turn-over-frequency value (TOF: 34.5 molH2 molCo0.67Ni0.33-1 min-1 at 298 K without base or additives) and relatively low activation energy (32.4 kJ mol-1) for the dehydrogenation of AB, but also superior catalytic activity (conversion yield reaching up to 100%) and selectivity (>99%) for the tandem reductive transformation of in excess of sixteen types of nitroaromatics to aromatic amines. Density functional theory (DFT) calculations suggest that the construction of the CoNi alloy optimized the electronic structure with respect to the pure component, promoting its activity for AB hydrolysis and nitroaromatics hydrogenation. Finally, the catalyst could be easily recycled using a magnet due to the magnetic properties of the Co0.67Ni0.33 alloy.
- Cheng, Sihang,Liu, Yanchun,Zhao, Yingnan,Zhao, Xinyu,Lang, Zhongling,Tan, Huaqiao,Qiu, Tianyu,Wang, Yonghui
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p. 17499 - 17506
(2019/12/23)
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- Synthesis of a highly active amino-functionalized Fe3O4@SiO2/APTS/Ru magnetic nanocomposite catalyst for hydrogenation reactions
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An amino-functionalized silica-coated Fe3O4 nanocomposite (Fe3O4@SiO2/APTS) was synthesized. The Fe3O4@SiO2 microspheres possessed a well-defined core–shell structure,
- Liu, Yue,Lv, Mingxin,Li, Lu,Yu, Hailong,Wu, Qiong,Pang, Jinhui,Liu, Yuxiang,Xie, Congxia,Yu, Shitao,Liu, Shiwei
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- Reduction of Nitroarenes to Anilines with a Benzothiazoline: Application to Enantioselective Synthesis of 2-Arylquinoline Derivatives
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The metal-free reduction of nitroarenes to aniline derivatives was accomplished in a short time by using a benzothiazoline as the hydrogen donor in combination with a Bronsted acid. An enantioselective synthesis of 2-arylquinolines was achieved by using 1-aryl-3-(2-nitrophenyl)propan-1-ones as starting materials and a combination of a benzothiazoline and a chiral phosphoric acid.
- Miyagawa, Masamichi,Yamamoto, Ryota,Kobayashi, Nanako,Akiyama, Takahiko
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supporting information
p. 499 - 502
(2019/02/26)
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