- Catalytic Activity of Cobalt Nanoparticles for Dye and 4-Nitro Phenol Degradation: A Kinetic and Mechanistic Study
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Cetyltrimethylammonium bromide (CTAB) capped nanosized α-cobalt hydroxides (CoNPs) were prepared to the removal of Congo red at room temperature in the absence and presence of sunlight. UV/visible spectra reveal that the CoNPs and NaBH4 have no catalytic effects toward Congo red and 4-nitrophenol (4-NP) degradation, whereas CoNPs act as an efficient catalyst with a small amount of NaBH4. The catalytic reaction has an induction period followed by an autoacceleration, which depends on the [NaBH4]. The reaction follows fractional-order kinetics with respect to [NaBH4] for Congo red degradation. The activation energies were found to be 24 and 74 kJ mol?1, respectively, for Congo red and 4-NP catalyzed reactions. The AgNPs has no catalytic activity toward Congo red. The degradation pathway mechanism with observed kinetics has been proposed and discussed, which follows the following rate law:. (Formula presented.).
- Khan, Mohammad Naved,Bashir, Ommer,Khan, Tabrez Alam,Al-Thabaiti, Shaeel Ahmed,Khan, Zaheer
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Read Online
- Surface Silylation of Hybrid Benzidinium Lead Perovskite and its Influence on the Photocatalytic Activity
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Surface coating of benzidinium lead iodide perovskite has been successfully accomplished by silanization with three different silylating agents, obtaining samples with average thickness from 2 to 6 nm as revealed by transmission electron microscopy. The obtained (organo)silica-coated hybrid perovskites exhibit enhanced hydrophobic character and, therefore, increased stability against moisture. However, its photocatalytic activity towards the cis-to-trans isomerization of stilbene diminishes as a function of the coating thickness, although a notable activity for this photocatalytic reaction is still observed.
- Peng, Yong,Albero, Josep,García, Hermenegildo
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Read Online
- Subcomponent Exchange Transforms an FeII4L4 Cage from High- to Low-Spin, Switching Guest Release in a Two-Cage System
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Subcomponent exchange transformed new high-spin FeII4L4 cage 1 into previously-reported low-spin FeII4L4 cage 2: 2-formyl-6-methylpyridine was ejected in favor of the less sterically hindered 2-formylpyridine, with concomitant high- to low-spin transition of the cage's FeII centers. High-spin 1 also reacted more readily with electron-rich anilines than 2, enabling the design of a system consisting of two cages that could release their guests in response to combinations of different stimuli. The addition of p-anisidine to a mixture of high-spin 1 and previously-reported low-spin FeII4L6 cage 3 resulted in the destruction of 1 and the release of its guest. However, initial addition of 2-formylpyridine to an identical mixture of 1 and 3 resulted in the transformation of 1 into 2; added p-anisidine then reacted preferentially with 3 releasing its guest. The addition of 2-formylpyridine thus modulated the system's behavior, fundamentally altering its response to the subsequent signal p-anisidine.
- McConnell, Anna J.,Aitchison, Catherine M.,Grommet, Angela B.,Nitschke, Jonathan R.
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Read Online
- Decoloration of azo and triarylmethane dyes in the aqueous phase by catalytic hydrotreatment with Pd supported on pillared clays
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Catalytic hydrotreatment of synthetic dyes as azo compounds and triarylmethanes has been carried out under ambient-like conditions (25-50 °C, 1 atm) with H2 using Pd supported on Al-pillared clays and Al2O3 as catalysts. The treatment leads to complete decoloration of aqueous solutions of the azo dyes (azobenzene, methyl orange, Congo red and oil red) due to the catalytic hydrogenation of the N=N bonds. Under acid pH the color removal was enhanced and a solid residue was formed in the case of Congo red, being completely removed. With aqueous solutions of the triarylmethane dyes crystal violet, fuchsine and malachite green complete decoloration was also achieved upon hydrogenation of the chromophore groups or modification of the chemical structure.
- Pizarro,Molina,Rodriguez
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p. 113820 - 113825
(2016)
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Read Online
- Ligand and Base Free Synthesis of Biaryls from Aryl Halides in Aqueous Media with Recyclable Ti0.97Pd0.03O1.97 Catalyst
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Abstract: Facile protocol for the synthesis of biaryls from aryl halides in presence of magnesium metal without prior formation of organometallic intermediate has been exploited. Irrespective of aqueous medium, Ti0.97Pd0.03O1.97 catalyst supports C–C bond formation reaction in presence of metals rather than dehalogenation without any additives. Homocoupling of 16 different aryl halides furnished corresponding biphenyls in good yield with better functional group tolerance. The recovery of the catalyst was carried out by employing catalyst coated cordierite monolith up to 7th cycle with high yields. A new approach for the cross-coupling reaction is also attempted. Graphic Abstract: [Figure not available: see fulltext.]
- Prasanna,Bhat, Shrikanth K.,Usha,Hegde
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p. 3313 - 3322
(2021/03/04)
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- Electrochemical coupling halobenzene into biphenyl on a reusable Pd nanoparticle-coated carbon-paper electrode at ambient conditions
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Electrochemical organic synthesis (EOS) employing electrons to directly activate the reactants can readily complete the chemical conversion under mild conditions. Here, it presented an efficient electrochemical coupling halobenzene into biphenyl on a Pd nanoparticle-coated cathode. The biphenyl product can be obtained with a yield up to 77% at 35 mA, 6 h (3.9 F mol?1). In addition, after consecutive fifth run of the coupling reaction, the yield still remained atca.40%, suggesting its considerable recyclable capacity. In addition, the preliminary kinetics studyviathe off-line gas chromatography analysis of the reaction mixture shows a two-section reaction process, including the introduction process (IP) and fast conversion process (FCP). Further, the estimated reaction kinetics constant value of 0.196 min?1for FCP suggests a more effective conversion than that obtained by the previous study. This study adopts a simple way to fabricate a low-cost and reusable Pd electrode, achieving a high-efficiency electrochemical strategy for the Ullmann-type coupling reaction at mild conditions, and holds a great promise to extend this synthesis route to other important organic synthesis.
- Wang, Chao-Nan,Lu, Yong-Heng,Liu, Yue,Liu, Jun,Yang, Yao-Yue,Zhao, Zhi-Gang
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p. 3997 - 4003
(2021/03/06)
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- Cu/CuxS-Embedded N,S-Doped Porous Carbon Derived in Situ from a MOF Designed for Efficient Catalysis
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The reasonable design of the precursor of a carbon-based nanocatalyst is an important pathway to improve catalytic performance. In this study, a simple solvothermal method was used to synthesize [Cu(TPT)(2,5-tdc)] ? 2H2O (Cu-MOF), which contains N and S atoms, in one step. Further in-situ carbonization of the Cu-MOF as the precursor was used to synthesize Cu/CuxS-embedded N,S-doped porous carbon (Cu/CuxS/NSC) composites. The catalytic activities of the prepared Cu/CuxS/NSC were investigated through catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results show that the designed Cu/CuxS/NSC has exceptional catalytic activity and recycling stability, with a reaction rate constant of 0.0256 s?1, and the conversion rate still exceeds 90 % after 15 cycles. Meanwhile, the efficient catalytic reduction of dyes (CR, MO, MB and RhB) confirmed its versatility. Finally, the active sites of the Cu/CuxS/NSC catalysts were analyzed, and a possible multicomponent synergistic catalytic mechanism was proposed.
- Wang, Dongsheng,Fan, Mingyue,He, Tingyu,Zeng, Fanming,Hu, Xiaoli,Li, Chun,Su, Zhongmin
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supporting information
p. 11468 - 11476
(2021/06/14)
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- Azo bond formation on metal surfaces
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The formation of azo compounds via redox cross-coupling of nitroarenes and arylamines, challenging in solution phase chemistry, is achieved by on-surface chemistry. Reaction products are analyzed with a cryogenic scanning tunneling microscope (STM) and X-ray photoelectron spectroscopy (XPS). By using well-designed precursors containing both an amino and a nitro functionality, azo polymers are prepared on surface via highly efficient nitro-amino cross-coupling. Experiments conducted on other substrates and surface orientations reveal that the metal surface has a significant effect on the reaction efficiency. The reaction was further found to proceed from partially oxidized/reduced precursors in dimerization reactions, shedding light on the mechanism that was studied by DFT calculations.
- Meng, Xiangzhi,Klaasen, Henning,Viergutz, Lena,Schulze Lammers, Bertram,Witteler, Melanie C.,M?nig, Harry,Amirjalayer, Saeed,Liu, Lacheng,Neugebauer, Johannes,Gao, Hong-Ying,Studer, Armido,Fuchs, Harald
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supporting information
p. 1458 - 1464
(2020/12/14)
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- Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
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A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
- Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
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supporting information
p. 10564 - 10567
(2021/10/19)
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- Catalytic synergy of Au@CeO2-rGO nanohybrids for the reductive transformation of antibiotics and dyes
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Au@CeO2-rGO nanohybrids (NHs) are synthesized using sucrose via a hydrothermal method. The interfacial interactions between gold encapsulated in CeO2 and rGO are observed by Raman and X-ray photoelectron spectroscopy (XPS). The optical properties and crystallinity of the nanohybrids are determined by using UV-Vis and X-ray diffraction (XRD), respectively. Elemental mapping using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) clearly demonstrates the Au@CeO2 core-shell sequence, in which the core of electron-dense Au NPs is encapsulated by the spherical CeO2 shell; these Au@CeO2 particles are then decorated on the reduced graphene oxide (rGO) nanosheets. As an application of the synthesized Au@CeO2-rGO nanohybrids, the reductive transformation of organic contaminants present in wastewater is accomplished. Ampicillin (AMP) gives 6-methyl-3-phenylpyrazin-2-ol and ciprofloxacin (CIP) affords 1-cyclopropyl-6-fluoro-3-(hydroxymethyl)-7-(piperazin-1-yl)-2,3-dihydroquinolin-4(1H)-one. Moreover, rhodamine B (RhB) forms (2-(3,6-bis(diethylamino)-9H-xanthen-9-yl)phenyl)methanol and Congo red (CR) produces benzidine and 3,4-diaminonaphthalene-1-sulfonic acid. The elimination of the antibacterial activities of AMP and CIP using reductive degradation and transformation shows the possibility of decreasing exposure of bacteria to antibacterial chemicals. The transformed by-product of CR is considered to be a potential anti-AIDS agent.
- Mishra, Kanchan,Pradhan, Samjhana,Akhtar, Muhammad Saeed,Yang, Won-Guen,Kim, Sung Hong,Lee, Yong Rok
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p. 8902 - 8909
(2021/06/01)
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- Compounds comprising benzophenone group, Organic electronic device comprising organic layers comprising the photo-cured of the monomer compounds
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The compound represented by Formula I or II is provided as an organic material layer material of an organic electronic device. The benzophenone functional group-containing compound represented by the following Chemical I or Chemical Formula II: I (Chemical Formula Ar -) (R). 1 -R2 -Bpm In the formula, m is 1 and 10, and Ar is a substituted or unsubstituted m having a C-order linking group. 6 -C60 Substituted or unsubstituted m having aryl group, C nd-linking group3 -C60 Substituted or unsubstituted fused m with heteroaryl groups or C primary linking groups6 -C60 Aryl group, R1 And R2 Each independently represents a simple bond, O - a substituted or unsubstituted C. 6 -C30 Arylene group, substituted or unsubstituted C3 -C30 Heteroarylene group, substituted or unsubstituted C1 -C10 The alkylene group and Bp are 1 divalent linking groups derived from benzophenone functional groups. Chemical Formula II. In the formula, n is at least 1 and Ar ' is a substituted or unsubstituted m having a C-order linking group. 6 -C60 Aryl group Substituted or unsubstituted m having a C nd order linker3 -C60 Substituted or unsubstituted fused m with heteroaryl groups or C primary linking groups6 -C60 Aryl group, R3 And R4 Each independently represents a simple bond, O - a substituted or unsubstituted C. 6 -C30 Arylene group, substituted or unsubstituted C3 -C30 Heteroarylene group, substituted or unsubstituted C6 -C30 Fused arylene groups, substituted or unsubstituted C1 -C10 The alkylene group and Bp ' are 1 divalent linking groups derived from benzophenone functional groups.
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Paragraph 0244-0247
(2021/03/09)
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- DIAMINE COMPOUND, POLYIMIDE PRECURSOR AND POLYIMIDE FILM PREPARED BY USING SAME
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The present invention discloses a novel diamine having a structure including an intramolecular imide group while having an aromatic ring group with a rigid structure. In addition, and by comprising the novel diamine as a polymerization component, the present invention can provide a polyimide film having improved mechanical and thermal properties while maintaining optical properties of polyimide.
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Paragraph 0250-0251; 0253
(2020/09/26)
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- DIAMINE COMPOUND, AND POLYIMIDE PRECURSOR AND POLYIMIDE FILM PREPARED BY USING THE SAME
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The present invention disclosed a novel diamine compound including a structure in which a phenylene linker (L) connecting an intramolecular imide ring and the imide ring is bonded to a phenyl ring substituted with -NH-(C=O)- or -O-(C=O)-. A polyimide film prepared by polymerizing the novel diamine compound has not only improved mechanical and thermal properties, but also an excellent refractive index.COPYRIGHT KIPO 2021
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Paragraph 0197; 0198; 0201; 0202; 0358; 0359; 0362; 0363
(2020/11/03)
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- Palladium Ion Catalysed Oxidative C–C Bond Formation Reactions in Arylboronic Acid: Application of Cordierite Monolith Coated Catalyst
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Abstract: Catalytic efficiency of palladium ion substituted in TiO2, Ti0.97Pd0.03O1.97 is successfully exploited for the oxidative homocoupling of arylboronic acid and oxidative Heck coupling reactions between arylboronic acid and olefins. The reaction protocol provides direct approach to synthesize biphenyls and cinnamates from moderate to good yield with good functional group tolerance. As a result, 11 symmetrical biaryls and 14 cinnamates were synthesized from readily available arylboronic acids. Ti0.97Pd0.03O1.97 powder catalyst is synthesized by solution combustion method and characterized by powder X-ray diffraction. The C–C bond formation reactions were carried out by catalyst cartridge method using Ti0.97Pd0.03O1.97 catalyst coated cordierite monolith. Coating of the catalyst on a cordierite monolith enhanced the applicability of the catalyst and made handling and recycling of the catalyst very easy. Catalyst was recovered and recycled for eight times in both homocoupling and oxidative Heck coupling reactions. The turnover number for both the reactions found to be 443 and 424, respectively. Graphic Abstract: [Figure not available: see fulltext.].
- Bhat, Shrikanth K.,Prasanna,Dasappa, Jagadeesh Prasad,Hegde
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p. 2911 - 2927
(2020/03/31)
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- Sulphonic acid functionalized porphyrin anchored with a: Meso -substituted triazolium ionic liquid moiety: A heterogeneous photo-catalyst for metal/base free C-C cross-coupling and C-N/C-H activation using aryl chloride under visible light irradiation
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We report an easy process to synthesize sulphonic acid functionalized porphyrin, anchored with a meso-substituted triazolium ionic liquid moiety (SAFPTILM) for metal/base free C-C cross-coupling and C-N/C-H activation using aryl chloride under visible light irradiation. The acid strength has been measured based on the Hammett indicator. The SAFPTILM photocatalyst comprising 18 π-conjugated electronic systems with the chromophore substituents in the meso-position can provide rapid electronic conducting channels during photocatalysis under the irradiation of visible light. It was found that SAFPTILM is an efficient photocatalyst for the Heck, Sonogashira, Buchwald, Ullmann/Fittig coupling and C-H activation of phenols with different aryl chlorides in the absence of a base/noble metal, using 5 W LED (yellow) light under ambient conditions. The photocatalyst with low band gap (1.55 eV) comprising conjugation, favors coupling reaction of unactivated aryl chlorides, by easy excitation of electrons and transfer to the conjugated benzimidazolium based phenylenediamine support delaying the recombination of photoinduced electron-hole pairs.
- Bhansali, Karan,Raut, Subodh,Barange, Shital,Bhagat, Pundlik
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supporting information
p. 19690 - 19712
(2020/12/04)
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- Compounds comprising benzophenone group, Organic electronic device comprising organic layers comprising the photo-cured of the monomer compounds
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The present invention provides a compound containing a benzophenone functional group represented by chemical formula I: Ar-(R_1-R_2-Bp)_m or chemical formula II as a material for an organic material layer of an organic electronic device, wherein the compound is the compound containing the benzophenone functional group.COPYRIGHT KIPO 2020
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Paragraph 0249-0252
(2020/08/12)
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- Superhydrophobic nickel/carbon core-shell nanocomposites for the hydrogen transfer reactions of nitrobenzene and N-heterocycles
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In this work, catalytic hydrogen transfer as an effective, green, convenient and economical strategy is for the first time used to synthesize anilines and N-heterocyclic aromatic compounds from nitrobenzene and N-heterocycles in one step. Nevertheless, how to effectively reduce the possible effects of water on the catalyst by removal of the by-product water, and to further introduce water as the solvent based on green chemistry are still challenges. Since the structures and properties of carbon nanocomposites are easily modified by controllable construction, a one step pyrolysis process is used for controllable construction of micro/nano hierarchical carbon nanocomposites with core-shell structures and magnetic separation performance. Using various characterization methods and model reactions the relationship between the structure of Ni?NCFs (nickel-nitrogen-doped carbon frameworks) and catalytic performance was investigated, and the results show that there is a positive correlation between the catalytic performance and hydrophobicity of catalysts. Besides, the possible catalytically active sites, which are formed by the interaction of pyridinic N and graphitic N in the structure of nitrogen-doped graphene with the surfaces of Ni nanoparticles, should be pivotal to achieving the relatively high catalytic performance of materials. Due to its unique structure, the obtained Ni?NCF-700 catalyst with superhydrophobicity shows extraordinary performances toward the hydrogen transfer reaction of nitrobenzene and N-heterocycles in the aqueous state; meanwhile, it was also found that Ni?NCF-700 still retained its excellent catalytic activity and structural integrity after three cycles. Compared with traditional catalytic systems, our catalytic systems offer a highly effective, green and economical alternative for nitrobenzene and N-heterocycle transformation, and may open up a new avenue for simple construction of structure and activity defined carbon nanocomposite heterogeneous catalysts with superhydrophobicity.
- Duan, Zhiying,Liu, Fangfang,Pang, Shaofeng,Su, Qiong,Wang, Yanbin,Xie, Xin,Zhang, Ping,Zhang, Yujing,Zhou, Feng
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p. 1996 - 2010
(2020/04/07)
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- Adsorption of Congo red (acid red 28) azodye on biosynthesized copper oxide nanoparticles
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A green synthesis of copper oxide nanoparticles and its removal efficiency of azodye were studied. Biosynthesis of stable copper oxide nanoparticles were preformed using Aloe barbadensis leaf extract as a size and shape-directing agent for preparing of spherical copper oxide nanoparticles by calcination at 400 °C. The leaf extract of Aloe barbadensis was prepared in deionized water. The produced copper particles were calcined at 400 °C to produce copper oxide nanoparticles. The characterization of copper oxide nanoparticles was performed by XRD, SEM, FTIR, UV spectroscopy. The XRD analysis showed that the average particle size was between 5-30 nm. The shape of the copper oxide nanoparticles was spherical and cubic. EDX of the synthesized nanoparticles showed the composition consists of 68 % copper. The UV-visible spectrum analysis confirms an absorption peak at 200-400 nm of the produced CuO nanoparticles. The FTIR analysis of the copper oxide particles indicate the presence of the organometallic Cu-O bond between Cu and O. The obtained copper oxide was used as a removing agent of Congo red dye. The effect of variables like concentration, time, pH, adsorbent dosage were studied. It was observed from the results that the maximum dye removal occurs at pH of 4, the concentration of nanoparticles was 1 mg/L and the maximum time for dye removal was 120 min. The Langmuir isotherm model was calculated to study the adsorption efficiency of the Congo red dye on the produced copper oxide nanoparticles. The kinetics of pseudo second order is followed by adsorption. The calculated sum of square was 0.012 and r2 = 0.98. it was observed that the model fit the best and straight line with r2 value of 0.991 and probability value of 1.6E-5. The nanoparticles remove 70 % of the Congo red dye from its solution. This showed that the copper oxide nanoparticles has efficient capacity of azodye degradation.
- Batool, Madiha,Qureshi, Muhammad Zahid,Hashmi, Farwa,Mehboob, Nida,Daoush, Walid M.
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p. 707 - 713
(2019/02/06)
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- Palladium nanoparticles immobilized on the magnetic few layer graphene support as a highly efficient catalyst for ligand free Suzuki cross coupling and homo coupling reactions
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In this study, we prepared a magnetic metal–graphene nanocomposite for the synthesis of substituted biaryls via Suzuki cross coupling and homo coupling reaction of aryl halides. The magnetic few layer graphene composite was synthesized by using one-step electrochemical exfoliation of graphite foil in aqueous iron (II) ammonium sulfate as electrolyte without using of any additive or corrosive media. Then, Fe2O3@FLG composite was used an efficient support for the immobilization and suitable dispersing of palladium nanoparticles. The obtained Fe2O3@FLG@Pd0 nanocomposite was characterized using FT-IR, SEM, TEM, EDS, XRD, VSM and ICP-AES analysis. Very low loading of this catalyst was displayed high activity in the producing substituted biaryls. It simply recovered from the reaction mixture and reused without any pre-activation in six consecutive runs with no loss of its catalytic activity or the observation of any detectable palladium leaching process.
- Rafiee, Fatemeh,Khavari, Parvaneh,Payami, Zahra,Ansari, Narges
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- Self-Assembled Magnetic Gold Catalysts from Dual-Functional Boron Clusters
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A new class of core–shell magnetic gold nanocomposites is prepared in a raspberry-like fashion by the controlled supramolecular host–guest assembly of γ-cyclodextrins (γ-CDs) and boron clusters. In this work, Cs2[closo-B12H12], a fundamental boron cluster, can play a dual role in the preparation of highly monodispersed Au nanoparticles and in the immobilization of Au nanoparticles on the γ-CDs@Fe3O4 surface as an effective anchor. This facile and spontaneous supramolecular strategy allows for the control of the size and composition of the highly stable gold composites. Furthermore, the obtained AuNPs@Fe3O4 composites exhibit an excellent catalytic activity and recyclability for the selective reduction of nitroaromatics to their corresponding aniline compounds, and the fastest reaction can be achieved within 20 s with a high conversion and selectivity at room temperature, which is better than that obtained previously in studies on metal nanoparticle composites as catalysts.
- Qi, Bin,Wu, Chenchen,Li, Xin,Wang, Dan,Sun, Liang,Chen, Bo,Liu, Wenjing,Zhang, Haibo,Zhou, Xiaohai
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p. 2285 - 2290
(2018/05/15)
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- Dimerization of Aromatic Compounds Using Palladium-Carbon-Catalyzed Suzuki-Miyaura Cross-Coupling by One-Pot Synthesis
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The aromatic dimers play a significant role in many aspects. Herein, we report a simple palladium-carbon catalyst that is highly effective for the dimerization of brominated aromatic compounds under mild conditions using abundant brominated aromatic compounds, bis(pinacolate)diboron and potassium acetate by a 'one-pot' method. This process, which we believe proceeds via a Suzuki-Miyaura cross-coupling reaction mechanism, allows access to a variety of aromatic compounds under mild reaction conditions and has a good functional group tolerance with moderate to high yields.
- Du, Fangyu,Zhou, Qifan,Liu, Dongdong,Fang, Ting,Shi, Yajie,Du, Yang,Chen, Guoliang
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supporting information
p. 779 - 784
(2018/02/09)
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- The first report on the transition metal-free homocoupling of aryl halides in the presence of l-cysteine
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A green and efficient methodology for the coupling of aryl halides without the addition of a transition metal catalyst has been presented. The biaryl coupling of haloarenes can be promoted by l-cysteine and potassium hydroxide. This is the first report on the synthesis of symmetrical biaryls under transition metal-free conditions.
- Ghorbani-Choghamarani, Arash,Taherinia, Zahra
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supporting information
p. 10989 - 10992
(2018/07/05)
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- One-Pot Palladium-Catalyzed Cross-Coupling Treble of Borylation, the Suzuki Reaction and Amination
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A methodology for a sequential palladium-catalyzed cross-coupling procedure consisting of borylation, the Suzuki reaction and amination has been developed for the assembly of molecules with multi-aryl backbones. The linchpin of this development is the meta-terarylphosphine ligand, Cy*Phine, which has been employed as an air- and moisture-stable precatalyst, Pd(Cy*Phine)2Cl2, to improve the efficiency of one-pot borylation–Suzuki reactions. Additionally, the reactivity of the Pd-Cy*Phine system could be tuned to furnish a one-pot, borylation–Suzuki reaction–amination (BSA) cross-coupling treble. The methodology successfully integrated complementary conditions for three distinctly different and modular reactions. Average yields of 74–94% could be achieved for each segment that cumulatively afforded 50–84% yield over the entire three-step sequence in a single pot. (Figure presented.).
- Jong, Howard,Eey, Stanley T.-C.,Lim, Yee Hwee,Pandey, Sangeeta,Iqbal, Nurul Azmah Bte,Yong, Fui Fong,Robins, Edward G.,Johannes, Charles W.
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supporting information
p. 616 - 622
(2017/02/23)
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- Carbon nitride supported palladium nanoparticles: An active system for the reduction of aromatic nitro-compounds
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Synthesis of carbon nitride supported highly dispersed ultrafine palladium nanoparticles has been reported for the reduction of aromatic nitro-compounds using hydrazine hydrate as a reducing agent. As a demonstration, the as-synthesized carbon nitride-palladium composite was shown to be a highly active and chemo-selective for the title reaction. Utilizing the optimized reaction conditions a set of aromatic nitro compounds have been converted to their corresponding amine derivatives with good to excellent yield ranging from 80% to 99%. The catalyst can be used for multiple times without affecting the catalytic performance and can also be stored for a long time at ambient condition maintaining the high catalytic efficiency.
- Nandi, Debkumar,Siwal, Samarjeet,Choudhary, Meenakshi,Mallick, Kaushik
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- The 4.4′-benzidine rearrangement of 4-alkyl substituted hydrazobenzenes
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When treated with dilute inorganic acids N,N′-diarylhydrazines (hydrazobenzenes) with an alkyl substituent in the 4-position undergo [5,5]-sigmatropic rearrangement reactions to furnish 4-(4′-aminophenyl)-4-alkylcyclohexa-2,5-dienimines (ipso-benzidines) in moderate to excellent yields. Steric bulk of the 4-alkyl substituent in the starting material decreases the yield of the respective ipso-benzidine. Additional electron-donating alkyl substituents in the ortho- and/or meta-positions on both rings generally promote the reaction and consequently increase the yield of the 4.4′-benzidine rearrangement product. Described herein are our findings regarding the scope and limits of this unusual benzidine rearrangement.
- Bouillon, Marc E.,Meyer, Hartmut H.
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p. 3151 - 3161
(2016/05/24)
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- Condensed compound and organic light emitting diode comprising the same
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Provided are a condensed cyclic compound represented by chemical formula 1 and an organic electroluminescent device comprising the same. In the chemical formula 1, X, and R1 to R10 refer to the detailed description of the present invention. An organic light emitting device having an organic layer comprising the condensed cyclic compound has properties of low driving voltage, high light emitting efficiency and long lifespan.COPYRIGHT KIPO 2016
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Paragraph 0305; 0307; 0310
(2016/12/01)
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- Synthesis of Mavatrep: A Potent Antagonist of Transient Receptor Potential Vanilloid-1
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The process development of Mavatrep (1), a potent transient receptor potential vanilloid-1 (TRPV1) antagonist, is described. The two key synthetic transformations are the synthesis of (E)-6-bromo-2-(4-(trifluoromethyl)styryl)1H-benzo[d]imidazole (4) and the Suzuki coupling of 4 with 3,3-dimethyl-3H-benzo[c][1,2]oxaborol-1-ol (5). Compound 1a was prepared in four chemical steps in 63% overall yield.
- Wells, Kenneth M.,Mehrman, Steven J.,Abdel-Magid, Ahmed F.,Ferraro, Caterina,Scott, Lorraine,Zhong, Hua Marlon,Teleha, Christopher A.,Ballentine, Scott,Li, Xun,Russell, Ronald K.,Spink, Jan M.,Diamond, Craig,Youells, Scott,Zhang, Yongzheng,Tsay, Fuh-Rong,Cesco-Cancia, Sergio,Manzo, Stephen M.,Beauchamp, Derek A.
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p. 1774 - 1783
(2015/12/01)
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- A porous trimetallic Au@Pd@Ru nanoparticle system: Synthesis, characterisation and efficient dye degradation and removal
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A facile room temperature one-pot synthesis of trimetallic porous Au@Pd@Ru nanoparticles (Au@Pd@RuNPs) has been developed. The trimetallic nanoparticles have been prepared by the successive sacrificial oxidation of cobalt nanoparticles (CoNPs). The average particle size of Au@Pd@RuNPs is 110 nm. The porous nature and the presence of Au, Pd and Ru have been confirmed via TEM, FE-SEM and EDS analyses. The trimetallic nanoparticles have shown excellent catalytic activity towards the reduction of p-nitrophenol and efficient degradation of various azo dyes. This has been further extended towards the removal of colour from waste water via the catalytic degradation of azo dyes. Moreover, the produced amine can be eliminated from the waste water via its sorption on an industrial solid waste dolochar.
- Sahoo, Anupam,Tripathy, Suman Kumar,Dehury, Niranjan,Patra, Srikanta
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p. 19376 - 19383
(2015/10/05)
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- A simple synthesis of anilines by LiAlH4/TiCl4 reduction of aromatic nitro compounds
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A rapid and efficient single-step synthesis of substituted anilines has been developed. The aromatic nitro compounds were reduced by using reducing systems generated by the action of an excess of LiAlH4 on TiCl4. Anilines substituted with different functional groups were synthesized in high yields and purity starting from the corresponding nitro compounds. The developed procedure is applicable to nitroaromatics containing both electron withdrawing and electron donating substituents. Substrates with electron donor substituents require a larger excess of LiAlH4. The reducing power of the prepared reactant systems depends on the used molar ratio of LiAlH4 and TiCl4.
- Di Gioia, Maria Luisa,Leggio, Antonella,Guarino, Isabella Federica,Leotta, Vanessa,Romio, Emanuela,Liguori, Angelo
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supporting information
p. 5341 - 5344
(2015/09/01)
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- Design, synthesis and biological evaluation of small-azo-dyes as potent Vesicular Glutamate Transporters inhibitors
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Vesicular Glutamate Transporters (VGLUTs) allow the loading of presynapic glutamate vesicles and thus play a critical role in glutamatergic synaptic transmission. VGLUTs have proved to be involved in several major neuropathologies and directly correlated to clinical dementia in Alzheimer and Parkinson's disease. Accordingly VGLUT represent a key biological target or biomarker for neuropathology treatment or diagnostic. Yet, despite the pivotal role of VGLUTs, their pharmacology appears quite limited. Known competitive inhibitors are restricted to some dyes as Trypan Blue (TB) and glutamate mimics. This lack of pharmacological tools has heavily hampered VGLUT investigations. Here we report a rapid access to small molecules that combine benefits of TB and dicarboxylic quinolines (DCQs). Their ability to block vesicular glutamate uptake was evaluated. Several compounds displayed low micromolar inhibitory potency when size related compounds are thirty to forty times less potent (i.e. DCQ). We then confirmed the VGLUT selectivity by measuring the effect of the series on vesicular monoamine transport and on metabotropic glutamate receptor activity. These inhibitors are synthesized in only two steps and count among the best pharmacological tools for VGLUTs studies.
- Favre-Besse, Franck-Cyril,Poirel, Odile,Bersot, Tiphaine,Kim-Grellier, Elodie,Daumas, Stephanie,El Mestikawy, Salah,Acher, Francine C.,Pietrancosta, Nicolas
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p. 236 - 247
(2014/04/17)
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- Synthesis, DNA binding and antileishmanial activity of low molecular weight bis-arylimidamides
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The effects of reducing the molecular weight of the antileishmanial compound DB766 on DNA binding affinity, antileishmanial activity and cytotoxicity are reported. The bis-arylimidamides were prepared by the coupling of aryl S-(2-naphthylmethyl)thioimidates with the corresponding amines. Specifically, we have prepared new series of bis-arylimidamides which include 3a, 3b, 6, 9a, 9b, 9c, 13, and 18. Three compounds 9a, 9c, and 18 bind to DNA with similar or moderately lower affinity to that of DB766, the rest of these compounds either show quite weak binding or no binding at all to DNA. Compounds 9a, 9c, and 13 were the most active against Leishmania amazonensis showing IC50 values of less than 1 μM, so they were screened against intracellular Leishmania donovani, showing outstanding activity with IC 50 values of 25-79 nM. Despite exhibiting little in vitro cytotoxicity these three compounds were quite toxic to mice.
- Banerjee, Moloy,Farahat, Abdelbasset A.,Kumar, Arvind,Wenzler, Tanja,Brun, Reto,Munde, Manoj M.,Wilson, W. David,Zhu, Xiaohua,Werbovetz, Karl A.,Boykin, David W.
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p. 449 - 454
(2012/11/07)
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- Diamination of phenylene dihalides catalyzed by a dicopper complex
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Diamination of phenylene dihalides with aqueous ammonia to give the corresponding phenylenediamines can be achieved by using a dicopper complex [Cu2(bpnp)(OH)(CF3COO)3] (1) (bpnp = 2,7-bis(pyridine-2-yl)-l,8-naphthyridine) as the catalyst in the presence of Bu4NBr and Cs2CO3 in high yields. In addition, 1,3,5-tribromobenzene was converted into benzenetriamine quantitatively under the same conditions. This method offers a new opportunity, particularly simplifying steps and increasing yields, for the preparation of aryl diamines.
- Liao, Bei-Sih,Liu, Shiuh-Tzung
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experimental part
p. 6653 - 6656
(2012/10/07)
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- Investigation of the catalytic activity of a Pd/biphenyl-based phosphine system in the Ullmann homocoupling of aryl bromides
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We described Ullmann homocoupling promoted by a Pd/biphenyl-based phosphine system using DMF as solvent. Using Hammett equation it is found that the rate determining step of the reaction depends on the electronic nature of substituents of aryl bromides. Increase the rate of reaction with decreasing the electron donating of the substituent from NH2 to H suggesting an oxidative addition step as the rate determining step. Decrease the rate of reaction with increasing the electron-withdrawing ability of the substituent from H to NO2 indicating a reductive elimination step as the rate determining step.
- Nadri, Shirin,Azadi, Ehsan,Ataei, Ali,Joshaghani, Mohammad,Rafiee, Ezzat
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experimental part
p. 2966 - 2970
(2011/09/15)
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- New role of graphene oxide as active hydrogen donor in the recyclable palladium nanoparticles catalyzed ullmann reaction in environmental friendly ionic liquid/supercritical carbon dioxide system
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An economical and green pathway: graphene oxide (GO)-supported palladium nanoparticles (Pd NPs) catalyzed a reductive Ullmann reaction of aryl chloride towards biaryl with high conversion and selectivity in ionic liquid (IL)-supercritical carbon dioxide (ScCO2). The combination of IL and ScCO2 provides superior advantages in product separation, catalyst recycling and reuse of the reaction media over traditional organic solvents. Further investigations showed that GO, the novel catalyst support bearing abundant carboxylic, hydroxyl, epoxy and aldehyde groups, can replace the traditional active hydrogen donor readily with much enhanced product separation efficiency. The use of IL, e.g. [hmim][Tf2N], led to obvious improved stability of the Pd NPs, which was helpful for catalyst recycling. Carbon dioxide, a naturally abundant, nonflammable, relatively nontoxic, economical and recyclable "greenhouse" gas, was found to significantly promote the selectivity of the graphene oxide-based Pd NP-catalyzed reductive Ullmann reaction of aryl chloride. Investigations showed that the Pd NP catalyst and IL can be recycled for more than 5 runs without obvious loss of conversion, indicating the economical viability of this process.
- Cheng, Jinsheng,Zhang, Gencheng,Du, Jin,Tang, Longhua,Xu, Jingying,Li, Jinghong
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scheme or table
p. 3485 - 3494
(2011/10/02)
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- CuI-nanoparticles-catalyzed selective synthesis of phenols, anilines, and thiophenols from aryl halides in aqueous solution
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CuI-nanoparticles-catalyzed selective synthesis of phenols, anilines, and thiophenols from aryl halides was developed in the absence of both ligands and organic solvents. Anilines were formed selectively with ammonia competing with hydroxylation and thiophenols were generated selectively with sulfur powder after subsequent reduction competing with hydroxylation and amination.
- Xu, Hua-Jian,Liang, Yu-Feng,Cai, Zhen-Ya,Qi, Hong-Xia,Yang, Chun-Yan,Feng, Yi-Si
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supporting information; experimental part
p. 2296 - 2300
(2011/06/17)
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- Arylation of adamantanamines: III.* Palladium-catalyzed arylation of adamantane-1,3-diyldimethanamine and 2,2′-(adamantane-1,3-diyl) diethanamine
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Palladium-catalyzed arylation of adamantane-1,3-diyldimethanamine and 2,2′-(adamantane-1,3-diyl) diethanamine with isomeric bromochloro- and dibromobenzenes was studied. The yields of N,N′-diarylation products depend on the initial diamine and dihalobenzene structure. Side reactions were revealed, which reduced the yield of the target products. The arylation of 2,2′-(adamantane-1,3-diyl)diethanamine gives the corresponding N,N′-diaryl derivatives with better yield. The possibility for synthesizing unsymmetrical N,N′-diaryl derivatives of 2,2′- (adamantane-1,3-diyl)diethanamine was demonstrated.
- Averin,Ulanovskaya,Buryak,Savel'ev,Orlinson,Novakov,Beletskaya
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experimental part
p. 30 - 40
(2011/04/26)
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- An economical, green pathway to biaryls: Palladium nanoparticles catalyzed ullmann reaction in ionic liquid/ supercritical carbon dioxide system
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In this paper, an economical, green pathway involving the palladium nanoparticles (Pd NPs) catalyzed reductive Ullmann reaction of an aryl chloride to afford a biaryl with high conversion and selectivity in an ionic liquid (IL)/supercritical carbon dioxide (ScCO2) system was developed. The combination of IL and ScCO2 provides superior advantages in product separation, catalyst recycling and reuse of reaction media over traditional organic solvents. Further investigations showed that the Bronsted-acidic imidazolium IL {e.g., (1-butyl-3-(sulfobutyl)-imidazolium) hydrogen sulfate, [bmim(HSO3C4)][HSO4]}, can replace the traditional active hydrogen donor readily with much enhanced product separation efficiency, the use of IL also led to an obvious improved stability of the Pd NPs, which was very helpful for catalyst recycling. Carbon dioxide, a naturally abundant, non-flammable, relatively non-toxic, economical and recyclable "greenhouse" gas, was found to significantly promote the selectivity of the Pd NPs-catalyzed aluminium-induced reductive Ullmann reaction of aryl chlorides. Investigations showed that the Pd NPs catalyst and IL can be recycled for at least five runs, indicating the economic viability of this process. Copyright
- Cheng, Jinsheng,Tang, Longhua,Xu, Jingying
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experimental part
p. 3275 - 3286
(2011/02/23)
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- Variation of the backbone conjugation in NLO model compounds: Torsion-angle-restricted, biphenyl-based push-pull-systems
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Terminal piperidinyl- and nitro-functionalized biphenyls, bridged between the 2 and. 2′ positions by a variable number of methylene groups, are synthesized and fully characterized. These push-pull systems with defined and restricted torsion angles between their phenyl rings are ideal model compounds to investigate the influence of the chromophore's conjugation in nonlinear optic (NLO) responses, A general synthetic route that can be implemented to access these model compounds is reported, starting from dibromo or ditriflate biphenyls. Hartwig-Buchwald cross-coupling, a selective azacycloalkylation of diaminobiphenyls and a mild oxidation of primary amines to nitro groups in the presence of a tertiary amine summarizes the synthetic pathway towards the desired model compounds. NLO properties of the series of torsionally constrained push-pull biphenyls are collected by electric-field-induced second-harmonic generation (EFISH) experiments. The results agree qualitatively with semi-empirical simulations based on the AM1 Hamiltonian. A. linear dependence of the quadratic response on the cos2(o) of the inter-aryl dihedral angle is observed, which points to oscillator strength loss as the dominant effect of increasing backbone twist
- Rotzler, Juergen,Vonlanthen, David,Barsella, Alberto,Boeglin, Alex,Fort, Alain,Mayor, Marcel
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experimental part
p. 1096 - 1110
(2010/04/27)
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- Palladium-catalyzed coupling of ammonia with aryl chlorides, bromides, iodides, and sulfonates: A general method for the preparation of primary arylamines
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We report that the complex generated from Pd[P(o-tol)3] 2 and the alkylbisphosphine CyPF-t-Bu is a highly active and selective catalyst for the coupling of ammonia with aryl chlorides, bromides, iodides, and sulfonates. The couplings of ammonia with this catalyst conducted with a solution of ammonia in dioxane form primary arylamines from a variety of aryl electrophiles in high yields. Catalyst loadings as low as 0.1 mol % were sufficient for reactions of many aryl chlorides and bromides. In the presence of this catalyst, aryl sulfonates also coupled with ammonia for the first time in high yields. A comparison of reactions in the presence of this catalyst versus those in the presence of existing copper and palladium systems revealed a complementary, if not broader, substrate scope. The utility of this method to generate amides, imides, and carbamates is illustrated by a one-pot synthesis of a small library of these carbonyl compounds from aryl bromides and chlorides, ammonia, and acid chlorides or anhydrides. Mechanistic studies show that reactions conducted with the combination of Pd[P(o-tol)3]2 and CyPF-t-Bu as catalyst occur with faster rates and higher yields than those conducted with CyPF-t-Bu and palladiun(II) as catalyst precursors because of the low concentration of active catalyst that is generated from the combination of palladium(II), ammonia, and base.
- Vo, Giang D.,Hartwig, John F.
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supporting information; experimental part
p. 11049 - 11061
(2009/12/05)
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- Homocoupling of halotropones promoted by bis(1,5-cyclooctadiene) nickel in the presence of tris(1-pyrazolyl)methane: an easy route to [Bi-1,3,5- cycloheptatrien-1-yl]-7,7'-diones
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An efficient homocoupling of 2-halotropones, to afford 2,2'-bitropones, occurs in toluene at rt in the presence of stoichiometric amounts of [Ni(cod)2] and tris(1-pyrazolyl)methane ligand, in a 1:1 molar ratio. This methodology was extended to aryl halides. Copyright Taylor & Francis Group, LLC.
- Funaioli, Tiziana,Cavazza, Marino
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experimental part
p. 1592 - 1600
(2009/10/17)
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- Blue-colored donor-acceptor [2]rotaxane
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Equation presented A guest molecule - a bis-N-tetraethyleneglycol- substituted 3,3′-difluorobenzidine derivative - has been synthesized, and its complexation with the host, cyclobis(paraquat-p-phenylene), has been investigated. This host-guest complex was then employed in the template-directed synthesis of a blue-colored [2]rotaxane. The color of this [2]rotaxane arises from the charge-transfer absorption band between the HOMO of the guest and the LUMO of the host. This host-guest complex, and the derived [2]rotaxane, completes the donor-acceptor-based RGB (red/green/blue) color complex set.
- Ikeda, Taichi,Aprahamian, Ivan,Stoddart, J. Fraser
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p. 1481 - 1484
(2008/02/02)
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- Electroreductive palladium-catalysed Ullmann reactions in ionic liquids: Scope and mechanism
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A room-temperature catalytic alternative to the Ullmann reaction is presented, based on electroreductive homocoupling of haloarenes catalysed by palladium naaoparticles. The particles are generated in situ in an electrochemical cell, and electrons are used to close the catalytic cycle and provide the motivating force for the reaction. This system gives good yields using iodo- and bromoarenes, and requires only electric current and water as reagents. Using an ionic liquid solvent combines the advantages of excellent conductivity and cluster stabilising. The solvent is reusable at least five times. Kinetic experiments at different electrode potentials show that the two-electron oxidation of water closes the catalytic cycle by regenerating the Pd(0). A mechanism involving radical anion formation is proposed. The advantages and limitations of this new system for carbon-carbon homocoupling and cross-coupling are discussed.
- Pachon, Laura Duran,Elsevier, Cornells J.,Rothenberg, Gadi
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p. 1705 - 1710
(2007/10/03)
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- High-intensity ultrasound and microwave, alone or combined, promote Pd/C-catalyzed aryl-aryl couplings
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Pd-catalyzed homo- and cross-couplings of boronic acids and aryl halides were successfully carried out both in aqueous media under high-intensity ultrasound (US) and in DME under microwave (MW). Heterogeneous catalysis with Pd/C was employed, avoiding phosphine ligands and phase-transfer catalysts. In a trial series involving 15 different iodo- and bromoaryls and 7 boronic acids, both energy sources drastically reduced reaction times affording biaryls in acceptable to good yields. With palladium(II) acetate as catalyst, electron-deficient aryl chlorides also reacted, affording a few biaryls in acceptable yields. Ullmann-type zinc-mediated homocoupling of iodo- and bromoaryls in the presence of Pd/C under CO2 atmosphere was achieved in aqueous media under US, though not under MW. Suzuki homo- and cross-couplings were also carried out in a new reactor developed in our laboratory, featuring combined US and MW irradiation, further improving a green synthetic method.
- Cravotto, Giancarlo,Beggiato, Marina,Penoni, Andrea,Palmisano, Giovanni,Tollari, Stefano,Lévêque, Jean-Marc,Bonrath, Werner
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p. 2267 - 2271
(2007/10/03)
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- New chemical synthesis of functionalized arylzinc compounds from aromatic or thienyl bromides under mild conditions using a simple cobalt catalyst and zinc dust
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A new chemical method for the preparation of arylzinc intermediates is described in acetonitrile, on the basis of the activation of aryl bromides by low-valent cobalt species arising from the reduction of cobalt halide by zinc dust. This procedure allows for the synthesis of a variety of functionalized aryl- and thienylzinc species in good to excellent yields. The versatility and the simplicity of that original method represent an alternative to most known procedures.
- Fillon, Hyacinthe,Gosmini, Corinne,Perichon, Jacques
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p. 3867 - 3870
(2007/10/03)
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- Detection and determination of aromatic amines as products of reductive splitting from selected azo dyes
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The current environment-friendly regulations concerning textile products ban the marketing of textiles dyed with azo dyes capable of reductively splitting carcinogenic aromatic amines. The study analyzes seven azo dyes whose chemical structure determines various quantities of splitting aromatic amines, such as benzidine. For tests, seven commercially available azo dyes with aromatic amines in their structure were selected. These included two hazardous dyes: Acid Red 85 and Direct Blue 6, both capable of reductively splitting carcinogenic benzidine. Of the remaining five azo dyes, three - Ponceau SS, Sudan II, and Disperse Yellow 7 - are capable of splitting p-phenylenediamine and aniline, while Mordant Orange 1 and Disperse Orange 3 can split only p-phenylenediamine. For Acid Red 85 and Direct Blue 6, the quantity of benzidine split from them was analyzed, depending on the conditions of the reduction process (e.g., in the HPLC method, 104 g/kg of dye for reduction in NaOH, and 41 g/kg of dye for reduction in acetate buffer). The spectrophotometric method proved useful for preliminary analysis of amine content in examined samples. Spectrophotometric analysis may be used to determine the total content of amines counted as aniline. A full qualitative and quantitative analysis of amines released from azo dyes is possible using high-performance liquid chromatography (HPLC).
- Pielesz,Baranowska,Rybak,Wlochowicz
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- Coupling reaction of aryl halides promoted by NiCl2/PPh3/Sm0
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An efficient synthesis of biaryls from various aryl halides has been developed and investigated. The coupling reagent is a catalytic mixture of anhydrous NiCl2 and PPh3 in the presence of metallic samarium. The reaction occurs rapidly under mild conditions, tolerates a variety of functional groups with high yields.
- Zheng, Xingliang,Zhang, Yongmin
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p. 562 - 563
(2007/10/03)
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- Photochemistry and photophysics of triarylmethane dye leuconitriles
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The photochemical reactions of crystal violet leuconitrile (CVCN) were investigated by the means of product analysis and trapping experiments, laser flash and steady-state photolysis, and steady-state fluorescence. The influence of oxygen on the reaction was examined in detail. The photochemistry of malachite green leuconitrile (MGCN), basic fuchsin leuconitrile (BFCN), and crystal violet leucomethyl (CVMe) and leucobenzyl (CVBn), as well as triphenylacetonitrile, was studied. The results suggest ionization occurs from S1, while the di-π-methane reaction is the photochemical route from T1.
- Jarikov,Neckers
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p. 659 - 671
(2007/10/03)
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- Novel seco cyclopropa[c]pyrrolo[3,2-e]indole bisalkylators bearing a 3,3′-arylenebisacryloyl group as a linker
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We synthesized the novel seco cyclopropa[c]pyrrolo[3,2-e]indole (CPI) bisalkylators and evaluated their antitumor activity. Among these derivatives, 11a (AT-760), in which the two seco 3-methoxycarbonyl-2-trifluoromethyl CPI (MCTFCPI) moieties are connected with a 3,3′-(1,4-phenylene)bisacryloyl group, was found to exhibit more potent cytotoxicity and antitumor activity against HeLaS3 human uterine cervix carcinoma cells and Colon 26 adenocarcinoma cells, respectively, than 8 (bizelesin, U-77,779). It also appeared that compound 11a exhibits improved in vivo efficacy in the human colon CX-1 model when compared to either compound 8 or mitomycin C (MMC). Efficacious doses for 11a were found to be 2-fold lower than those for 8.
- Fukuda,Seto,Furuta,Ebisu,Oomori,Terashima
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p. 1396 - 1406
(2007/10/03)
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- Process
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A process for the production of a fluorescent whitening agent of formula: in which X and Z are as defined herein, comprising A) rearranging a hydrazobenzene compound having the formula: in which Z is as defined herein, to produce in situ a compound having the formula: B) diazotising the compound of formula (3) to produce a compound having the formula: in which Z has its previous significance and G1 is a counter ion; and C) reacting the compound of formula (4) with 2 moles of a compound having the formula: in which X and n have their previous significance, in the presence of an inorganic or organic palladium salt, or a mixture thereof, as catalyst-precursor, to produce a compound having the formula (1).
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- Electrochemical polymerization of aniline investigated using on-line electrochemistry/electrospray mass spectrometry
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A thin-layer electrochemical flow cell coupled on-line with electrospray mass spectrometry (EC/ES-MS) was used to investigate the soluble products from the controlled-potential anodic polymerization of aniline in H2O and H2O/CH3O H (1/1 v/v) with ammonium acetate and acetic acid or ammonium hydroxide as electrolytes (pH 4, 6.5, or 9). At a working electrode (glassy carbon) potential of 1.0 V versus Ag/AgCl, singly protonated aniline oligomers containing as many as 10 aniline units (10-mer) were observed in the ES mass spectra when the polymerization in H2O/CH3OH at pH 4 was carried out. The abundance of the higher n-mers decreased at higher solution pH and in 100% H2O at pH 4. Most of the oligomers were observed in more than one redox state ranging from fully oxidized (all imine nitrogens) to fully reduced (all amine nitrogens). The number of different redox states observed for the n-mers increased with increasing n. The structures of the reduced (m/z 185) and oxidized (m/z 183) aniline dimer ions (head-to-tail, tail-to- tail, or head-to-head) produced from the polymerization of aniline at pH 4, 6.5, and 9 in H2O/CH3OH were revealed to vary as a function of pH by comparison of their tandem mass spectrometry product ion spectra with the product ion spectra of the dimer standards. EC/ES-MS potential scan experiments, in which the working electrode current and major n-mer ions for n = 2, 3, and 4 were monitored as a function of electrode potential, were used to probe the growth mechanism to higher aniline oligomers. Under the conditions used, the controlled-current electrolytic process inherent to the operation of the ES ion source did not significantly influence the formation or nature of the oligomers observed. Beyond the current application, the results presented here serve to demonstrate the utility of EC/ES-MS as a tool in identifying the initial products of electropolymerization and in studying the products of electrode reactions in general.
- Deng, Haiteng,Van Berkel, Gary J.
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p. 4284 - 4293
(2007/10/03)
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