- Nickel nanoparticles as efficient catalyst for electron transfer reactions
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The catalytic efficiency of nickel nanoparticles was investigated in some electron transfer reactions. The nanoparticles brought about rapid roomtemperature reduction of a number of nitro aromatics in an aqueous medium with high chemoselectivity and also helped to speed up redox reaction of Fe(CN)-36and S2O-23. In addition, interesting results were obtained for microwave assisted decolourization of azo dye. The reactions were monitored through UV-Vis spectroscopy. The present study has additional advantages of reusability of catalysts and aqueous medium. The ultimate goal was to assess the suitability of low cost nanocatalyst for electron transfer reactions under aqueous conditions. Springer Science+Business Media New York 2013.
- Rathore, Puran Singh,Patidar, Rajesh,Rathore, Sonika,Thakore, Sonal
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- STUDY OF THE CATALYTIC ACTIVITY OF METAL COMPLEXES ATTACHED TO A SOLID SUPPORT. 6. REDUCTION OF NITROBENZENE AND ITS HALOGENATED DERIVATIVES BY CHEMICALLY BOUND HYDROGEN IN THE PRESENCE OF IMMOBILIZED Rh COMPLEXES.
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Rh complexes attached to modified silica gels catalyze the reaction of hydrogen transfer from 2-propanol (P-2) to cyclohexanone, styrene, allylbenzene, and cyclohexene-2-one.It was previously found that triphenylphosphine complexes of Rh and Ru are active in the reaction of reduction of nitrobenzene (NB) by 2-propanol.It is known that complex hydrides, NaBH4 in particular, are also used for reduction of NB on metal complexes.The catalytic properties of Rh complexes immobilized on silica gels containing amino groups and aminophosphine groups in reduction of NB and different halonitrobenzenes by transfer of hydrogen from P-2 and NaBH4 were investigated in the present study.
- Sharf, V. Z.,Dovganyuk, V. F.,Isaeva, V. I.,Maksimov, B. I.
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- Hydrogenation of substituted aromatic nitrobenzenes over 1% 1.0 wt.%Ir/ZrO2 catalyst: Effect of meta position and catalytic performance
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This study is based on 1%Ir/ZrO2 catalyst which was studied in the hydrogenation of aromatic meta-substituted nitrobenzene in liquid phase. The catalyst was prepared by traditional impregnation method using IrCl3 and it has been characterized in terms of temperature-programmed reduction (TPR), ICP-MS, BET area, X-ray diffraction, HR-TEM and XPS measurements. The hydrogenation was evaluated in a batch type reactor at 298 K using ethanol like a solvent. The catalyst showed the formation of zero valent and partially oxidized Iridium (Irδ+) is established post-TPR and XPS characterization. The metal particle size exhibited a wide distribution with mean size 1.8 nm. Ir/ZrO2 was active in all the hydrogenation reactions with elevated conversion and promoted exclusive NO2 group reduction, resulting in the sole formation of the corresponding amino-compound except for CHO and CHCH2 meta-substituted nitrobenzene. We associate this response to a reducible group competition between NO2 and CHO or CHCH2. Reactant activation on the catalyst generates a negatively charged intermediate, consistent with a nucleophilic mechanism. The presence of electron-donating substituents is shown to decrease NO2 reduction rate. This effect is quantified in terms of the Hammett relationship where a linear correlation between the substituent constant (σi) and rate is established and a reaction constant (ρ) 0.639. The data generated provide the first report of the catalytic action of supported Ir in the hydrogenation of meta-substituted nitroarenes and establish the nature of the hydrogenation en liquid phase.
- Campos, Cristian,Torres, Cecilia,Oportus, Marcelo,Pe?a, Miguel A.,Fierro,Reyes, Patricio
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- A suitable modified palladium immobilized on imidazolium supported ionic liquid catalysed transfer hydrogenation of nitroarenes
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The first well-defined modified palladium immobilized on imidazolium supported ionic liquid catalyst has been developed for the transfer hydrogenation of nitroarenes to anilines in good to excellent yields with formic acid as reducing agent. This methodology applies eco-friendly a reducing agent which is non-toxic, water soluble, more stable and simpler to handle. Particularly, the process constitutes a rare model of base-free transfer hydrogenations. The catalyst was reused up to nine consecutive cycles without any significance loss in its activity.
- Atheeswari, Alagudurai,Kanimozhi, Nallusamy,Karthikeyan, Parasuraman,Shanmugapriya, Ramasamy
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- A practical and selective reduction of nitroarenes using elemental sulfur and mild base
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A method was developed to reduce aromatic nitro compounds to the corresponding anilines using sulfur and base. The method tolerates a range of functional groups on the benzene ring, avoids the use of hydrogen and transition metals and provides the anilines in moderate to high yields.
- McLaughlin, Maureen A.,Barnes, David M.
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- MIL-53 (Al) derived single-atom Rh catalyst for the selective hydrogenation of m-chloronitrobenzene into m-chloroaniline
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The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical industry. Chemoselective hydrogenation poses a significant challenge, which requ
- Cao, Wenxiu,Chen, Shaohua,Chen, Tiehong,Li, Zhi,Lin, Lu,Luo, Wenhao,Qi, Haifeng,Song, Weiyu,Tang, Nanfang,Wang, Aiqin,Wang, Weiyin,Zou, Xiaoxuan
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- Catalytic applications of a versatile magnetically separable Fe-Mo (Nanocat-Fe-Mo) nanocatalyst
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A novel nano-Fe3O4-MoO3 (Nanocat-Fe-Mo) catalyst was prepared via simple wet impregnation and characterized by several techniques. The synthesized Nanocat-Fe-Mo was found to be a highly active and efficient catalyst in the
- Gawande, Manoj B.,Branco, Paula S.,Nogueira, Isabel D.,Ghumman, C. Amjad A.,Bundaleski, Nenad,Santos, Aderito,Teodoro, Orlando M.N.D.,Luque, Rafael
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- Catalytic transfer hydrogenation of aromatic nitro compounds by employing ammonium formate and 5% platinum on carbon
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Aromatic nitro compounds were reduced to respective amines in high yields by using 5% platinum on carbon with ammonium formate or formic acid as hydrogen donor. It was observed that the former was mote efficient donor than the later. Further we have found that reduction of nitro groups occurs without hydrogenolysis of halogens and the reducible substituents which remains unchanged under the reaction conditions.
- Gowda,Mahesh
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- Heterogeneous catalytic transfer hydrogenation of aromatic nitro and carbonyl compounds over cobalt(II) substituted hexagonal mesoporous aluminophosphate molecular sieves
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Catalytic transfer hydrogenation of aromatic nitro and carbonyl compounds was carried out using novel cobalt(II) substituted hexagonal mesoporous aluminophosphate molecular sieves. The catalyst showed excellent yield with good recycling capability.
- Mohapatra, Susanta K,Sonavane, Sachin U,Jayaram, Radha V,Selvam, Parasuraman
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- Bio-synthesis and structural characterization of highly stable silver nanoparticles decorated on a sustainable bio-composite for catalytic reduction of nitroarenes
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Bio-polymers are the most significant natural alternative stabilizers compared to their synthetic counterparts for fabrication of noble metal nanoparticles because of their higher thermal stability, renewability, low cost, eco-friendliness, strong mechanical capacity, and biodegradability properties. Therefore, a new bio-composite (CMC-Pct-AG), which is consisted of sodium carboxymethyl cellulose, agar, and pectin natural biopolymers, was fabricated as an immobilizing agent in this study. Then, highly stable silver nanoparticles (Ag NPs@CMC-AG-Pct) were successfully decorated on the surface of designed CMC-Pct-AG without the use of any hazardous reducing agents, and their chemical structures were illuminated with Uv–Vis, FT-IR, TG/DTG, SEM, EDS, XRD, and ICP-OES analyses. Subsequently, the catalytic performance of Ag NPs@CMC-AG-Pct was studied in the reduction of various nitroarenes in the presence of NaBH4 at room temperature. These tests indicate that Ag NPs@CMC-AG-Pct is an efficient catalyst which converts nitroarenes to desired amines with good yields and short reaction times. Reproducibility of the catalyst was also investigated, and it is found that Ag NPs@CMC-AG-Pct served several times as a retrievable and reusable catalyst for catalytic reduction of nitroarenes.
- Baran, Talat
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- A FACILE REDUCTION PROCEDURE FOR NITROARENES WITH Al-NiCl2-THF SYSTEM
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It has been demonstrated that aromatic nitro compounds could be reduced to the corresponding amines very efficiently using reagent system consisting of Al-NiCl2*6H2O-THF.
- Sarmah, Parijat,Barua, Nabin C.
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- Ultrasonic and photochemical degradation of chlorpropham and 3-chloroaniline in aqueous solution
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Sonolysis and photolysis are compared for the transformation of chlorpropham, a systemic herbicide belonging to the carbamate group, and 3-chloroaniline, the main intermediate often observed in the degradation of chlorpropham. In both cases the ultrasonic degradation is much more efficient at 482 kHz than at 20 kHz. The main identified sonoproducts formed in the degradation of chlorpropham are 3-chloroaniline, formic acid, carbon monoxide and dioxide and chloride ions. The degradation of 3-chloroaniline also leads to Cl-, CO and CO2 but chlorohydroquine was also detected as an intermediate. Two different mechanisms are involved in the ultrasonic transformation: pyrolysis resulting from the implosion of cavitation microbubbles and oxidation by hydroxyl radicals formed by sonolysis of water. Photolysis is more specific: 3-chloroaniline is initially quantitatively transformed into 3-aminophenol. A heterolytic mechanism is suggested. Resorcinol and some unidentified photoproducts are formed in a second stage. The same type of reaction is involved in the photo-transformation of chlorpropham, but the reaction is not so specific. In both cases the photolysis at 254 nm leads to a complete disappearance of phenolic and quinonic compounds. Sonolysis and photolysis are compared for the transformation of chlorpropham, a systemic herbicide belonging to the carbamate group, and 3-chloroaniline, the main intermediate often observed in the degradation of chlorpropham. In both cases the ultrasonic degradation is much more efficient at 482 kHz than at 20 kHz. The main identified sonoproducts formed in the degradation of chlorpropham are 3-chloroaniline, formic acid, carbon monoxide and dioxide and chloride ions. The degradation of 3-chloroaniline also leads to Cl-, CO and CO2 but chlorohydroquine was also detected as an intermediate. Two different mechanisms are involved in the ultrasonic transformation: pyrolysis resulting from the implosion of cavitation microbubbles and oxidation by hydroxyl radicals formed by sonolysis of water. Photolysis is more specific: 3-chloroaniline is initially quantitatively transformed into 3-amino-phenol. A heterolytic mechanism is suggested. Resorcinol and some unidentified photoproducts are formed in a second stage. The same type of reaction is involved in the photo-transformation of chlorpropham, but the reaction is not so specific. In both cases the photolysis at 254 nm leads to a complete disappearance of phenolic and quinonic compounds.
- David,Lhote,Faure,Boule
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- A New Reaction of the Azoxy Group with Alkyl Thiolates: Reduction to Amino via a Sulfenamido Intermediate
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A novel alkyl thiolate-induced reduction of azoxybenzenes is reported to yield anilines via in situ decomposition of the corresponding sulfenamides formed as primary reaction products.
- Dario, Maria Teresa,Montanari, Stefano,Paradisi, Cristina,Scorrano, Gianfranco
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- Solvent dispersible nanoplatinum-carbon nanotube hybrids for application in homogeneous catalysis
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Solvent-dispersible carbon nanotubes/nanoplatinum hybrid structures are presented, which show excellent catalytic activity under both heterogeneous and homogeneous conditions.
- Chen, Yuhong,Zhang, Xueyan,Mitra, Somenath
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- ZnAl-Hydrotalcite-Supported Au25Nanoclusters as Precatalysts for Chemoselective Hydrogenation of 3-Nitrostyrene
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Chemoselective hydrogenation of 3-nitrostyrene to 3-vinylaniline is quite challenging because of competitive activation of the vinyl group and the nitro group over most supported precious-metal catalysts. A precatalyst comprised of thiolated Au25nanoclusters supported on ZnAl-hydrotalcite yielded gold catalysts of a well-controlled size (ca. 2.0 nm)—even after calcination at 500 °C. The catalyst showed excellent selectivity (>98 %) with respect to 3-vinylaniline, and complete conversion of 3-nitrostyrene over broad reaction duration and temperature windows. This result is unprecedented for gold catalysts. In contrast to traditional catalysts, the gold catalyst is inert with respect to the vinyl group and is only active with regard to the nitro group, as demonstrated by the results of the control experiments and attenuated total reflection infrared spectra. The findings may extend to design of gold catalysts with excellent chemoselectivity for use in the synthesis of fine chemicals.
- Tan, Yuan,Liu, Xiao Yan,Zhang, Leilei,Wang, Aiqin,Li, Lin,Pan, Xiaoli,Miao, Shu,Haruta, Masatake,Wei, Haisheng,Wang, Hua,Wang, Fangjun,Wang, Xiaodong,Zhang, Tao
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- The Bamberger reaction in hydrogen fluoride: the use of mild reductive metals for the preparation of fluoroaromatic amines
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The reduction of nitroaromatic compounds by various metals (tin, lead, bismuth) in liquid hydrogen fluoride under an inert atmosphere leads to fluoroaromatic amines, in accord with the Bamberger reaction.Generally, a co-solvent such as pentane or methylene chloride is used.Some non-fluorinated arylamines are also formed by a competitive direct reduction of the N-arylhydroxylamine intermediate.Of the mild reductive metals studied, bismuth was the most selective. - Keywords: Bamberger reaction; Hydrogen fluoride; Mild reductive metals; Fluoroaromatic amines; NMR spectroscopy
- Tordeux, Marc,Wakselman, Claude
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- A Mild and Chemoselective Reduction of Nitro and Azo Compounds Catalyzed by a Well-Defined Mo3S4 Cluster Bearing Diamine Ligands
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Herein, we report a novel well-defined diamino Mo3S4-based catalyst system for the reduction of nitroarenes and azo compounds to the corresponding anilines with silanes as reducing agents. This catalytic protocol provides a facile route to access aromatic amines under mild conditions in good to excellent yields. Notably, even anilines functionalized with other potentially reducible moieties are obtained with high selectivity. The new chemoselective catalyst of formula [Mo3S4Cl3(dmen)3](BF4) (dmen: N,N′-dimethylethylenediamine) is conveniently synthesized through coordination of the diamine ligand to the incomplete Mo3S4 cubane-type cluster core in a one-pot two-step procedure. The crystal structure of the [Mo3S4Cl3(dmen)3]+ cation confirms the formation of a single isomer in which the chlorine atom lies trans to the bridging sulfur atom to afford a C3 symmetry complex with intrinsic backbone chirality. The structure is preserved in solution, as evidenced by multinuclear NMR spectroscopy and electrospray-ionization mass spectrometric techniques.
- Pedrajas, Elena,Sorribes, Iván,Junge, Kathrin,Beller, Matthias,Llusar, Rosa
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- Regio- and chemoselective reduction of nitroarenes and carbonyl compounds over recyclable magnetic ferrite-nickel nanoparticles (Fe3O 4-Ni) by using glycerol as a hydrogen source
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Reduction by magnetic nano-Fe3O4-Ni: A facile, simple and environmentally friendly hydrogen-transfer reaction that takes place over recyclable ferrite-nickel magnetic nanoparticles (Fe3O 4-Ni) by using glycerol as hydrogen source allows aromatic amines and alcohols to be synthesized from the precursor nitroarenes and carbonyl compounds (see figure). Copyright
- Gawande, Manoj B.,Rathi, Anuj K.,Branco, Paula S.,Nogueira, Isabel D.,Velhinho, Alexandre,Shrikhande, Janhavi J.,Indulkar, Utkarsha U.,Jayaram, Radha V.,Ghumman, C. Amjad A.,Bundaleski, Nenad,Teodoro, Orlando M. N. D.
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- Regioselective dechlorination of 2,3-dichloronitrobenzene into 3-chloronitrobenzene and regioselective dechlorination-hydrogenation into 3-chloroaniline
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Tetrakis(triphenylphosphine)palladium, Pd(PPh3)4, is an efficient catalyst for the selective dechlorination of 2,3-dichloronitrobenzene into 3-chloronitrobenzene. During the reaction the selectivity is over 90% in a very reproducible manner and the reaction can be stopped at the maximum selectivity. Pd(PPh3)4 is also a catalyst for the one-pot transformation of 2,3-dichloronitrobenzene into 3-chloroaniline (selectivity >60%).
- Angeloff, Ariane,Brunet, Jean-Jacques,Legars, Pierre,Neibecker, Denis,Souyri, Denis
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- Selective reduction of nitro-compounds to primary amines by tetrapyridinoporphyrazinato zinc (II) supported on DFNS
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Here, we created and synthesized a heterogeneous catalyst from porphyrazinatozinc (tmtppa-Zn) supported on DFNS (tmtppa-Zn/DFNS). This is a simple method for hydrogenation of nitro-compounds and their conversion to primary amines without producing toxic by-products. These reactions take place under mild reaction situations. The catalyst system was comfortably retrieved and reutilized in at least ten runs without the reduction of catalytic activity.
- Hosseiny, Malihesadat,Khosroyar, Susan,Kiani, Zahra,Motavalizadehkakhky, Alireza,Zhiani, Rahele
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- Hybrid ceria and chitosan supported nickel nanoparticles: A recyclable nanocatalytic system in the reduction of nitroarenes and the synthesis of benzopyran derivatives in green solvent
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Mesoporous, highly temperature resistant, magnetically separable, bimetallic, and organic-based photoluminescent nanocatalyst has been prepared. Chitosan can act efficiently as a support material for preparing nanocatalysts. Hybrid ceria, that is, iron-do
- Mahajan, Ankush,Gupta, Monika
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- Transition metal based ionic liquid (bulk and nanofiber composites) used as catalyst for reduction of aromatic nitro compounds under mild conditions
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Ionic liquid (1,1′-hexane-1,6-diylbis (3-methylpyridinium) tetrachloronickelate (II)) and PVDF-IL ([C6(mpy)2] [NiCl4]2-) nanofiber composites are synthesized and used as catalysts for the reduction of nitroarenes with NaBH4/H 2O system at ambient temperature. Ionic liquid containing nickel halide anion well dispersed on the PVDF nanofibers. It efficiently catalyzes the reduction of functionalized nitroarenes to the corresponding substituted anilines, avoiding the need for inert atmosphere, and additional base or other additives. The catalytic system gives good yields with other functional groups remaining intact.
- Chinnappan, Amutha,Kim, Hern
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- Safe and Efficient Decarboxylation Process: A Practical Synthetic Route to 4-Chlorobenzo[b]thiophene
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We established an improved synthetic route to 4-chlorobenzo[b]thiophene, a key intermediate in brexpiprazole synthesis, via a practical decarboxylation process in three steps. Thermal analysis demonstrated that the coexistence of the decarboxylated product with DBU should be avoided and that removal of the product outside the reactor was vital. Our process yields the target compound by distillation under reduced pressure and is safe, highly batch efficient, cost-effective, and high yielding. Furthermore, manufacturing on a pilot scale was also accomplished through our approach.
- Miyake, Masahiro,Shimizu, Masamichi,Tsuji, Koichi,Ikeda, Keiichi
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- Solvent-Free Hydrogenation of Nitrobenzene Catalyzed by Magnetically Recoverable Pt Deposited on Multiwalled Carbon Nanotubes
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The hydrogenation of nitrobenzene was investigated over magnetically recoverable Pt deposited on multiwalled carbon nanotubes. Under optimal reaction conditions (333 K, 4 MPa), high yield of aniline (>99%) was observed in solvent-free conditions. The Pt/MWCNTs catalyst cannot be reused while the Pt/MWCNTs-Fe3O4 can be recycled four times without any loss of activity. The results of characterization showed the existence of interaction between MWCNTs and Fe3O4, which can effectively stabilize the Pt nanoparticles. Moreover, the magnetic nanocomposites can be readily isolated from the reaction system by a magnet.
- Fan, Guang-Yin,Huang, Wen-Jun
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- Palladium Immobilized on a Polyimide Covalent Organic Framework: An Efficient and Recyclable Heterogeneous Catalyst for the Suzuki–Miyaura Coupling Reaction and Nitroarene Reduction in Water
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An efficient and recyclable Pd nano-catalyst was developed via immobilization of Pd nanoparticles on polyimide linked covalent organic frameworks (PCOFs) that was facilely prepared through condensation of melamine and 3,3′,4,4′-biphenyltetracarboxylic dianhydride. The Pd nanoparticles (Pd NPs) catalyst was thoroughly characterized by FT-IR, XRD, SEM, TEM. Furthermore, the catalytic activity of Pd NPs catalyst was evaluated by Suzuki–Miyaura coupling reaction and nitroarene reduction in water, respectively. The excellent yields of corresponding products revealing revealed that the Pd NPs catalyst could be applied as an efficient and reusable heterogeneous catalyst for above two reactions. Graphical Abstract: [Figure not available: see fulltext.]
- Dong, Zhenhua,Pan, Hongguo,Gao, Pengwei,Xiao, Yongmei,Fan, Lulu,Chen, Jing,Wang, Wentao
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p. 299 - 306
(2021/05/10)
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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 0197-0200
(2021/02/06)
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- Rhodium nanoparticles supported on 2-(aminomethyl)phenols-modified Fe3O4 spheres as a magnetically recoverable catalyst for reduction of nitroarenes and the degradation of dyes in water
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A magnetic nanostructured catalyst (Fe3O4@SiO2-Amp-Rh) modified with 2-(aminomethyl)phenols (Amp) was designed and prepared, which is used to catalyze the reduction of aromatic nitro compounds into corresponding amines and the degradation of dyes. The 2-aminomethylphenol motif plays a vital role in the immobilization of rhodium nanoparticles to offer extraordinary stability, which has been characterized by using various techniques, including transmission electron microscopy (TEM), thermal gravimetric analyzer (TGA), X-Ray Diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). A variety of nitroaromatic derivatives have been reduced to the corresponding anilines in water with up to yields of 99% within 1?h at room temperature. In addition, the catalyst system is effective in catalyzing the reduction of toxic pollutant 4-nitrophenol and the degradation of MO, MB and RhB dyes. Importantly, this catalyst Fe3O4@SiO2-Amp-Rh can be easily recovered by an external magnetic field because of the presence of magnetic core of Fe3O4, and the activity of Fe3O4@SiO2-Amp-Rh does not decrease significantly after 7 times’ recycling, which indicates that the catalyst performed high reactivity as well as stability. Graphical abstract: [Figure not available: see fulltext.]
- Chen, Tian,Chen, Zhangpei,Hu, Jianshe,Lv, Kexin,Reheman, Aikebaier,Wang, Gongshu
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- In situcreation of multi-metallic species inside porous silicate materials with tunable catalytic properties
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Porous metal silicate (PMS) material PMS-11, consisting of uniformly distributed multi-metallic species inside the pores, is synthesized by using a discrete multi-metal coordination complex as the template, demonstrating high catalytic activity and selectivity in hydrogenation of halogenated nitrobenzenes by synergistically activating different reactant moleculesviaNi and Co transition metal centers, while GdIIILewis acid sites play a role in tuning the catalytic properties.
- Liu, Yang-Yang,Wu, Chuan-De,Zhan, Guo-Peng
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supporting information
p. 6185 - 6188
(2021/06/30)
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- Highly efficient hydrogenation reduction of aromatic nitro compounds using MOF derivative Co-N/C catalyst
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The direct hydrogenation reduction of aromatic nitro compounds to aromatic amines with non-noble metals is an attractive area. Herein, the pyrolysis of Co(2-methylimidazole)2 metal-organic framework successfully produces a magnetic Co-N/C nanocomposite, which exhibits a porous structure with a high specific area and uniform Co nanoparticle distribution in nitrogen-doped graphite. In addition, the Co-N/C catalysts possess high cobalt content (23%) with highly active β-Co as the main existing form and high nitrogen content (3%). These interesting characteristics endow the Co-N/C nanocomposite with excellent catalytic activity for the hydrogenation reduction of nitro compounds under mild conditions. In addition, the obtained Co-N/C nanocomposites possess a broad substrate scope and good cycle stability for the reduction of halogen-substituted or carbonyl substituted phenyl nitrates. This journal is
- Dai, Yuyu,Li, Xiaoqing,Wang, Likai,Xu, Xiangsheng
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p. 22908 - 22914
(2021/12/24)
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- A novel water-dispersible and magnetically recyclable nickel nanoparticles for the one-pot reduction-Schiff base condensation of nitroarenes in pure water
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In this work, a heterogeneous nanocatalyst called Ni-Fe3O4@Pectin~PPA ~ Piconal was first synthesized, which was investigated as a bifunctional catalyst containing nickel functional groups. On the other hand, this Ni-Fe3O4@Pectin~PPA ~ Piconal catalyst in aqueous solvents shows a very effective performance at ambient temperature for the nitroarene reduction reaction with sodium borohydride, for which NaBH4 is considered as a reducing agent. This is a novelty magnetic catalyst that was approved by various methods, including Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), Dynamic light scattering (DLS), Transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Inductively coupled plasma (ICP), Energy-dispersive X-ray spectroscopy (EDX), and Field emission scanning electron microscopy (FESEM) analyses. From the satisfactory results obtained from the reduction of nitrogen, this catalytic system is used for a one-pot protocol containing a reduction-Schiff base concentration of diverse nitroarenes. It was corroborated with the heterogeneous catalytic experiments on the one-pot tandem synthesis of imines from nitroarenes and aldehydes. Finally, the novel Ni-Fe3O4@Pectin~PPA ~ Piconal catalyst could function as a more economically desirable and environmentally amicable in the catalysis field. The favorable products are acquired in good to high performance in the attendance of Ni-Fe3O4@Pectin~PPA ~ Piconal as a bifunctional catalyst. This catalyst can be recycled up to six steps without losing a sharp drop.
- Ghamari Kargar, Pouya,Ravanjamjah, Asiye,Bagherzade, Ghodsieh
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p. 1916 - 1933
(2021/07/10)
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- Development of sustainable and efficient nanocatalyst based on polyoxometalate/nickel oxide nanocomposite: A simple and recyclable catalyst for reduction of nitroaromatic compounds
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In this paper, we report the synthesis and characterization of NiO@PolyMo nanocomposite. The newly synthesized nanocomposite was characterized by transmission electronmicroscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and powder X-ray diffraction (XRD). The particle sizes of the NiO@PolyMo nanocatalyst are in the range of 10–20 nm. Powder XRD patterns show that the phase of NiO@PolyMo remains unaltered even after the functionalization of NiO. The lattice fringes of d = 0.20 nm were observed, which correspond to the (111) plane of NiO phase. The newly synthesized material shows excellent catalytic performance and good selectivity for reduction of nitroarenes. The advantages of the present protocols are mild, and can be carried out using water as a solvent, which is an eco-friendly benign.
- Kurbah, Sunshine Dominic
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p. 1487 - 1495
(2021/04/22)
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- Highly efficient N-doped carbon supported FeSx-Fe2O3 catalyst for hydrogenation of nitroarenes via pyrolysis of sulfurized N,Fe-containing MOFs
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Integrating MOFs as precursor, especially for employing N-containing organic linkers, with sulfides is an effective method to prepare the highly efficient N-doped carbon supported metal-based catalysts for hydrogenation of nitroarenes. In this work, a N,Fe-containing metal organic frameworks (MOFs; termed as MIL88-HMTA) with spindle-like structure was prepared via self-assembly method, in which hexamethylenetetramine (HMTA) linker was introduced as N source. Subsequently, N-doped carbon supported FeSx-Fe2O3 catalyst (named FeSx-Fe2O3@CN) was fabricated upon the pyrolysis of sulfurized MIL88-HMTA. Catalytic experiments reveal that the FeSx-Fe2O3@CN delivered excellent performance for hydrogenation of nitroarenes in comparison with those of catalyst without sulfidation process (Fe2O3@CN) and conventional MIL88 derived catalyst (Fe2O3@C). The XRD, TEM, SEM/EDX, Raman, UV, and XPS analyses have revealed that the developed FeSx-Fe2O3@CN catalyst exhibited outstanding catalytic efficiency was ascribed to synergistic effect between FeSx and Fe2O3 species, abundant structural defects, more Fe-Nx species, and strengthened decomposition ability of hydrazine hydrate (N2H4?H2O). Furthermore, the effect of sulfidation ratio (the mass ratio between thioacetamide and MIL88-HMTA) towards preparation of the developed FeSx-Fe2O3@CN on the catalytic activity of hydrogenation reaction was also systematically performed. Notably, the optimized catalyst (denoted as FeSx-Fe2O3@CN-8) exhibited unexpected performance and recyclability for hydrogenation of nitroarenes under mild condition. The pyrolysis of sulfurized N-containing MOFs may present a facile approach for fabricating MOFs-derived N-doped carbon supported catalysts, which provides a potential application in heterogeneous catalytic reactions.
- Li, Xuewei,She, Wei,Wang, Jing,Li, Weizuo,Li, Guangming
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- Novel mesoporous Ag@SiO2nanospheres as a heterogeneous catalyst with superior catalytic performance for hydrogenation of aromatic nitro compounds
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Mesoporous core-shell structure Ag@SiO2 nanospheres are constructed to prevent Ag nanoparticles from aggregation during the hydrogenation reaction. The prepared catalyst shows superior catalytic performance for hydrogenation of nitro compounds with 100% conversion and selectivity without any by-products, which also indicates good recycling performance for several times use.
- Lang, Leiming,Li, Wenyan,Lin, Xinying,Liu, Guangxiang,Long, Jing,Pan, Zhaorui,Zheng, Bo
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p. 37708 - 37712
(2021/12/09)
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- Activated Mont K10-Carbon supported Fe2O3: A versatile catalyst for hydration of nitriles to amides and reduction of nitro compounds to amines in aqueous media
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The iron oxide was successfully supported on activated clay/carbon through an experimentally viable protocol for both hydrations of nitrile to amide and reduction of nitro compounds to amines. The as-prepared catalyst has been extensively characterised by XPS, SEM-EDX, TEM, TGA, BET surface area measurements and powdered X-ray diffraction (PXRD). A wide variety of substrates could be converted to the desired products with good to excellent yields by using water as a green solvent for both the reactions. The catalyst was recyclable and reusable up to six consecutive cycles without compromising its catalytic proficiency. Graphical abstract: Activated Mont K10 carbon-supported Fe2O3 is a very efficient and versatile heterogeneous catalytic system for hydration of nitriles to amides and reduction of nitro compounds to amines and can be reused up to six consecutive cycles without significant loss in catalytic activity.[Figure not available: see fulltext.].
- Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K
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- High yielding electrophilic amination with lower order and?higher order organocuprates: Application of acetone O-(4-Chlorophenylsulfonyl)oxime in the construction of the C?N bond at room temperature
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Electrophilic amination reaction was performed with lower order and?higher order organocuprates using acetone O-(4-Chlorophenylsulfonyl)oxime (1). It was proceeded smoothly at room temperature in the presence of organocuprates to provide the corresponding primary amines in good yields with 10 and 60 min, respectively. The primary amine yields of the electrophilic amination of bromomagnesium organocyanocuprates and dibromomagnesium diorganocyanocuprates were obtained 52–72% and 58–83%, respectively. We observed that higher order organocuprates were more successful than lower order organocuprates in the synthesis of functionalized arylamines by electrophilic amination.
- Duran, Serdar,Korkmaz, Adem
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p. 2077 - 2087
(2021/05/27)
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- Room-temperature copper-catalyzed electrophilic amination of arylcadmium iodides with ketoximes
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We started our study by preparation two ketoximes. Later, there were studies to reveal these ketoximes' effects in the electrophilic amination reaction with organocadmium reagents. Primarily, it was observed that arylcadmium iodides could not be reacted with ketoximes at room temperature in the absence of a catalyst. CuCN was a suitable catalyst for this electrophilic amination reaction of arylcadmium iodides and allowed the preparation of functionalized aniline derivatives in good yields under mild reaction conditions. We obtained the results indicated that the yield of primary arylamines was strongly dependent on the steric and electronic effects of organocadmium reagent and amination agent. In the case of both amination reagents, meta-substituted arylamines were obtained in higher yields than para-substituted arylamines. We observed that acetone O-(4-chlorophenylsulfonyl)oxime, 1, as an aminating agent, was more successful than acetone O-(2-Naphthylsulfonyl)oxime, 2, in the synthesis of functionalized arylamines by electrophilic amination of corresponding aryl cadmium iodides. In this method, there is no cadmium release to the environment.
- Korkmaz, Adem
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p. 3119 - 3125
(2021/05/10)
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- Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
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Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
- Zhao, Huaibo,Leonori, Daniele
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supporting information
p. 7669 - 7674
(2021/03/08)
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- Designing of Highly Active and Sustainable Encapsulated Stabilized Palladium Nanoclusters as well as Real Exploitation for Catalytic Hydrogenation in Water
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Abstract: Encapsulated nanoclusters based on palladium, 12-tunstophosphoric acid and silica was designed by simple wet impregnation methodology. The catalyst was found to be very efficient towards cyclohexene hydrogenation up to five catalytic runs with substrate/catalyst ratio of 4377/1 at 50?°C as well as for alkene, aldehyde, nitro and halogen compounds. Graphic Abstract: Silica encapsulated Pd nanoclusters stabilized by 12-tungstophosphoric acid is proved to be sustainable and excellent for water mediated hydrogenation reaction with very high catalyst to substrate ratio as well as TON.[Figure not available: see fulltext.]
- Patel, Anish,Patel, Anjali
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p. 803 - 820
(2020/08/12)
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- Pd Nanoparticles Assembled on Metalporphyrin-Based Microporous Organic Polymer as Efficient Catalyst for Tandem Dehydrogenation of Ammonia Borane and Hydrogenation of Nitro Compounds
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Abstract: Metalporphyrin-based porous polymers supporting high dispersed Pd nanoparticle (NP) catalysts (HUST-1-Pd) were prepared with a novel solvent-knitting hyper-crosslinked polymer method using 5-, 10-, 15-, and 20-tetraphenylporphyrin (TPP) as building blocks. The N2 sorption isotherms of the catalysts show that the HUST-1-Pd possesses many ultra-micropores and continuous mesopores. The NPs are assembled on tetraphenylporphyrin structures and show Pd-N4 composition-dependent catalysis for methanolysis of ammonia borane (AB) and hydrogenation of aromatic nitro compounds to primary amines in methanol solutions at room temperature. The nano-palladium reduced by NaBH4 has efficient catalytic activity for AB methanolysis. A variety of R-NO2 derivatives were reduced selectively into R-NH2 via palladium catalyzed tandem reactions with 5–30?min of reaction time with conversion yields reaching up to 90%. The derivatives also give excellent recycling performance (more than 10 times). Furthermore, the turnover frequency (TOF) can reach 87,209?h?1. The HUST-1-Pd compounds represent a unique metal catalyst for hydrogenation reactions in a green environment without using pure hydrogen. Graphic Abstract: A monodisperse Pd NPs embed in porphyrin-based microporous organic polymer was reported to catalyse the tandem dehydrogenation of ammonia borane and hydrogenation of R-NO2 to R-NH2 at room temperature. The catalyst is efficient and reusable in an environment-friendly process with short reaction times and high yields.[Figure not available: see fulltext.]
- Zou, Zhijuan,Jiang, Yaya,Song, Kunpeng
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p. 1277 - 1286
(2019/11/20)
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- Ultrasonic promoted synthesis of Ag nanoparticle decorated thiourea-functionalized magnetic hydroxyapatite: A robust inorganic-organic hybrid nanocatalyst for oxidation and reduction reactions
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In this research, ultrasonic synthesis is applied for the fabrication of a novel catalyst, based on immobilization of silver nanoparticles (AgNPs) on thiourea functionalized magnetic hydroxyapatite. A recoverable Ag nano-catalyst is constructed by decoration of AgNPs on the surface of thiourea modified magnetic hydroxyapatite. Magnetic hydroxyapatite is used as an organic-inorganic hybrid support for the catalyst. The organic-inorganic hybrid support is prepared by co-precipitation, followed by its surface modification through covalent functionalization of 1-(3,5-bis(trifluoromethyl)phenyl)-3-propyl)thiourea. The fabricated catalyst has been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) analysis. The nanoparticles are mostly tubular in shape and their particle sizes are smaller than 100 nm. This nanocatalyst shows efficient and robust catalytic activity in different reactions, including selective reduction of 4-nitrophenol (4NP) and oxidation of primary amines by applying NaBH4and urea hydrogen peroxide (UHP) as reagents, respectively. The catalyst shows good reusability in 10 sequential reaction runs.
- Bahadorikhalili, Saeed,Arshadi, Hosein,Afrouzandeh, Zahra,Ma'mani, Leila
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p. 8840 - 8848
(2020/06/08)
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- Tuneable Copper Catalysed Transfer Hydrogenation of Nitrobenzenes to Aniline or Azo Derivatives
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A highly versatile and flexible copper nanoparticle (Cu(0) NPs) catalytic system has been developed for the controlled and selective transfer hydrogenation of nitroarene. Interestingly, the final catalytic product is strongly dependent on the nature of the hydrogen donor source. The yield of nitrobenzene reduction to aniline increased from 20% to an almost quantitative yield over a range of alcohols, diols and aminoalcohols. In glycerol at 130 °C aniline was isolated in 93% yield. In ethanolamine, the reaction was conveniently performed at a lower temperature (55 °C) and gave selectively substituted azobenzene (92% yield). Experimental studies provide support for a reaction pathway in which the Cu(0) NPs catalysed transfer hydrogenation of nitrobenzene to aniline proceeds via the condensation route. The high chemoselectivity of both protocols has been proved in experiments on a panel of variously substituted nitroarenes. Enabling technologies, microwaves and ultrasound, used both separately and in combination, have successfully increased the reaction rate and reaction yield. (Figure presented.).
- Moran, Maria Jesus,Martina, Katia,Baricco, Francesca,Tagliapietra, Silvia,Manzoli, Maela,Cravotto, Giancarlo
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supporting information
p. 2689 - 2700
(2020/05/18)
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- Immobilization of Au nanoparticles on poly(glycidyl methacrylate)-functionalized magnetic nanoparticles for enhanced catalytic application in the reduction of nitroarenes and Suzuki reaction
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We report a novel strategy for the synthesis of magnetic nanocomposite for highly efficient catalysis. Poly(glycidyl methacrylate) (PGMA) chains were grafted to the surface of magnetic nanoparticles (MNPs) through surface-initiated reversible addition-fragmentation chain transfer polymerization. Then, the oxirane rings in the PGMA chains were opened with 2,6-diamino pyridine (DAP) molecules as ligands to prepare the solid support. Finally, this magnetic nanocomposite was used for the immobilization of gold nanoparticles. Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, gel permeation chromatography, vibrating sample magnetometry, and atomic absorption spectroscopy were used for characterization of the catalyst. The loading of gold nanoparticles on the solid support was 0.52 mmol/g. The catalytic activity of the prepared catalyst (MNP@PGMA@DAP@Au) was evaluated for the reduction of nitro compounds and C–C coupling reaction in water. The catalyst can be easily recovered and reused seven times without significant loss of catalytic activity.
- Pourjavadi, Ali,Kohestanian, Mohammad,Keshavarzi, Nahid
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- Ultrasound-assisted rapid reduction of nitroaromatics to anilines using gallium metal
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The reduction of nitroaromatic compounds to anilines is widely used throughout organic synthesis. Typical methods of performing this transformation utilize hydrogenation over a pyrophoric catalyst or a finely divided reducing metal, which often affords heterogeneous mixtures that are difficult to purify. Herein, we report for the first time the use of gallium metal as a reducing agent in organic synthesis. The reaction proceeds under aerobic conditions and affords homogeneous mixtures for a convenient workup. Using this method, twelve anilines were obtained in 33% to quantitative yields with short reaction times of 10-60 minutes.
- Bento, Ian,Bernaldez, Mabel,Noguchi, Ryden,Kawakami, Joel
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supporting information
p. 1404 - 1407
(2020/03/31)
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- Acceptorless dehydrogenative oxidation of primary alcohols to carboxylic acids and reduction of nitroarenes via hydrogen borrowing catalyzed by a novel nanomagnetic silver catalyst
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A novel silver nano magnetic catalyst was devised for dehydrogenative oxidation of aromatic and aliphatic alcohols to the corresponding acid with water as the sole oxygen source and hydrogen gas as the only by-product. The designed catalytic system advantages from easy recovery of magnetic materials i.e. magnetic decantation, being economically viable and environmentally friendly. Furthermore, the catalytic reaction is able to reduce aryl nitro compounds in the absence of any reducing agent.
- Yazdani, Elahe,Heydari, Akbar
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supporting information
(2020/08/14)
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- Mild deprotection of the: N-tert -butyloxycarbonyl (N -Boc) group using oxalyl chloride
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We report a mild method for the selective deprotection of the N-Boc group from a structurally diverse set of compounds, encompassing aliphatic, aromatic, and heterocyclic substrates by using oxalyl chloride in methanol. The reactions take place under room temperature conditions for 1-4 h with yields up to 90percent. This mild procedure was applied to a hybrid, medicinally active compound FC1, which is a novel dual inhibitor of IDO1 and DNA Pol gamma. A broader mechanism involving the electrophilic character of oxalyl chloride is postulated for this deprotection strategy. This journal is
- Awuah, Samuel G.,George, Nathaniel,Ofori, Samuel,Parkin, Sean
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p. 24017 - 24026
(2020/07/23)
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- Intermediate formation enabled regioselective access to amide in the Pd-catalyzed reductive aminocarbonylation of olefin with nitroarene
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An efficient route for the palladium-catalyzed reductive aminocarbonylation of olefins with nitroarenes was developed using carbon monoxide (CO) as both reductant and carbonyl source, which enables facile access to amides with excellent regioselectivity a
- Li, Fuwei,Shi, Lijun,Xia, Chungu,Yang, Li
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p. 1152 - 1160
(2020/03/13)
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- Novel protocol for synthesis of 1,4-diiminocurcumin stabilized silver nanoparticles and application as heterogenous recyclable catalyst and antibacterial agent
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Abstract: Curcumin [(1E, 6E)-1,7-bis(4-hydroxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione] is a low molecular weight yellow-orange polyphenolic pigment extracted from the powdered rhizome of Curcuma longa. Curcumin has wide medicinal applications as an antioxidant, anti-inflammatory, cancer chemopreventive, and potentially chemotherapeutic agents as well as stabilizer/reducing agent in silver nanoparticles (AgNPs) synthesis. However, the low solubility of curcumin in aqueous solutions limits its applications and also, many of AgNP synthetic processes lack a greener synthetic route. In the present work, a Schiff base of curcumin is synthesized condensing curcumin and 1,4-diaminobutane in 2:1 ratio. The resulting product shows improvement in solubility in water and favours the synthesis of AgNPs in aqueous medium at room temperature, acting as a self-reducing/stabilizing agent. This proposed synthetic route is simple, feasible and green. The size and morphology of AgNPs are analyzed by TEM, SEM, EDS and XRD techniques. The recyclable AgNPs as a heterogeneous catalyst in the reduction of nitroaromatics to amino compounds is environmentally benign and can be re-used up to 5th cycle without considerable loss of its catalytic activity. Moreover, both Cur-1,4 and AgNPs show bactericidal properties against bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) which find medicinal importance in future. Graphic abstract: A greener approach has been proposed for the preparation of AgNPs stabilized on curcumin based Schiff base. The AgNPs finds applications as efficient, easily recyclable heterogenous catalyst in the reduction of nitroaromatics to environmentally benign aminoaromatics as well as an antibacterial agent.[Figure not available: see fulltext.].
- Gogoi, Nishi Gandha,Handique, Jyotirekha G
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- Hydrogenation of Functionalized Nitroarenes Catalyzed by Single-Phase Pyrite FeS2 Nanoparticles on N,S-Codoped Porous Carbon
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Catalytic hydrogenation of nitroarenes is an industrially very important and environmentally friendly process for the production of anilines; however, highly chemoselective reduction of nitroarenes decorated with one or more reducible groups in a nitroarene molecule remains a challenge. Herein, a novel hybrid non-noble iron-based nanocatalyst (named as FeS2/NSC) was developed, which was prepared from biomass as C and N source together with inexpensive Fe(NO3)3 as Fe source through high-temperature pyrolysis in a straightforward and cost-effective procedure. Comprehensive characterization revealed that single-phase pyrite FeS2 nanoparticles with precisely defined composition and uniform size were homogeneously dispersed on N,S-codoped porous carbon with large specific surface area, hierarchical porous channels, and high pore volume. The resultant catalyst FeS2/NSC demonstrated good catalytic activity for hydrogenation of functionalized nitroarenes with good tolerance of various functional groups in water as a sustainable and green solvent. Compared with bulk pyrite FeS2 and other non-noble metal-based heterogeneous catalysts reported in the literature, a remarkably enhanced activity was observed under mild reaction conditions. More importantly, FeS2/NSC displayed exclusive chemoselectivity for the reduction of nitro groups for nitroarenes bearing varying readily reducible groups.
- Duan, Yanan,Dong, Xiaosu,Song, Tao,Wang, Zhaozhan,Xiao, Jianliang,Yuan, Youzhu,Yang, Yong
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- Hydrogenation of nitroarenes to anilines in a flow reactor using polystyrene supported rhodium in a catalyst-cartridge (Cart-Rh@PS)
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The present methodology described the chemo-selective hydrogenation of various nitroarenes in a flow reactor under polystyrene supported rhodium in a catalyst-cartridge (Cart-Rh@PS) as a heterogeneous nano-catalyst. The polystyrene supported Rh (Rh@PS) nanoparticles (NPs) were prepared by following our earlier reported protocol and packed inside the catalyst-cartridge (Cat-Cart) to obtain Cart-Rh@PS, which is compatible with ThalesNano's H-Cube Pro flow system. The advantages of the prepacked catalyst Cart-Rh@PS are as follows: no need for catalyst activation up to 12 runs, negligible metal leaching detected by ICP-AES analysis and significantly less back pressure generated under the flow conditions. The same catalyst, Cart-Rh@PS, was also effective up to a 1 gram scale for the reduction of nitroarenes and reusable for successive runs. The hydrogenation in the flow reactor is a greener approach for the reduction of nitroarenes to their corresponding anilines in high yields.
- Sharma, Saurabh,Yamini,Das, Pralay
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supporting information
p. 1764 - 1769
(2019/01/28)
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- Cobalt nanoparticles anchoring on nitrogen doped carbon with excellent performances for transfer hydrogenation of nitrocompounds to primary amines and N-substituted formamides with formic acid
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Cobalt nanoparticles anchoring on nitrogen doped carbon derived from pyrolysis of a cobalt complex and chitosan were developed for reduction of nitrocompounds with neat formic acid to their corresponding amines or N-substituted formamides by switch of solvents. Characterization results revealed that most of the nitrogen atoms are present as graphitic N and pyridinic N as anchoring sites, and the cobalt nanoparticles are wrapped by nitrogen doped carbon layers, endowing the catalyst with excellent activity and superior reusability.
- Zhang, Yuecheng,Cao, Pengwei,Zhang, Hong-Yu,Yin, Guohui,Zhao, Jiquan
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- Electronic Modulation of Palladium in Metal Phosphide Nanoparticles for Chemoselective Reduction of Halogenated Nitrobenzenes
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Tuning the electronic property of a transition metal plays an important role in the selective catalysis. Herein, the control synthesis of (PdxNiy)-P nanoparticles is reported. The binding energy of Pd3d5/2 as a function of
- Zhao, Ming,Feng, Baoming,Qiao, Xiaofei,Zhong, Ning,Ge, Xuemei,Ji, Yuan
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supporting information
p. 407 - 410
(2019/01/14)
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- METHOD AND CATALYST FOR PREPARING ANILINE COMPOUNDS AND USE THEREOF
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The present invention provides a method for preparing aniline compounds, and also provides a kind of catalyst and use thereof. This method for synthesizing an aniline compound in the invention includes following steps: use molybdenum oxide and activated carbon as catalyst, hydrazine hydrate as reducing agent, then reduce aromatic nitro compounds to aniline compounds. This method is green and high efficiency, and easy to be applied in industry.
- -
-
Paragraph 0046-0047
(2019/04/18)
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- Method for synthesizing aniline compound, catalyst and application thereof
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The invention provides a method for synthesizing an aniline compound, and further provides a catalyst and an application thereof. The method for synthesizing the aniline compound includes the following steps: taking molybdenum-based oxide and activated carbon as catalysts; taking hydrazine hydrate as a reducing agent; and reducing an aromatic nitro compound to the aniline compound. The method forsynthesizing the aniline compound has the characteristics of green and high efficiency, easy industrial application and the like.
- -
-
Paragraph 0048; 0049; 0050
(2019/04/17)
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- Metal-free chemoselective reduction of nitroaromatics to anilines via hydrogen transfer strategy
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A novel protocol for chemoselective reduction of aromatic nitro compounds to aromatic amines has been established. The metal-free reduction goes through a hydrogen transfer process. Various easily reducible functional groups can be well tolerated under the optimized reaction conditions.
- Shuai, Qi,Li, Jun,Zhao, Feng,Su, Weike,Deng, Guojun
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p. 965 - 975
(2019/04/13)
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- One-Pot Synthesis of Heterobimetallic Metal–Organic Frameworks (MOFs) for Multifunctional Catalysis
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A one-pot synthesis of bimetallic metal–organic frameworks (Co/Fe-MOFs) was achieved by treating stoichiometric amounts of Fe and Co salts with 2-aminoterephthalic acid (NH2-BDC). Monometallic Fe (catalyst A) and Co (catalyst F) were also prepared along with mixed-metal Fe/Co catalysts (B–E) by changing the Fe/Co ratio. For mixed-metal catalysts (B–E) SEM energy-dispersive X-ray (EDX) analysis confirmed the incorporation of both Fe and Co in the catalysts. However, a spindle-shaped morphology, typically known for the Fe-MIL-88B structure and confirmed by PXRD analysis, was only observed for catalysts A–D. To test the catalytic potential of mixed-metal MOFs, reduction of nitroarenes was selected as a benchmark reaction. Incorporation of Co enhanced the activity of the catalysts compared with the parent NH2-BDC-Fe catalyst. These MOFs were also tested as electrocatalysts for the oxygen evolution reaction (OER) and the best activity was exhibited by mixed-metal Fe/Co-MOF (Fe/Co batch ratio=1). The catalyst provided a current density of 10 mA cm?2 at 410 mV overpotential, which is comparable to the benchmark OER catalyst (i.e., RuO2). Moreover, it showed long-term stability in 1 m KOH. In a third catalytic test, dehydrogenation of sodium borohydride showed high activity (turnover frequency=87 min?1) and hydrogen generation rate (67 L min?1 g?1 catalyst). This is the first example of the synthesis of bimetallic MOFs as multifunctional catalysts particularly for catalytic reduction of nitroarenes and dehydrogenation reactions.
- Iqbal, Bushra,Saleem, Murtaza,Arshad, Salman Noshear,Rashid, Jamshaid,Hussain, Naveed,Zaheer, Muhammad
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p. 10490 - 10498
(2019/07/15)
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- Utilization of a Hydrogen Source from Renewable Lignocellulosic Biomass for Hydrogenation of Nitroarenes
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Exploring of hydrogen source from renewable biomass, such as glucose in alkaline solution, for hydrogenation reactions had been studied since 1860s. According to proposed pathway, only small part of hydrogen source in glucose was utilized. Herein, the utilization of a hydrogen source from renewable lignocellulosic biomass, one of the most abundant renewable sources in nature, for a hydrogenation reaction is described. The hydrogenation is demonstrated by reduction of nitroarenes to arylamines in up to 95 % yields. Mechanism studies suggest that the hydrogenation occurs via a hydrogen transformation pathway.
- Tan, Fang-Fang,Tang, Kai-Li,Zhang, Ping,Guo, Yan-Jun,Qu, Mengnan,Li, Yang
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p. 4189 - 4195
(2019/03/07)
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- Michael addition reaction catalyzed by imidazolium chloride to protect amino groups and construct medium ring heterocycles
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An effective approach for amino protection and construction of a seven-membered ring has been developed. The method uses imidazolium chloride to carry out the Michael addition reaction at low temperatures and perform amino deprotection or construction of a seven-membered ring at high temperatures.
- Dai, Zeshu,Li, Dan,Li, Yanwu,Li, Zhiyao,Luo, Wen,Shang, Suqin,Tian, Qingqiang,Wang, Xuetong,Yuan, Jianyong,Zhang, Ying
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supporting information
(2019/12/04)
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- COMPOUNDS FOR THIOL-TRIGGERED COS AND/OR H2S RELEASE AND METHODS OF MAKING AND USING THE SAME
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Disclosed herein are embodiments of a compound that is capable of releasing COS and/or H2S upon reaction with a thiol-containing compound. The compound embodiments also can produce a detectable signal (e.g., a fluorescent signal) substantially concomitantly with COS and/or H2S release and/or can release an active agent, such as a therapeutic agent. Methods of making and using the compound embodiments also are disclosed.
- -
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Page/Page column 35
(2019/12/25)
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- Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
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A ruthenium(II)-catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2-methylallyl)2(COD)], 1,1,1-tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction-sensitive. The choice of hydrogen source and acid co-catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway. (Figure presented.).
- Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
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supporting information
p. 3800 - 3806
(2019/07/12)
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- AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
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In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
- -
-
Paragraph 0098; 0134; 0135; 0176
(2018/03/25)
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- A fragrant amines for the preparation of compounds (by machine translation)
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The invention discloses a fragrant amines preparation method of the compound, the method in a certain amount of supported cobalt-containing catalyst and a certain amount of fragrant nitryl compounds added in the reactor, then adding ammonium formate, and tetrahydrofuran mixed solvent with water, under stirring, the reaction temperature is 80 - 200 °C, reaction 0.5 - 24 h, to get the corresponding sweet-smelling amines compound. According to the preparation method of this invention the use of inexpensive, renewable bamboo shoots as raw materials for preparing carbon precursor, environmental protection, simple and easy to obtain, without adding nitrogen source material; at the same time in order to triphenylphosphine as the phosphorus source, low price. The substituted ammonium hydrogen as the reducing agent, the operation is simple, mild reaction conditions, in particular to an easily reducible functional group containing fragrant nitryl compounds for chemical selectivity can be controlled more easily. (by machine translation)
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Paragraph 0041-0045
(2018/11/10)
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- The Direct Synthesis of Imines, Benzimidazoles and Quinoxalines from Nitroarenes and Carbonyl Compounds by Selective Nitroarene Hydrogenation Employing a Reusable Iron Catalyst
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The “replacement” of noble metals by earth abundant metals is a desirable aim in catalysis and a possible way of conserving rare elements. The “replacement” is especially attractive if novel selectivity patterns are observed permitting the development of novel coupling reactions. Herein, we report on a novel, robust and reusable iron catalyst, which permits the selective hydrogenation of nitroarenes in the presence of hydrogenation-sensitive functional groups. Based on the selectivity pattern observed, the direct iron-catalyzed synthesis of imines and benzimidazoles from nitroarenes and aldehydes becomes feasible. In addition, we introduce the direct synthesis of quinoxalines from nitroarenes and diketones applying our catalyst.
- B?umler, Christoph,Kempe, Rhett
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supporting information
p. 8989 - 8993
(2018/05/30)
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- N-Heterocyclic Carbene-Modified Au–Pd Alloy Nanoparticles and Their Application as Biomimetic and Heterogeneous Catalysts
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The preparation of water-soluble, N-heterocyclic-carbene-stabilized Au–Pd alloy nanoparticles by a straightforward ligand exchange process is presented. Extensive analysis revealed excellent size retention and stability over years in water. The alloy nanoparticles were applied as biomimetic catalysts for aerobic oxidation of d-glucose, for which monometallic Au and Pd nanoparticles showed no or negligible activity. The alloy nanoparticles were further applied as titania-supported heterogeneous catalysts for the mild hydrogenation of nitroarenes and the semihydrogenation of 1,2-diphenylacetylene with a solvent-dependent selectivity switch between E- and Z-stilbene.
- Tegeder, Patricia,Freitag, Matthias,Chepiga, Kathryn M.,Muratsugu, Satoshi,M?ller, Nadja,Lamping, Sebastian,Tada, Mizuki,Glorius, Frank,Ravoo, Bart Jan
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supporting information
p. 18682 - 18688
(2018/11/23)
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- Visible-Light-Driven Chemoselective Hydrogenation of Nitroarenes to Anilines in Water through Graphitic Carbon Nitride Metal-Free Photocatalysis
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Green and efficient procedures are essential for the chemoselective hydrogenation of functionalized nitroarenes to form industrially important anilines. Herein, it is shown that visible-light-driven, chemoselective hydrogenation of functionalized nitroarenes with groups sensitive to forming anilines can be achieved in good to excellent yields (82–100 %) in water under relatively mild conditions and catalyzed by low-cost and recyclable graphitic carbon nitride. The process is also applicable to gram-scale reaction, with a yield of aniline of 86 %. A study of the mechanism reveals that visible-light-induced electrons are responsible for the hydrogenation reactions, and thermal energy can also promote the photocatalytic activity. A study of the kinetics shows that this reaction possibly occurs through one-step hydrogenation or stepwise condensation routes. A wide range of applications can be expected for this green, efficient, and highly selective photocatalysis system in reduction reactions for the synthesis of fine chemicals.
- Xiao, Gang,Li, Peifeng,Zhao, Yilin,Xu, Shengnan,Su, Haijia
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p. 1950 - 1955
(2018/07/31)
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- Half-Sandwich Ruthenium Phenolate-Oxazoline Complexes: Experimental and Theoretical Studies in Catalytic Transfer Hydrogenation of Nitroarene
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In this work, five ruthenium complexes [Ru(p-cymene)LCl] containing phenolate-oxazoline ligands [L = 2-(4,5-dihydrooxazol-2-yl)phenol (1); L = 2-(4-methyl-4,5-dihydrooxazol-2-yl)phenol (2); L = 2-(4-ethyl-4,5-dihydrooxazol-2-yl)phenol (3); L = 2-(4-phenyl-4,5-dihydrooxazol-2-yl)phenol (4); and 2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)phenol (5)] were synthesized and characterized. The solid-state structures of all ruthenium complexes were determined by single-crystal X-ray diffraction. The catalytic activities of these complexes in the transfer hydrogenation reaction of nitroarene to aniline were investigated. Aniline and their derivatives were obtained in good to excellent yields with isopropanol as the hydride source. The present protocol provides an environmentally benign synthetic method for the reduction of nitroarenes to anilines without employing harsh reaction conditions. Theoretical studies employing density functional theory were carried with the aim to propose a feasible reaction mechanism and to draw insights into the reactivity of the half-sandwich ruthenium catalyst.
- Jia, Wei-Guo,Ling, Shuo,Zhang, Hai-Ning,Sheng, En-Hong,Lee, Richmond
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- Ethyl 6-Hydroxyfulvene-1-Carboxylate: A Reagent Discriminating Primary Amines from Secondary Amines
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A highly chemo-selective reaction was observed when ethyl 6-hydroxyfulvene-1-carboxylate 1 was treated with different nucleophiles such as primary amines, secondary amines, alcohols, and thiols. Among them, only primary amines are reactive toward 1 to afford the condensation products 3, which exhibit good stability under both weakly acidic and basic conditions. The condensation process proved to be reversible between different primary amines. On the basis of this observation, the chemical selectivity of typical primary aromatic amines was evaluated quantitatively by determining equilibrium constants of the condensation reactions with aniline as a reference. Moreover, the primary amines of 3 can be readily released upon treatment with aqueous ammonia, making 6-hydroxyfulvene-1-carboxylate 1 a promising protecting reagent for primary amines.
- Yang, Sen,Lu, Dengfu,Zhu, Yuequan,Shi, Mei,Luo, Fan,Gong, Yuefa
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p. 6681 - 6689
(2018/06/11)
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- Direct ortho-Selective Amination of 2-Naphthol and Its Analogues with Hydrazines
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Described herein is a regioselective ortho-amination of 2-naphthol and its analogues with substituted hydrazines. It provides a direct methodology for the synthesis of N-arylaminated naphthol derivatives without the formation of related 1,1′-biaryl-2,2′-diamine or carbazole byproducts. Specifically, using N,N-disubstituted hydrazine precursors, N-unsubstituted ortho-aminated derivatives and related secondary amines can be formed in ethylene glycol in moderate to excellent yields. Variation of substrates to N,N′-diarylhydrazines and N-methyl-N,N′-diarylhydrazines led to N-aryl-1-amino-2-naphthol compounds. It is noted that biologically interesting indazole motifs can be facilely created by the reaction of N,N′-dialkylhydrazines with 2-naphthols. These ortho-amination reactions have the advantage of one-pot operation without the use of transition metal catalysts.
- Jia, Lei,Tang, Qiang,Luo, Meiming,Zeng, Xiaoming
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p. 5082 - 5091
(2018/05/15)
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- Visible-light-driven Efficient Photocatalytic Reduction of Organic Azides to Amines over CdS Sheet–rGO Nanocomposite
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CdS sheet–rGO nanocomposite as a heterogeneous photocatalyst enables visible-light-induced photocatalytic reduction of aromatic, heteroaromatic, aliphatic and sulfonyl azides to the corresponding amines using hydrazine hydrate as a reductant. The reaction shows excellent conversion and chemoselectivity towards the formation of the amine without self-photoactivated azo compounds. In the adopted strategy, CdS not only accelerates the formation of nitrene through photoactivation of azide but also enhances the decomposition of azide to a certain extent, which entirely suppressed formation of the azo compound. The developed CdS sheet-rGO nanocomposite catalyst is very active, providing excellent results under irradiation with a 40 W simple household CFL lamp.
- Singha, Krishnadipti,Mondal, Aniruddha,Ghosh, Subhash Chandra,Panda, Asit Baran
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p. 255 - 260
(2018/01/15)
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