122-80-5Relevant articles and documents
A ternary Cu2O-Cu-CuO nanocomposite: A catalyst with intriguing activity
Sasmal, Anup Kumar,Dutta, Soumen,Pal, Tarasankar
, p. 3139 - 3150 (2016)
In this work, the syntheses of Cu2O as well as Cu(0) nanoparticle catalysts are presented. Copper acetate monohydrate produced two distinctly different catalyst particles with varying concentrations of hydrazine hydrate at room temperature without using any surfactant or support. Then both of them were employed separately for 4-nitrophenol reduction in aqueous solution in the presence of sodium borohydride at room temperature. To our surprise, it was noticed that the catalytic activity of Cu2O was much higher than that of the metal Cu(0) nanoparticles. We have confirmed the reason for the exceptionally high catalytic activity of cuprous oxide nanoparticles over other noble metal nanoparticles for 4-nitrophenol reduction. A plausible mechanism has been reported. The unusual activity of Cu2O nanoparticles in the reduction reaction has been observed because of the in situ generated ternary nanocomposite, Cu2O-Cu-CuO, which rapidly relays electrons and acts as a better catalyst. In this ternary composite, highly active in situ generated Cu(0) is proved to be responsible for the hydride transfer reaction. The mechanism of 4-nitrophenol reduction has been established from supporting TEM studies. To further support our proposition, we have prepared a compositionally similar Cu2O-Cu-CuO nanocomposite using Cu2O and sodium borohydride which however displayed lower rate of reduction than that of the in situ produced ternary nanocomposite. The evolution of isolated Cu(0) nanoparticles for 4-nitrophenol reduction from Cu2O under surfactant-free condition has also been taken into consideration. The synthetic procedures of cuprous oxide as well as its catalytic activity in the reduction of 4-nitrophenol are very convenient, fast, cost-effective, and easily operable in aqueous medium and were followed spectrophotometrically. Additionally, the Cu2O-catalyzed 4-nitrophenol reduction methodology was extended further to the reduction of electronically diverse nitroarenes. This concise catalytic process in aqueous medium at room temperature revealed an unprecedented catalytic performance which would draw attention across the whole research community.
Development of a continuous-flow system for catalysis with palladium(0) particles
Solodenko, Wladimir,Wen, Hongliang,Leue, Stefanie,Stuhlmann, Friedrich,Sourkouni-Argirusi, Georgia,Jas, Gerhard,Schoenfeld, Hagen,Kunz, Ulrich,Kirschning, Andreas
, p. 3601 - 3610 (2004)
Heterogeneous catalysis for organic synthesis under continuous-flow conditions becomes possible by a new reactor-based approach. Continuous-flow reactors with a monolithic glass/polymer composite interior are loaded with palladium particles by ion exchange followed by reduction. When incorporated into a continuous-flow setup (PASSflow) this reactor allows the transfer-hydrogenation of alkenes, alkynes, nitro-substituted aromatic compounds and benzyl ethers in the flow-through mode. In addition, the activity of the catalysts is well suited to achieve Suzuki, Sonogashira and Heck cross-coupling reactions in the absence of phosphanes or any other ligands, resulting in a greatly simplified purification. As an extension to this concept a bifunctional support was prepared inside the reactor consisting of Pd particles and an ion-exchange group (hydroxide form). In the Suzuki-Miyaura reaction the reactor serves as a base for immobilisation and activation of the boronic acid as boronate and as a catalyst for promoting the C-C coupling reaction under continuous-flow conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Chemoselective reduction of nitroaromatics to anilines using decaborane in methanol
Bae, Jong Woo,Cho, Young Jin,Lee, Seung Hwan,Yoon, Cheol Min
, p. 175 - 177 (2000)
Nitrobenzenes were chemoselectively reduced to the corresponding anilines using decaborane (B10H14) in the presence of Pd/C and two drops of acetic acid at reflux under nitrogen atmosphere in high yields.
Efficient reductions of nitroarenes with SnCl2 in ionic liquid
De, Prithwiraj
, p. 1835 - 1837 (2004)
Mild, eco-friendly and fast reductions of nitroarenes to aminoarenes have been accomplished using stannous chloride dihydrate in ionic liquid tetrabutylammonium bromide (TBAB) that provides unsolvated nucleophilic bromide ion. Improved yields, lower reaction time, generality, and a less demanding work-up procedure are the notable features of this protocol.
Reduction of nitro-aryl compounds with zinc in the presence of poly[N-(2-aminoethyl)acrylamido]-trimethylammonium chloride as a phase-transfer catalyst
Mahdavi, Hossen,Tamami, Bahman
, p. 1121 - 1127 (2005)
The new polymeric phase-transfer catalyst, poly[N-(2-aminoethyl)acrylamido] trimethylammonium chloride resin, catalyzes the reduction of nitroarenes to the corresponding aromatic amines with zinc powder in water and in high yields under mild conditions. Copyright Taylor & Francis, Inc.
Copper nanoparticles (CuNPs) catalyzed chemoselective reduction of nitroarenes in aqueous medium
Chand, Dillip Kumar,Rai, Randhir
, (2021/08/20)
Abstract: A procedure for practical synthesis of CuNPs from CuSO4·5H2O is established, under appropriate reaction conditions, using rice (Oryza sativa) as an economic source of reducing as well as a stabilizing agent. Optical and microscopic techniques are employed for the characterization of the synthesized CuNPs and the sizes of the particles were found to be in the range of 8 ± 2 nm. The nanoparticles are used as a catalyst for chemoselective reduction of aromatic nitro compounds to corresponding amines under ambient conditions and water as a reaction medium. Graphic abstract: CuNPs are synthesized using hydrolysed rice and used as catalyst for chemoselective reduction of nitroarenes to their corresponding amines in water. [Figure not available: see fulltext.]
Chemoselective reduction of nitroarenes, N-acetylation of arylamines, and one-pot reductive acetylation of nitroarenes using carbon-supported palladium catalytic system in water
Zeynizadeh, Behzad,Mohammad Aminzadeh, Farkhondeh,Mousavi, Hossein
, p. 3289 - 3312 (2021/05/11)
Developing and/or modifying fundamental chemical reactions using chemical industry-favorite heterogeneous recoverable catalytic systems in the water solvent is very important. In this paper, we developed convenient, green, and efficient approaches for the chemoselective reduction of nitroarenes, N-acetylation of arylamines, and one-pot reductive acetylation of nitroarenes in the presence of the recoverable heterogeneous carbon-supported palladium (Pd/C) catalytic system in water. The utilize of the simple, effective, and recoverable catalyst and also using of water as an entirely green solvent along with relatively short reaction times and good-to-excellent yields of the desired products are some of the noticeable features of the presented synthetic protocols. Graphic abstract: [Figure not available: see fulltext.].
Synthesis of ring-opened derivatives of triazole-containing quinolinones and their antidepressant and anticonvulsant activities
Song, Ming-Xia,Huang, Yu-Shan,Zhou, Qiu-Gui,Deng, Xian-Qing,Yao, Xiao-Dong
, (2020/12/07)
Based on the potent antidepressant and anticonvulsant activities of the triazole-containing quinolinones reported in our previous work, a series of ring-opened derivatives of them were designed, synthesized in this work. Their antidepressant and anticonvulsant activities were screened using the forced swimming test (FST) and the maximal electroshock seizure test (MES), respectively. The results showed that compounds 4a, 5a, 6c-6e, 6g-6i, and 7 led to significant reductions in the accumulated immobility time in the FST at a dose of 50 mg/kg. Especially compound 7 exhibited higher levels of efficacy than the reference standard fluoxetine in the FST and the tail suspension test. The results of an open field test excluded the possibility of central nervous stimulation of 7, which further confirmed its antidepressant effect. Meanwhile, compounds 6a-6i and 7 showed different degrees of anticonvulsant activity in mice at the doses range from 300 to 30 mg/kg in the MES. Among them, compounds 6e and 7 displayed the ED50 of 38.5 and 32.7 mg/kg in the MES, and TD50 of 254.6 and 245.5 mg/kg, respectively. No one showed neurotoxicity at the dose of 100 mg/kg. The preliminary investigation forward to their mechanism indicated that regulation of GABAergic system might contribute to their anticonvulsive and anti-depressive action.
A Concise Route to Cyclic Amines from Nitroarenes and Ketoacids under Iron-Catalyzed Hydrosilylation Conditions
Ammaiyappan, Yuvaraj,Darcel, Christophe,Tongdee, Satawat,Wu, Jiajun
, p. 3859 - 3865 (2021/07/12)
Starting from nitroarenes, under hydrosilylation conditions, using a well-defined N-heterocyclic carbene iron(0) catalyst, (IMes)Fe(CO)4, the corresponding aniline derivatives were produced in 61–92% isolated yields. More impressively, a selective synthesis of cyclic amines such as pyrrolidines, piperidines and azepanes were conducted from levulinic acid, 1,5- and 1,6-keto acids, respectively. The sequential procedure proceeded under both visible light irradiation and thermal conditions with 20 examples in isolated yields up to 69%. (Figure presented.).
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
