87-59-2Relevant academic research and scientific papers
Electrophilic Amination of Methylbenzenes with the System NaN 3-AlCl3-HCl. Effects of the Solvent, Crown Ether, and Substrate Structure
Borodkin,Elanov,Popov,Pokrovskii,Shubin
, p. 672 - 679 (2003)
Using mesitylene and o-xylene as examples, it was shown that the solvent nature strongly affects the conversion of methylbenzenes in electrophilic amination with the system NaN3-AlCl3-HCl. Two-parameter correlations were found between the substrate conversion, on the one hand, and dielectric constant and number of heavy atoms in the solvent, on the other. A considerable solvent effect on the regioselectivity of amination of o-xylene was observed. The presence of 18-crown-6 weakly affects the ratio of isomeric amines, but the conversion of o-xylene sharply decreases. Solid aromatic substrates, such as durene and pentamethylbenzene can also be involved in electrophilic amination with the system NaN3-AlCl3-HCl. On the basis of the experimental data and the results of quantum-chemical calculations, participation of a nitrenium intermediate in this reaction was postulated.
Aluminum Metal-Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Dwivedi, Ashutosh,Manna, Kuntal
, p. 3943 - 3957 (2021/04/12)
The development of chemoselective and heterogeneous earth-abundant metal catalysts is essential for environmentally friendly chemical synthesis. We report a highly efficient, chemoselective, and reusable single-site nickel(II) hydride catalyst based on robust and porous aluminum metal-organic frameworks (MOFs) (DUT-5) for hydrogenation of nitro and nitrile compounds to the corresponding amines and hydrogenolysis of aryl ethers under mild conditions. The nickel-hydride catalyst was prepared by the metalation of aluminum hydroxide secondary building units (SBUs) of DUT-5 having the formula of Al(μ2-OH)(bpdc) (bpdc = 4,4′-biphenyldicarboxylate) with NiBr2 followed by a reaction with NaEt3BH. DUT-5-NiH has a broad substrate scope with excellent functional group tolerance in the hydrogenation of aromatic and aliphatic nitro and nitrile compounds under 1 bar H2 and could be recycled and reused at least 10 times. By changing the reaction conditions of the hydrogenation of nitriles, symmetric or unsymmetric secondary amines were also afforded selectively. The experimental and computational studies suggested reversible nitrile coordination to nickel followed by 1,2-insertion of coordinated nitrile into the nickel-hydride bond occurring in the turnover-limiting step. In addition, DUT-5-NiH is also an active catalyst for chemoselective hydrogenolysis of carbon-oxygen bonds in aryl ethers to afford hydrocarbons under atmospheric hydrogen in the absence of any base, which is important for the generation of fuels from biomass. This work highlights the potential of MOF-based single-site earth-abundant metal catalysts for practical and eco-friendly production of chemical feedstocks and biofuels.
Pd nanoparticles/graphene quantum dot supported on chitosan as a new catalyst for the reduction of nitroarenes to arylamines
Kalanpour, Nastaran,Nejati, Saeid,Keshipour, Sajjad
, p. 1243 - 1250 (2020/10/29)
A new heterogeneous catalyst was obtained by growing graphene quantum dots on chitosan and subsequent immobilization of Pd nanoparticles. The catalyst after characterization was used in the reduction of nitroarenes to the corresponding amines by NaBH4 as a weak reducing agent of nitro compounds. The catalyst exhibited excellent catalytic activity and selectivity under mild reaction conditions in water as a green solvent during 1?h. Additionally, the catalyst can be reused for five consecutive runs without any significant decrease in its activity and selectivity.
Single-atom Fe-N4site for the hydrogenation of nitrobenzene: theoretical and experimental studies
Dong, Panpan,He, Rong,Liu, Yan,Lu, Ning,Mao, Junjie,Wu, Konglin,Zhang, Wenzhuang,Zheng, Yamin
supporting information, p. 7995 - 8001 (2021/06/21)
The hydrogenation of nitrobenzene to aniline is an important process in the industry of fine chemicals, but developing inexpensive catalysts with expected activity and selectivity still remains a challenge. By using density functional theory calculations, we demonstrated that the isolated Fe atom not only can weaken the adsorption of reactants and reaction intermediates as compared to Fe nanoparticles, but also remarkably decrease the reaction barrier for the hydrogenation of nitrobenzene to aniline. Thus, the Fe single-atom (Fe SA) catalyst is considered as an ideal catalyst for this reaction. This theoretical prediction has been subsequently confirmed by experimental results obtained for the Fe SAs loaded on N-doped hollow carbon spheres (Fe SAs/NHCSs) which achieved a conversion of 99% with a selectivity of 99% for the hydrogenation of nitrobenzene. The results significantly outperformed the Fe nanoparticles for this reaction. This work provides theoretical insight for the rational design of new catalytic systems with excellent catalytic properties.
The immobilized Cu nanoparticles on magnetic montmorillonite (MMT?Fe3O4?Cu): As an efficient and reusable nanocatalyst for reduction and reductive-acetylation of nitroarenes with NaBH4
Zeynizadeh, Behzad,Rahmani, Soleiman,Tizhoush, Hengameh
, (2019/11/28)
In this study, the immobilization of copper nanoparticles on superparamagnetic montmorillonite, MMT?Fe3O4?Cu, was studied. Magnetically nanoparticles (MNPs) of iron oxide (Fe3O4) were primarily prepared by a chemical co-precipitation method. Next, the prepared Fe3O4 MNPs were intercalated within the interlamellar spaces and external surface of sodium-exchanged montmorillonite. Finally, Cu NPs were immobilized on magnetic montmorillonite by a simply mixing of an aqueous solution of CuCl2·2H2O with MMT?Fe3O4 followed by the reduction with NaBH4. Characterization of MMT?Fe3O4 clay system represented that through the immobilization of Fe3O4 MNPs, disordered-layers structure of MMT was easily reorganized to an ordered-layers arrangement. The synthesized composite systems were characterized using FT-IR, SEM, EDX, XRD, VSM, BET and ICP-OES analyses. SEM analysis exhibited that dispersion of Cu NPs, with the size distribution of 15–25 nm, on the surface of magnetic clay was taken place perfectly. BET surface analysis indicated that after the immobilization of Fe3O4 and Cu species, the surface area and total pore volume of MMT?Fe3O4?Cu system was decreased. Next, the Cu-clay nanocomposite system showed a perfect catalytic activity towards reduction of nitroarenes to anilines as well as reductive-acetylation of nitroarenes to acetanilides using NaBH4 and Ac2O in water as a green and economic solvent. The copper magnetic clay catalyst can be easily separated from the reaction mixture by an external magnetic field and reused for six consecutive cycles without the significant loss of its catalytic activity.
The immobilized copper species on nickel ferrite (NiFe2O4@Cu): a magnetically reusable nanocatalyst for one-pot and quick reductive acetylation of nitroarenes to N-arylacetamides
Zeynizadeh, Behzad,Shokri, Zahra,Mohammadzadeh, Iman
, p. 859 - 870 (2019/12/24)
In this study, a green protocol for synthesis of N-arylacetamides was introduced. Magnetically, nanoparticles of the immobilized copper species on nickel ferrite, NiFe2O4@Cu, were synthesized and then characterized using SEM, EDX, XRD, VSM, ICP-OES, BET and XPS analyses. The XPS analysis approved that the immobilized copper species on NiFe2O4 only contain Cu(0) and its oxide form as CuO. The prepared nanocomposite system represented a perfect catalytic activity toward one-pot and quick reductive acetylation of various nitroarenes to the corresponding N-arylacetamides. All reactions were carried out in a mixture of H2O–EtOH (1.5–0.5) within 2–10?min using the combination system of NaBH4 and Ac2O in a one-pot approach and via a two-step procedure. The utilized Cu nanocomposite was magnetically separated from the reaction mixture and reused for 5 consecutive cycles without the significant loss of its catalytic activity.
C-H Amination of Arenes with Hydroxylamine
See, Yi Yang,Sanford, Melanie S.
supporting information, p. 2931 - 2934 (2020/04/09)
This Letter describes the development of a TiIII-mediated reaction for the C-H amination of arenes with hydroxylamine. This reaction is applied to a variety of electron-rich (hetero)arene substrates, including a series of natural products and pharmaceuticals. It offers the advantages of mild conditions (room temperature), fast reaction rates (30 min), compatibility with ambient moisture and air, scalability, and the use of inexpensive commercial reagents.
The immobilized Ni(II)-thiourea complex on silica-layered copper ferrite: A novel and reusable nanocatalyst for one-pot reductive-acetylation of nitroarenes
Zeynizadeh, Behzad,Shokri, Zahra,Hasanpour Galehban, Morteza
, (2019/01/16)
In this study, magnetically nanoparticles of CuFe2O4@SiO2@PTMS@Tu@Ni(II) as novel and reusable catalyst were prepared. Synthesis of the Ni (II)-nanocatalyst was carried out through the complexation of Ni(OAc)2·4H2O with the immobilized thiourea on silica-layered CuFe2O4. The prepared nanocomposite system was then characterized using SEM, EDX, XRD, VSM, ICP-OES, Raman, UV–Vis and FT-IR analyses. Catalytic activity of the Ni(II)-CuFe2O4 system was investigated towards rapid reduction of aromatic nitro compounds to arylamines with sodium borohydride as well as one-pot reductive-acetylation of nitroarenes to acetanilides with NaBH4/Ac2O system without the isolation of intermediate arylamines. All reactions were carried out in H2O within 3–7?min to afford the products arylamines/acetanilides in high to excellent yields. Reusability of the Ni(II)-nanocatalyst was examined for seven consecutive cycles without the significant loss of the catalytic activity.
Photocatalytic hydrogenation of nitroarenes: supporting effect of CoOx on TiO2 nanoparticles
Amanchi, Srinivasa Rao,Ashok Kumar,Lakshminarayana, Bhairi,Satyanarayana,Subrahmanyam
, p. 748 - 754 (2019/01/10)
Cobalt oxide visible light-active photo-catalysts supported on TiO2 nanoparticles with varying amount of cobalt oxide [3% CoOx/TiO2 (A), 4% CoOx/TiO2 (B), 5% CoOx/TiO2 (C)] were synthesized by solid-state method followed by calcination. The as-synthesized catalysts were characterized by various techniques such as powder XRD, TEM, EDX, UV-Vis-DRS and XPS analysis. The photocatalytic activity of the as-synthesized materials was studied for the reduction of nitroarenes to the corresponding amines using hydrazine monohydrate as the reductant. Cobalt(ii) oxide is responsible for the reduction of nitroarenes and then, cobalt(iii) is reduced back to the original compound by hydrazine hydrate, thus ascertaining the catalytic nature of this hydrogenation process. XPS suggests the presence of Co(ii) in CoOx/TiO2.
Synthesis of magnetic Fe3O4@SiO2@Cu–Ni–Fe–Cr LDH: an efficient and reusable mesoporous catalyst for reduction and one-pot reductive-acetylation of nitroarenes
Gilanizadeh, Masumeh,Zeynizadeh, Behzad
, p. 2821 - 2837 (2018/10/31)
Abstract: Magnetically recoverable Fe3O4@SiO2@Cu–Ni–Fe–Cr LDH was prepared under co-precipitation conditions. Characterization of the mesoporous catalyst was confirmed using Fourier-transformed infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, vibration sample magnetometer, Brunauer–Emmett–Teller, thermogravimetric, differential thermogravimetric analyses and transmission electron microscopy. Reduction of nitroarenes to the corresponding arylamines and one-pot reductive-acetylation of nitroarenes to acetanilides were carried out successfully by nanoparticles of the immobilized Cu–Ni–Fe–Cr layered double hydroxide on silica-coated Fe3O4 in water as a green solvent. All reactions were carried out within 6–22?min affording arylamines and N-arylacetamides in high-to-excellent yields. Reusability of the core–shell nanocatalyst was examined six times without significant loss of its catalytic activity.
