104-94-9Relevant articles and documents
Synthesis, structures and catalytic activities of half-sandwich ruthenium complexes based on Schiff Base ligands
Jia, Wei-Guo,Zhang, Hui,Zhang, Tai,Ling, Shuo
, p. 15 - 18 (2016)
A series of half-sandwich ruthenium(II) complexes containing Schiff-base ligands [Ru(p-cymene)LCl] [HL = (E)-4-X-2-((phenylimino)methyl)phenol, X = H (2a); X = CH3 (2b); X = Cl (2c) and X = Br (2d)] have been synthesized and fully characterized by 1H and 13C NMR spectra, elemental analyses and infrared spectrometry. Moreover, the molecular structures of ruthenium complexes 2b and 2c were confirmed by single-crystal X-ray diffraction methods. These half-sandwich ruthenium complexes are highly catalyzed hydrogenation of nitroarenes to aromatic anilines to proceed in the presence of sodium borohydride reducing agent in ethanol solvent. Notably, complex 2c was found to be a very efficient catalyst toward reduction of nitroarene compounds with wide functional group compatibility and substrate scope.
Novel conversion of 3-(α-hydroxybenzyl)flavones to 3-benzoylchromones and 3-cyanoflavones with NaN3/TFA
Mallik, Asok K.,Chattopadhyay, Falguni,Dey, Sankar P.
, p. 4929 - 4931 (2000)
On treatment with NaN3/TFA, 3-(α-hydroxybenzyl)flavones are converted to 3-benzoylchromones and 3-cyanoflavones, plausible mechanisms for which have been suggested. (C) 2000 Elsevier Science Ltd.
Sonication and Microwave-Assisted Primary Amination of Potassium- Aryltrifluoroborates and Phenylboronic Acids under Metal-Free Conditions
Kuik, Dale,McCubbin, J. Adam,Tranmer, Geoffrey K.
, p. 2555 - 2561 (2017)
The transition-metal-free generation of a series of primary arylamines from potassium aryltrifluoroborates and phenylboronic acids- is reported. The method uses a mild, inexpensive source of nitrogen (hydroxylamine-O-sulfonic acid) in cooperation with aqueous sodium hydroxide in acetonitrile. Both a sonication and a microwave-assisted method were developed, which are capable of converting ArBF3K functionalities into primary arylamines (ArNH2) in isolated yields of up to 78% (10 examples for each method). This report represents the first general method for the conversion of aryltrifluoroborates into primary arylamines under mild, transition-metal-free conditions in moderate to very good yields. The method is applicable to a wide array of substrates containing electron-donating, electron-neutral, or electron-withdrawing substituents. Both the sonication and microwave methods were also applied to the generation of anilines from phenylboronic acids in isolated yields of up to 96% (12 examples for each method) that were superior to existing room temperature methods in terms of yield, while also offering much shorter reaction times (15 min vs 16 h). In particular, the microwave method is the first to allow for the conversion of arylboronic acids containing strongly electron-withdrawing substituents into the corresponding anilines in good yields, along with electron-donating- substituents in very good to excellent yields.
Selective Reduction of Nitroarenes Catalyzed by Sustainable and Reusable DNA-supported Nickel Nanoparticles in Water at Room Temperature
Niakan, Mahsa,Asadi, Zahra
, (2019)
Abstract: In this research, a novel, biodegradable and environmentally friendly catalyst composed of nickel nanoparticles supported on DNA was prepared and fully characterized by Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, UV–vis spectroscopy, inductively coupled plasma optical emission spectroscopy, and elemental analysis. The catalyst exhibited remarkable catalytic activity and chemoselectivity for the reduction of various substituted nitroarenes with sodium borohydride (NaBH4) as the source of inexpensive hydride in water at room temperature. High turnover frequency and selectivity were observed for the reduction of all tested substrates. Interestingly, the catalyst could be recovered conveniently for multiple recycling reactions with sustained activity. Furthermore, nearly no nickel species was leached out from the catalyst during the course of reaction, proving the true heterogeneity in the present catalytic protocol. Graphical Abstract: The reduction of various nitroaromatic compounds into their corresponding amines is achieved by DNA supported nickel nanoparticles with the sodium borohydride as the reducing agent in water at room temperature. [Figure not available: see fulltext.].
Atomically dispersed Ni as the active site towards selective hydrogenation of nitroarenes
Yang, Fan,Wang, Minjian,Liu, Wei,Yang, Bin,Wang, Ying,Luo, Jun,Tang, Yushu,Hou, Liqiang,Li, Yun,Li, Zihui,Zhang, Bing,Yang, Wang,Li, Yongfeng
, p. 704 - 711 (2019)
Rational design of heterogeneous non-noble metal catalysts as highly efficient and selective catalysts for hydrogenation of nitroarenes with hydrogen as the reducing agent is currently a great challenge, which has attracted a great deal of attention. Herein, a new strategy for achieving atomic dispersion of Ni atoms on nitrogen-doped porous carbon (Ni-N-C) with a specific surface area of up to 810 m2 g-1 and nickel loading as high as 4.4 wt% is developed, yielding high activity, chemoselectivity, and reusability of catalysts in the hydrogenation of nitroarenes using hydrogen as the reductant with a turnover of number (TON) value of 84 and a turnover of frequency (TOF) value of 8.4 h-1 for the first time. The Ni single atoms anchored on N-doped porous carbon by binding with nitrogen/carbon have been proved to be the active sites. Importantly, the Ni-N3 active species is found to contribute more activity compared with Ni-N2 and Ni-N4. Density functional theory (DFT) calculations also reveal that the Ni-N3 structure exhibits the highest activity according to the lowest adsorption energy and the longest elongation N-O bonds of nitrobenzene, which originated from the induced charge transfer. This work opens a new route for rational design and accurate modulation of nanostructured organic molecular transformation catalysts at the atomic scale.
A new linker for anchoring/masking primary amines on solid support
Paladino, Antonietta,Mugnaini, Claudia,Botta, Maurizio,Corelli, Federico
, p. 565 - 568 (2005)
(Chemical Equation Presented) A polymer-supported diketone was synthesized and used to fully protect/mask primary amines by the formation of a pyrrole ring. Various reactions can be performed on this system which then can be cleaved with full restoration of the amine functionality. The resin can also be recycled at least once without loss of purity of the final compound.
Controllable Synthesis of Mesoporous Iron Oxide Nanoparticle Assemblies for Chemoselective Catalytic Reduction of Nitroarenes
Papadas, Ioannis T.,Fountoulaki, Stella,Lykakis, Ioannis N.,Armatas, Gerasimos S.
, p. 4600 - 4607 (2016)
Iron(III) oxide is a low-cost material with applications ranging from electronics to magnetism, and catalysis. Recent efforts have targeted new nanostructured forms of Fe2O3 with high surface area-to-volume ratio and large pore volume. Herein, the synthesis of 3D mesoporous networks consisting of 4-5 nm γ-Fe2O3 nanoparticles by a polymer-assisted aggregating self-assembly method is reported. Iron oxide assemblies obtained from the hybrid networks after heat treatment have an open-pore structure with high surface area (up to 167 m2 g-1) and uniform pores (ca. 6.3 nm). The constituent iron oxide nanocrystals can undergo controllable phase transition from γ-Fe2O3 to α-Fe2O3 and to Fe3O4 under different annealing conditions while maintaining the 3D structure and open porosity. These new ensemble structures exhibit high catalytic activity and stability for the selective reduction of aryl and alkyl nitro compounds to the corresponding aryl amines and oximes, even in large-scale synthesis.
Electrophilic amination of aromatics with sodium azide in BF3-H2O
Prakash, G.K. Surya,Gurung, Laxman,Marinez, Eric R.,Mathew, Thomas,Olah, George A.
, p. 288 - 291 (2016)
Boron trifluoride monohydrate is an excellent Br?nsted acid catalyst system for a wide range of reactions. It is a non-oxidizing acid catalyst prepared easily by bubbling BF3 into water. We have found boron trifluoride monohydrate/sodium azide combination to be an efficient reagent system for aromatic electrophilic amination. The present method avoids the use of expensive superacids such as trifluoromethanesulfonic acid and provides a facile access to aromatic amines directly from aromatics.
Redox and acidity properties of 4-substituted aniline radical cations in water
Jonsson, Mats,Lind, Johan,Eriksen, Trygve E.,Merényi, Gábor
, p. 1423 - 1427 (1994)
By means of pulse radiolysis the one-electron reduction potentials of twelve 4-substituted aniline radical cations and the pKa values of eight 4-substituted aniline radical cations have been determined. Both the potentials and the pKa values were shown to be linearly dependent on the Brown σp+ values for the 4-substituents. The one-electron reduction potentials were also compared to previously reported electrochemically determined E1/2 values resulting in good agreement between the two sets of data. By combining the one-electron reduction potentials and the pKa values the N-H bond dissociation energies of some 4-substituted anilines were calculated, also showing a linear substituent dependence. The absolute N-H bond dissociation energy of aniline found was close to a previously reported value.
Regio- and chemoselective catalytic transfer hydrogenation of aromatic nitro and carbonyl as well as reductive cleavage of azo compounds over novel mesoporous NiMCM-41 molecular sieves
Mohapatra, Susanta K.,Sonavane, Sachin U.,Jayaram, Radha V.,Selvam, Parasuraman
, p. 4297 - 4300 (2002)
(equation presented) Regio-and chemoselective reduction of nitroarenes and carbonyl compounds and reductive cleavage of azo compounds, including bulkier molecules, was achieved by the catalytic transfer hydrogenation method (CTH) using a novel nickel-containing mesoporous silicate (NiMCM-41) molecular sieve catalyst. In addition, the catalyst was also found to behave as a truly heterogeneous catalyst as the yield was practically unaffected.
