13556-84-8Relevant articles and documents
The effect of the catalyst on the synthesis of 2,2′- dichlorohydrazobenzene during the electrochemical reduction of o-chloronitrobenzene
Liu, Ling,Chen, Jiang-Hua,Meng, Qing-Han,Cao, Bing
, p. 671 - 678 (2012)
In this paper, 2,2′-dichlorohydrazobenzene was synthesized by the electrochemical reduction of o-chloronitrobenzene using the ion-exchange membrane method. The effects of different catalysts (litharge, lead tetroxide, and lead nitrate) on the synthesis were investigated. The influence of different catalyst loading approaches on the electrochemical reduction were also examined. The structure and surface morphology of the catalysts were characterized by X-ray diffraction and scanning electron microscopy. Catalyst activity was examined by dynamic potential analyses and cyclic voltammetry. Litharge was found to induce the greatest improvement in the electrolysis reaction rate and also decreases the reaction time. Coating the catalyst on the cathode helps enhance the product yield. The possible reaction mechanism was studied, and the catalyst was found to play a key role in transforming raw substances into intermediates. However, there is little effect on intermediate product transformation into the desired product.
The effect of water on the hydrogenation of o-chloronitrobenzene in ethanol, n-heptane and compressed carbon dioxide
Cheng, Haiyang,Meng, Xiangchun,Yu, Yancun,Zhao, Fengyu
, p. 8 - 15 (2013)
Water as a clean solvent and promoter in the organic synthesis have attracted more attention, herein the effect of water was studied for the hydrogenation of o-chloronitrobenzene (o-CNB) over Pt/C and Pd/C catalysts in ethanol, n-heptane and compressed CO2. Very interesting, the reaction rate decreased in ethanol, but increased in n-heptane and compressed CO 2 with the addition of water. The role of water in the reaction was mainly discussed from the experimental data and phase behavior analysis, one is to activate the functional group of NO2 through the interactions via a hydrogen bonding, and the other is to affect the solubility of hydrogen in ethanol and n-heptane. The positive effect of the interaction between water and reactants may be counteracted by the negative effect of hydrogen solubility in ethanol. However, the concentration of o-CNB and hydrogen changed slightly in n-heptane with the addition of water, so the interaction of water with reactants may play a main role in improving the TOF. The combination of H2O and CO2 is more efficient than the pure H2O, CO 2 and H2O-n-heptane systems. The phase behavior may play important role also for the improved activity except for the interactions of H2O and CO2 with the reactants. o-CNB phase was expanded in the compressed CO2 and so the concentration of H2 in o-CNB phase increased due to the miscible of CO2 and H2, resulting in the enhancement of reaction rate and the maximum conversion at pressure of 9 MPa CO2, at which the volume was expanded to the largest one. The similar results were also obtained in the compressed CO 2 system without H2O. In addition, the stability of Pt/C and Pd/C was studied in H2O-n-heptane and H2O-CO 2. As a result, the H2O-CO2 media and Pt/C catalyst is one of the most effective systems for the hydrogenation of o-CNB.
Selective hydrogenation of chloronitrobenzene to chloroaniline in supercritical carbon dioxide over Ni/TiO2: Significance of molecular interactions
Meng, Xiangchun,Cheng, Haiyang,Fujita, Shin-ichiro,Hao, Yufen,Shang, Yanjiao,Yu, Yancun,Cai, Shuxia,Zhao, Fengyu,Arai, Masahiko
, p. 131 - 139 (2010)
The hydrogenation of chloronitrobenzene to chloroaniline was investigated over Ni/TiO2 at 35 °C in supercritical CO2 (scCO2), ethanol, and n-hexane. The reaction rate followed the order of scCO2 > n-hexane > eth
Chemoselective electrochemical reduction of nitroarenes with gaseous ammonia
Chang, Liu,Li, Jin,Wu, Na,Cheng, Xu
supporting information, p. 2468 - 2472 (2021/04/02)
Valuable aromatic nitrogen compounds can be synthesized by reduction of nitroarenes. Herein, we report electrochemical reduction of nitroarenes by a protocol that uses inert graphite felt as electrodes and ammonia as a reductant. Depending on the cell voltage and the solvent, the protocol can be used to obtain aromatic azoxy, azo, and hydrazo compounds, as well as aniline derivatives with high chemoselectivities. The protocol can be readily scaled up to >10 g with no decrease in yield, demonstrating its potential synthetic utility. A stepwise cathodic reduction pathway was proposed to account for the generations of products in turn.
The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
supporting information, p. 5680 - 5686 (2021/08/16)
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.