The Experts below are selected from a list of 426 Experts worldwide ranked by ideXlab platform
Lei Wang - One of the best experts on this subject based on the ideXlab platform.
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merging visible light photocatalysis and palladium catalysis for c h acylation of azo and Azoxybenzenes with α keto acids
ChemInform, 2016Co-Authors: Zuguang Xie, Lei WangAbstract:An efficient C—H acylation of azo- and Azoxybenzenes with aromatic α-keto acids is developed combining palladium and visible-light photoredox catalysis under blue LED irradiation.
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merging visible light photocatalysis and palladium catalysis for c h acylation of azo and Azoxybenzenes with α keto acids
Chemistry: A European Journal, 2016Co-Authors: Zuguang Xie, Lei WangAbstract:An efficient C-H acylation of azo- and Azoxybenzenes with α-keto acids has been developed by a combination of palladium catalysis and visible-light photoredox catalysis at room temperature under 1.5 W blue LED irradiation. This method tolerates a variety of disubstituted azo- and Azoxybenzenes, as well as α-keto acids regardless of the nature of the substituents. A number of aryl ketones were obtained in good yields under mild reaction conditions.
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a green chemoenzymatic process for the synthesis of Azoxybenzenes
Chemcatchem, 2015Co-Authors: Fengjuan Yang, Zhi Wang, Xiaowen Zhang, Liyan Jiang, Lei WangAbstract:An efficient chemoenzymatic process for the synthesis of Azoxybenzenes was developed. A peracid was generated in situ by Novozym 435, and then a range of anilines were oxidized by the produced peracid to afford Azoxybenzenes in yields ranging from 63.1 to 94.1 %. This method expands the application of lipase in organic synthesis and provides an alternative method for the synthesis of Azoxybenzenes.
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palladium catalyzed direct ortho ethoxycarbonylation of azobenzenes and Azoxybenzenes with diethyl azodicarboxylate
Organic and Biomolecular Chemistry, 2015Co-Authors: Yicheng Zhang, Lei WangAbstract:A palladium-catalyzed direct ortho-ethoxycarbonylation of azobenzenes and Azoxybenzenes with diethyl azodicarboxylate (DEAD) was developed. In the presence of Cu(OAc)2 or (NH4)2S2O8 as the oxidant, this protocol allowed using both electron-deficient and electron-rich azobenzenes and Azoxybenzenes to produce the corresponding products in moderate to good yields.
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unprecedented ortho acylation of Azoxybenzenes with α oxocarboxylic acids by pd catalyzed c h activation and decarboxylation
Chemical Communications, 2013Co-Authors: Qiong Zhao, Lei WangAbstract:A palladium-catalyzed ortho-acylation reaction of Azoxybenzenes with α-oxocarboxylic acids was developed in the presence of K2S2O8. The established methodology provides a direct approach to obtain acylated Azoxybenzenes in good yields.
Rajaram Bal - One of the best experts on this subject based on the ideXlab platform.
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low temperature catalytic oxidation of aniline to Azoxybenzene over an ag fe2o3 nanoparticle catalyst using h2o2 as an oxidant
New Journal of Chemistry, 2019Co-Authors: Bappi Paul, Siddhartha Sankar Dhar, Sachin K Sharma, Shubhadeep Adak, Rubina Khatun, Gurmeet Singh, Dipak Das, Vedant Joshi, Sahil Bhandari, Rajaram BalAbstract:An in situ modified hydrothermal synthesis of Ag/Fe2O3 nanoparticles (NPs) and studies of their catalytic activity as a simple, eco-friendly and recyclable catalyst for one-pot conversion of aniline to Azoxybenzene were performed. The as-synthesized nanostructured material was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), SEM-mapping, temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherms (BET), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma–atomic emission spectroscopy (ICP-AES), ultraviolet-visible spectroscopy (UV-vis) and vibrating sample magnetometer spectroscopy (VSM). The most active and recyclable catalyst with 2–5 nm diameters of the metallic Ag particles supported on 10–50 nm Fe2O3 nanoparticles was formed with a silver loading of 1.8 wt%. A high turnover number of ∼592 was achieved with 92% conversion of aniline and 94% selectivity towards the target product Azoxybenzene under atmospheric conditions. The effects of various reaction parameters including the reaction time, temperature and substrate to H2O2 molar ratio were screened and studied in detail. The results reveal the role of a synergistic effect between the surface Ag nanoparticles and Fe2O3 nanospheres for high catalytic activity.
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room temperature selective oxidation of aniline to Azoxybenzene over a silver supported tungsten oxide nanostructured catalyst
Green Chemistry, 2015Co-Authors: Shilpi Ghosh, Shankha S Acharyya, Takehiko Sasaki, Rajaram BalAbstract:Heterogeneous catalysts comprising silver nanoparticles supported on nanostructured tungsten oxide were applied for room temperature oxidative coupling of aniline to Azoxybenzene, an important chemical intermediate and a chemical of industrial interest. The catalytic protocol features high activity and selectivity to the target product Azoxybenzene with a turnover number of ∼368. The catalyst was characterized by XRD, XPS, ICP-AES, FT-IR, TGA, EXAFS, SEM and TEM. The silver-tungsten nanomaterial acts as an excellent catalyst for selective oxidation of aniline to Azoxybenzene using H2O2 as an oxidant. An aniline conversion of 87% with 91% selectivity of Azoxybenzene was achieved without the use of any external additives. Moreover, a high stability and recyclability of the catalyst is also observed under the investigated conditions.
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catalytic oxidation of aniline to Azoxybenzene over cucr2o4 spinel nanoparticle catalyst
ACS Sustainable Chemistry & Engineering, 2014Co-Authors: Shankha S Acharyya, Shilpi Ghosh, Rajaram BalAbstract:Cationic surfactant cetyltrimethylammonium chloride-mediated hydrothermal preparation of CuCr2O4 spinel nanoparticles has been reported. This CuCr2O4 spinel nanoparticle catalyst has been characterized by XRD, XPS, SEM, TEM, TGA, and ICP-AES. Characterization results showed the formation of CuCr2O4 spinel nanoparticles with sizes between 25 and 50 nm. It was found that the catalyst can selectively convert aniline to Azoxybenzene with H2O2 as oxidant. The effect of different reaction parameters like reaction temperature, H2O2 to aniline molar ratio, reaction time, and so forth have been studied in detail. An aniline conversion of 78% with Azoxybenzene selectivity of 92% can be achieved over this catalyst at 70 °C. The catalyst did not show any leaching up to five reuses, showing the true heterogeneity of the catalyst. However, significant H2O2 decomposition occurs on the catalyst necessitating its usage in five-fold excess.
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Catalytic Oxidation of Aniline to Azoxybenzene Over CuCr2O4 Spinel Nanoparticle Catalyst
2014Co-Authors: Shankha S. Acharyya, Shilpi Ghosh, Rajaram BalAbstract:Cationic surfactant cetyltrimethylammonium chloride-mediated hydrothermal preparation of CuCr2O4 spinel nanoparticles has been reported. This CuCr2O4 spinel nanoparticle catalyst has been characterized by XRD, XPS, SEM, TEM, TGA, and ICP-AES. Characterization results showed the formation of CuCr2O4 spinel nanoparticles with sizes between 25 and 50 nm. It was found that the catalyst can selectively convert aniline to Azoxybenzene with H2O2 as oxidant. The effect of different reaction parameters like reaction temperature, H2O2 to aniline molar ratio, reaction time, and so forth have been studied in detail. An aniline conversion of 78% with Azoxybenzene selectivity of 92% can be achieved over this catalyst at 70 °C. The catalyst did not show any leaching up to five reuses, showing the true heterogeneity of the catalyst. However, significant H2O2 decomposition occurs on the catalyst necessitating its usage in five-fold excess
Olivier Guillou - One of the best experts on this subject based on the ideXlab platform.
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a new family of lanthanide based coordination polymers with Azoxybenzene 3 3 5 5 tetracarboxylic acid as ligand
Inorganica Chimica Acta, 2019Co-Authors: Jinzeng Wang, Carole Daiguebonne, Yan Suffren, Thierry Roisnel, Stephane Freslon, Guillaume Calvez, Kevin Bernot, Olivier GuillouAbstract:Abstract Reactions by solvothermal methods of lanthanide nitrates and Azoxybenzene-3,3′,5,5′-tetracarboxylic acid (H4aobtc) lead to a family of isostructural lanthanide-based coordination polymers with general chemical formula [Ln(Haobtc)(H2O)2·2H2O]∞ with Ln = Nd − Er plus Y. The crystal structure has been solved on the basis of the Y3+-derivative. It crystallizes in the triclinic system, space group P-1 (n°2) with the following cell parameters: a = 6.6890(18) A, b = 10.052(3) A, c = 13.879(4) A,α = 75.756(9)°, β = 77.551(9)°, γ = 83.964(9)° and Z = 2. The crystal structure is two-dimensional (2D). Thermal properties and luminescent properties of the Nd3+-containing compound have been studied.
Jinzeng Wang - One of the best experts on this subject based on the ideXlab platform.
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a new family of lanthanide based coordination polymers with Azoxybenzene 3 3 5 5 tetracarboxylic acid as ligand
Inorganica Chimica Acta, 2019Co-Authors: Jinzeng Wang, Carole Daiguebonne, Yan Suffren, Thierry Roisnel, Stephane Freslon, Guillaume Calvez, Kevin Bernot, Olivier GuillouAbstract:Abstract Reactions by solvothermal methods of lanthanide nitrates and Azoxybenzene-3,3′,5,5′-tetracarboxylic acid (H4aobtc) lead to a family of isostructural lanthanide-based coordination polymers with general chemical formula [Ln(Haobtc)(H2O)2·2H2O]∞ with Ln = Nd − Er plus Y. The crystal structure has been solved on the basis of the Y3+-derivative. It crystallizes in the triclinic system, space group P-1 (n°2) with the following cell parameters: a = 6.6890(18) A, b = 10.052(3) A, c = 13.879(4) A,α = 75.756(9)°, β = 77.551(9)°, γ = 83.964(9)° and Z = 2. The crystal structure is two-dimensional (2D). Thermal properties and luminescent properties of the Nd3+-containing compound have been studied.
Takeo Konakahara - One of the best experts on this subject based on the ideXlab platform.
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highly selective conversion of nitrobenzenes using a simple reducing system combined with a trivalent indium salt and a hydrosilane
ChemInform, 2010Co-Authors: Norio Sakai, Kohji Fujii, Shinya Nabeshima, Reiko Ikeda, Takeo KonakaharaAbstract:The reducing system consisting of a trivalent indium salt and a hydrosilane allows the selective conversion of aromatic nitro compounds (I) into Azoxybenzenes (II), azobenzenes (III), diarylhydrazines (IV) and anilines (V).
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highly selective conversion of nitrobenzenes using a simple reducing system combined with a trivalent indium salt and a hydrosilane
Chemical Communications, 2010Co-Authors: Norio Sakai, Kohji Fujii, Shinya Nabeshima, Reiko Ikeda, Takeo KonakaharaAbstract:Controlling the type of indium salt and hydrosilane enables a highly selective reduction of aromatic nitro compounds into three coupling compounds, Azoxybenzenes, azobenzenes and diphenylhydrazines, and one reductive compound, anilines.