51789-07-2

Upstream product

• 332-07-0 bis-(4-fluorophenyl)diazene 
• 371-40-4 4-fluoroaniline 
• 332-06-9 (4,4'-difluoro)-1,2-diphenylhydrazine 
• 7022-92-6 (15N)-aniline 
• 352-15-8 4-fluoro-nitrosobenzene 
• 332-07-0 (E)-bis(4-fluorophenyl)diazene 
• 350-46-9 4-Fluoronitrobenzene 

Downstream Products

• 332-06-9 (4,4'-difluoro)-1,2-diphenylhydrazine 
• 332-07-0 bis-(4-fluorophenyl)diazene 
• 81701-86-2 5-fluoro-2-(4-fluorophenylazo)phenol 
• 81701-82-8 C₁₂H₈F₂N₂O 
• 1545-85-3 4-hydroxyphenylazo-4'-fluorobenzene 
• 81701-84-0 C₁₄H₁₀F₂N₂O₂ 
• 120455-03-0 5-methoxy-2-phenyl-2H-indazole 
• 120455-06-3 5-methoxy-2-(4-methoxyphenyl)-2H-indazole 
• 1562-94-3 4,4'-dimethoxyazoxybenzene 
• 1689-82-3 4-hydroxyazobenzene 
• 2396-60-3 4-methoxyazobenzene 
• 2050-16-0 4,4'-dihydroxyazobenzene 
• 371-40-4 4-fluoroaniline 
• 1456728-88-3 C₁₉H₁₂F₂N₂O₂ 

Relevant academic research and scientific papers

Nb2O5 supported on mixed oxides catalyzed oxidative and photochemical conversion of anilines to azoxybenzenes

The synthesis of novel supported niobium oxide catalysts and their application for aniline conversion to azoxybenzenes is described. The catalysts were successfully prepared by thermal decomposition of layered double hydroxides (LDHs), containing M2+ (M = Mg2+ and/or Zn2+) and Al3+ as layer cations, followed by niobium oxide incorporation employing the wetness impregnation method. These catalysts were fully characterized by both experimental techniques and theoretical calculations, and then successfully applied to the selective conversion of anilines into azoxybenzene derivatives, with up to 98% conversion and 92% isolated yield in the presence of violet light. Control experiments and DFT calculations revealed that the catalyst has a dual role in this transformation, acting both as a Lewis acid in the oxidative step and as a photocatalyst in the dimerization of the nitrosobenzene intermediate.

Selective Oxidation of Anilines to Azobenzenes and Azoxybenzenes by a Molecular Mo Oxide Catalyst

Aromatic azo compounds, which play an important role in pharmaceutical and industrial applications, still face great challenges in synthesis. Herein, we report a molybdenum oxide compound, [N(C4H9)4]2[Mo6O19] (1), catalyzed selective oxidation of anilines with hydrogen peroxide as green oxidant. The oxidation of anilines can be realized in a fully selectively fashion to afford various symmetric/asymmetric azobenzene and azoxybenzene compounds, respectively, by changing additive and solvent, avoiding the use of stoichiometric metal oxidants. Preliminary mechanistic investigations suggest the intermediacy of highly active reactive and elusive Mo imido complexes.

SO2F2-mediated oxidation of primary and tertiary amines with 30% aqueous H2O2 solution

A highly efficient and selective oxidation of primary and tertiary amines employing SO2F2/H2O2/base system was described. Anilines were converted to the corresponding azoxybenzenes, while primary benzylamines were transformed into nitriles and secondary benzylamines were rearranged to amides. For tertiary amine substrates quinolines, isoquinolines and pyridines, their oxidation products were the corresponding N-oxides. The reaction conditions are very mild and just involve SO2F2, amines, 30% aqueous H2O2 solution, and inorganic base at room temperature. One unique advantage is that this oxidation system is just composed of inexpensive inorganic compounds without the use of any metal and organic compounds.

Chemoselective electrochemical reduction of nitroarenes with gaseous ammonia

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.

Tandem selective reduction of nitroarenes catalyzed by palladium nanoclusters

We report a catalytic tandem reduction of nitroarenes by sodium borohydride (NaBH4) in aqueous solution under ambient conditions, which can selectively produce five categories of nitrogen-containing compounds: anilines, N-aryl hydroxylamines, azoxy-, azo- and hydrazo-compounds. The catalyst is in situ-generated ultrasmall palladium nanoclusters (Pd NCs, diameter of 1.3 ± 0.3 nm) from the reduction of Pd(OAc)2 by NaBH4. These highly active Pd NCs are stabilized by surface-coordinated nitroarenes, which inhibit the further growth and aggregation of Pd NCs. By controlling the concentration of Pd(OAc)2 (0.1-0.5 mol% of nitroarene) and NaBH4, the water/ethanol solvent ratio and the tandem reaction sequence, each of the five categories of N-containing compounds can be obtained with excellent yields (up to 98%) in less than 30 min at room temperature. This tunable catalytic tandem reaction works efficiently with a broad range of nitroarene substrates and offers a green and sustainable method for the rapid and large-scale production of valuable N-containing chemicals.

Low-temperature catalytic oxidation of aniline to azoxybenzene over an Ag/Fe2O3 nanoparticle catalyst using H2O2 as an oxidant

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.

Method for synthesizing oxidized azo compound through selective oxidation of aromatic amine

The invention discloses a method for synthesizing an oxidized azo compound through selective oxidation of an aromatic amine, wherein an aromatic amine is used as a raw material, hydrogen peroxide is used as an oxidizing agent, a titanium-silicon molecular sieve or a metal modified titanium-silicon molecular sieve is used as a catalyst, and the aromatic amine is subjected to selective catalytic oxidation to prepare the corresponding oxidized azobenzene compound. According to the present invention, the method has advantages of environmental protection, good selectivity, high product yield, easyseparation and recycling of the catalyst, simple instrument required by the reaction, and easy operation.

Highly selective reduction of nitrobenzenes to azoxybenzenes with a copper catalyst

A convenient protocol for highly selective delivery of azoxybenzenes from reduction of nitrobenzenes was developed by utilizing a copper catalyst. A variety of functional groups and substitution were well tolerated.

A Highly Selective Amidation of Azoxybenzenes with Sulfonamides via Rhodium(III)-Catalyzed C-H Activation

A new amidation of azoxybenzenes with sulfonamides catalyzed by a rhodium(III) salt has been developed. This sulfonamidation proceeds efficiently under mild reaction conditions to generate new C-N bonds through C-H bond activation and functionalization, affording the corresponding 2-sulfonamidoazoxybenzenes in good yields with high regioselectivity.

Organocatalytic oxidation of substituted anilines to azoxybenzenes and nitro compounds: Mechanistic studies excluding the involvement of a dioxirane intermediate

An organocatalytic and environmentally friendly approach for the selective oxidation of substituted anilines was developed. Utilizing a 2,2,2-trifluoroacetophenone-mediated oxidation process, substituted anilines can be transformed into azoxybenzenes, while a simple treatment with MeCN and H2O2 leads to the corresponding nitro compounds, providing user-friendly protocols that can be easily scaled up. Various substitution patterns and functional groups were tolerated leading to products in high to excellent yields. Mechanistic studies utilizing HRMS provide clear evidence for the distinct mechanistic intermediates that are involved. This study constitutes an indirect proof excluding the involvement of a dioxirane intermediate in the green organocatalytic oxidation, utilizing 2,2,2-trifluoroacetophenone as the catalyst.