51789-00-5

Upstream product

• 106-49-0 p-toluidine 
• 371-40-4 4-fluoroaniline 
• 108-42-9 3-chloro-aniline 
• 350-46-9 4-Fluoronitrobenzene 
• 108-44-1 1-amino-3-methylbenzene 
• 326-04-5 N,N'-Bis-(4-fluoro-phenyl)-diazene N-oxide 
• 58-27-5 menadione 
• 352-15-8 4-fluoro-nitrosobenzene 
• 1073-69-4 N-4-chlorophenylhydrazine 
• 332-07-0 (E)-bis(4-fluorophenyl)diazene 
• 3382-69-2 C₁₄H₁₂FNO₂ 
• 1545-83-1 4-fluoroazobenzene 
• 3296-02-4 p-azidofluorobenzene 
• 106-40-1 4-bromo-aniline 

Downstream Products

• 332-06-9 (4,4'-difluoro)-1,2-diphenylhydrazine 
• 150207-14-0 η2-N,N-di(4-fluorophenyl)diazene-tris(trimethylphosphine)cobalt(0) 
• 1239969-18-6 C₁₉H₂₂F₂N₂Si 
• 1595026-04-2 2-(4-methylphenylsulfonamido)-4,4'-difluoroazobenzene 
• 81701-86-2 5-fluoro-2-(4-fluorophenylazo)phenol 
• 326-04-5 N,N'-Bis-(4-fluoro-phenyl)-diazene N-oxide 
• 1128-61-6 6-fluoro-2-methyl-quinoline 
• 367-25-9 2,4-difluorophenylamine 
• 1545-83-1 4-fluoroazobenzene 

Relevant academic research and scientific papers

Correlation studies in the oxidation of Vanillin Schiff bases by acid bromate - A kinetic and semi-empirical approach

Kinetics and mechanistic aspects of oxidation of Vanillin Schiff bases (obtained from Vanillin and p-substituted anilines) by bromate in acid medium has been studied at 313 ?K. The reaction exhibited first order in [bromate] and less than unity order each in [Vanillin Schiff base] and [acid]. The increase in the rate of reaction with decrease in dielectric constant of the medium is observed with all the studied substrates. The reaction failed to induce the polymerization of acrylonitrile. Electron withdrawing substituents in the aniline ring moiety of Vanillin Schiff base accelerate the rate of oxidation to a large extent and electron releasing substituents retard the rate. The order of reactivity is found to be p-nitro ?> ?p-bromo ?> ?p-chloro ?> ?–H ?> ?p-fluoro ?> ?p-methyl ?> ?p-methoxy ?> ?p-ethoxy and the sensitivity of the substrates towards the reaction rate is further supported by the semi-empirical calculation of electronic properties and global descriptors of the substrates (Vanillin Schiff bases) with different substituents in the aniline ring moiety. The observed trend in the reactivity of the substrates was correlated with the calculated descriptors like electronegativity, chemical potential, electrophilicity index, chemical hardness and frontier molecular orbitals. The linear free-energy relationship is characterized by a straight line in the Hammett's plot of log k versus σ. The ρ values are positive and increase with increase in temperature. From the Exner and Arrhenius plots, the isokinetic relationship is discussed. Oxidation products identified are p-substituted azobenzene and vanillic acid. Based on the experimental observations, a plausible mechanism is proposed and rate law is derived.

Invisible Silver Guests Boost Order in a Framework That Cyclizes and Deposits Ag3Sb Nanodots

The infusion of metal guests into (i.e., metalating) the porous medium of metal-organic frameworks (MOFs) is a topical approach to wide-ranging functionalization purposes. We report the notable interactions of AgSbF6 guests with the designer MOF host ZrL1 [Zr6O4(OH)7(L1)4.5(H2O)4]. (1) The heavy-atom guests of AgSbF6 induce order in the MOF host to allow the movable alkyne side arm to be fully located by X-ray diffraction, but they themselves curiously remain highly disordered and absent in the strucutral model. The enhanced order of the framework can be generally ascribed to interaction of the silver guests with the host alkyne and thioether functions, while the invisible heavy-atom guest represents a new phenomenon in the metalation of open framework materials. (2) The AgSbF6 guests also participate in the thermocyclization of the vicinal alkyne units of the L1 linker (at 450 °C) and form the rare nanoparticle of Ag3Sb supported on the concomitantly formed nanographene network. The resulted composite exhibits high electrical conductivity (1.0 S/cm) as well as useful, mitigated catalytic activity for selectively converting nitroarenes into the industrially important azo compounds, i.e., without overshooting to form the amine side products. The heterogeneous/cyclable catalysis entails only the cheap reducing reagents of NaBH4, ethanol, and water, with yields being generally close to 90%.

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.

Manganese Catalyzed Hydrogenation of Azo (N=N) Bonds to Amines

We report the first example of homogeneously catalyzed hydrogenation of the N=N bond of azo compounds using a complex of an earth-abundant-metal. The hydrogenation reaction is catalyzed by a manganese pincer complex, proceeds under mild conditions, and yields amines, which makes this methodology a sustainable alternative route for the conversion of azo compounds. A plausible mechanism involving metal-ligand cooperation and hydrazine intermediacy is proposed based on mechanistic studies. (Figure presented.).

Cu(OTf)2-Mediated Cross-Coupling of Nitriles and N-Heterocycles with Arylboronic Acids to Generate Nitrilium and Pyridinium Products**

Metal-catalyzed C–N cross-coupling generally forms C?N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C–N cross-coupling that uses a dative N-ligand in the bond-forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a CuII complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative CuIII complex enables the oxidative C–N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp2) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.

Photocatalytic oxidative coupling of arylamines for the synthesis of azoaromatics and the role of O2 in the mechanism

The photocatalytic oxidative coupling of aryl amines to selectively synthesize azoaromatic compounds has been realized. Multiple different photocatalysts can be used to perform the general reaction; however, Ir(dF-CF3-ppy)2(dtbpy)+, where dF-CF3-ppy is 2-(2,4-difluorophenyl)-5-(trifluoromethyl)-pyridine and dtpby is 4,4′-tert-butyl-2,2′-bipyridine, showed the greatest range of reactivity with various amine substrates. Both electron-rich and -deficient amines can be coupled with yields up to 95% under an ambient air atmosphere. Oxygen was deemed to be essential for the reaction and is utilized in the regeneration of the photocatalyst. Fluorescence quenching and radical trap experiments indicate an amine radical coupling mechanism that proceeds through a hydrazoaromatic intermediate before further oxidation occurs to form the desired azoaromatic products.

Hydrogen peroxide based oxidation of hydrazines using HBr catalyst

Azo compounds (RN = NR′) are an important class of organic molecules that find wide application in organic synthesis. Herein, we report an efficient, practical and metal-free oxidation of hydrazines (RNH-NHR’) to azo compounds using 5 mol% HBr and hydrogen peroxide as terminal oxidant. This new method has been demonstrated by 40 examples with excellent yields. In addition, we showcased two examples of the one-pot sequential reactions involving our hydrazine oxidation/hydrolysis/Heck reaction or Cu-catalyzed N-arylation with aryl boronic acid. The distinct advantages of this protocol include metal-free catalysis, waste prevention, and easy operation.

Azo synthesis meets molecular iodine catalysis

A metal-free synthetic protocol for azo compound formation by the direct oxidation of hydrazine HN-NH bonds to azo group functionality catalyzed by molecular iodine is disclosed. The strengths of this reactivity include rapid reaction times, low catalyst loadings, use of ambient dioxygen as a stoichiometric oxidant, and ease of experimental set-up and azo product isolation. Mechanistic studies and density functional theory computations offering insight into this reactivity, as well as the events leading to azo group formation are presented. Collectively, this study expands the potential of main-group element iodine as an inexpensive catalyst, while delivering a useful transformation for forming azo compounds.

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.

Selective Propargylation of Diaryl Azo Compounds Using Metallic Barium

The Barbier-type propargylation of azo compounds with α,γ-disubstituted propargylic tosylates was achieved by using metallic barium as the promoter. Various propargylated hydrazines (α-adducts) were exclusively synthesized from the corresponding propargylic tosylates and azobenzenes (diaryldiazenes). The thus-obtained propargylic hydrazines were further efficiently converted into propargylic amines by reductive N-N bond cleavage. Benzidine rearrangement of the propargylic hydrazines was also attempted.