Zur Oxydation von Anilin und substituierten Anilinen mit Hydroperoxiden

Kosswig, K.

doi:10.1002/jlac.19717490125

Cited by 28 publications

(3 citation statements)

References 3 publications

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“…The oxidation of aromatic amines may produce a large number of products. The most important of them are phenylhydroxylamine, nitrosobenzene, nitrobenzene, azobenzene, azoxybenzene, and oligomers and polymers of aniline. − In the past two decades, relatively long-lived chromium(V) intermediates have been detected in the reaction of Cr(VI) both in vivo and in vitro. Since Cr(V) intermediates are generally considered labile and reactive, this chromium species is considered to be the key species in the mechanism of Cr(VI) carcinogenesis.…”

Section: Introductionmentioning

confidence: 99%

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

et al. 2004

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The kinetics of oxidation of 16 meta-, ortho-, and para-substituted anilines with nine oxo(salen)chromium(V) ions have been studied by spectrophotometric, ESIMS, and EPR techniques. During the course of the reaction, two new peaks with lambda(max) at 470 and 730 nm appear in the absorption spectrum, and these peaks are due to the formation of emeraldine forms of oligomers of aniline supported by the ESIMS peaks with m/z values 274 and 365 (for the trimer and tetramer of aniline). The rate of the reaction is highly sensitive to the change of substituents in the aryl moiety of aniline and in the salen ligand of chromium(V) complexes. Application of the Hammett equation to analyze kinetic data yields a rho value of -3.8 for the substituent variation in aniline and +2.2 for the substituent variation in the salen ligand of the metal complex. On the basis of the spectral, kinetic, and product analysis studies, a mechanism involving an electron transfer from the nitrogen of aniline to the metal complex in the rate controlling step has been proposed. The Marcus equation has been successfully applied to this system, and the calculated values are compliant with the measured values.

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Section: Introductionmentioning

confidence: 99%

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

et al. 2004

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“…The herein presented catalytic protocol arose while studying the oxidation of aryl amines by hydrogen peroxide (H 2 O 2 ) in the presence of metal oxide catalysts. Precedent is the first work by Kosswing who investigated the transformation of aniline into azoxybenzene on Ti IV substances using t BuOOH 16a. Later on, Tuel and co‐worker studied the oxidation of aniline with H 2 O 2 and tert ‐butyl hydroperoxide ( t BuOOH) in the presence of various titanium silicalite catalysts.…”

Section: Resultsmentioning

confidence: 99%

Reversible Light‐Driven Polymerization of Polyoxometalate Tethered with Coumarin Molecules

Tong

Chen

Ritchie

et al. 2014

Chemistry A European J

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A new photosensitive polyoxometalate (POM) organic-inorganic hybrid compound has been prepared by covalently tethering coumarin moieties onto a Mn-Anderson cluster. This compound has been fully characterized by (1)H NMR, (13)C NMR, FTIR, and UV/Vis spectroscopy, and ESI-MS. This organic-inorganic hybrid compound can undergo reversible light-driven polymerization and this process has been characterized in detail.

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“…Dimeric products such as azo-or azoxy-derivatives 9,13a as well as over-oxidation to the nitro compounds 7,10,11 were often observed as by-products or sometimes as main products. 6,14 Some methods for the direct oxidation of aromatic amines to nitro derivatives were described with peracids, 15 and more recently with dioxirane, 16 tert-butyl peroxide or H 2 O 2 as oxidants and metal peroxocomplexes (Mo, 17 W, 6,10,11 V, 17 Zr, 12 Re 18 ) or with chromium silicalit 13 as catalyst.…”

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confidence: 99%

Simple Preparation of Nitroso Benzenes and Nitro Benzenes by Oxidation of Anilines with H₂O₂Catalysed with Molybdenum Salts

Defoin¹

2004

Synthesis

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Nitroso arenes 2a-k are prepared in 53-80% yield from anilines 1a-k by oxidation with H 2 O 2 catalysed with MoO 3 /KOH, ammonium molybdate or other molybdenum salts. Further oxidation to nitro arenes 3a,d,j in 66-90% is also described.Classic methods for the preparation of aromatic nitroso compounds are oxidation of anilines with peracids, 1 particularly Caro acid, 2 peracetic acid, 1 perbenzoic acid, 3,4 trifluoroperacetic acid 5 or more recently molybdic peroxo-complexes. 6 Catalytic methods using H 2 O 2 or tertbutyl peroxide as oxidant and sodium tungstate, 7 oxomolybdate complexes, 8 phosphotungstate, 9-11 phosphomolybdate 10,11 or zirconate salts 12 were published later. Dimeric products such as azo-or azoxy-derivatives 9,13a as well as over-oxidation to the nitro compounds 7,10,11 were often observed as by-products or sometimes as main products. 6,14 Some methods for the direct oxidation of aromatic amines to nitro derivatives were described with peracids, 15 and more recently with dioxirane, 16 tert-butyl peroxide or H 2 O 2 as oxidants and metal peroxocomplexes (Mo, 17 W, 6,10,11 V, 17 Zr, 12 Re 18 ) or with chromium silicalit 13 as catalyst.We describe herein a simple oxidation method of anilines, resulting in the corresponding nitroso compounds using 30% H 2 O 2 and molybdenum trioxide or other molybdenum salts as catalyst without the formation of azo-or azoxy-derivatives. Further oxidation to nitro compounds was examined in some cases. Oxidation of Anilines to Nitroso ArenesOxidation of anilines 1a-k was carried out in a watermethanol solution in which the anilines were only slightly soluble but the resulting nitroso compounds 2a-g,j,k were insoluble and could be isolated by filtration (Scheme 1). Side-reactions such as formation of nitro derivatives and dimeric compounds such as azo-or azoxy-derivatives was also minimised. This method appeared to be better than the previous two-phase preparation. 4,8,9,11 A complete oxidation and a sufficient reaction rate required an excess of H 2 O 2 (4 equiv) and 0.1 mol of molybdic derivative per 1 mol of aniline, smaller proportions of oxidant or catalyst led to slower or incomplete reactions and favoured the formation of azo-azoxy-or coloured-compounds. Scheme 1 a) Dependence on the pH-Valuep-Chloroaniline 1a was used as the model compound and the standard catalyst was 10 mol% MoO 3 in the presence of KOH as the base, which was added in various quantities. Oxidation of p-chloroaniline is very dependent on MoO 3 /KOH molar ratio. The results are listed in Table 1, and summarised here.-With MoO 3 only without added base, the oxidation occurred cleanly, but the progress of the reaction was slow (15% reaction after 1 d).-With MoO 3 and 1-1.8 equiv KOH, the oxidation rate increased with the concentration of base, but coloured impurities were formed when 1.5-1.8 equiv of base (pH value 5-7) were added. The best condition for the oxidation to the nitroso compound was with 1-1.2 equiv KOH, then the oxidation occurred cleanly and gave good yields (86-94%) of the nitro...

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Zur Oxydation von Anilin und substituierten Anilinen mit Hydroperoxiden

Cited by 28 publications

References 3 publications

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

Reversible Light‐Driven Polymerization of Polyoxometalate Tethered with Coumarin Molecules

Simple Preparation of Nitroso Benzenes and Nitro Benzenes by Oxidation of Anilines with H₂O₂Catalysed with Molybdenum Salts

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Zur Oxydation von Anilin und substituierten Anilinen mit Hydroperoxiden

Cited by 28 publications

References 3 publications

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

Reversible Light‐Driven Polymerization of Polyoxometalate Tethered with Coumarin Molecules

Simple Preparation of Nitroso Benzenes and Nitro Benzenes by Oxidation of Anilines with H2O2Catalysed with Molybdenum Salts

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Simple Preparation of Nitroso Benzenes and Nitro Benzenes by Oxidation of Anilines with H₂O₂Catalysed with Molybdenum Salts