Nitro compounds aromatic, review

This review covers the personal view of the authors deduced from the literature starting in the middle of the Nineties with special emphasis on the very last years former examples of structure-sensitive reactions up to this date comprise, for example, the Pd-catalyzed hydrogenation of butyne, butadiene, isoprene [11], aromatic nitro compounds [12], and of acetylene to ethylene [13], In contrast, benzene hydrogenation over Pt catalysts is considered to be structure insensitive [14] the same holds true for acetonitrile hydrogenation over Fe/MgO [15], CO hydrogenation over Pd [16], and benzene hydrogenation over Ni [17]. For earlier reviews on this field we refer to Coq [18], Che and Bennett [9], Bond [7], as well as Ponec and Bond [20]. 

Electrocatalytic hydrogenation has the advantage of milder reaction conditions compared to catalytic hydrogenation. The development of various electrode materials (e.g., massive electrodes, powder cathodes, polymer film electrodes) and the optimization of reaction conditions have led to highly selective electrocatalytic hydrogenations. These are very suitable for the conversion of aliphatic and aromatic nitro compounds to amines and a, fi-unsaturated ketones to saturated ketones. The field is reviewed with 173 references in [158]. While the reduction of conjugated enones does not always proceed chemoselectively at a Hg cathode, the use of a carbon felt electrode coated with polyviologen/Pd particles provided saturated ketones exclusively (Fig. 34) [159]. 

Spectroscopic data of nitroaromatics have been reviewed D in addition, several papers on luminescence of nitroaromatic compounds have appeared recently. The phosphorescence polarization of several aromatic nitro compounds has been studied and recent triplet-triplet absorption data on 1- and 2-nitro-naphthalene have become available ). 

Many compounds have been tested as ignition quality improvers—additives which shorten the ignition delay to a desirable duration. An extensive review in 1944 (6, 43) listed 303 references, 92 dealing with alkyl nitrates and nitrites 61 with aldehydes, ketones, esters, and ethers 49 with peroxides 42 with aromatic nitro compounds 29, with metal derivatives 28 with oxidation and oxidation products 22 with polysulfides 16 with aromatic hydrocarbons nine with nitration and four with oximes and nitroso compounds. In 1950, tests at the U. S. Naval Engineering Experiment Station (48) showed that a concentration of 1.5% of certain peroxides, alkyl nitrates, nitroaikanes, and nitrocarbamates increased cetane number 20 or more units. 

The most studied kinds of explosives are nitroaromatic explosives and their metabolites. Therefore, the emphasis of this review is on properties of nitroaromatic explosives, rather than propellants, pyrotechnics, or munitions, and their interactions with soils. Nitroaromatic explosives are toxic, and their environmental transformation products, including arylamines, arylhydroxyl-amines, and condensed products such azoxy- and azo-compounds, are equally or more toxic than the parent nitroaromatic [3]. Aromatic amines and hydroxylamines are implicated as carcinogenic intermediates as a result of nitrenium ions formed by enzymatic oxidation [4], Aromatic nitro compounds... 

Nitro compounds were the objective of much research. Certain aspects of this field of organic chemistry are discussed in many monographs and reviews. Well known treatise is a monograph on the chemistry of nitro and nitroso groups edited by Feuer [1], The chemistry and technology of aromatic nitro compounds is considered in monographs [2-4], Much attention has been given to unsaturated [5], aliphatic and alicyclic nitro compounds [6],... 

Nitro compounds are versatile synthetic intermediates which have found widespread utility in industrial applications. Aromatic nitro compounds are the usual starting materials for commercial applications, but aliphatic compounds exhibit a greater diversity of chemical behavior under reducing conditions. " Nitroso compounds, hydroxylamines, oximes, amines, nitrones, ketones and silyl nitronates are frequently encountered during the reduction of nitro compounds. Several specialized reviews have appeared which highlight the versatility of the nitro group in organic chemistry. ... 

Numerous published papers have dealt with infra-red and Raman spectroscopy of nitro compounds. A general description is given in the monograph by Bellamy [26] and more recent reviews by Rao [27] and for non-aromatic nitro compounds by Novikov and co-authors [7]. 

Aromatic nitro compounds which in ortho position have azido group can readily be transformed into benzofuroxanes (31, 33). An excellent review on furoxanes was written by Kaufman and Picard [206]. Recent works on the structure of benzotrifuroxane were also published on X-ray analysis [207, 208), vibrational and Raman spectra [209 210], nitrogen NMR [211], carbon 13 NMR [212]. Explosive properties were also discussed [213]. 

Fields and Meyerson [127] have described in numerous papers the formation of free radicals from aromatic nitro compounds at temperatures of 400-600 C. Their work has been summarized in a review paper [128]. They found that the C — N bond in nitroaromatics breaks above 400 C generating phenyl and similar... 

An excellent review was given by Frolov, Kuznetsov and Hltsov [52] on the photoreduction of aromatic nitro compounds through intermolecular action. Alcohols and hydrochloric acid supply the hydrogen needed for reduction alcohols are converted into aldehydes, as in reaction (1) and hydrochloric acid... 

Topics that have formed the subjects of reviews this year include contemporary issues in electron transport research, dynamics of bimolecular photoelectron transfer reactions, photophysical properties of functionalised fullerene derivatives, carbon-carbon bond formation via radical ions, photoinduced electron transfer processes in ketone, aldehyde, and ester synthesis, photochemical reactions between arenenitriles and benzylic donors, photo-oxidation of conjugated dienes, photoredox reactions of aromatic nitro compounds, electron transfer-mediated photochemistry of some unsaturated nitrogen-containing compounds, reactions of 02( Ag), carbon dioxide activation by aza-macrocyclic complexes, and photochromism of chalcone derivatives. ... 

There have been numerous applications of controlled-potential coulometry to analysis. Many electrodeposition reactions that are the basis of electrogravimetric determinations can be employed in coulometry as well. However, some electrogravimetric determinations can be used when the electrode reactions occur with less than 100% current efficiency, for example, the plating of tin on a solid electrode. Coulometric determinations can, of course, also be based on electrode reactions in which soluble products or gases are formed (e.g., reduction of Fe(III) to Fe(II), oxidation of 1 to I2, oxidation of N2H4 to N2, reduction of aromatic nitro compounds). Many reviews concerned with controlled-potential coulometric analysis have appeared (1, 20-22) some typical applications are given in Table 11.3.2. 

Sulfonation of nitroso compounds by sodium hydrogen sulfite leads to amino sulfonic acids by simultaneous reduction.1240 194 When aromatic nitro compounds are subjected to this reaction, sulfonation in the ring is accompanied by formation of arylamine-JV-sulfonic acids (arylsulfamic acids), which on acid fission also give amino sulfonic acids this reaction, known in the literature as the Piria reaction, has been reviewed in papers by Hunter and his co-workers.195... 

Reviews relevant to this section which have been published within the year describe general photo-substitution reactions,72 and the mechanism of photoaddition-substitution reactions of six-membered aza-aromatic compounds,73 but both of these are in Russian. The reactions of aromatic nitro-compounds via their triplet states have received a very comprehensive review treatment hydrogen abstraction, reduction, incorporation of solvent fragments, and addition and substitution processes have been described for a wide variety of systems.74 In view ... 

Newman (1999) published a review of the known chemistry of caustic hydrolysis of energetic materials used in assembled chemical weapons, and recent work on the destruction of aromatic nitro compounds (TNT and tetryl) by alkaline hydrolysis has been reported (Bishop et al., 2000). 

In this review, we consider aromatic nitro compounds (nitroarenes) with the vacant orf/io-position relative to the nitro group, as a basis for the synthesis of condensed nitrogen heterocycles (benzo-annelated N-heterocycles) (Scheme 1). 

Recent advances in developing important intermediate aromatic nitro compounds, useful in synthetic organic chemistry, have been reviewed. This article includes topics such as the nitration of aromatic hydrocarbons, aryl boronic acids, aryl halides and pseudohalides, aryl carboxylic acids, and the oxidation of aryl primary amines and azide. ... 

There has been a major review of substitution by the radical-chain 5rn1 mechanism. It has been shown that reaction by the SrnI pathway of the enolate anions of 2- and 3-acetyl-l-methylpyrrole may yield a-substituted acetylpyrroles. The dichotomy of reactions of halonitrobenzenes with nucleophiles has been nicely summarized major pathways include reduction via radical pathways and. SnAt substitution of halogen. EPR spectroscopy has been used to detect radical species produced in the reactions of some aromatic nitro compounds with nucleophiles however, whether these species are on the substitution pathway is questionable. The reaction of some 4-substimted N,N-dimethylanilines with secondary anilines occurs on activation by thallium triacetate to yield diphenylamine derivatives radical cation intermediates are proposed. ... 

A wide range of mechanisms are involved in the degradation and transformation of aromatic compounds with nitro substituents. These include reduction of the nitro group, and dioxygenation, monooxygenation, and reduction of the aromatic ring. A review devoted to 2,4,6-trinitrotolune is available (Esteve-Nunez et al. 2001). 

Photoreduction of aromatic and aliphatic nitro compounds gives hydroxylamines or amines, which is well reviewed.125 The radical reaction of primary nitro compounds with tin hydride does not give the denitrated product (see Chapter 7), but give the corresponding oximes (Eq. 

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