Nitrous oxide catalysed

C.,g and C20 fatty acids of the (n-9), (n-6) and (n-3) families are the most abundant trienoic fatty acids in animal tissues they elute in this order on polar stationary phases and some ECL data are contained in Table 5.3. All of the eight possible geometrical isomers of 9,12,15-octadecatrienoic acid (a-linolenic acid) have been prepared by nitrous oxide-catalysed elaidinisation [21-23,815] and by total synthesis [747]. Ackman and Hooper [21-23] were able to predict their ECL values, from data for the appropriate monoenes obtained on a WCOT column coated with Silar 5CP , by applying diethylenic... 

Hanson, C. et al., Proc. Int. Solvent Extr. Conf. (Liege), 1980, 2, paper 80-70 The solvent ( Butex ), an extractant in nuclear reprocessing may decompose violently in contact with nitric acid. Hydrolysis to butanol, followed by violent oxidation, catalysed by nitrous acid, is involved. 

Ph,P)4Pd(0) and quaternary ammonium salts catalyse the oxidation of benzylic halides by nitrous oxide in a basic medium into O-benzylic ethers of the corresponding aryl aldoximes, ArCH=NOCH2Ar (20-40%) [21 ]. The procedure does not have a great synthetic appeal. 

Laboratory studies have indicated an increasing number of further processes for which iron oxides may be used as catalysts. A sodium promoted iron oxide on a support of Si02 catalyses the gas phase oxidation (377-427 °C) by nitrous oxide, of pro-pene to propene oxide (Duma and Honicke, 2000). Ferrihydrite or akaganeite can be used to catalyse the reduction (at 55-75 °C) by hydrazine, of aromatic nitro compounds to aromatic amines (which are the starting materials for a huge range of chemicals) these Fe oxides have the potential to provide a safe and economical pathway to the production of these important organics (Lauwiner et al., 1998). 

The nitrosation of phenol and cresols in buffer solutions involves a diffusion-controlled C-nitrosation followed by rate-limiting proton loss. /r-Crcsol is much less reactive than the other substrates.79 Nitrosation in trifluoroacetic acid or in acetic-sulfuric acid mixtures is regioselective (e.g. 4-nitroso-m-xylene is fonned from m-xylene) and possible non-selective nitrous acid-catalysed nitration can be eliminated by purging reaction solutions with nitric oxide.80... 

In their roles as catalysts, the activity of carbons has been ascribed to several factors, depending on the reaction that is promoted. Hence, for example, Coughlin has attempted to describe most catalytic properties in terms of electronic effectshowever it has been suggested that the decomposition of hydrogen peroxide and nitrous oxide is controlled by the presence of surface complexes. On the other hand, the microporosity of carbons has been suggested to be very important in the catalysed oxidation of hydrogen sulphide. ... 

In this chapter, we present an example of a study following the second line of approach. The catalytic activity of a highly divided stoichiometric nickel oxide, one of the best catalysts in oxidation reactions (18), has been studied, for several years, first at the Faculty des Sciences of Lyon and, then, at the Institut de Recherches sur la Catalyse, Villeurbanne, France, in carbon monoxide oxidation and related reactions (oxygen isotopic exchange, nitrous oxide decomposition) with the help of different experimental techniques. It is fortunate that the same type of investigations on the same material were also conducted at the Institute of Physical-Chemistry in Prague, Czechoslovakia. This allowed many comparisons and checks of experimental results and interpretations. 

Intense sodium D-line chemiluminescence has also been observed in the low-pressure sodium catalysed CO—N2O flame [268]. The presumed reaction sequence involves reaction of a sodium atom with nitrous oxide. 

Andrews and co-workers have used the matrix reaction between lithium atoms and some inorganic compounds to produce species of spectroscopic interest. Reaction of lithium with molecular oxygen [301] produces, in addition to the molecule Li02, the molecule LiO and a dimer Li2 02. Reaction with nitric oxide produced a nitroxide compound [302], but analysis of the infrared spectrum indicated that in this compound the lithium atom was bound to the oxygen atom (LiON), rather than to the nitrogen atom (LiNO), as would be expected by analogy with the known compounds HNO and RNO. The matrix deposition of lithium and nitrous oxide [303] leads to the formation of LiO and LijO. The other alkali metals have also been reacted in the same way with nitrous oxide [304]. Potassium, rubidium and caesium all led to the formation of the compounds MO and M2O. No sodium oxides were produced when sodium and nitrous oxide were co-deposited. This is to be compared with the mechanism advanced for the sodium-catalysed gas-phase reaction between N2O and CO, where sodium is assumed to react with N2O, (Section 4, ref. 

At the present time, it is not possible to identify the exact role of the dihydroxybenzene in this reaction. Two possibilities can be considered first, whether it acts like a reducing agent on the hydrogen peroxide to give the hydroxyl radical, in a similar way to the Fenton reaction [10] or whether, after its oxidation by hydrogen peroxide into quinone, it causes an electron transfer from the phenol to give the phenoxy radical, in a similar role to the nitrosonium cation in the nitrous acid catalysed nitration of phenols [11]. In either case, this peculiar characteristic of the hydroxylation reaction explains the good behaviour... 

Reaction of CoH(N2)(PPha)3 with nitrous oxide gives triphenylphosphine oxide. This could be considered part of a potentially catalytic cycle for triphenylphosphine oxidation. Acetylacetone complexes of cobalt(ii) catalyse oxidation of isopropylbenzene. ... 

An n.m.r, study of B(OMe)3 in methanol shows fast methyl exchange, with / (MeOH)/ (MeOD)= l. Reaction is catalysed by both acids and bases. The decomposition of the A-nitrosohydroxylamine-A-sulphonate anion to nitrous oxide and sulphate ion is catalysed by boric acid ... 

Nitrate reduction In the narrow sense, N.r. is the reduction of the nitrate ion (NOj") to nitrite (N02"), catalysed by Nitrate reductase (see). In the broad sense, it is the reduction of nitrate to gaseous products (nitrous oxide or nitrogen), or to ammonia. 

Nitrous oxide is reduced by CO in the presence of [Rh(C0)2C1]2 and base to N2 and C02 21 The mechanism of the reduction of aromatic nitro compounds by CO to give isocyanates has been studied by IR the catalyst is trans-PdCl2(pyridine)2.212 PeiCOg, Ru3(C0)x2 Rh6(C0)xg convert ortho-nitrostyrenes and CO into indoles in up to 75 selectivity (eq.21).213 Nil2(PPh3)2 under CO pressure catalyses the conversion of nitrobenzene and aniline to diphenylurea and CO2 the amine is used as the solvent.214 Ru3(C0)i2 catalyses the carbonylation of amines to formamides and the hydroamidation of olefins to carboxylic amides.215... 

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