Carbonyl oxides saturated hydrocarbon oxidation

Surface modification of LDPE film can also be brought about by chemical treatment [118] with an aqueous solution of ammoniacal ammonium persulphate in the presence of Ni+2 ions under variable reaction conditions. The investigation of treated surface showed the presence of polar groups (viz. carbonyl and hydroxyl) in the infrared (IR) spectroscopy, with characteristic bands at 1700, 1622 and 3450 cm-1. It is known that the persulphate ion attacks the double-bond-producing epoxy or diol group. However, the destructive oxidation of saturated hydrocarbons does not occur with persulphate alone, but requires the presence of the nickel (II) ion. The authors have proposed the following mechanism of chemical treatment ... 

The low-pressure acetic acid process was developed by Monsanto in the late 1960s and proved successful with commercialization of a plant producing 140 X 10 metric tons per year in 1970 at the Texas City (TX, USA) site [21]. The development of this technology occurred after the commercial implementation by BASF of the cobalt-catalyzed high-pressure methanol carbonylation process [22]. Both carbonylation processes were developed to utilize carbon monoxide and methanol as alternative raw materials, derived from synthesis gas, to compete with the ethylene-based acetaldehyde oxidation and saturated hydrocarbon oxidation processes (cf. Sections 2.4.1 and 2.8.1.1). Once the Monsanto process was commercialized, the cobalt-catalyzed process became noncom-... 

The oxidation of saturated hydrocarbons by alkyl hydroperoxides catalyzed by various metal complexes yields alcohols, carbonyl compounds (ketones and aldehydes) and peroxides. Examples of recent works devoted to these reactions are given in Table X.3. Usually ferf-butyl hydroperoxide is employed for these oxidations. Other hydroperoxides, e.g., cumyl hydroperoxide [38a, 42a], have been also reported to oxygenate alkanes. 

Aldehydes are stoichiometrically decarbonylated by reaction with (XL) under mild conditions (77, 98,110,113). Aromatic aldehydes yield aromatic hydrocarbons whereas aliphatic aldehydes form saturated hydrocarbons and olefins. The latter minor products can be considered to arise from a reverse hydroformylation reaction. The initial step of this reaction is probably the oxidative addition of an aldehyde C—H bond to the rhodium(I) complex. However, a stable adduct of this type has not yet been reported. The driving force in these reactions is derived from the stability of the carbonyl (LXIX). 

Palladiumdiacetate in trifluoroacetic acid (Pd(02CCF3)2) gives a mixture of o- and p-trifluoroacetoxylated products. The reagent is also capable of oxidizing saturated hydrocarbons such as adamantane and methane. In the presence of carbon monoxide and with sodium acetate as co-catalyst, carbonylation of aromatic C-H bonds occurs, eventually yielding acid anhydrides. ... 

Many different substrates can undergo oxidative carbonylations, such as unsaturated and saturated hydrocarbons, aromatic and heteroaromatic derivatives, alcohols, phenols, and amines, giving a number of carbonyl compounds in a regio- and stereocontrolled fashion and with high degree of chemoselectivity. Oxidative car-bonylation reactions have been recently and carefully reviewed [10-13]. In this section a general overview of the most recent developments in oxidative carbonylations mediated by catalytic palladium(II) compounds and directed toward the synthesis of heterocyclic compounds is presented. As already reported in the introduction, the cyclocarbonylation reactions ending with the synthesis of simple lactones and lactams are reported in the chapter that discusses the carbonylation of alcohols and amines and are recently been reviewed [7,9,79]. 

Various reaction mechanisms have been proposed for the formation of carbonyl sulfide and carbon disulfide and for their subsequent hydrolysis to hydrogen sulfide and carbon dioxide (Paskall and Sames, 1992). The plant data available indicate that carbonyl sulfide is formed primarily from the reaction between elemental sulfur and carbon monoxide, which in turn are derived from hydrogen suUide and carbon oxides present during combustion of the feed gas in the Claus thermal stage. The production of carlxin disulfide in the thermal stage is usually attributed to the presence of hydrocarbons in the feed gas because carbon disulfide is produced commercially by reacting elemental sulfur with saturated hydrocarbons. The... 

Most organic reactions are Lewis acid/base processes that involve the interaction of a nucleophilic center with an electrophilic center. Because electrochemistry provides the ultimate nucleophile via the electrons at the cathode surface and the ultimate electrophile via the electron holes at the anode surface, it is the ideal methodology for the characterization of the electrophilicity and nucleophilic-ity of molecules. Thus, the carbon centers of saturated hydrocarbons (e.g., CH4) are resistant to electrochemical reduction and oxidation because of their inert nature (all valence electrons are stabilized in sigma bonds an absence of any Lewis acid/base character). However, organic molecules with electrophilic components [e.g., alkyl-, aryl-, and acyl- halides carbonyl groups unsaturated and aromatic hydrocarbons nitro groups Brpnsted... 

Cytochrome P450 enzymes catalyze dehydrogenation as well as oxygenation reactions, including the oxidation of saturated to unsaturated hydrocarbons, alcohols to carbonyl compounds, and amines to imines or other unsaturated products. The most extensively investigated of these reactions in terms of mechanism is the desaturation of valproic acid to 2-/i-propyl-4-pentenoic... 

Aldol condensations can be efficiently carried out in the liquid or gas phase. These processes are in some cases catalyzed by supported transition metals, occasionally by acids, and more frequently by bases (1,9). The choice of a appropriate catalyst is necessary for obtaining the desired final product Aldol condensations catalyzed by supported metals in the presence of hydrogen yield a saturated carbonyl (10), whereas the acid-catalyzed reaction leads mainly to hydrocarbons and the base-catalyzed reaction is suitable for the synthesis of heavier a,j8-unsaturated carbonyl polymers. The majority of the heterogeneous catalysts are acidic or basic metal oxides or mixtures of metal oxides. 

The volatile components of raw chicken breast muscle include mainly carbonyls, thiols, sulfides and alcohols. The major volatile components of fried chicken are similar to volatiles of the meat of farm animals (e.g. common aldehydes, ketones, hydrocarbons and other compounds). Sulfur-containing compounds generated during thermal processing are also important for the flavour of chicken meat. Saturated and unsaturated aldehydes are very important - these are produced easily by oxidation of lipids and manifest negatively in stored poultry meat, which quickly becomes rancid. Feed plays an important role in imparting certain flavour characteristics to poultry meat. 

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