Oxidative generation

The oxidative generation of o-aminophenylacetaldehydes can be done by ozonolysis (retrosynthetic path d in Scheme 2.2) but this requires an elec-... 

Acetaldehyde oxidation generates peroxyacetic acid which then reacts with more acetaldehyde to yield acetaldehyde monoperoxyacetate [7416-48-0], the Loesch ester (26). Subsequently, parallel reactions lead to formation of acetic acid and anhydride plus water. 

Methanol [67-56-1] (methyl alcohol), CH OH, is a colorless Hquid at ambient temperatures with a mild, characteristic alcohol odor. Originally called wood alcohol siace it was obtained from the destmctive distillation of wood, today commercial methanol is sometimes referred to as synthetic methanol because it is produced from synthesis gas, a mixture of hydrogen and carbon oxides, generated by a variety of sources. 

Reactions of Goal Ash. Mineral matter impurities have an important effect on the utili2ation of a coal. One of the constituents of greatest concern is pyrite because of the potential for sulfur oxide generation on combustion. The highest concentrations of pyrite are associated with coal deposition under marine environments, as typified by the Illinois Basin, including parts of Illinois, Indiana, and Kentucky. Additionally, the mineral matter... 

Oxidation of diethyl 3,6-hexanooxepin-4,5-dicarboxylate with ruthenium(VIII) oxide, generated from ruthenium(III) chloride and sodium periodate in situ, gives the corresponding hexa-no-bridged furan 1 a with loss of two carbon atoms (see Houben-Weyl, Vol. E6a, p 77).200 201 One of the central methylene groups can be replaced by a carbonyl group to give lb.200... 

The Tafel slopes obtained under concentrations of the chemical components that we suspect act on the initiation reaction (monomer, electrolyte, water contaminant, temperature, etc.) and that correspond to the direct discharge of the monomer on the clean electrode, allow us to obtain knowledge of the empirical kinetics of initiation and nucleation.22-36 These empirical kinetics of initiation were usually interpreted as polymerization kinetics. Monomeric oxidation generates radical cations, which by a polycondensation mechanism give the ideal linear chains ... 

In 2000, it was proposed that the regioselectivity of the [3 + 2] cycloaddition of fullerenes could be modified under microwave irradiation. Under conventional heating, N-methylazomethine yhde and fullerene-(C7o) gave three different isomeric cycloadducts because of the low symmetry of C70 vs. Ceo. Using microwave irradiation and o-dichlorobenzene as a solvent, only two isomers were obtained, the major cycloadduct 114 being kinetically favored (Scheme 39) [75]. The same authors had previously reported the 1,3-dipolar cyclo addition of pyrazole nitrile oxides, generated in situ, to Geo under either conventional heating or microwave irradiation. The electrochemical characteristics of the cycloadduct obtained with this method made this product a candidate for photophysical apphcations [76]. 

A nitrile oxide generated from a sugar derived aldoxime 30 underwent INOC reaction to the chiral pyranoisoxazoline 31 (Eq. 4) [20]. Reductive cleavage of isoxazoline 31 followed by acetylation provided the tetrasubstituted pyran 32. 

The red cell contains a battery of cytosolic enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, to dispose of powerful oxidants generated during its metabolism. 

Timmins GS, S Master, F Rusnak, V Deretic (2004) Nitric oxide generated from isoniazid activation by KatG source of nitric oxide and activity against tunerculosis. Antimicrob Agents Chemother 48 3006-3009. 

Weiss, S.J., Lampert, M.B. and Test, S.T. (1983). Long lived oxidants generated by human neutrophils characterization and bioactivity. Science 222, 625-628. 

Hydroxyl radical is a strong indiscriminate outer-sphere oxidant (generating OH ) and H-atom abstractor (generating H2O) [Huie and Neta, 1999]. Simple Fe porphyrins are known to promote 0-0 bond homolysis in reaction with H2O2 [Watanabe, 2000]. Because of its high reactivity, once generated, "OH probably reacts with the... 

Entries 10 to 12 are examples of oxidative generation of radicals, followed by tandem cyclization. The reaction in Entry 10 includes a lanthanide catalyst. Entry 11... 

Fig. 59. Molecular modification of semiconductor silicon surfaces. Removal of the oxide generates a hydrogen-terminated layer that reacts with a range of molecular functional groups including alkenes. 

The oxidation generates highly delocalized phenoxy radicals (PhO, Scheme 2.21), which may initiate (i) a radical polymerization process, trapping the reactant (CF) to give a benzyl radical intermediate (QMR), or it may (ii) follow a radical coupling to produce the p-QM p-O-QM, which being a reactive electrophile could undergo cationic polymerization. 

Scheme 8.1. Enzymatic oxidative generation of a diene followed by a Diels-Alder reaction...

Complex (17) of Class 3 has no chiral auxiliary, but is endowed with facial chirality by the presence of a bridging strap (Figure 4).65 Treatment of (17) with oxidant generates metal oxo bonds, preferentially on the sterically less hindered (nonbridged) side of the complex, and epoxidation with (17) is low in enantioselectivity (Scheme 10). However, the enantioselectivity is considerably improved by the addition of imidazole. The imidazole has been considered to coordinate the metal center from the nonbridged side and to force the formation of metal oxo bonds on the bridged (chiral) side, thus enhancing enantioselectivity. 

Nature of Oxidants Generated From Fatty Acid Hydroperoxides... 

S. Mesaros, Z. Vankova, A. Mesarosova, P. Tomcik, and S. Grunfeld, Electrochemical determination of superoxide and nitric oxide generated from biological samples. Bioelectrochem. Bioenerg. 46, 33-37 (1998). 

The nitrile oxide generated in situ by oxidation of oxime 325 gives the dimer 326 in 15% yield (Equation 72) <2001J(P1)415>. 

Because the redox potential of selenides is sufficiently low, oxidative generation of Se-Se and S-Se dications on treatment with sulfuric acid is more general than in the case of disulfonium dications. For example, formation of dications 106 and 108 occurs readily when the corresponding bis-selenide 105 and... 

Common synthesis of disulfonium dications involves formation of a S-S bond by oxidative coupling of two sulfide moieties. Involving for oxidative generation of S-S bond, thiocarbonyl compounds can lead to new-type dications containing disulfide moieties between two positively charged fragments. There are several disulfide dications of this type derived from thioureas, thiocarbon-ates and thioketones as well as selenium derivatives.137 148... 

Decomposition of the primary products of lipid oxidation generates a complex mixture including saturated and unsaturated aldehydes such as hexanal. Hexanal is the most commonly measured end product of lipid oxidation, and both sensory and physicochemical methods are used for its determination. Where other antioxidant activity tests may be nonspecific, physicochemical measurement of hexanal offers the advantage of analyzing a single, well-defined end product. 

Measurement of the total antioxidative overall efficacy in an oxidant-generating test system is considered a physiologically relevant alternative to selective determination of individual components. 

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