130. The autoxidation of isopropylbenzene

Armstrong, G. P.; Hall, Ross H.; Quin, D. C.

doi:10.1039/jr9500000666

Cited by 33 publications

(8 citation statements)

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“…N-(4-Chlorophenyl)hydroxylamine was synthesized by the method of Bamberger (1890) and stored at -200C under N2. Cumene hydroperoxide was purchased from Merck A.G. (Darmstadt, Germany) and purified by established procedures (Armstrong et al, 1950).…”

Section: Chemicalsmentioning

confidence: 99%

Comparative studies on the cumene hydroperoxide- and NADPH-supported N-oxidation of 4-chloroaniline by cytochrome P-450

Hlavica¹,

Golly²,

Mietaschk³

1983

Biochemical Journal

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The present study confirms that cytochrome P-450 can act as a catalyst in the cumene hydroperoxide-supported N-oxidation of 4-chloroaniline. Analogous to the NADPH/O2-driven N-oxidation process, product dissociation is likely to limit the overall rate of cytochrome P-450 cycling also in the peroxidatic pathway. The oxy complexes involved in either metabolic route differ with respect to stability, spectral properties and need for thiolate-mediated resonance stabilization. With the organic hydroperoxide, the metabolic profile is shifted from the preponderant production of N-(4-chlorophenyl)hydroxylamine to the formation of 1-chloro-4-nitrobenzene. This finding suggests that the peroxide-sustained N-oxidation mechanism differs in several ways from that functional in the NADPH/O2-dependent oxenoid reaction. Thus one-electron oxidation, triggered by homolytic cleavage of the oxygen donor, is proposed as the mechanism of peroxidatic transformation of 4-chloroaniline.

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Section: Chemicalsmentioning

confidence: 99%

Comparative studies on the cumene hydroperoxide- and NADPH-supported N-oxidation of 4-chloroaniline by cytochrome P-450

Hlavica¹,

Golly²,

Mietaschk³

1983

Biochemical Journal

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“…The other process, the so-called dry process, consists in passing air or oxygen into cumene heated to 120° in the presence of metallic copper, which acts as catalyst. The process first mentioned was developed by the DISTILLERS CO. LTD. [81]. It is carried out somewhat as follows (see Fig.…”

Section: E Phenol and Acetone From Cumenementioning

confidence: 99%

“…Emulsifiers which can be used are Teepol (Na salt of a secondary alkyl sulphate (see p. 689)), sodium lauryl sulphate, and sodium stéarate. after ARMSTRONG et al [81] Now, with stirring at 130°, air at 5-10 atm is forced in and the cumene is subjected to approximately 25% conversion. Preferably, a little cumene hydroperoxide is added in order to eliminate an incubation period.…”

Section: E Phenol and Acetone From Cumenementioning

confidence: 99%

The Alkylation of Aromatic Compounds With Olefins

Asinger¹

1968

Mono-Olefins

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“…a,a-Dimethylbenzyl, a-methylbenzyl, and benzyl hydroperoxides were purified by the method of Armstrong et al (23). Attempts to obtain t-butyl hydroperoxide free of t-butanol and acetone were unsuccessful, but control experiments showed that these contaminants had no effect on the rates of NADPH oxidation and product formation from hydroperoxides.…”

Section: Methodsmentioning

confidence: 99%

Hydrocarbon formation in the reductive cleavage of hydroperoxides by cytochrome P-450.

Vaz¹,

Coon²

1987

Proc. Natl. Acad. Sci. U.S.A.

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Evidence is presented that cytochrome P-450 catalyzes the reductive cleavage of hydroperoxides. For example, in a reconstituted system containing rabbit liver microsomal P-450 form 2, NADPH-cytochrome P-450 reductase, and NADPH, cumyl hydroperoxide yields acetophenone and methane, but no cumyl alcohol is formed. The stoichiometry of the reaction and similar results with a-methylbenzyl, benzyl, and t-butyl hydroperoxides are in accord with the following general equation, in which X represents an alkyl group and R and R' are either alkyl groups or hydrogen atoms in the starting peroxide: XRR'C-OOH + NADPH + H' -* XRCO + R'H + H20 + NADP+. Because 13-hydroperoxy-9,11-octadecadienoic acid yields pentane under these conditions, we propose that the known formation of alkanes and aldehydes in membrane lipid peroxidation involves reductive cleavage by P-450 to give the products predicted by the above equation. The cleavage reaction is thought to involve stepwise one-electron transfer, resulting in homolysis of the peroxide oxygen-oxygen bond and generation of an alkoxy radical, with f3-scission of the latter followed by reduction of the secondary radical to the hydrocarbon. In accordance with this scheme, when the cleavage reaction with cumyl hydroperoxide was done in 2H20, deuteromethane was formed.The cytochrome P-450 family of enzymes is a versatile group of heme proteins well known for their ability to catalyze the monooxygenation of a large variety of endobiotic and xenobiotic compounds (1-3). Whereas molecular oxygen and a reduced pyridine nucleotide are required for such hydroxylation reactions, these components can be replaced by a peroxy compound as shown with liver microsomal suspensions (4, 5) and subsequently with the reconstituted enzyme system containing purified rabbit liver microsomal cytochrome P-450 [P-450 form (or isozyme) 2] (6). The stoichiometry was determined and found to be in accordance with the following reaction, in which P-450 functions as a peroxygenase, RH and ROH represent the substrate and product, respectively, and XOOH is the peroxy compound serving as oxygen donor (6):[11 Thus, with cumyl hydroperoxide the product is cumyl alcohol. As reviewed elsewhere (1,7,8), several lines of evidence indicate that in reaction 1 the peroxide oxygen-oxygen bond cleavage is homolytic and therefore distinct from the heterolytic cleavage typical of reactions catalyzed by peroxidases.In a recent study on the reduction of hydroperoxides undertaken to develop a model for the four-electron reduc-

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130. The autoxidation of isopropylbenzene

Cited by 33 publications

References 0 publications

Comparative studies on the cumene hydroperoxide- and NADPH-supported N-oxidation of 4-chloroaniline by cytochrome P-450

Comparative studies on the cumene hydroperoxide- and NADPH-supported N-oxidation of 4-chloroaniline by cytochrome P-450

The Alkylation of Aromatic Compounds With Olefins

Hydrocarbon formation in the reductive cleavage of hydroperoxides by cytochrome P-450.

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