Catechol, reaction with compound

These compounds have been prepared via oxidative addition reactions between the appropriate phosphate or phosphine and either a quinone or via displacement reactions with a suitable diol. Compounds 81 and 83 were prepared by such a displacement reaction between monocyclic pentaoxyphosphorane 317 and 3-fluorocatechol or catechol in toluene, respectively. This reaction takes advantage of the chelation effect of forming a bicyclic system from a monocyclic one <1997IC5730>. Compound 82 and compound 84 were synthesized via oxidation addition between tetrachloroquinone and the respective sulfur-containing cyclic phosphate or phosphine <1997IC5730>. Compound 93 was prepared from the phosphine 318 and the diol 319 in the presence of iV-chlorodiisopropylamine in an ether solution <1998IC93>. 

Various hydroxyl and amino derivatives of aromatic compounds are oxidized by peroxidases in the presence of hydrogen peroxide, yielding neutral or cation free radicals. Thus the phenacetin metabolites p-phenetidine (4-ethoxyaniline) and acetaminophen (TV-acetyl-p-aminophenol) were oxidized by LPO or HRP into the 4-ethoxyaniline cation radical and neutral V-acetyl-4-aminophenoxyl radical, respectively [198,199]. In both cases free radicals were detected by using fast-flow ESR spectroscopy. Catechols, Dopa methyl ester (dihydrox-yphenylalanine methyl ester), and 6-hydroxy-Dopa (trihydroxyphenylalanine) were oxidized by LPO mainly to o-semiquinone free radicals [200]. Another catechol derivative adrenaline (epinephrine) was oxidized into adrenochrome in the reaction catalyzed by HRP [201], This reaction can proceed in the absence of hydrogen peroxide and accompanied by oxygen consumption. It was proposed that the oxidation of adrenaline was mediated by superoxide. HRP and LPO catalyzed the oxidation of Trolox C (an analog of a-tocopherol) into phenoxyl radical [202]. The formation of phenoxyl radicals was monitored by ESR spectroscopy, and the rate constants for the reaction of Compounds II with Trolox C were determined (Table 22.1). 

The majority of systems studied have been aqueous solutions of either aromatic compounds or halogenated hydrocarbons. Such materials represent models for the major classes of organic pollutants in waste and ground water. The primary products resulting from the sonochemical treatment of phenol at 541 kHz (27 °C with bubbled air) are hydroquinone and catechol [22]. These compounds are easy to monitor and are clearly seen to be intermediates which disappear as the reaction progresses (Fig. 4.1). Similarly the sonolysis of aqueous 4-chlorophenol leads to products mainly characteristic of oxidation by OH radical e. g. 4-chlorocatechol but in both cases the final organic products are CO, CO2 and HCOOH (Scheme 4.2) [22-25]. 

Bisphenol A, a compound highly used in the production of epoxy resins and polycarbonate plastics, forms monochloro-, dichloro, trichloro-, and tetrachloro derivatives when chlorinated [127], Its reaction with ozone produces as major transformation products, catechol, orthoquinone, muconic acid derivatives of bisphenol A, benzoquinone, and 2-(4-hydroxyphenyl)-propan-2-ol [128],... 

Anodic oxidation of catechols enables the unstable quinones to be prepared and reacted in situ. Reaction of the 1,2-quinone with a 1,3-dicarbonyi compound gives a high yield of a benzofuran [123, 124]. Both 1,2- and 1,4-quinones, prepared electrochemically in nitromethane, are efficiently topped in Diels-Alder reactions with butadienes [125]. 

Ferapontova EE, Castello J, Gorton L (2006) Bioelectrocatalytic properties of lignin peroxidase from Phanerochaete chrysosporium in reactions with phenols, catechols and lignin-model compounds. Biochim Biophys Acta 1760 1343-1354... 

Cyclization of intermediates 165 and 166 occurred at the position with a larger superdelocalizability (see Section VI,A). PPP Calculations also support the angular forms. These compounds were not stable their color changed even in polar solvents. The salt from the reaction of 3,6-bis(bro-momethyl)catechol diacetate with 2-(l, 3-dioxolan-2-yl)pyridine was easily cyclized with 30% HBr in AcOH to afford the 6,7-dihydroxy derivative 164 (84%) (65JOC252). 

The Lewis acidic character of reactive pentacoordinate silicon compounds has been unequivocally confirmed by Corriu, Sakurai and Hosomi [90]. Allylsilicates prepared from allylsilanes and catechol can undergo allylation reaction with aldehydes in the absence of Lewis acid promoter (Sch. 51). 

The molecular characterization of methylarsonic acid, phenylarsonic acid and the inorganic anion, arsenate, found in a methanol extract of a Green River Formation Oil shale sample was accomplished by HPLC-GFAA analysis In addition, derivatization of the acids, HPLC purified, by reaction with 3-methylcatechol to form the five coordinate organoarsenic catecholates as well as reaction, via trimethylsilylation, of the ammonium salt of arsenate to form tristrimethylsilylarsenate was followed by GC-EIMS analysis to provide unequivocal evidence for the presence of these organometallic and inorganic compounds of arsenic as natural products in oil shale ... 

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