Oxidation bromamines

An alternative oxidation using O2 and a RuCls catalyst converted pyridine to pyridine A-oxide. Bromamine-T and RuCls in aq. acetonitrile also oxidizes pyridine to the A-oxide. Tertiary amines are oxidized to the A-oxide with O2 and Fe203 in the presence of an aliphatic aldehyde. " Oxygen and a cobalt-Schiff base complex also oxidzes tertiary amines, including pyridine. ... 

Urea (24), amino acids (25), and creatinine (26) are also decomposed during superchlorination or shock treatment, with formation of N2 and other oxidation products. However, the process is slower than with ammonium ion (see Chloramines and BROMAMINEs). Urea is the principal nitrogen-containing compound in swimming pools. Since it is an amide, it reacts slowly with chlorine, yielding N2, NCl, and NO/ (27). 

As with chlorine-containing oxidants, JV-bromo species have been used to oxidize sulphoxides to sulphones (with no bromine incorporation) through the initial formation of a bromosulphonium ion, by nucleophilic attack of the sulphoxide sulphur atom on the electrophilic halogen atom. Such reactions involve JV-bromosuccinimide ° bromamine-T, iV-bromoacetamide ° and iV-bromobenzenesulphonamide. All reported studies were of a kinetic nature and yields were not quoted. In acid solution all oxidations occurred at or around room temperature with the nucleophilic attack on the electrophilic bromine atom being the rate-limiting step. In alkaline solution a catalyst such as osmium tetroxide is required for the reaction to proceed . ... 

Ruthenium(in) catalyses the oxidative decarboxylation of n-butyric acid and isobutyric acid by ceric sulfate in aqueous acid. A mechanism for the Ru(III)-catalysed oxidation of o-hydroxybenzoic acid by an acidic solution of bromamine-B (PhS02-NNaBr, BAB) has been proposed based on a kinetic smdy. An ionic mechanism is suggested for the ruthenium(III) analogue of the Udenfriend-type system Ru(III)-EDTA-ascorbate-02, for the selective oxygen-atom transfer to saturated and unsaturated hydrocarbons. The kinetics of the oxidation of p-XC6H4CHPhOH(X =... 

H, Cl, Br, NO2, Me, MeO) by bromamine-B, catalysed in the presence of HCl in 30% aqueous methanol by RuCls have been smdied and a biphasic Hammett a-relationship derived. A kinetic study of the ruthenium(in)-catalysed oxidation of aliphatic primary amines by sodium A-bromo-j -toluenesulfonamide (bromamine-T, BAT) in hydrochloric acid medium has been undertaken and the mechanism of the reaction discussed. A concerted hydrogen-atom transfer one-electron transfer mechanism is proposed for the ruthenium(in)-catalysed oxidation of 2-methylpentane-2,4-diol by alkaline hexacyanoferrate(III). The kinetics of the oxidation of propane-... 

I, 3-diol under the same conditions have been studied. Ruthenium(in) catalyses the oxidation of primary alcohols by bromamine-B. A Taft LFE reaction constant of p = —0.77 indicates the development of positive charge in the transition state. ... 

A primary kinetic isotope effect (kn/ko = 6.03 at 298 K) was observed for the oxidation of formic and oxalic acids by benzyltrimethylammonium tribromide (BTMAB) to carbon dioxide. The kinetics of oxidation of pyridoxine to pyridoxal by broma-mine-T and bromamine-B ° and caffeine by bromamine-B have been investigated. 

Kinetic studies of the oxidation of aspirin by bromamine-T, A-bromosuccinimide (NBS), and A-bromophthalimide (NBP) support a mechanism in which the unpro-tonated oxidant is the active species. " The ultimate product of the reaction is 2,4,6-tribromophenol, which arises through decarboxylation, bromination and loss of acetic acid. The NBP and NBS oxidations of -hydroxy acids are found to be similar in mechanism. 

Catalysis of the oxidation of allyl and crotyl alcohols with chloramine-T, 375 chloramine-B, bromamine-T, and bromamine-B Catalysis of the chloramine-T oxidation of glycolic and lactic acids 376... 

The kinetics of oxidation of caffeine by sodium IV-bromo-p-toluenesulfonamide (bromamine-T) in dilute HC1 have been studied.138 In the oxidation of a-phenylbenzenemethanols by bromamine-T catalysed by ruthenium(III), the reaction constant p is —2.1 for electron-releasing substituents.139 It is proposed that the... 

The Ru(III)-catalysed oxidation of o-, m-, and p- hydroxybenzoic acids156-158 with bromamine-B (BAB) in acidic solution showed a first-order dependence on the reductant, BAB, and Ru(III). An inverse first-order dependence with respect to acidity has been observed. Mechanistic aspects have been discussed. 

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