Chloramine T, oxidation

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... 

At neutral and slightly alkaline pH, N-chlorosuccinimide (NCS) and N-chloro-p-toluenesulfonamide (chloramine-T) oxidize methionine residues in peptides and proteins to methionine sulfoxides (31). Chlor-amine-T is more selective than NCS it does not react with tryptophan whereas NCS does. However both of these reagents react with cysteine. Treating the Ca2+-dependent protein modulator with NCS in the presence of Ca2+ resulted in selective oxidation of methionines 71, 72, 76, and possibly 109 in the modulator sequence with concomitant loss in interaction with cyclic nucleotide phosphodiesterase (32). Methionine residues have been implicated in the activation of cyclic nucleotide phosphodiesterase by the Ca2+-dependent protein modulator. 

Labeling antibody with can be accomplished in several different ways (see the review by Skelley et alA) among the commonly used methods are (a) various modifications of Hunter and Greenwood s chloramine-T oxidation method, including that of Bolton and Hunter (b) the use of catalytic amounts of lactoperoxidase for iodination. ... 

JUWEID, M.E., Radioimmunotherapy of B-cell Non-Hodgkin s lymphoma From clinical trials to clinical practice, J. Nucl. Med. 43 (2002) 507-1529. ROBLES, A.M., BALTER, H., OLIVER, P., WELLING, M., PAUWELS, E.K.J., Improved radioiodination of biomolecules using exhaustive chloramine-T oxidation, Nucl. Med. Biol. 28 (2001) 999-1008. 

The iodized protein does not exhibit specific binding Often, the incorporated iodine is to blame, but the reagents used for the iodination can also inactivate the protein. For example, chloramine T oxidizes not only 1 but the a-amino group of peptides and amino acids to nitrile. Sensitive phenol derivatives are also destroyed. By the way, these reactions were the basis for the application of chloramine T as a disinfectant during World War I (Dakin et al. 1996). 

Both uncatalysed and RhCl3-catalysed oxidations of amodiaquine hydrochloride (AQ) with CAT have a negative fractional order in OH ions, whereas the catalysed reaction has a fractional order in the catalyst. The rates of Ir(III) catalysed chloramine-T oxidation of serine in acidic medium show a positive effect of substrate and H+ ion and a negative effect of Cr ion. ... 

Other oxidants may be used in place of PTAB chloramine-T efficiently azir-idinates a range of alkenes in the presence of H202 (Scheme 4.20) [25]. 

The commercially available chloramine-T trihydrate (TsNNaCl 3H20) could also be used directly as the oxidant, although slightly more dilute concentrations (0.2 m vs. 0.5 m) had to be employed to ensure comparable yields. The applicability of this trihydrate version to large-scale syntheses was demonstrated by the aziridination of cyclopentene on a 0,5 mol scale reaction, providing 6-tosylazabicyclo-[3.1.0]hexane in 80% isolated yield (Scheme 12.14). 

Despite the effectiveness of chloramine-T in this new method, removal of the toluenesulfonyl group from the newly introduced nitrogen substituent requires harsh conditions. The finding that the N-chloramine salt of tert-butylsulfonamide is also an efficient nitrogen source and the terminal oxidant for aziridination of... 

Chloramine-B (CAB, PhS02NClNa) and chloramine-T (CAT, p-Me-C6H4S02NClNa) have also been used for the oxidation of sulphoxides107-115. The required sulphone is produced after initial attack by the sulphoxide sulphur atom on the electrophilic chlorine-containing species, forming a chlorosulphonium intermediate as shown in equation (34). These reactions take place at room temperature, in water and aqueous polar solvents such as alcohols and dioxane, in both acidic and basic media. In alkaline solution the reaction is slow and the rate is considerably enhanced by the use of osmium tetroxide as a catalyst115. 

A variety of chloramine T reagents, involving the use of chloramine T for chlorination or oxidation reactions, have been described in the literature. These are described in detail individually in the following monographs. 

Purine derivatives (e. g. xanthine) are oxidized by chloramine T in the presence of hydrochloric acid and form purple-red anunonium salts of purpuric acid (murexide) with ammonia. Whether the murexide reaction is also the cause of the fluorescence is open to question. 

Aldoximes can be oxidatively dehydrogenated to nitrile oxides using a variety of oxidants such as lead tetraacetate [16a], alkali hypohalites [lla],NBS in DMF followed by base treatment [16b], chloramine-T [11b], 1-chlorobenzotriazole [16c], mercuric acetate [ 16 d], etc. However, we employed either NaOCl or chloramine-T for most of our INOC reactions. For instance, a piperidine ring fused to an isoxazoline as in 14 was constructed using the INOC methodology (Scheme 3) [17]. Monoalkylation of N-tosylallylamine 10 with the bromoacetal... 

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