Kinetics and mechanism of oxidation of some alpha-amino acids by benzyltrimethylammonium chlorobromate

The oxidation of nine a-amino acids by benzyltrimethylammonium chlorobromat e (BTMACB) in aqueous acetic acid leads to the formation of the correspondi ng carbonyl compounds. The reaction is first order each with respect to the amino acid and BTMACB. The reaction does not induce the polymerization of acrylonitrile. There is no effect of added benzyltrimethylammonium chloride or bromide ion on the reaction rate. The oxidation of perdeuterioglycine s hows the absence of a kinetic isotope effect. The effect of solvent composi tion indicates that the reaction rate increases with an increase in the pol arity of the solvent. Chlorobromate ion has been postulated as the reactive oxidizing species. The reaction is susceptible to both polar and steric ef fects of the substituents. A suitable mechanism has been proposed.