The kinetics of the oxidation of a-amino acids (glutamic acid and aspartic acid) by alkaline hexacyanoferrate(Il1) were studied at constant ionic strength and over the temperature range 323-348 K. The rate was dependent on the first power of the concentrations of substrate and oxidant, but was independent of the concentration of alkali in the range studied. The value of k~/ k~ was in the range 8.1-8.3 for the slow step, indicating the loss of a hydrogen atom from the C-H bond, giving a radical species which was characterized by ESR spectroscopy. The reaction proceeds by way of the a-imino acid, formed in a fast step, which undergoes hydrolysis to give the corresponding a-keto acid.

The kinetics of oxidation of styrene and substituted styrenes by quinolinium dichromate (QDC) in dimethyl formamide, in the presence of acid, has been investigated. The rate of the reaction is dependent on the first powers of the concentrations of substrate, oxidant, and acid. A small inverse kinetic isotope effect has been observed (k d k D = 0.80). Correlation with cr yielded a p value of-4.0, suggesting the formation of a cationic intermediate in the rate-determining step of the reaction. Subsequent cleavage of the carbon-carbon bond yielded benzaldehyde and formaldehyde.

The kinetics of oxidation of substituted 2‐furaldehydes by quinolinium dichromate in sulfuric acid, using 50% acetic acid as the solvent, was studied. The rate of the reaction was first order in each of the substrate, oxidant and acid. The kinetic data are discussed with reference to the aldehyde hydration equilibria. The kinetic results support a mechanistic pathway proceeding via a rate‐determining oxidative decomposition of the chromate ester of the aldehyde hydrate. Copyright © 2003 John Wiley & Sons, Ltd.

Quinolinium dichromate (QDC) in water oxidizes vicinal and nonvicinal diols to the corresponding alpha-hydroxy carbonyl compound. The rate is proportional to the concentrations of diol, oxidant and hydrogen ions, and the reactions proceed almost twice as fast in D(2)O than in H(2)O. These data can be correlated with a mechanistic pathway involving the intermediate formation of a chromate ester, which undergoes decomposition to give the product.

The kinetics of the oxidation of α‐amino acids (glutamic acid and aspartic acid) by alkaline hexacyanoferrate(III) were studied at constant ionic strength and over the temperature range 323–348 K. The rate was dependent on the first power of the concentrations of substrate and oxidant, but was independent of the concentration of alkali in the range studied. The value of kH/kD was in the range 8·1–8·3 for the slow step, indicating the loss of a hydrogen atom from the CH bond, giving a radical species which was characterized by ESR spectroscopy. The reaction proceeds by way of the α‐imino acid, formed in a fast step, which undergoes hydrolysis to give the corresponding α‐keto acid.