Simple and economical conversion of organic compounds with H2O2 catalyzed by ruthenium (III) chloride

Six aromatic aldehydes, two hydrocarbons, one cycloalcohol and one aromatic alcohol, viz. benzaldehyde, p-chlorobenzaldehyde, cinnamaldehyde, 4-methoxybenzaldehyde, o-hydroxybenzaldehyde, 4-hydroxy, 3-methoxybenzaldehyde, anthracene, phenanthrene, cyclohexanol and benzyl alcohol dissolved in acetic acid, were oxidized in quantitative to moderate yields by 50% H2O2 in the presence of traces of RuCl3 (substrate:catalyst ratio 85 400 to 387 500:1). Conditions for highest yields, under most economical conditions, were obtained. Higher catalyst concentrations decreased the yield. Oxidation in aromatic aldehydes is selective at aldehydic group only, and other groups remain unaffected. The extent of oxidation in phenanthrene depends on temperature or the relative amount of substrate or both. In this new, simple and economical method, which is environmentally safe and requires less time, oxocentered carboxylate species of ruthenium (III) probably catalyze the oxidation. Copyright © 2005 John Wiley & Sons, Ltd.