Simple one-pot conversion of organic compounds by hydrogen peroxide activated by ruthenium(III) chloride: organic conversions by hydrogen peroxide in the presence of ruthenium(III)

Abstract

The aromatic compounds p-nitrobenzaldehyde, p-hydroxybenzaldehyde, naphthalene, toluene, catechol, quinol, aniline and toluidine dissolved in aqueous acetic acid or aqueous medium were oxidized in quantitative to good yields by 50% H2O2 in the presence of traces of RuCl3 (∼10−8 mol; substrate/catalyst ratio 1488:1 to 341 250:1). Conditions for highest yields, in the most economical way, were obtained. Higher catalyst concentrations decrease the yield. Oxidation in aromatic aldehydes is selective at the aldehydic group only. In the case of hydrocarbons, oxidation results in the introduction of a hydroxyl group with >85% (in the case of toluene) selectivity for the ortho position. Formation of low-molecular-weight polyaniline was reduced to 10%, along with 90% formation of higher molecular weight polyaniline. In this new, simple and economical method, which is environmentally safe and requires less time, oxo-centered carboxylate species of ruthenium(III) in acetic acid medium and hydrated ruthenium(III) chloride in aqueous medium probably catalyze the oxidation. Copyright © 2005 John Wiley & Sons, Ltd.