Organocatalyzed oxidation of alcohols to aldehydes with molecular oxygen

The first direct organocatalytic system for oxidizing alcohols to aldehydes with molecular oxygen is described. The catalytic activity of 9,10-diaminophenanthrene with and without the presence of transition metals was studied in the oxidation of benzylic alcohols to corresponding aldehydes. The catalytic reaction occurs at elevated dioxygen pressure and temperature in alkaline aqueous solutions. Up to 80% conversions were observed in organocatalytic oxidation of 3,4-dimethoxybenzyl alcohol to corresponding aldehydes. Addition of transition metal ions to reaction solution increased the catalytic activity significantly. Complete conversions of 3,4-dimethoxybenzyl alcohol to aldehydes were observed in the presence of copper and iron ions. (c) 2007 Elsevier B.V. All rights reserved.