Low temperature selective catalytic oxidation and nitration using environmentally friendly reagents

The selective oxidation of benzyl, phenylethyl and phenoxybenzyl alcohols can be performed using metallic nitrates supported on clays. It is shown here that similar or better yields can be achieved by simple addition of iron, bismuth or copper nitrates and a dealuminated or a natural clay to the reaction mixture, instead of their supported equivalent. The acid catalytic role of the clay is suggested by its concentration effect on the reaction rate. These observations open up new opportunities for easy scale-up of selective oxidation of fragile organic compounds such as phenoxybenzyl alcohol. The selective nitration of 4-hydroxybenzaldehyde also gives good yields with the same catalytic system.