Clean preparation of methyl esters in one-step oxidative esterification of primary alcohols catalyzed by supported gold nanoparticles

Abstract

Methyl esters were prepared by the clean, one-step catalytic esterification of primary alcohols using molecular oxygen as a green oxidant and a newly developed SiO₂-supported gold nanoparticle catalyst. The catalyst was highly active and selective in a broad range of pressure and temperature. At 3 atm O₂ and 130 °C benzyl alcohol was converted to methyl benzoate with 100% conversion and 100% selectivity in 4 h of reaction. This catalytic process is much “greener” than the conventional reaction routes because it avoids the use of stoichiometric environmentally unfriendly oxidants, usually required for alcohol oxidation, and the use of strong acids or excess of reactants or constant removal of products required to shift the equilibrium to the desired esterification product.