Stabilization of Catalytic Sol-Gel Entrapped Perruthenate

Organically modified silica gels doped with perruthenate anion are effective catalysts for the oxidation of alcohols by a variety of terminal oxidants including dioxygen. However, especially with the latter, the observed catalyst turnover numbers are still far from those requested for profitable industrial applications. A combination of more stable counter-cation (tetraphenylphosphonium in place of tetrapropylammonium), of local basic microenvironment and of a non-solubiliziting reaction medium respect with the catalyst (supercritical CO2) allow a significant improvement in the life-cycle and reusability of the catalyst.