Palladium/polyoxometalate as a cooperative and reusable catalytic system for room temperature aerobic oxidation of alcohols to the corresponding carbonyl compounds in aqueous media
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
The design of cooperative catalytic systems modeled on nature is a significant development in organic synthesis. In this research, selective oxidation of the primary and secondary alcohols to the corresponding carbonyl compounds using oxygen as an environmentally friendly oxidant and in the presence of the heterogeneous cooperative catalytic system of palladium, sandwich type polyoxometalate [(OCe) 3 (PW 9 O 34 ) 2 ] 12− and hydroquinone (HQ) were investigated. In the first method, palladium nanoparticles on siliceous mesocellular foam (MCF) and polyoxometalate (POM) on Nd-doped TiO 2 nanoparticles were immobilized. Then the aerobic oxidation of the alcohols to the corresponding carbonyl compounds in the presence of the Pd@MCF/POM@TiO 2 /HQ catalytic system in THF solvent at 40 o C was investigated. In the second method, both palladium and polyoxometalate nanoparticles were immobilized on the same MCF. Then, POM-Pd@MCF/HQ as an efficient and reusable biomimetic catalytic system was used for the aerobic oxidation of the alcohols to the corresponding carbonyl compounds with good to excellent yields in water as solvent at room temperature. The Pd@MCF, POM@TiO 2 and POM-Pd@MCF compounds were identified and confirmed by various techniques.
