The aerobic oxidation of alcohols with a ruthenium porphyrin catalyst in organic and fluorinated solvents

Abstract

Carbonylruthenium tetrakis(pentafluorophenyl)porphyrin Ru(TPFPP)(CO) was utilized for the aerobic oxidation of alcohols. The in situactivation of the catalyst with mCPBA provided a species capable of catalyzing the oxidation of alcohols with molecular oxygen. The choice of solvent and additive was crucial to obtaining high activity and selectivity. Secondary aromatic alcohols were oxidized in the presence of the ruthenium porphyrin and tetrabutyl ammonium hydroxide in the solvent bromotrichloromethane, enabling high yields to be achieved (up to 99%). Alternatively, alcohols could be oxidized in perfluoro(methyldecalin) with the ruthenium porphyrin at higher temperatures (140 °C) and elevated oxygen pressures (50 psi).