Alcohol oxidation with dioxygen mediated by oxotitanium porphyrin and related transition metal complexes

Abstract

Oxotitanium porphyrin ( TTP ) Ti = O and related transition metal complexes were shown to catalyze the oxidation of alcohols using dioxygen as the oxidant. Vicinal diols were cleaved to carbonyl compounds in the presence of catalytic amounts of ( TTP ) Ti = O , ( TTP ) V = O or ( Saldach ) V = O . α-Hydroxy ketones were oxidized to α-diketones with ( TTP ) Ti = O . Benzyl alcohol was converted to benzaldehyde in modest to high yields by a number of high valent transition metal complexes. Reaction pathways for the transformations mediated by ( TTP ) Ti = O are discussed. Formation of diolato and enediolato complexes is believed to be the key step in the diol cleavage and α-hydroxy ketone oxidation, respectively.