Partial oxidation of alkanes by dioxiranes formed at low temperature.

Partial oxidation catalysts capable of efficiently operating at low temperatures may limit the over-oxidation of alkane substrates and thereby improve selectivity. This work focuses on examining alkane oxidation using completely metal-free organocatalysts, dioxiranes. The dioxiranes employed here are synthesized by oxidation of a ketone using a terminal oxidant, such as hydrogen peroxide. Our work generates the dioxirane , so that the process can be catalytic with respect to the ketone. To date, we have demonstrated selective partial oxidation of adamantane using ketone catalysts resulting in yields upwards of 60% towards 1-adamantanol with greater than 99% selectivity. Furthermore, we have demonstrated that changing the electrophilic character of the ketone R groups to contain more electron-donating ligands facilitates the dioxirane ring formation and improves overall oxidation yields. Isotopic labelling studies using HO show the preferential incorporation of an O label into the parent ketone, providing evidence for a dioxirane intermediate formed The isotopic labelling studies, along with solvent effect studies, suggest the formation of peracetic acid as a reactive intermediate.This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.