Selective Catalytic Oxidations in Supercritical Carbon Dioxide

Abstract

Supercritical carbon dioxide is ideally suited as reaction medium for catalytic oxidations of organic substrates, and it may be exploited as one of the most promising strategies to realize some fundamental chemical transformations under environmentally benign conditions. The use of supercritical carbon dioxide as solvent for unselective hydrocarbons auto-oxidations is extensively described in the literature. Conversely, only a limited number of reports deal with selective oxidations carried out by molecular oxygen or by other primary oxidants such as hydrogen peroxide, alkyl hydroperoxides, monopersulfate, etc. In this paper recent developments in selective catalytic oxidations are reviewed and particular attention is devoted to those processes in which a metal derivative, capable of selectively oxidizing various substrates, is formed by action of a terminal oxidant such as oxygen or an organic or inorganic peroxide. Keywords: supercritical fluids, supercritical carbon dioxide, triple point, oxidation, dioxygen, cyclohexanone