Aerobic Oxidation of Pd^II to Pd^IV by Active Radical Reactants: Direct C–H Nitration and Acylation of Arenes via Oxygenation Process with Molecular Oxygen

Abstract

A Pd-catalyzed aerobic oxidative C–H nitration and acylation of arenes with simple and readily available tert-butyl nitrite (TBN) and toluene as the radical precursors has been developed. Molecular oxygen is employed as the terminal oxidant and oxygen source to initiate the active radical reactants. Many different directing groups such as pyridine, pyrimidine, pyrazole, pyridol, pyridylketone, oxime, and azo groups can be employed in these novel transformations. The PdII/PdIV catalytic cycle through a radical process is the most likely pathway for these oxidative C–H nitration and acylation reactions.