Oxidation catalysis in air with Cp*Ir: influence of added ligands and reaction conditions on catalytic activity and stability†
We describe the systematic evaluation of Cp*Ir catalysts for the aerobic oxidation of alcohols. Our results demonstrate turnover numbers up to 270 per [Cp*IrCl2]2 which have not been previously achieved for this reaction. Using air as the sole oxidant under base-free conditions, the effects of solvent systems and additives on the catalytic activity are documented systematically. We further elucidate the role of additives in catalyst decomposition processes and establish a novel buffer system which results in significant catalyst stabilization upon prolonged reaction times.