Non-directed, carbonate-mediated C-H activation and aerobic C-H oxygenation with Cp*Ir catalysts

The effect of oxidatively stable L- and X-type additives on the activity of Cp*Ir catalyst precursors in the C-H activation of arenes has been studied. Turnover numbers for C-H activation of up to 65 can thus be achieved, as determined by H/D exchange in MeOH-D-4. In particular, carbonate additives are found to enhance the C-H activation reactivity of Cp*Ir(H2O)(3)(OTf)(2) (1) more significantly than L-type ligands investigated in this study. Based on these studies, Cp*Ir/carbonate systems are developed that catalyze the aerobic C-sp3-H oxygenation of alkyl arenes, employing air as oxidant.