Regioselective C–H hydroxylation of n-alkanes using Shilov-type Pt catalysis in perfluorinated micro-emulsions†
Shilov-chemistry inspired catalysis has remained largely overlooked as a tool for establishing the remote hydroxylation of non-polar compounds, such as long linear alkanes, due to the need for an acidic aqueous solution. To circumvent the solubility issue, the concept of micellar catalysis is introduced, using PtII in perfluorinated micro-emulsions. Notably, the terminal C–H activation of n-heptane is demonstrated under an oxygen atmosphere using perfluorooctanoic acid (PFOA) as a surfactant, along with the intrinsic ability of PtII to convert the highly inert primary C–H bonds. Coordination of PtII to the carboxylate groups of PFOA proved to be particularly important for achieving maximum catalyst activity towards the hydrocarbon substrate solubilized inside the micelle interior. Based on these insights, optimization of the reaction parameters allowed a positional selectivity of 60% for 1-heptanol, among the C7 alcohols, to be achieved, using low catalyst and surfactant loadings under acid-free conditions.