Ruthenium-Catalyzed Csp^³-H Oxidation of Tertiary Alkanes

Significance

The combination of catalytic RuCl₃˙xH₂O and pyridine with KBrO₃ as oxidizing agent proved as an efficient system for the hydroxylation of unactivated tertiary C-H bonds. The reaction proceeds chemoselectively with a preference for the tertiary C-H bond at the low end. High selectivities can be achieved if one of the two tertiary C-H bonds is more proximal to an electron-deficient group. Non-oxidizable functional groups, such as tertiary alcohols, epoxides, acyl-oxazolidinones, sulfones and sulfamates are well tolerated.