Ruthenium-Catalyzed Hydroxylation of Unactivated Tertiary C−H Bonds

The combination of catalytic RuCl(3) and pyridine with KBrO(3) as the stoichiometric oxidant is shown to efficiently promote the hydroxylation of unactivated tertiary C-H bonds. Substrates possessing different polar functional groups--ester, epoxide, sulfone, oxazolidinone, carbamate, and sulfamate--are found to engage in this reaction to give alcohol products in yields generally exceeding 50%. As judged based on efficiency, ease of operation, substrate scope, and selectivity toward tertiary C-H centers, the method appears competitive with other C-H hydroxylation processes.