A Rapid and Efficient Synthesis of Quinone Derivatives: Ru(II)‐ or Ir(I)‐Catalyzed Hydrogen Peroxide Oxidation of Phenols and Methoxyarenes

Hydroquinone and methoxybenzene derivatives were catalytically oxidized promptly to the corresponding quinones in up to 99% yield. With a catalyst loading of 0.01 mol %, a maximum TON of 8.4×10³ was attained in the case of Ru(II)‐complex. Ru(II)(pybox‐dh)(pydic) is able to enhance the hydrogen peroxide oxidation of substituted hydroquinones as well as methoxybenzenes, but Ir[(coe)₂Cl]₂ and Ir[(cod)Cl]₂ were found to be effective catalysts only for the former substrates under similar oxidation conditions.