A Novel Process for Selective Ruthenium‐Catalyzed Oxidation of Naphthalenes and Phenols

Arenes are selectively oxidized to the corresponding quinones employing ruthenium(2,2′,6′:2′′‐terpyridine)(2,6‐pyridinedicarboxylate) [Ru(tpy)(pydic] as catalyst and hydrogen peroxide as the terminal oxidant. Applying alkylated naphthalenes and phenols, benzo‐ and naphthoquinones are obtained in up to 93% yield. The industrially interesting oxidation of 2‐methylnaphthalene gave 74% of the corresponding quinones and 60% of menadione (vitamin K3). 2,3,5‐Trimethylbenzoquinone which constitutes the key intermediate for vitamin E is obtained in 83% yield.