Oxidative combination of aromatic compounds in systems containing ruthenium complexes

1. A small yield of diphenyl is obtained in the presence of ruthenium hydroxychloride and oxalic acid in 50% ethyl alcohol. 2. The ruthenium hydroxychloride -sodium acetate system in acetic acid is an agent for oxidative combination of phenols. 3. In the presence of ruthenium hydroxychloride as catalyst hydrogen peroxide oxidizes 2,4,6-triterbutylphenol to 2,6-diterbutyl-1,4-benzoquinone and 4-hydroxy-2,4,6-triterbutyl-2,5-cyclohexadiene-1-one and oxidizes phenols (V) and (VI) to products of oxidative combination. 4. In the presence of palladium chloride and sodium acetate in an atmosphere of oxygen (or argon) only the products of oxidative combination of phenols (III) and V are obtained.