Quinone Dehydrogenation. Oxidation of Benzylic Alcohols with 2,3-Dichloro-5,6-dicyanobenzoquinone

Article abstract of DOI:10.1021/jo01297a010

2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ) reacts with primary and secondary aryl-substituted alcohols under mild conditions in dioxane solution to give the corresponding carbonyl compounds in high yields.In contrast to other oxidants, DDQ can be applied advantageously for the oxidation of hydroxyaryl-substituted alcohols.A mechanism involving participation of the phenolic hydroxyl group in the dehydrogenation reaction is discussed.Oxidations of hydroxyaryl-substituted alcohols by DDQ in methanolsolution resulting in the formation of benzoquinones by loss of the hydroxyaryl side chain are interpreted in terms of phenol oxidation.An example of a pyridine-catalyzed Smiles rearrangement of an o-hydroxy-substituted diphenyl ether is reported.