Palladium-catalyzed oxidation of cyclohexanones to conjugated enones using molecular oxygen

Oxidation of cyclohexanones into conjugated enones with molecular oxygen as oxidant was achieved by palladium catalysts. A catalyst system consists of I mol % Pd(OCOCF3)(2) and 5,5'-dimethyl-2,2'-bipyridine accomplished maximum 84% yield for the oxidation of cyclohexanone and 51-78% yields for 4-SLibstituted-cyclohexanones. (C) 2007 Elsevier Ltd. All rights reserved.