PALLADIUM(II) SULFATE-HETEROPOLY ACID-CATALYZED OXIDATION OF CYCLOOLEFINS IN LIQUID PHASE.

Article abstract of DOI:10.1246/bcsj.57.1908

Heteropoly acid (HPA) was used as an oxidant in the Wacker catalyst system. Among the catalyst systems examined, the PdSO//4-H//3PMo//6W//6O//4//0 catalyst system showed the highest activity with regard to the oxidation of cycloolefins, particularly cyclopentene and cyclohexene, to the corresponding cyclic ketones. The largest total turnover number with respect to Pd**3** plus was found to be 85 in water containing 20% N-methylformamide by volume. The rate-determining step was suggested as being where cyclohexene was oxidized to cyclohexanone by Pd(II) salt. The apparent activation energy was 7. 8 kcal mol** minus **1 (1 cal equals 4. 18 J). In the catalytic oxidation of cycloolefins (C//nH//2//n// minus //2: n equals 5, 6, 7, and 8), the yield of alicyclic ketone decreased as the carbon number n increased.