Catalysis of acetoacetonate complexes for the selective oxidation of p-chlorotoluene with oxygen in the presence of ethanal was first reported. The effects of the center metal ions, the amount of catalyst and ethanal, the oxygen pressure, the reaction time, and the reaction solvents on the selective oxidation were investigated. The results showed that among the acetoacetonate complexes, Co(acac)₃ had the best catalytic activity. The optimum reaction conditions were as follows: 0.764 mmol of Co(acac)₃, molar fraction of ethanal 10% based on the substrate, room temperature, oxygen pressure 2 MPa, reaction time 11 h and acetonitrile as solvent. Under these conditions, 13.34% p-chlorobenzaldehyde was obtained with 15.3% conversion and 87.16% selectivity. The oxidation can also be carried out without solvent with 8.14% conversion, 89.08% selectivity and 7.25% yield respectively.

Key words: p-chlorobenzaldehyde, selective oxidation, biomimetic catalysis, p-chlorotoluene