Highly efficient catalysts of chitosan-Schiff base Co(II) and Pd(II) complexes for aerobic oxidation of cyclohexane in the absence of reductants and solvents

Three chitosan-Schiff base Co(II) and Pd(II) complexes were prepared and characterized. The complexes have shown high catalytic activities for cyclohexane oxidation with molecular oxygen without any solvents and reductants. When chitosan-salicyaldehyde Schiff base Co(II) complex was used as catalyst, 9100 turnover numbers and 96% selectivity were obtained. The complexes can be reused several times and are also efficient for the oxidation of bulky cyclic alkanes and linear alkanes.