The catalytic activity of a water-soluble Mn(salen)OAc complex in the epoxidation of alkenes and hydroxylation of alkanes was studied in acetonitrile, at room temperature, using sodium periodate as an oxygen source. The effect of various axial ligands as co-catalyst such as triethylamine, diethylamine, piperidine, 4-cyanopyridine, 2-methylpyridine, 4-methylpyridine, 4-tert-butylpyridine, 2-methylimidazole, pyrazine, quinalidine, morpholine, triphenylphosphine and dimethylformamide were investigated in the epoxidation of cyclooctene. Imidazole as a strong pi-donor was the best axial ligand. The effect of different solvents was studied in the epoxidation of cyclooctene and CH3CN/H2O was chosen as solvent. The effect of the oxygen donors such as NaIO4, Bu4NIO4, KHSO5, H2O2, H2O2/urea, NaOCl and tert-BuOOH was also studied in the epoxidation of cyclooctene where NaIO4 was selected as an oxygen donor. (c) 2005 Elsevier B.V. All rights reserved.