The complexes (PPh4)(2)[(MoO2)-O-VI(NCS)(4)] (1), (MoO2)-O-VI(NCS)(2)(di-tBu-bipy) (2) and Mo (2) (VI) O-5(NCS)(2)(di-tBu-bipy)(2) (3) (di-tBu-bipy = 4,4'-di-tert-butyl-2,2'-bipyridine) were studied as catalyst precursors for the oxidation of cyclooctene (Cy8) and benzyl alcohol (BzOH), using either dimethyl sulfoxide (DMSO) or tert-butyl hydroperoxide (TBHP) as oxidant. By dissolving complex 2 in the room temperature ionic liquid 1-butyl-3-methylpyridinium tetrafluoroborate, the catalytic performance with TBHP was improved (higher selectivity to the aldehyde and higher Cy8 conversions). For Cy8 oxidation, the unreacted substrate and products were easily extracted with n-hexane, and the ionic phase containing the catalyst could be reused without loss of catalytic performance.