Epoxidation of alkenes by a highly reusable and efficient polymer-supported molybdenum carbonyl catalyst

Molybdenum hexacarbonyl was immobilized on polystyrene (2% cross-linked with divinylbenzene) via imidazole linkage to obtain a polymer-supported molybdenum carbonyl catalyst (2). High conversion of a range of alkenes to epoxides was achieved with tert-butyl hydroperoxide and this catalyst. cis and trans stilbenes have been completely converted to their corresponding epoxides. Epoxidation of trans-stilbene led to only trans epoxide whereas cis-stilbene produced a 23.3:1 mixture of cis/trans epoxides, respectively. The supported catalyst is highly reusable and it was reused 10 times without a considerable change in its activity.