Solvent and ligand effects on α-pinene epoxidation with Methyltrioxorhenium/hydrogen peroxide system (MTO/H2O2)

Several ligands were studied as co-catalysts for α-pinene epoxidation with MTO/H2O2. Pyridine is an efficient co-catalyst with dichlorometane, tetrahydrofuran or ethyl acetate. However, large amounts of pyridine are required. In contrast, with relatively small amounts of the Aromox surfactant, high activity and selectivity to α-pinene epoxide are obtained. The latter system has the additional advantage of requiring no chlorinated solvents which are environmentally less friendly.