H. Adolfsson et al., Efficient Epoxidation of alkenes with aqueous hydrogen peroxide catalyzed by methyltrioxorhenium and 3-cyanopyridine, J ORG CHEM, 65(25), 2000, pp. 8651-8658
The epoxidation of alkenes with 30% aqueous hydrogen peroxide:is catalyzed
efficiently by methyltrioxorhenium (MTO) in the presence of pyridine additi
ves. The addition of 1-10 mol % of 3-cyanopyridine increases the system's e
fficiency for terminal and trans-disubstituted alkenes resulting in high is
olated yields of the corresponding epoxides. The system allows for epoxidat
ion of alkenes with Various functional groups. Alkenes leading to acid-sens
itive products are efficiently epoxidized using a mixture of pyridine and 3
-cyanopyridine as additives. This method is operationally very simple and u
ses an environmentally benign oxidant.,The effects of different pyridine ad
ditives on the alkene conversion and the catalyst lifetime are discussed.