Other Metal-Catalysed Epoxidations of Unfunctionalised Olefins

4 Other Metal-Catalysed Epoxidations of Unfunctionalised Olefins 

Whilst the Sharpless epoxidation with titanium catalysts and the Jacobsen-Katsuki epoxidation with manganese(salen) complexes are at the forefront of enantioselec-tive epoxidation with metal catalysts, there are alternative systems available. Ruthenium pyridinebisoxazoline (PYBOX) complexes have been independently reported, using either phenyliodinium diacetate or sodium periodate as 

Enantiomerically pure manganese complexes using ligands other than the salen structure have been reported, but so far with lower enantioselectiv-ities. Better results have been achieved using molybdenum complexes bearing hydroxamic acid ligands and TBHP or cumylhydroperoxide as oxidant. This system has been used to effect the epoxidation of a range of olefins with up to 96% ee. 

---