Enantioselective Epoxidation of cis-Alkenyl-silanes

Significance

Enantioselective epoxidation of terminal olefins remains an important problem of asymmetric catalysis. Alongside with direct epoxidation of the olefins, the corresponding epoxides can be prepared via epoxidation of alkenylsilanes. However, asymmetric variants of this synthetic approach have not been extensively studied so far. Titanium salalen and salan complexes, previously developed by the group of Katsuki, have been successfully employed for the preparation of cis-epoxysilanes with the use of aqueous hydrogen peroxide as an oxidant. The products can undergo desilylation or alkylation reactions providing access to various terminal epoxides with complete retention of enantiomeric purity.