Heterogeneous Catalyst for Enantioselective Epoxidation of α,β-Unsaturated Ketones

Significance

Highly enantioselective epoxidation of α,β-unsaturated ketones with cumene hydro­peroxide is accomplished with heterogenization of Shibasaki’s Binol/La catalyst. While many different linkers were tested with different topologies the simple 1,4-ethynyl-phenylene showed consistently high yields and enantioselectivities. The catalyst was formed by addition of the chiral unit to a solution of the metal in THF. The precipitated solid catalyst was shown to have high activity and selectivity through six runs at a loading of 5 mol%.