Asymmetric Epoxidations of Disubstituted Enones with Iron

Significance

Asymmetric epoxidation is a highly investigated field, featuring many diverse catalysts which can react with a broad range of substrates. Despite years of study, the epoxidation of acyclic β,β-disubstituted enones is still a synthetic challenge. These substrates are typically less electrophilic than their monosubstituted derivatives because of their increased steric bulk and lack of conjugation between the alkene and carbonyl group due to steric repulsion. The authors have developed an iron catalyst with novel chiral phenanthroline ligands that allows asymmetric ­epoxidation of these substrates in good yields and enantiomeric excess.