Enantioselective Epoxidation of Electron‐Deficient Alkenes Catalyzed by Manganese Complexes with Chiral N₄ Ligands Derived from Rigid Chiral Diamines

A series of tetradentate sp 2 N/ sp 3 N hybrid chiral N 4 ligands derived from rigid chiral diamines were synthesized, which enabled the first manganese‐catalyzed enantioselective epoxidation of electron‐deficient alkenes with hydrogen peroxide (H 2 O 2 ) as an oxidant. The reaction furnishes enantiomerically pure epoxy amides, epoxy ketones as well as epoxy esters in good yields and excellent enantioselectivities (up to 99.9% ee ) with lower catalyst loading. Preliminary studies on structure–activity relationship demonstrated that maintaining comparatively lower electron‐donating ability of the sp 3 N and relatively higher electron‐donating ability of sp 2 N of the N 4 ligands is beneficial to getting higher activity and selectivity, thus providing us a new view to understand epoxidation with H 2 O 2 . magnified image