Study On Copper-Catalyzed Asymmetric Henry Reaction

The Henry reaction as a classical named reaction is frequently used in the carbon-carbon bond formation.Due to these reaction products can be further transformed to valuable synthetic intermediates,it is essential to study asymmetric Henry reaction.Based on related references,we conclude that chiral diamines coordinated with copper can catalyze asymmetric Henry reaction effectively.Chiral diamines can form stable metal complexes which concurrently activate electrophile(aldehyde)and nucleophile(nitrosoalkane).However,for creating a chiral environment in asymmetric transformations,it is essential to modify the ligands by introducing some effective functional groups.Considering the special structural and electronic properties of ferrocene,its derivatives have been widely used in asymmetric catalysis.In this paper,we first synthesized new copper complexes of ferrocene-derived diamine ligands,using this stereoscopic columnar structure of ferrocene as the bulky fragment,which could exert beneficial influence on the enantioselectivities.Copper complexes of ferrocene-derived diamine ligands can catalyze asymmetric Henry reaction effectively,obtaining corresponding products with good yield(up to 94%yield)and high enantioselectivity(87?93%ee).Through chemical calculation,complex geometry was optimized for explaining possible transition state.The experimental results expand the applications of chiral diamine in the asymmetric Henry reaction.Meanwhile,we have studied the diastereoselective Henry reaction,getting corresponding products with moderate enantioselectivity.