Asymmetric Michael Reaction of Malononitrile and α,β-Unsaturated Aldehydes Catalyzed by Diarylprolinol Silyl Ether

An asymmetric Michael reaction of malononitrile and alpha,beta-unsaturated aldehydes catalyzed by a diarylprolinol silyl ether was developed. Michael products were obtained in good yields and with excellent enantioselectivities without the formation of overreaction products. As a malononitrile moiety can be transformed into an alkoxy or amino carbonyl moiety by oxidative transformation, alpha-chiral esters or amides with all-carbon quaternary centers can be synthesized with excellent enantioselectivities.