Asymmetric Conjugate Addition of α-Cyanoketones to Benzoyl Acrylonitrile Derivatives Using a Diaminomethylenemalononitrile Organocatalyst

A diaminomethylenemalononitrile (DMM) organocatalyst was used to efficiently promote asymmetric conjugate addition of various α-cyanoketones to benzoyl acrylonitrile derivatives. The corresponding 1,5-dicarbonyl compounds containing vicinal tertiary and quaternary stereogenic centers are versatile synthetic intermediates and were obtained in good yields and with excellent enantioselectivities (up to 96% ee). The present study describes the first successful examples of asymmetric conjugate addition reactions of α-cyanoketones with benzoyl acrylonitriles. In addition, the DMM organocatalyst can be recovered and reused up to five times without significant loss of either catalytic activity or enantioselectivity.