Asymmetric Conjugate Addition of Phosphonates to Enones Using Cinchona–Diaminomethylenemalononitrile Organocatalysts

Abstract

Asymmetric conjugate additions of phosphonates to <i>trans</i>-crotonophenone and chalcone derivatives using a diaminomethylenemalononitrile organocatalyst resulted in the generation of the corresponding chiral γ-ketophosphonates in high yields with excellent enantioselectivities (up to 95% ee). This report is the first successful example of asymmetric 1,4-additions of phosphonate to α,β-unsaturated ketones using an organocatalyst.