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

Asymmetric conjugate additions of phosphonates to trans-crotonophenone and chalcone derivatives using a diamino-methylenemalononitrile organocatalyst resulted in the generation of the corresponding chiral gamma-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 alpha,beta-unsaturated ketones using an organocatalyst.