No abstract

No abstract

No abstract

Asymmetric conjugate additions of phosphonates to trans-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.

A diaminomethylenemalononitrile organocatalyst efficiently promotes the asymmetric direct vinylogous conjugate additions of α-angelica lactones to benzoyl acrylonitrile derivatives, resulting in the corresponding addition products bearing vicinal tertiary and quaternary stereogenic centers with excellent enantioselectivities (up to 99% ee). This report is the first successful example of the asymmetric conjugate additions of α-angelica lactone to benzoyl acrylonitriles. The chiral γ,γ-disubstituted γ-butenolides obtained can be readily transformed to the bicyclic γ-lactam derivative as a valuable synthetic intermediate.