Stereoselective domino conjugate addition of Grignard reagents to lactones followed by reaction with activated alkenes catalyzed by ferrocenyl carbene ligands

Ferrocenyl phosphane-carbene ligands catalyze domino reactions composed of conjugate addition of Grignard reagents to α,β-unsaturated lactone followed by enolate trapping with activated alkenes. The corresponding α,β-disubstituted lactones were obtained in medium yields, but with high diastereomeric and enantiomeric purities up to 98:2 er.