Ferrocene phosphane–carbene ligands in Cu-catalyzed enantioselective 1,4-additions of Grignard reagents to α,β-unsaturated carbonyl compounds

•Ferrocenyl phosphane–carbene ligands are useful for Cu-catalyzed conjugate addition of Grignard reagents.•Best Michael acceptors are 5,6-dihydro-2H-pyran-2-one and cyclohex-2-enone.•The ligands are applicable also to domino conjugate addition followed by aldol or Mannich reaction.•NMR shows coordination of copper with carbene and weak coordination with phosphorus.

Chiral ferrocene phosphane–carbenes are good ligands for the copper-catalyzed 1,4-addition of Grignard reagents to various Michael acceptors. The products were obtained in high enantiomeric purity (up to e.r. = 95:5) and excellent regioselectivity (r.r. = 99:1). These ligands are also useful for domino conjugate addition followed by enolate trapping with imine and aldehyde.

Graphical abstractChiral ferrocene phosphane–carbenes are useful in the copper-catalyzed 1,4-addition of Grignard reagents to cyclic α,β-unsaturated carbonyl compounds. The products were obtained in high enantiomeric purity (up to e.r. = 95:5) and excellent regioselectivity. These ligands are applicable also for domino conjugate addition followed by reaction with imine or aldehyde.Figure optionsDownload full-size imageDownload as PowerPoint slide