Formation of quaternary chiral centers by N-heterocyclic carbene-Cu-catalyzed asymmetric conjugate addition reactions with Grignard reagents on trisubstituted cyclic enones.

The copper-catalyzed conjugate addition of Grignard reagents to 3-substituted cyclic enones allows the formation of all-carbon chiral quaternary centers. We demonstrate in this article that N-heterocyclic carbenes act as efficient chiral ligands for this transformation. High enantioselectivities (up to 96% ee) could be obtained for a variety of substrates.

Enantioselective organocatalytic conjugate addition of alpha-aminoketone to nitroolefins.

The enantioselective organocatalytic conjugate addition of alpha-aminoketone to nitroolefins is reported.

Copper-catalyzed asymmetric conjugate addition of Grignard reagents to trisubstituted enones. Construction of all-carbon quaternary chiral centers.

The copper-catalyzed asymmetric conjugate addition of Grignard reagents to trisubstituted cyclic enones affords enantioenriched all-carbon quaternary centers with up to 96% ee. The chiral ligand is a diaminocarbene, directly generated in situ. The combination of Grignard reagent and diaminocarbene is unprecedented in conjugate addition, and the additon of the phenyl group, on such enones, cannot be done by other conjugate addition methods.