Enantioselective Michael Addition-Cyclization Reaction

Significance

This is one of the first reports of a successful intramolecular trapping of zinc-enolates (generated through copper-catalyzed Michael addition of organozinc reagents). Phosphor­amidite ligands used for this transformation are easily accessible and, combined with Cu(II), provide a highly efficient catalytic system. The reaction proceeds smoothly to give cyclic products in only two diastereomeric forms and moderate to high enantio­selectivities. The biggest advantage of this methodology is the generation of multifunctional products with consecutive stereocenters capable of further synthetic elaboration.