Highly diastereo- and enantioselective organocatalytic Michael addition of alpha-ketoamides to nitroalkenes
Résumé
The first organocatalytic enantio- and diastereoselective conjugate addition of r-ketoamides to nitroalkenes has been achieved using a bifunctional amino thiourea catalyst. In this new approach, the substrate amide proton plays a critical role in the formation of the Michael anti-adducts in high yields and high stereoselectivities. To illustrate the high synthetic potential of this methodology, the diastereo- and enantioselective synthesis of a hexasubstituted cyclohexane via a Michael-Michael-Henry cascade reaction is described.