Bifunctional Guanidine via an Amino Amide Skeleton for Asymmetric Michael Reactions of β‐Ketoesters with Nitroolefins: A Concise Synthesis of Bicyclic β‐Amino Acids

Two activations are better than one: The chiral bifunctional guanidine 1, which features an amino amide backbone, catalyzes the asymmetric Michael addition of a range of substrates and gives products with excellent stereoselectivities. The method also allows the efficient synthesis of optically pure beta-amino acid esters. Both the guanidine group and the NH proton of the amide were important for the dual activation.