Organocatalytic Mannich type reactions of glyoxylate imines and related compounds

Chiral β-amino carbonyl compounds serve as a useful building block in synthesizing diverse molecules. Organocatalytic Mannich-type reactions of glyoxylate imines provide efficient access to compounds with additional ester functionality. This article overviews recent advances in Mannich-type reactions using iminoester acceptor derivatives. In the first part, organocatalysts operating via covalent activation are discussed. The focus is on enamine-forming organocatalysts such as pyrrolidine-derived catalysts as well as catalysts based on other structural motifs. The second part deals with non-covalent organocatalysts, such as thioureas, squaramides, and more acidic chiral Brønsted acids. The new catalysts or their combinations allow for achieving high enantioselectivities and desired diastereoselectivities. Applications in the synthesis of target compounds are also demonstrated.