Annulation of the Ugi Products Using Palladium Catalysts

Abstract

For almost half a century of efforts to make them, the importance of Ugi products has substantially expanded because they are used as precursors for the synthesis of more complex structures, such as peptides, amino acids, pharmaceutical compounds, and heterocycles. Through the introduction of a double or triple bond along with a carbon‐halide bond in the starting materials, the Ugi adduct can be cyclized through Pd‐catalyzed intramolecular reactions to create sophisticated heterocycles. This article discusses the role of palladium in the catalytic cyclization of the Ugi adducts and covers the published research from 2000 to 2022. Moreover, the proposed mechanisms of Pd‐catalyzed annulation of Ugi adducts are also reviewed.