Ligand- and Substrate-Controlled Chemodivergent Pd-Catalyzed Annulations of Cyclic β-Keto Esters with 3-Aryl-2H-azirines

Recent advances in ligand-enabled palladium-catalyzed divergent synthesis

Developing efficient and straightforward strategies to rapidly construct structurally distinct and diverse organic molecules is one of the most fundamental tasks in organic synthesis, drug discovery and materials science. In recent years, divergent synthesis of organic functional molecules from the same starting materials has attracted significant attention and has been recognized as an efficient and powerful strategy. To achieve this objective, the proper adjustment of reaction conditions, such as catalysts, solvents, ligands, etc., is required. In this review, we summarized the recent efforts in chemo-, regio- and stereodivergent reactions involving acyclic and cyclic systems catalyzed by palladium complexes. Meanwhile, the reaction types, including carbonylative reactions, coupling reactions and cycloaddition reactions, as well as the probable mechanism have also been highlighted in detail.

Enantio- and Diastereoselective Copper-Catalyzed Synthesis of Chiral Aziridines with Vicinal Tetrasubstituted Stereocenters

A Cu-catalyzed coupling of cyclic imino esters with 2H-azirines has been developed to synthesize novel optically active aziridines in high yields with excellent levels of diastereo- and enantioselectivities under mild conditions. This novel protocol features a broad substrate scope and good functional group compatibility, and it enriches the existing reaction type of rapid synthesis of optically active aziridines bearing vicinal tetrasubstituted stereogenic carbon centers.