Enantiomerically Enriched Aziridine‐2‐carboxylates via Copper‐Catalyzed Reductive Kinetic Resolution of 2 <i>H</i> ‐Azirines

Abstract

Abstract We present the first reductive kinetic resolution of racemic 2 H ‐azirines to prepare optically enriched N ‐H aziridine‐2‐carboxylates, which are bench stable and readily diversifiable building blocks, concomitantly with the corresponding enantiomerically enriched 2 H ‐azirines. The N ‐H aziridines were obtained with excellent diastereoselectivity (&gt;20:1) and high enantioselectivity (up to 94%). A Hammett study revealed a linear free energy relationship between the ΔΔG ⧧ of the diastereomeric transition states and the σ p − values. density functional theory (DFT) calculations and non‐covalent interaction analysis suggested that non‐classical H–bonding interactions and edge‐to‐face aromatic interactions between the substrate and the ligand are responsible for the stereoselectivity and also for the substrate electronic effects observed in the Hammett study.