Unraveling the Regio- and Enantioselective Control in Transition Metal-Catalyzed Reductive Hydrofunctionalization of <i>N</i> -Heteroendocyclic Alkenes

-heteroalkenes has emerged as a powerful strategy for the construction of enantiopure 2-/3-substituted pyrrolidine derivatives. However, the origin of the regio- and enantioselective control, particularly under the modulation of bisoxazoline (BOX) ligands, remains to be fully elucidated. Herein, our density functional theory (DFT) studies revealed that the chain-walking process governs the regioselectivity, while the hydrogen atom transfer (HAT) step dictates the enantioselectivity. Energy decomposition analysis reveals that orbital interactions, complemented by electrostatic effects, serve as the predominant factors in governing both regio- and stereoselectivity. Furthermore, the noncovalent interactions between the substrate and the BOX ligand serve to further stabilize the preferred transition states, thereby fine-tuning the energetic landscape of the reaction. These insights provide a rational basis for the development of transition-metal-catalyzed precise functionalization of heterocycles.