Biomimetic Fe(Pytacn)-Catalyzed Intramolecular C(sp3)–H Amination: Access to Heteroarene-Functionalized Sultams

Abstract A new Fe(Pytacn)-catalyzed intramolecular aliphatic C(sp3)–H amination system is reported for the first time via metal-nitrene-mediated C–H insertion. This protocol operates under mild room-temperature conditions, affording 20 structurally diverse sultams in up to 90% yield with up to >20:1 dr, including synthetically challenging substrates bearing heteroatoms or bulky substituents. Mechanistic studies demonstrate a radical pathway, with both Pytacn ligand and acac counterion being critical; the kinetic isotopic effect indicates C–H insertion is rate-determining. The products can be easily modified with various building blocks via simple chemical transformations.