Atroposelective Synthesis of Pyridoindolones Bearing Two Remote Distinct C–N Axes through Cobalt-Catalyzed Enantioselective C–H Activation

C–N axially chiral compounds represent an important class of atropisomers that are prevalent in bioactive and material molecules. Despite recent advances in synthetic methodologies, the asymmetric construction of atropisomers featuring multiple C–N axes has been rarely explored, significantly limiting their further applications. Herein, we report a novel atroposelective synthesis of diaxially chiral pyridoindolones featuring both six–five and six–six C–N axes through cobalt-catalyzed asymmetric C–H annulation. This approach demonstrates exceptional efficiency, yielding a diverse array of chiral pyridoindolones with excellent yields and atroposelectivities (60 examples, up to >99% yield, >99% ee, and >20:1 dr). Mechanistic studies revealed that the stereochemistry of both C–N axes were generated and fixed simultaneously during the C–H cyclometalation step, along with an unexpected asymmetric amplification effect. The practicality of this protocol is further underscored by successful gram-scale syntheses and various transformations, including the formation of a chiral phosphine ligand. Notably, exceptional photoluminescence quantum yields (ΦF up to 0.99) and positive solvatochromism were observed, coupled with significant chiroptical properties, underscoring the potential applications of these compounds in organic fluorescent materials.