Axially chiral heterobiaryl anilines are privileged scaffolds widely embedded in natural products and bioactive molecules, and they serve as highly efficient chiral ligands or organocatalysts owing to their outstanding catalytic performance. As a result, the development of efficient asymmetric synthetic methods for these architectures has attracted intense attention. Photoredox/nickel dual catalysis has emerged as a versatile and mild platform for the construction of diverse C(sp²)-heteroatom bonds; however, its enantioselective variant remains extremely rare. Herein, we develop a single-electron-transfer (SET)-based photoredox/nickel dual catalytic system that accomplishes atroposelective C(sp²)-N bond formation between readily available arylamines and racemic heterobiaryl triflates. After systematic optimization of the reaction parameters, the desired axially chiral products were obtained in up to 98% yield and 86% enantiomeric excess (ee). The general procedure for this atroposelective C-N coupling is as follows: inside a nitrogen-filled glovebox, NiBr₂(DME) (10 mol%) and chiral ligand (12 mol%) were combined with photocatalyst (2 mol%) in anhydrous toluene (3.0 mL) and stirred at room temperature for 30 min. Subsequently, racemic heterobiaryl triflates (0.1 mmol, 1.0 equiv.), arylamines (1.5 equiv.), N-tert-butylisopropylamine (1.5 equiv.), and ethyl acetate (3.0 mL) were added. The vial was sealed, brought out of the glovebox, and stirred under irradiation with 45 W blue LEDs at 0 ^oC for 12 h. After completion of the reaction, the mixture was concentrated in vacuo and purified by silica gel chromatography to afford the pure product. The substrate scope proved to be broad: a range of substituted anilines, heterocyclic arylamines, and structurally diverse heterobiaryl triflates were well tolerated. Mechanistic experiments demonstrated that the reaction operates through a SET pathway rather than an energy-transfer mechanism. This work not only provides a new strategy for photoredox/nickel dual-catalyzed asymmetric C(sp²)-N coupling but also opens an avenue for the enantioselective synthesis of axially chiral biaryl anilines.

Key words: Asymmetric C(sp²)-N bond coupling, Photoredox/Ni cocatalysis, (Hetero)Biaryl atropisomer, Axial chirality, Asymmetric catalysis