Photoredox/Nickel‐Cocatalyzed Asymmetric C–O and C–S Couplings for Atroposelective Synthesis of <i>N</i> ‐Heterobiaryls

Abstract

Abstract Photoredox/nickel‐cocatalyzed cross‐couplings have emerged as powerful methods for constructing carbon–heteroatom bonds under mild conditions. Despite their rapid development, catalytic asymmetric C( sp 2 )–heteroatom couplings remain largely underexplored and challenging. Herein, we established photoredox/nickel‐cocatalyzed asymmetric C–O and C–S couplings of racemic heterobiaryl triflates with diverse oxygen and sulfur nucleophiles. This straightforward protocol enables highly enantioselective C( sp 2 )–O and C( sp 2 )–S bond formation under mild reaction conditions, providing diverse axially chiral N ‐heterobiaryls (&gt;100 examples) with excellent atroposelectivity and functional group tolerance. These axially chiral N ‐heterobiaryls can be further transformed into valuable chiral compounds, including commonly used chiral ligands and organocatalysts, while the resultant C–S coupling products can serve directly as chiral ligands in asymmetric catalysis. This study represents the first highly enantioselective photoredox/Ni‐cocatalyzed asymmetric C( sp 2 )–heteroatom bond coupling and introduces a new strategy for atroposelective synthesis of N ‐heterobiaryl atropisomers with wide applicability. Mechanistic investigations reveal that both C–O and C–S couplings proceed via an energy‐transfer pathway: the C–O coupling follows a kinetic resolution mechanism, while the C–S coupling proceeds via dynamic kinetic asymmetric transformation, thus providing valuable insights into this class of C( sp 2 )–heteroatom couplings and advancing this field.