Recent Advances in the Synthesis of C-N/N-N Atropisomers via Asymmetric Annulation.

C-N/N-N atropisomers constitute pivotal structural elements in privileged scaffolds of natural products, bioactive compounds, chiral ligands, and advanced functional materials. With these wide-ranging utilities, the construction of these axially chiral frameworks has garnered increasing attention from chemists. This review highlights asymmetric annulation as a powerful and efficient strategy to construct such scaffolds, enabling simultaneous aromatic ring formation and axial chirality control in a single step. Recent advances up to August 2025 are summarized, covering both transition metal catalysis (eg., palladium, rhodium, copper, cobalt with chiral ligands) and organocatalysis (e.g., chiral phosphoric acids and N-heterocyclic carbenes). Key methodologies include [4 + 2] cyclizations, ynamide annulations, C-H activation, and annulations involving acroleins or aminocarbonyls, offering versatile routes to diverse C-N and N-N atropisomers with high enantioselectivity. This work provides an integration of catalytic systems previously reviewed in isolation, underscoring the progress in synthetic efficiency and catalytic system diversity.