Enantioselective Pyrazole Alkylation via Iridium and Squaramide Catalyzed N-H Insertion.

); the combination of Ir and squaramide catalysts mediates asymmetric protonation with excellent enantiocontrol. These findings establish a strategy for the asymmetric N-H insertion of pyrazoles, providing access to chiral nitrogen heterocycles previously inaccessible by asymmetric catalysis. This concept extends to indazole functionalization and enables the first disclosed asymmetric synthesis of a PARP7 inhibitor.