Ligand relay catalysis enables asymmetric migratory dearomative annulation of N-heteroarenes

Chiral N-spiroheterocycles are privileged yet synthetically challenging scaffolds for ligands, functional materials, and drug discovery. Here we show a cobalt-catalyzed asymmetric migratory dearomative annulation of electron-deficient N‑heteroarenes for their construction. The success of this transformation hinges on a dynamic ligand relay catalysis strategy, wherein two distinct ligands work in tandem: one facilitates a 1,4-cobalt/hydride shift, and the other governs the enantioselective dearomative annulation, delivering chiral N-spiroheterocycles with high efficiency and selectivity. Despite their importance in ligand development, functional materials, and drug discovery, chiral N-spiroheterocycles remain challenging synthetic targets. Here, the authors report a cobalt-catalyzed asymmetric migratory dearomative annulation of electron-deficient N-heteroarenes enabling streamlined access to these frameworks.