Pd-Catalyzed Domino Narasaka–Heck/C–H Activation/Amination Reactions: Synthesis of Bis-heterocyclic Spirocycles

The palladium-catalyzed synthesis of bis-heterocyclic spirocycles containing both pyrroline and indoline motifs is reported. Di-tert-butyldiaziridinone is used to functionalize palladacycles generated in situ via domino Narasaka–Heck/C–H activation reactions. The reaction is readily scalable, and the spirocyclic products can undergo deprotection, reduction, and (3 + 2) cycloadditions, highlighting their synthetic utility. Additionally, kinetic isotope effect experiments support a turnover-limiting C–H functionalization step in the catalytic cycle.