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.