Assembly of spirocyclic pyrazolone-pyrrolo[4,3,2-de]quinoline skeleton via cascade [1,5] hydride transfer/cyclization by C(sp3)–H functionalization

Abstract

Herein, a highly efficient, scalable, and cascade [1,5] hydride transfer/cyclization method for constructing unique spirocyclic pyrazolone-pyrrolo[4,3,2-de]quinoline structures via C(sp³)–H functionalization is achieved, using pyrazolones and oxindoles attached to C4 amines. This strategy represents a limited approach utilizing C–H activation to construct spirocyclic pyrazolone scaffolds with moderate to excellent reaction performance.