Synthesis of N-fused polycyclic indoles via a Pd-catalyzed multicomponent cascade reaction consisting of an amide-directed [3+1+1] annulation reaction of 3-diazo oxindole and isocyanides

Abstract

Herein, we report a Pd-catalyzed multicomponent cascade reaction of 3-diazo oxindole and isocyanides to synthesize N-fused polycyclic indoles consisting of an in situ generated amide-assisted regioselective [3+1+1] annulation reaction. Additionally, a mechanism is proposed and investigated using DFT that strongly favors the role of amide in assisting the annulation reaction, which is further confirmed using control experiments.