Palladium-Catalyzed Cascade Process Consisting of Isocyanide Insertion and Benzylic C(sp3)–H Activation: Concise Synthesis of Indole Derivatives

Abstract

Synthesis of the indole skeleton was achieved using a Pd-catalyzed cascade process consisting of isocyanide insertion and benzylic C(sp(3))-H activation. It was found that slow addition of isocyanide is effective for reducing the amount of catalyst needed and Ad(2)P(n)Bu is a good ligand for C(sp(3))-H activation. The construction of the tetracyclic carbazole skeleton was also achieved by a Pd-catalyzed domino reaction incorporating alkyne insertion.