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

Synthesis of the indole skeleton was achieved using a Pd-catalyzed cascade process consisting of isocyanide insertion and benzylic C(sp³)–H activation. It was found that slow addition of isocyanide is effective for reducing the amount of catalyst needed and Ad₂P^<i>n</i>Bu is a good ligand for C(sp³)–H activation. The construction of the tetracyclic carbazole skeleton was also achieved by a Pd-catalyzed domino reaction incorporating alkyne insertion