Synthesis of 1H-Indole-3-carboxamidines through a Palladium-Catalyzed Three-Component Reaction Involving Isocyanide Insertion as a Key Step

A three-component reaction involving isocyanides, o-alkynyltrifluoroacetanilides, and amines for the efficient synthesis of 2-substituted 1H-indole-3-carboxamidines has been developed. The reaction proceeds through intramolecular aminopalladation of alkynes activated by isocyanide-ligated palladium(II) species. Dioxygen acts as the sole oxidant to regenerate the active palladium(II) species.