Palladium-Catalyzed Reaction of Arylamine and Diarylacetylene: Solvent-Controlled Construction of 2,3-Diarylindoles and Pentaarylpyrroles

By choosing DMF and dioxane as solvent, skeletons of indoles and pyrroles were constructed from alkynes and amines in the presence of PdCl2, respectively. These Pd-catalyzed reactions were phosphane-free with high atom efficiency and could be conducted under mild basic conditions. The proposed mechanism for the selective formation of indoles and pyrroles in different solvents is also discussed in this paper.