Synthesis of Indenones via Palladium‐Catalyzed Ligand‐Free Carbonylation

A palladium‐catalyzed ligand‐free carbonylation reaction has been developed for the synthesis of indenones. Under CO atmosphere, this cascade reaction proceeded smoothly to provide the desired indenones in moderate to excellent yields with good functional‐group compatibility. The mechanistic investigations suggested the in situ formation of palladium nanoparticles and this transformation was driven by a controlled reaction sequence of alkyne insertion followed by carbonylation and annulation to form the indenone framework. magnified image