Ruthenium‐Catalyzed Cascade CH Functionalization of Phenylacetophenones

Three orthogonal cascade CH functionalization processes are described, based on ruthenium‐catalyzed CH alkenylation. 1‐Indanones, indeno indenes, and indeno furanones were accessed through cascade pathways by using arylacetophenones as substrates under conditions of catalytic [{Ru(p‐cymene)Cl2}2] and stoichiometric Cu(OAc)2. Each transformation uses CH functionalization methods to form CC bonds sequentially, with the indeno furanone synthesis featuring a CO bond formation as the terminating step. This work demonstrates the power of ruthenium‐catalyzed alkenylation as a platform reaction to develop more complex transformations, with multiple CH functionalization steps taking place in a single operation to access novel carbocyclic structures.