A two-step access to fused-/spiro-polycyclic frameworks via double Heck cascade and acid-driven processes.

This report illustrates the rapid construction of two divergent classes of polycyclic frameworks, benzo[ a ]fluorenones and spiro-chromenone indenes, via a double Heck cascade and an acid-driven cyclization from easily accessible precursors, alkyl 2-bromocinnamate esters and diphenylacetylenes. The present strategy has surveyed a broad substrate scope and delivered an array of products with interesting structural features. Besides, fluorescence studies were performed for the synthesized benzo[ a ]fluorenones.