Ring Selective Generation of Isobenzofuran for Divergent Access to Polycyclic Aromatic Compounds.

Ring selective generation of isobenzofuran, a formal equivalent to bis-isobenzofuran, was developed. Importantly, selective introduction of functionalities and/or fused rings in the isobenzofuran core by iterative cycloadditions can achieve the divergent construction of polycyclic compounds. This selective approach enables us to prepare a regioisomeric pair of pentacenes.