One-pot synthesis of fused-rings heterocyclic systems based on symmetrically benzofuran annulated 1,8-naphthalimides

A useful and straightforward synthetic approach to afford heteroarenes by symmetrical annulation of two benzofuran units to 1,8-naphthalene anhydrides, through a regioselective one-pot Sn–Ar/C–H activation tandem reaction is introduced herein. Two synthetic pathways are compared, highlighting that the utilization of diester derivatives improves: (i) the compatibility with the key ring expansion step, (ii) the solubility of the intermediate thus facilitating its purification, and (iii) the versatility of the final imidization. The electrochemical and spectral properties of this new class of compounds are investigated.