Convergent synthetic approaches to polycyclic aromatic dicarboximides

Polycyclic aromatic dicarboximides (PADIs) as represented by naphthalene and perylene bis(dicarboximides) are useful molecules for a variety of functional materials and remain important synthetic targets for organic chemists. In this review, we summarize recent developments in the convergent synthetic approaches using palladium-catalysed annulation of peri-activated naphthalimides. Contrary to conventional linear synthetic methods where a single starting material is converted into a target molecule through a stepwise manner, the herein discussed convergent synthetic method enables rapid extension of the π-scaffold by combining multiple polyaromatic substrates into one. This method opened new possibilities for π-extended dicarboximides with so far up to five imide groups. Further exploration of annulation strategies may allow the preparation of previously inaccessible PADIs with fascinating molecular and material properties.