Synthetically versatile electron-deficient π-electron systems are urgently needed for organic electronics, yet their design and synthesis are challenging due to the low reactivity from large electron affinities. In this work, we report a benzo[de]isoquinolino[1,8-gh]quinoline diamide (BQQDA) π-electron system. The electron-rich condensed amide as opposed to the generally-employed imide provides a suitable electronic feature for chemical versatility to tailor the BQQDA π-electron system for various electronic applications. We demonstrate an effective synthetic method to furnish the target BQQDA parent structure, and highly selective functionalization can be performed on bay positions of the π-skeleton. In addition, thionation of BQQDA can be accomplished under mild conditions. Fine-tuning of fundamental properties and supramolecular packing motifs are achieved via chemical modifications, and the cyanated BQQDA organic semiconductor demonstrates a high air-stable electron-carrier mobility.