Designed non-symmetrical 4,7-pi-extended-2,1,3-benzothiadiazole derivatives: Synthesis guided by DFT predictions

A series of rationally designed, non‐symmetrical, 4,7‐π‐extended‐2,1,3‐benzothidiazole derivatives had their electronic and geometrical properties evaluated by means of DFT calculations. The data obtained from the calculated 2,1,3‐benzothiadiazole (BTD) intermediates allowed the design and synthesis of a final structure bearing a fluorine‐containing aromatic group on one side of the BTD ring and a C≡C spacer linking a long chain‐containing (C8) aromatic group on the other side. This specific molecular architecture is expected to display liquid crystalline behavior. The new designed structure was therefore synthesized in good overall yield using cross‐coupling reactions (Suzuki and Sonogashira reactions). Copyright © 2013 John Wiley & Sons, Ltd. A series of rationally designed, non‐symmetrical, 4,7‐pi‐extended‐2,1,3‐benzothidiazole (BTD) derivatives had their electronic and geometrical properties evaluated by means of DFT calculations. The new designed structures were therefore synthesized guide by DFT predictions. The monosubstituted derivatives were obtained through Suzuki cross‐coupling reactions using Dupont's catalyst. The final designed BTD had its second pi‐extension through two consecutives Sonogashira couplings in good overall yields.