Concise Synthesis of Dithiophene Derivatives by a Palladium‐ Catalyzed Multiple C–S Cross Coupling/Cyclization Sequence

The facile synthesis of new sulfur-containing fused heterocycles was achieved by a two-fold domino reaction consisting of a carbon-sulfur cross-coupling, followed by a 5-endo-dig cyclization. Using this strategy a series of benzo-, thiopheno-, pyridine- and pyrazino-dithienoacenes with electron-neutral (-C6H4-n-Hex), electron-rich (-C6H4-NPh2) and electron-deficient (-C4H3N2) substituents was synthesized in high yields. The developed method was applied in the efficient synthesis of a complex donor-acceptor molecule. The photophysical and electrochemical properties of the products were analyzed by UV-VIS/luminescence spectroscopy and cyclic voltammetry.