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 (‐C 6 H 4 ‐ n‐ Hex), electron‐rich (‐C 6 H 4 ‐NPh 2 ) and electron‐deficient (‐C 4 H 3 N 2 ) 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. magnified image