Succinct New Synthetic Route to Tetrathienoanthracene‐Based Hole‐Transporting Materials via Pd‐Catalyzed Direct CH/CBr Coupling Reactions

Tetrathienoanthracene ( TTA ) is a π‐extended derivative of anthracene fused with four thiophene rings. TTA core‐based small‐ and macromolecules have been extensively studied in the field of organic optoelectronic materials. However, by far, the existing synthetic routes to TTA ‐relevant molecules all relied on the traditional multistep synthesis involving tedious substrate prefunctionalization operations (10 steps). Herein, we reported a succinct new synthetic pathway (4 steps) to TTA core‐based oligoarenes via palladium‐catalyzed direct CH/CBr cross‐couplings. Reaction conditions for the multifold direct CH (hetero)arylations were optimized, thus allowing the smooth production of four new small molecules π‐extended from the TTA core. These obtained oligoaryls were fabricated as hole‐transport material in perovskite solar cells. Devices utilizing one of the TTA ‐based oligoaryls as hole‐transport layer exhibited power conversion efficiencies up to 13.61%.