A Concise and Efficient Route to Electron‐Accepting 2,2′‐[2,2′‐Arenediylbis(11‐oxoanthra[1,2‐b]thiophene‐6‐ylidene)]dipropanedinitriles

• Published in: European journal of organic chemistry Vol. 2018; no. 19; pp. 2259 - 2266
• Main Authors: Baranov, Denis S., Uvarov, Mikhail N., Kazantsev, Maxim S., Glebov, Evgeni M., Nevostruev, Danil A., Mostovich, Evgeny A., Antonova, Olga V., Kulik, Leonid V.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 24.05.2018; Wiley Subscription Services, Inc
• Subjects: Annulation; Chemical reactions; Chemistry; Chemistry, Organic; Construction standards; Electron paramagnetic resonance; Electron transfer; Electrons; Electron‐deficient compounds; Fluorescence; Functional organic materials; Fused‐ring systems; Molecular chains; Organic chemistry; Physical Sciences; Polycycles; Quinones; Science & Technology; Sodium sulfide; Spectrum analysis; Substrates; Sulfur heterocycles; POLYMERS; DESIGN; SMALL MOLECULES; PERFORMANCE; NON-FULLERENE ACCEPTORS; SULFUR; ORGANIC SEMICONDUCTORS; Polycycles; ASYMMETRIC LINEAR ACENES; ACETYLENIC DERIVATIVES; Quinones; Sulfur heterocycles; BASIS-SETS; Annulation; Fused-ring systems; Functional organic materials; Electron-deficient compounds
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201800275

A concise organolithium‐free route to build electron‐accepting molecules consisting of two 2‐(11‐oxoanthra[1,2‐b]thiophen‐6‐ylidene)propanedinitrile units connected by functionalized π‐conjugated linkers was developed. Annulation of two thiophene rings in one step was achieved through chemoselective cyclocondensation of a bis(ethynylanthraquinone) substrate with sodium sulfide. Finally, electron‐accepting dicyanomethylene moieties were introduced by Knoevenagel condensation with malodinitrile. The synthesized 2,2′‐[2,2′‐arenediylbis(11‐oxoanthra[1,2‐b]thiophene‐6‐ylidene)]dipropanedinitriles were studied by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, and DFT calculations. The acceptor properties of these compounds were confirmed by efficient light‐induced electron transfer in their blend with a donor polymer, poly(3‐hexylthiophene‐2,5‐diyl), detected by electron paramagnetic resonance spectroscopy. A three‐step sequence involving Sonogashira coupling, double thiophene annulation, and Knoevenagel condensation provides a concise and efficient route to build electron‐accepting molecules consisting of two 2‐(11‐oxoanthra[1,2‐b]thiophen‐6‐ylidene)propanedinitrile units connected by functionalized π‐conjugated linkers.