Copper-Catalyzed Double S-Arylation of Potassium Thioacetate with Dibenziodolium Triflates: Facile Synthesis of Unsymmetrical Dibenzothiophenes

• Published in: European journal of organic chemistry Vol. 2016; no. 16; pp. 2785 - 2788
• Main Authors: Shimizu, Masaki, Ogawa, Mai, Tamagawa, Tomokazu, Shigitani, Ryosuke, Nakatani, Masaki, Nakano, Yoshiki
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 01.06.2016; Wiley; Wiley Subscription Services, Inc
• Subjects: Annulation; Chemistry; Chemistry, Organic; Copper; Fused-ring systems; Hypervalent compounds; Physical Sciences; Science & Technology; Sulfur heterocycles; PALLADIUM; CROSS-COUPLING REACTION; ONE-POT SYNTHESIS; POLYCYCLIC AROMATIC-HYDROCARBONS; Hypervalent compounds; EFFICIENT SYNTHESIS; DIARYL THIOETHERS; C-H ACTIVATION; CASCADE REACTION; CYCLIC DIARYLIODONIUMS; Sulfur heterocycles; ARYL HALIDES; Copper; Annulation; Fused-ring systems
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201600357

Much interest has been paid to cyclic diaryliodonium salts as bis(electrophile)s in transition‐metal‐catalyzed annulation reactions to produce polycyclic (hetero)aromatic hydrocarbons. Herein, we report that dibenziodolium triflates smoothly react with potassium thioacetate in the presence of CuCl2 in THF or DMSO at 100–110 °C to afford the corresponding dibenzothiophenes in good‐to‐high yields. The coupling reaction tolerates reactive functional groups such as chloro and cyano and serves as a facile and reliable method for the synthesis of unsymmetrical dibenzothiophenes. The CuCl2‐catalyzed annulation of dibenziodolium triflates with potassium thioacetate is described. This method provides a facile and reliable synthesis of unsymmetrical dibenzothiophenes including donor–π–acceptor‐type compounds. A gram‐scale synthesis is also demonstrated.