Synthesis of 3‐Thiocyanobenzothiophene via Difunctionalization of Active Alkyne Promoted by Electrochemical‐Oxidation

• Published in: Chemistry : a European journal Vol. 29; no. 17; pp. e202203306 - n/a
• Main Authors: Zhang, Dong, Yang, Qijun, Cai, Jinlin, Ni, Chunjie, Wang, Qingdong, Wang, Qingming, Yang, Jinming, Geng, Rongqing, Fang, Zheng
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 22.03.2023; Wiley Subscription Services, Inc
• Subjects: Alkynes; benzothiophene; Catalysts; Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; Continuous flow; difunctionalization; electrochemical synthesis; Electrochemistry; environmentally friendly; Flow system; Oxidants; Oxidation; Oxidizing agents; Physical Sciences; Potassium; Reagents; Science & Technology; Substrates; Thiocyanates; thiocyanation; ROUTE; electrochemical synthesis; ACIDS; difunctionalization; BOND FORMATION; thiocyanation; C-H FUNCTIONALIZATION; DISCOVERY; STRATEGIES; (+/-)-FASICULARIN; CYCLIZATION REACTIONS; benzothiophene; CHEMISTRY; environmentally friendly
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202203306

A novel and green method for the synthesis of 3‐thiocyanatobenzothiophenes via electrochemical‐oxidation promoted difunctionalization of active alkyne has been developed. In this protocol, inexpensive and easily available potassium thiocyanate was chosen as the thiocyanation reagent, 2‐alkynylthioanisoles as the substrates, a variety of 3‐thiocyanatobenzothiophenes were obtained in moderate to good yields under oxidant‐ and catalyst‐free conditions. Moreover, the continuous flow system has good applicability for this transformation, the use of continuous flow system has overcome the disadvantage of low efficiency in traditional electrochemical amplification, and realized the stable and excellent yields of target products in the scale‐up reactions. A clean and efficient electrochemical method for the preparation of 3‐thio/selenocyanatobenzothiophenes has been developed. This method features excellent functional group compatibility, broad substrate scope and easy to scale‐up in continuous flow.