Transition‐Metal‐Free Allylic Defluorination Cross‐Electrophile Coupling Employing Rongalite

• Published in: Chinese journal of chemistry Vol. 42; no. 12; pp. 1360 - 1366
• Main Authors: Chen, Xiang‐Long, Wu, Chun‐Yan, Yang, Dong‐Sheng, Tang, Bo‐Cheng, Wang, Huai‐Yu, Yu, Zhi‐Cheng, Li, Anling, Wu, Yan‐Dong, Wu, An‐Xin
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 15.06.2024; Wiley Subscription Services, Inc
• Subjects: Alkenes; Catalysts; Cross coupling; C—C coupling; Defluorination; Defluoroarylation; gem‐Difluoroalkenes; Inflammation; Redox reactions; Reducing agents; Rongalite; Single electron transfer; Substrates; Transition metal free
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.202300751

Comprehensive Summary The conversion of CF3‐alkenes to gem‐difluoroalkenes using reductive cross‐coupling strategy has received much attention in recent years, however, the use of green and readily available reducing salt to mediate these reactions remains to be explored. In this work, a concise construction of gem‐difluoroalkenes, which requires neither a catalyst nor a metal reducing agent, was established. Rongalite, a safe and inexpensive industrial product, was employed as both a radical initiator and reductant. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates (>70 examples). The utility of this approach was demonstrated through gram‐scale synthesis and efficient late‐stage functionalizations of anti‐inflammatory drugs. A transition‐metal‐free allylic defluorination reductive cross‐coupling between CF3‐alkenes and diaryliodonium salts mediated by rongalite has been described for the first time. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates. The utility of this approach was demonstrated through gram‐scale synthesis and efficient late‐stage functionalizations of anti‐inflammatory drugs.