Visible‐Light‐Induced Selective Defluoroborylation of Polyfluoroarenes, gem‐Difluoroalkenes, and Trifluoromethylalkenes

• Published in: Angewandte Chemie Vol. 132; no. 10; pp. 4038 - 4045
• Main Authors: Xu, Wengang, Jiang, Heming, Leng, Jing, Ong, Han‐Wee, Wu, Jie
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 02.03.2020
• Subjects: Atom economy; Boranes; Borylradikale; Catalysis; Catalysts; Chemistry; Defluorborylierung; Fluorination; Organic compounds; Photokatalyse; Polyfluorarene; Regioselectivity; Substrates; Wasserstoffatomtransfer
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201911819

Fluorinated organoboranes serve as versatile synthetic precursors for the preparation of value‐added fluorinated organic compounds. Recent progress has been mainly focused on the transition‐metal catalyzed defluoroborylation. Herein, we report a photocatalytic defluoroborylation platform through direct B−H activation of N‐heterocyclic carbene boranes, through the synergistic merger of a photoredox catalyst and a hydrogen atom transfer catalyst. This atom‐economic and operationally simple protocol has enabled defluoroborylation of an extremely broad scope of multifluorinated substrates including polyfluoroarenes, gem‐difluoroalkenes, and trifluoromethylalkenes in a highly selective fashion. Intriguingly, the defluoroborylation protocol can be transition‐metal free, and the regioselectivity obtained is complementary to the reported transition‐metal‐catalysis in many cases. Die selektive Defluorborylierung von Polyfluorarenen, gem‐Difluoralkenen und Trifluormethylalkenen gelingt durch Photoredox‐ und Wasserstoffatomtransfer‐induzierte B‐H‐Aktivierung. Die Reaktionen liefern fluorierte Organoborane als Bausteine für höherwertige Organofluorverbindungen.