Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides

• Published in: Angewandte Chemie Vol. 132; no. 42; pp. 18805 - 18813
• Main Authors: Forni, José A., Micic, Nenad, Connell, Timothy U., Weragoda, Geethika, Polyzos, Anastasios
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 12.10.2020
• Subjects: amides; Amines; Aromatic compounds; Bromides; carbonylation; Carbonyls; Catalysis; Catalysts; Chemistry; flow chemistry; Halides; Iodides; Iridium; Natural products; Photoredox catalysis; tandem reactions
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202006720

We report a new visible‐light‐mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)2(dtb‐bpy)]+ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional‐group tolerance, and enables the late‐stage amidation of complex natural products. A photoredox‐catalyzed radical carbonylative amidation of aryl, heteroaryl, and alkyl halides has been developed. The tandem catalytic cycle of [Ir(ppy)2(dtb‐bpy)]+ engages aryl bromides, iodides, and chlorides as well as primary, secondary, and tertiary alkyl iodides through a multiphoton‐initiated secondary catalytic cycle. In combination with continuous flow processing, this method furnishes diverse amides with mild reaction conditions.