Photoredox‐Catalyst‐Enabled para‐Selective Trifluoromethylation of tert‐Butyl Arylcarbamates. Issue 35 (20th July 2021)

• Record Type: Journal Article
• Authors: Jiang, Yaqiqi; Li, Bao; Ma, Nana; Shu, Sai; Chen, Yujie; Yang, Shan; Huang, Zhibin; Shi, Daqing; Zhao, Yingsheng
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 35(2021)
• Page Start: 19030
• Page End: 19034
• Publication Date: 2021-07-20
• Subjects: photoirradiation -- site selectivity -- ten gram scale -- trifluoromethylation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202105631
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The direct incorporation of a trifluoromethyl group on an aromatic ring using a radical pathway has been extensively investigated. However, the direct highly para ‐selective C−H trifluoromethylation of a class of arenes has not been achieved. In this study, we report a light‐promoted 4, 5‐dichlorofluorescein (DCFS)‐enabled para ‐selective C−H trifluoromethylation of arylcarbamates using Langlois reagent. The preliminary mechanistic study revealed that the activated organic photocatalyst coordinated with the arylcarbamate led to para ‐selective C−H trifluoromethylation. Ten‐gram scale reaction performs well highlighting the synthetic importance of this new protocol. Abstract : We report a light‐promoted 4, 5‐dichlorofluorescein (DCFS)‐enabled para ‐selective C−H trifluoromethylation of arylcarbamates using the Langlois reagent. Arylcarbamates, including the bioactive compound chlorzoxazone, vorinostat precursor, chlorpropham, and teriflunomide precursors, were suitable for this reaction, leading to the formation of the corresponding products in moderate to good yields.