Hydrogen Atom Transfer Reactions via Photoredox Catalyzed Chlorine Atom Generation. Issue 48 (19th October 2018)

• Record Type: Journal Article
• Authors: Rohe, Samantha; Morris, Avery O.; McCallum, Terry; Barriault, Louis
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 48(2018)
• Page Start: 15664
• Page End: 15669
• Publication Date: 2018-10-19
• Subjects: alkyl radicals -- C−H functionalization -- chlorine -- hydrogen atom transfer -- photoredox catalysis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201810187
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The selective functionalization of chemically inert C−H bonds remains to be fully realized in achieving organic transformations that are redox‐neutral, waste‐limiting, and atom‐economical. The catalytic generation of chlorine atoms from chloride ions is one of the most challenging redox processes, where the requirement of harsh and oxidizing reaction conditions renders it seldom utilized in synthetic applications. We report the mild, controlled, and catalytic generation of chlorine atoms as a new opportunity for access to a wide variety of hydrogen atom transfer (HAT) reactions owing to the high stability of HCl. The discovery of the photoredox mediated generation of chlorine atoms with Ir‐based polypyridyl complex, [Ir(dF(CF3 )ppy)2 (dtbbpy)]Cl, under blue LED irradiation is reported. Abstract : A HAT trick : The generation of highly reactive chlorine atoms through photoredox mediated reductive quenching of *[Ir(dF(CF3 )ppy)2 (dtbbpy)] + with chloride is reported. The C−H functionalization of a variety of alkanes, alcohols, ethers, ester, amides, aldehydes, and silanes through hydrogen atom transfer (HAT) processes with chlorine atoms underwent efficient redox‐neutral coupling reactions with activated alkenes.