Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
J Am Chem Soc. 2022 Jul 6;144(26):11888-11896. doi: 10.1021/jacs.2c04822. Epub 2022 Jun 23.
Ketone-olefin coupling reactions are common methods for the formation of carbon-carbon bonds. This reaction class typically requires stoichiometric or super stoichiometric quantities of metal reductants, and catalytic variations are limited in application. Photoredox catalysis has offered an alternative method toward ketone-olefin coupling reactions, although most methods are limited in scope to easily reducible aromatic carbonyl compounds. Herein, we describe a mild, metal-free ketone-olefin coupling reaction using an excited-state acridine radical super reductant as a photoredox catalyst. We demonstrate both intramolecular and intermolecular ketone-olefin couplings of aliphatic and aromatic ketones and aldehydes. Mechanistic evidence is also presented supporting an "" ketone-olefin coupling mechanism.
酮-烯烃偶联反应是形成碳-碳键的常用方法。该反应通常需要化学计量或超化学计量的金属还原剂，且催化变体的应用受到限制。光氧化还原催化为酮-烯烃偶联反应提供了一种替代方法，尽管大多数方法的适用范围仅限于易于还原的芳香族羰基化合物。在此，我们描述了一种温和的、无金属的酮-烯烃偶联反应，使用激发态吖啶自由基超还原剂作为光氧化还原催化剂。我们证明了脂肪族和芳香族酮和醛的分子内和分子间酮-烯烃偶联。还提出了支持“酮-烯烃偶联机制”的机理证据。
