A cooperative NHC/nickel catalytic methodology has been developed for the synthesis of ketones employing aromatic aldehydes and tertiary alkyl iodides. All key steps of the postulated catalytic cycle were validated with comprehensive stoichiometric and electrochemical studies, including reduction of Ni^II by the deprotonated Breslow intermediate, Ni⁰ promoted halogen-atom abstraction to generate transient tertiary alkyl radicals, and coupling between the latter with the persistent acyl thiazolium radical intermediate. Such a broadly proposed and accepted, yet elusive, acyl thiazolium radical intermediate has been isolated and studied by a single-crystal X-ray diffraction study.

中文翻译：

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用镍化学促进 N-杂环卡宾自由基有机催化：一种基于合理机理研究的方法

开发了一种 NHC/镍合作催化方法，用于使用芳香醛和叔烷基碘合成酮。假设的催化循环的所有关键步骤都通过全面的化学计量和电化学研究进行了验证，包括通过去质子化的 Breslow 中间体还原 Ni ^{II ，Ni 0}促进卤素原子抽象以产生瞬态叔烷基自由基，以及后者与持久叔烷基自由基之间的偶联。酰基噻唑自由基中间体。这种被广泛提出和接受但难以捉摸的酰基噻唑鎓自由基中间体已通过单晶 X 射线衍射研究进行了分离和研究。