Zheng Shuai, Gutiérrez-Bonet Álvaro, Molander Gary A
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
These authors contributed equally to this work.
Chem. 2019 Feb 14;5(2):339-352. doi: 10.1016/j.chempr.2018.11.014. Epub 2019 Jan 3.
The integration of amidyl radicals with cross-coupling chemistry opens new venues for reaction design. However, the lack of efficient methods for the generation of such radical species has prevented many such transformations from being brought to fruition. Herein, the amidoarylation of unactivated olefins by a cascade process from non-functionalized amides is reported by merging, for the first time, photoredox proton-coupled electron transfer (PCET) with nickel catalysis. This new technology grants access to an array of complex molecules containing a privileged pyrrolidinone core from alkenyl amides and aryl- and heteroaryl bromides in the presence of a visible light photocatalyst and a nickel catalyst. Notably, the reaction is not restricted to amides - carbamates and ureas can also be used. Mechanistic studies, including hydrogen-bond affinity constants, cyclization rate measurements, quenching studies, and cyclic voltammetry were central to comprehend the subtleties contributing to the integration of the two catalytic cycles.
酰胺基自由基与交叉偶联化学的结合为反应设计开辟了新途径。然而，缺乏生成此类自由基物种的有效方法阻碍了许多此类转化的实现。本文首次通过将光氧化还原质子耦合电子转移（PCET）与镍催化相结合，报道了从未官能化酰胺通过级联过程对未活化烯烃进行酰胺芳基化反应。这项新技术在可见光光催化剂和镍催化剂存在下，能够从烯基酰胺以及芳基和杂芳基溴化物制备一系列含有特殊吡咯烷酮核心的复杂分子。值得注意的是，该反应不仅限于酰胺——氨基甲酸酯和脲也可使用。包括氢键亲和常数、环化速率测量、猝灭研究和循环伏安法在内的机理研究对于理解促成两个催化循环整合的微妙之处至关重要。
