A new catalytic method for the denitrogenative transannulation/cyclopropanation of in‐situ‐generated 2‐(diazomethyl)pyridines is described using a cobalt‐catalyzed radical‐activation mechanism. The method takes advantage of the inherent properties of a Co^III‐carbene radical intermediate and is the first report of denitrogenative transannulation/cyclopropanation by a radical‐activation mechanism, which is supported by various control experiments. The synthetic benefits of the metalloradical approach are showcased with a short total synthesis of (±)‐monomorine.

中文翻译：

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基于钴（II）的2-（重氮甲基）吡啶金属自由基活化，用于自由基转环和环丙烷化

介绍了一种利用钴催化的自由基活化机理对原位生成的2-（重氮甲基）吡啶进行脱氮环转移/环丙烷化的新催化方法。该方法利用了Co ^III-卡宾自由基中间体的固有性质，并且是通过自由基激活机制进行脱氮脱环/环丙烷化的第一篇报道，并得到了各种控制实验的支持。（±）-单morine的总合成时间短，证明了金属-金属法的综合优势。