Li Hao, Xia Hong-Cheng, Nie Fang-Yuan, Song Qin-Hua
Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China.
J Org Chem. 2021 Jun 18;86(12):8308-8318. doi: 10.1021/acs.joc.1c00749. Epub 2021 May 27.
A facile and effective synthesis of 2-chloromethylpyridines was developed by a one-pot reaction of 2-alkylpyridin--oxides and triphosgene at room temperature. As starting materials, -oxides of 2-alkylpyridine derivatives, including 2-alkylpyridines, 2-methyl quinolines, and phenanthroline, can react rapidly with triphosgene in the presence of triethylamine, affording 2-chloromethylpyridines in good to excellent yields (52-95%). Using the 2-methylquinoline substrate for the mechanistic study, it has been well demonstrated that the chlorination reaction undergoes a [3,3]-sigmatropic rearrangement, which can be observed as a reversible process by monitoring the intermediates. Moreover, the chlorination reaction can be used to construct a rapid and sensitive fluorescent probe for the detection of phosgene.
通过2-烷基吡啶-N-氧化物与三光气在室温下的一锅法反应，开发了一种简便有效的2-氯甲基吡啶合成方法。作为起始原料，2-烷基吡啶衍生物的N-氧化物，包括2-烷基吡啶、2-甲基喹啉和菲咯啉，在三乙胺存在下能与三光气快速反应，以良好至优异的产率（52-95%）得到2-氯甲基吡啶。以2-甲基喹啉底物进行机理研究，充分证明氯化反应经历了[3,3]-σ迁移重排，通过监测中间体可观察到这是一个可逆过程。此外，氯化反应可用于构建一种快速灵敏的用于检测光气的荧光探针。
