Department of Chemistry, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Frontiers Science Center for Synthetic Biology (Ministry of Education), and Tianjin Collaborative Innovation Center of Chemical Science & Engineering, Tianjin University, Tianjin 300072, P. R. China.
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, P. R. China.
Org Lett. 2021 Aug 6;23(15):6062-6066. doi: 10.1021/acs.orglett.1c02139. Epub 2021 Jul 28.
A diethylzinc-promoted unconventional annulation reaction of 2,2,2-trifluorodiazoethane with 2-azirines is described. This transformation involves two [3 + 2] cycloaddition steps and one dinitrogen extrusion process in one pot, thus giving a broad array of 3-trifluoromethyl pyrazolines in good yields with excellent diastereoselectivities. Further transformations provide facile access to 3-trifluoromethyl pyrazoles and 3,5-ditrifluoromethyl pyridazines with good efficiency.
本文描述了二乙基锌促进的 2,2,2-三氟重氮乙烷与 2-氮丙啶的非常规环加成反应。该转化在一锅反应中涉及两个 [3 + 2] 环加成步骤和一个二氮分子的释放过程，因此以优异的非对映选择性得到了广泛的 3-三氟甲基吡唑啉类化合物，产率良好。进一步的转化提供了以良好的效率获得 3-三氟甲基吡唑和 3,5-二三氟甲基哒嗪的简便途径。
