Pietrasiak Ewa, Ha Seongmin, Jeon Seungwon, Jeong Jongheon, Lee Jiyeon, Seo Jongcheol, Lee Eunsung
Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, South Korea.
J Org Chem. 2022 Jul 1;87(13):8380-8389. doi: 10.1021/acs.joc.2c00221. Epub 2022 Jun 22.
C(aryl)-OMe bond functionalization catalyzed by cobalt(II) chloride in combination with a nacnac-type ligand and magnesium as a reductant is reported. Borylation and benzoylation of aryl methoxides are demonstrated, and C(aryl)-SMe bond borylation can be achieved under similar conditions. This is the first example of achieving these transformations using cobalt catalysis. Mechanistic studies suggest that a Grignard reagent is generated as an intermediate in a rare example of a magnesiation a C-O bond activation reaction. Indeed, an organomagnesium species could be directly observed by electrospray ionization mass spectroscopic analysis. Kinetic experiments indicate that a heterogeneous cobalt catalyst performs the C-O bond activation.
据报道，氯化钴与一种nacnac型配体以及镁作为还原剂相结合可催化芳基甲醚的C(芳基)-OMe键官能化反应。已证明芳基甲醚的硼化和苯甲酰化反应，并且在类似条件下可实现C(芳基)-SMe键的硼化反应。这是使用钴催化实现这些转化的首个实例。机理研究表明，格氏试剂作为一种中间体在罕见的镁化——C-O键活化反应中生成。实际上，通过电喷雾电离质谱分析可直接观察到有机镁物种。动力学实验表明，一种多相钴催化剂可进行C-O键活化反应。
