Synthesis of <i>N</i>-Arylpyrazoles by Palladium-Catalyzed Coupling of Aryl Triflates with Pyrazole Derivatives
作者:Shunsuke Onodera、Takuya Kochi、Fumitoshi Kakiuchi
DOI:10.1021/acs.joc.9b00673
日期:2019.5.17
palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C–N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives proceeded efficiently to give N-arylpyrazole products in high yields. 3-Trimethylsilylpyrazole was found to be an excellent pyrazole substrate for the coupling, and the corresponding
描述了通过钯催化的芳基三氟甲磺酸酯与吡唑衍生物的偶合来合成N-芳基吡唑的方法。使用t BuBrettPhos作为配体,钯催化的各种芳基三氟甲磺酸酯(包括邻位取代的芳基三氟甲磺酸酯)与吡唑衍生物的C-N偶联有效地进行,以高收率得到N-芳基吡唑产物。发现3-三甲基甲硅烷基吡唑是偶联的极佳吡唑底物,相应的产物1-芳基-3-三甲基甲硅烷基吡唑也可作为合成N-芳基吡唑衍生物的很好模板,如在该区域的区域选择性卤化所证明的那样。吡唑环的3位,4位和5位。