Synthesis and Modular Reactivity of Pyrazole 5-Trifluoroborates: Intermediates for the Preparation of Fully Functionalized Pyrazoles
作者:Prisca Fricero、Laurent Bialy、Andrew W. Brown、Werngard Czechtizky、María Méndez、Joseph P. A. Harrity
DOI:10.1021/acs.joc.6b02847
日期:2017.2.3
The regioselective condensation of hydrazines and ynone trifluoroborates provides access to a range of pyrazole 5-trifluoroborates. The stability of the borate unit allows chemoselective halogenation of the heteroaromatic ring, thereby delivering pyrazole scaffolds that allow orthogonal functionalization at C5 and C4. The modular reactivity of these intermediates is exemplified by cross-coupling reactions
肼和乙炔酮三氟硼酸酯的区域选择性缩合提供了一系列吡唑5-三氟硼酸酯的入口。硼酸酯单元的稳定性允许杂芳族环的化学选择性卤化,从而提供吡唑支架,该支架允许在C 5和C 4处进行正交官能化。这些中间体的模块化反应性通过交叉偶联反应来举例说明,从而可以进行区域控制的全官能化吡唑的合成衍生品。