区域选择性合成三芳基取代的含氟吡唑

Facile Access to Triaryl-Substituted Pyrazoles via a Regioselective 1,3-Dipolar Cycloaddition Reaction

本文报道了碱促进下的三氟甲基取代炔与原位生成的腈亚胺的[1,3]-偶极环加成反应。该反应具有操作简单、条件温和、官能团兼容性好的特点,能以良好的产率和优异的区域选择性得到含有三氟甲基取代的吡唑杂环化合物。目标产物结构均经过1H NMR、13C NMR、19F NMR、HRMS等确证。该反应有望在生物活性分子合成中得到应用。

A convenient and efficient route for the synthesis of trifluomethyl-substituted pyrazoles via a 1 , 3- dipolar cycloaddition reaction of trifluoromethylated alkynes and nitrile imines, which generated in situ from the corresponding hydrazonoyl chlorides, is described. This reaction proceeds with good functional group tolerance, excellent regioselctivity, mild reaction conditions, and moderate to good yields. All of the products were characterized by 1H NMR, 13C NMR, 19F NMR and HRMS analysis. Moreover, this methodology will serve as an important tool for the construction of 4-trifluoinethylpyrazole derivatives with biological activities.