作者:Haruo Matsuzaki、Norihiko Takeda、Motohiro Yasui、Yuta Ito、Keiji Konishi、Masafumi Ueda
DOI:10.1021/acs.orglett.0c03465
日期:2020.12.4
A Brønsted acid-mediated synthesis of pyrazoles from conjugated hydrazones through a β-protonation/nucleophilic addition/cyclization/aromatization sequence was developed. This protocol utilizing the ambiphilic reactivity of hydrazones enables not only self-condensation but also cross-condensation, affording multisubstituted pyrazoles in high yields, with a broad substrate scope. This sequential reaction
通过β-质子化/亲核加成/环化/芳构化序列,开发了布朗斯台德酸介导的共轭from合成吡唑的方法。该方案利用the的两亲反应性,不仅可以进行自缩合,而且还可以进行交叉缩合,从而以高收率提供多取代的吡唑,具有广泛的底物范围。通过简单的操作,该顺序反应在温和条件下进行。而且,该方法可以应用于非甾体抗炎药Lonazolac的合成。