Regioselective Decarboxylative Cycloaddition Route to Fully Substituted 3‐CF
<sub>3</sub>
‐Pyrazoles from Nitrilimines and Isoxazolidinediones
作者:Yu‐Chen Tian、Jun‐Kuan Li、Fa‐Guang Zhang、Jun‐An Ma
DOI:10.1002/adsc.202100091
日期:2021.4.13
1,4‐Diaryl‐5‐carboxamido substituted 3‐trifluoromethylpyrazoles are obtained with exclusive regioselectivity under transition‐metal‐free conditions. This decarboxylative [3+2] cycloaddition protocol was enabled by employing trifluoromethyl nitrilimines as 1,3‐dipoles, and isoxazolidinediones as CO2‐masked alkynyl dipolarophiles. The applicability of this method is further manifested by its compatibility
在无过渡金属的条件下,具有唯一的区域选择性,可得到1,4-二芳基-5-甲酰胺基取代的3-三氟甲基吡唑。该脱羧[3 + 2]环加成方案是通过使用三氟甲基腈亚胺作为1,3-偶极子和使用异恶唑烷二酮作为CO 2掩盖的炔基双极性亲和剂来实现的。该方法的适用性进一步证明了其与二氟甲基,烷基,芳基和杂芳基亚硝胺的相容性,以及药物Celebrex的4-羧基酰胺基类似物的制备。