Regioselective Synthesis of 5-Trifluoromethylpyrazoles by [3 + 2] Cycloaddition of Nitrile Imines and 2-Bromo-3,3,3-trifluoropropene
作者:Hao Zeng、Xiaojie Fang、Zhiyi Yang、Chuanle Zhu、Huanfeng Jiang
DOI:10.1021/acs.joc.0c02765
日期:2021.2.5
A general and practical method for the synthesis of 5-trifluoromethylpyrazoles is reported that occurs by the coupling of hydrazonyl chlorides with environmentally friendly and large-tonnage industrial feedstock 2-bromo-3,3,3-trifluoropropene (BTP). This exclusively regioselective [3 + 2] cycloaddition of nitrile imines and with BTP is catalyst-free and operationally simple and features mild conditions
据报道,通过将酰氯与环境友好的大吨位工业原料2-溴-3,3,3-三氟丙烯(BTP)偶合,可以合成5-三氟甲基吡唑的通用方法。腈亚胺和BTP的这种唯一的区域选择性[3 + 2]环加成反应无催化剂,操作简单,具有温和的条件,高收率,可克级缩放,广泛的底物范围和有价值的官能团耐受性。重要的是,我们的方法已用于合成鞘氨醇1-磷酸受体活性激动剂的关键中间体。