从现成的三氟甲基结构单元(如三氟甲基 N-酰基腙或三氟乙酰肼基溴化物与马来酰亚胺)的 [3 + 2] 环加成反应,开发了一种高效实用的三氟甲基吡咯并吡唑衍生物制备方案。该方法得到 3-三氟甲基化吡咯烷并 [3,4- c ]pyrazolidin-4,6-dione 和 3-三氟甲基化二氢吡咯并 [3,4-c]pyrazole-4,6(1 H ,5 H )-diones在温和的反应条件下获得优异的产率。3-三氟甲基化二氢吡咯并[3,4- c ]吡唑-4,6(1 H ,5 H )-二酮可以顺利氧化为3-三氟甲基化吡咯并[3,4-c]pyrazole-4,6(1H,5H)-diones by TCCA under mild reaction conditions.
Synthesis of trifluoromethylated pyrazolidines by [3 + 2] cycloaddition
作者:Xiansha Peng、Danfeng Huang、Ke-Hu Wang、Yalin Wang、Juanjuan Wang、Yingpeng Su、Yulai Hu
DOI:10.1039/c7ob01299c
日期:——
A highly efficient [3 + 2] cycloaddition between trifluoromethylated N-acylhydrazones and nitroolefins in the presence of potassium hydroxide under phase transfer catalysis is developed to afford potentially bioactive trifluoromethylated pyrazolidines, which can be further transformed into trifluoromethylated pyrazoles in good yields.
[3+2] Cycloaddition of Trifluoromethylated N-Acylhydrazones with Maleates: Synthesis of Trifluoromethylated Pyrazolidines
作者:Lan Wen、Danfeng Huang、Ke-Hu Wang、Yuxiang Wang、Lili Liu、Zheng Yang、Yingpeng Su、Yulai Hu
DOI:10.1055/s-0036-1591768
日期:2018.5
developed under basic conditions. This protocol provides an easy access to potentially bioactive trifluoromethylated pyrazolidines in moderate to excellent yields. It also illustrates that the trifluoromethylated N-acylhydrazones are useful trifluoromethyl building blocks for the synthesis of trifluoromethylated N-heterocycles. An efficient [3+2] cycloaddition reaction of trifluoromethylated N-acylhydrazones
Synthesis of 3-Trifluoromethyl-1,2,4-triazolines and 1,2,4-Triazoles via Tandem Addition/Cyclization of Trifluoromethyl <i>N</i>-Acylhydrazones with Cyanamide
作者:Xiaoling Liu、Haimei Liu、Chang Bian、Ke-Hu Wang、Junjiao Wang、Danfeng Huang、Yingpeng Su、Xiaobo Lv、Yulai Hu
DOI:10.1021/acs.joc.2c00176
日期:2022.5.6
A tandem addition/cyclization reaction between trifluoromethyl N-acylhydrazones and cyanamide is described, which provides a novel and efficient process for the synthesis of polysubstituted 3-trifluoromethyl-1,2,4-triazolines and their derivatives. The method has the advantages of mild reaction conditions, a broad substrate scope, good product yields, and atom economy.
Synthesis of trifluoromethyl formazans by reaction of trifluoromethyl N-acylhydrazones/N-Aryl hydrazones and aryldiazonium tetrafluoroborates
作者:Ke-Hu Wang、Chang Bian、Xiuwen Liang、Wenjing Luo、Junjiao Wang、Danfeng Huang、Yulai Hu
DOI:10.1016/j.jfluchem.2023.110211
日期:2023.11
azo-coupling reaction of trifluoromethyl N-acylhydrazones/N-aryl hydrazones with aryldiazonium tetrafluoroborates was developed for the synthesis of various trifluoromethyl formazans. This protocol has the advantages of mild reaction condition, broad substrate scope and easy operation, which extends the application of trifluoromethyl N-acylhydrazones/N-aryl hydrazones as versatile trifluoromethyl building blocks
The cyclization/rearrangement of α-hydroxy ketones with trifluoromethyl <i>N</i>-acylhydrazones to synthesize multi-substituted trifluoromethyloxazolines
A highly efficient and metal-free [3+2] cyclization/rearrangement reaction toward the synthesis of multisubstituted trifluoromethyloxazolines from α-hydroxyketones and trifluoromethyl N-acylhydrazones has been developed. The unprecedented rearrangement of the amide fragment under acidic conditions after cleavage of the N–N bond of acylhydrazones has opened up new avenues for the development of reactions