铜催化合成 5-芳基-6-(三氟甲基)-2,3-二氢吡唑并[1,2-a]吡唑-1(5H)-酮。

Copper-Catalyzed Synthesis of 5-Aryl-6-(Trifluoromethyl)-2,3-Dihydropyrazolo[1,2-a]Pyrazol-1(5H)-One.

机构信息

Fujian Provincial Key Laboratory of Electrochemical Energy Storage Materials and Key Laboratory of Molecule Synthesis and Function Discovery College of Chemistry, Fuzhou University, Fuzhou, 350108, P. R. China.

Testing and Analysis Center, Soochow University, Suzhou, 215123, P. R. China.

出版信息

Chem Asian J. 2021 Sep 20;16(18):2669-2673. doi: 10.1002/asia.202100693. Epub 2021 Aug 10.

DOI:10.1002/asia.202100693

PMID:34313007

Abstract

An efficient protocol for the synthesis of 5-aryl-6-(trifluoromethyl)-2,3-dihydropyrazolo[1,2-a]pyrazol-1(5H)-one derivatives through a copper-catalyzed [3+2]-cycloaddition of azomethine imines with 3,3,3-trifluoropropyne (generated in situ from dehydrobromination of 2-bromo-3,3,3-trifluoropropene under base conditions) is developed. The advantages of this transformation are the broad substrate scope and the good functional group compatibility. The subsequent oxidation and nucleophilic substitution/aromatization provide a new approach to 4-trifluoromethylated pyrazol-1-yl propanoic acids.

摘要

通过铜催化的亚胺与 3,3,3-三氟丙炔（在碱条件下由 2-溴-3,3,3-三氟丙烯脱溴生成）的[3+2]-环加成反应，开发了一种高效合成 5-芳基-6-(三氟甲基)-2,3-二氢吡唑并[1,2-a]吡唑-1(5H)-酮衍生物的方法。该转化的优点是底物范围广，官能团兼容性好。随后的氧化和亲核取代/芳构化提供了一种新的方法来制备 4-三氟甲基吡唑-1-基丙酸。