[3+2]-Cycloaddition of azomethine imines with 3,3,3-trifluoropropyne catalyzed by copper is achieved for the convenient access of 5-aryl-6-(trifluoromethyl)-2,3-dihydropyrazolo[1,2-a]pyrazol-1(5H)-one. The consecutive oxidation and nucleophilic substitution/aromatization of these trifluoromethyl substituted N,N-bicyclic pyrazolidinones give 4-trifluoromethylated pyrazol-1-yl propanoic acids.

中文翻译：

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铜催化合成 5-Aryl-6-(Trifluoromethyl)-2,3-Dihydropyrazolo[1,2-a]Pyrazol-1(5H)-One

铜催化下偶氮甲亚胺与 3,3,3-三氟丙炔的 [3+2]-环加成反应可方便地获得 5-芳基-6-(三氟甲基)-2,3-二氢吡唑并[1,2- a ]吡唑-1(5 H )-一。这些三氟甲基取代的N，N-双环吡唑烷酮的连续氧化和亲核取代/芳构化得到 4-三氟甲基化吡唑-1-基丙酸。