Under the catalysis of PhCO2H, the 1,3-dipolar [3+2] cyclo­addition between pyrazolone-based olefins and N,N′-cyclic azomethine imines proceeded readily, thus delivering structurally novel spiropyrazolones with up to 98% yield and >20:1 dr. The relative stereochemical configuration of the obtained spiropyrazolones was unambiguously ­assigned by X-ray single-crystal structure analysis. The diastereoselective formation of the title spiropyrazolones was interpreted by the hypothesized reaction mechanism.

中文翻译：

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通过基于吡唑啉酮的烯烃和 N,N'-环偶氮甲碱亚胺之间的 1,3-偶极 [3+2] 环加成非对映选择性合成螺吡唑啉酮

在 PhCO2H 的催化下，基于吡唑啉酮的烯烃和 N,N'-环状偶氮甲亚胺之间的 1,3-偶极 [3+2] 环加成反应很容易进行，从而以高达 98% 的产率和 >20 的方式提供结构新颖的螺吡唑啉酮： 1 博士 通过 X 射线单晶结构分析明确指定了获得的螺吡唑啉酮的相对立体化学构型。标题螺吡唑啉酮的非对映选择性形成通过假设的反应机制进行解释。