In this article we report on the mechanistic studies of the Michael addition of amines and hydrazines to nitrostyrenes. Under the present conditions, the corresponding N-alkyl/aryl substituted benzyl imines and N-methyl/phenyl substituted benzyl hydrazones were observed via a retro-aza-Henry-type process. By combining organic synthesis and characterization experiments with computational chemistry calculations, we reveal that this reaction proceeds via a protic solvent-mediated mechanism. Experiments in deuterated methanol CD₃OD reveal the synthesis and isolation of the corresponding deuterated intermediated Michael adduct, results that support the proposed slovent-mediated pathway. From the synthetic point of view, the reaction occurs under mild, noncatalytic conditions and can be used as a useful platform to yield the biologically important N-methyl pyrazoles in a one-pot manner, simple starting with the corresponding nitrostyrenes and the methylhydrazine.

中文翻译：

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胺和肼向硝基苯乙烯的迈克尔加成反应的机理研究：通过逆转氮杂亨利型方法消除硝基烷

在本文中，我们报告了将胺和肼加成至硝基苯乙烯的机理研究。在当前条件下，通过逆转氮杂亨利型方法观察到了相应的N-烷基/芳基取代的苄基亚胺和N-甲基/苯基取代的苄基hydr。通过将有机合成和表征实验与计算化学计算相结合，我们揭示了该反应是通过质子溶剂介导的机理进行的。氘代甲醇CD _3的实验OD揭示了相应的氘代中间体迈克尔加合物的合成和分离，结果支持所提出的slovent介导的途径。从合成的观点来看，该反应在温和的非催化条件下进行，可以用作一锅法以生物学上重要的N-甲基吡唑的有用平台，简单地从相应的硝基苯乙烯和甲基肼开始。