The multicomponent reaction mechanisms of prop-2-en-1-amine and ethyl propiolate with alloxan were studied using density functional theory. The reaction mechanisms were found to consist of two stages. First, the prop-2-en-1-amine reacts with ethyl propiolate to form an β-aminoacrylate through two competitive channels (channels a and b). Second, a nucleophilic addition of β-aminoacrylate to alloxan occurs via four possible channels (channels b1, b2, b3 and b4). The calculated results revealed that the most energetically favorable path is channel b4 and suggested that the water molecule plays as a proton transfer intermediate in the reaction. Our calculations demonstrated that the reaction occurs easily at room temperature, which agrees well with the experiment.

中文翻译：

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丙-2-烯-1-胺和丙酸乙酯与四氧嘧啶衍生物的多组分反应机理的认识：密度泛函理论研究

利用密度泛函理论研究了丙-2-烯-1-胺和丙酸乙酯与四氧嘧啶的多组分反应机理。发现反应机理包括两个阶段。首先，丙-2-烯-1-胺与丙酸乙酯反应，通过两个竞争性通道（通道a和b）形成β-氨基丙烯酸酯。其次，通过四个可能的通道（通道b1，b2，b3和b4）将β-氨基丙烯酸酯亲核加成到四氧嘧啶中。计算结果表明，最节能的路径是通道b4，这表明水分子在反应中起质子转移中间体的作用。我们的计算表明该反应在室温下很容易发生，这与实验吻合得很好。