Huisgen's 1960 announcement of the concept of 1,3‐dipolar cycloadditions was published the year before Alder's study of the reaction of diazomethane and dimethylfulvene. The diazomethane reaction was studied again in 1970 by Houk et al. and shown to give a [6+4] adduct. Padwa's nitrile ylide cycloaddition to dimethylfulvene (1978) gave [6+4] and [4+2] adducts. We performed computational studies of these reactions with density functional theory (DFT) and show that they involve ambimodal [6+4]/[4+2] transition states that can lead to either type of cycloadduct from one transition state. We dedicate this paper to the extraordinary life and humanity of Rolf Huisgen, and to the undying influence of his discoveries on chemistry.

中文翻译：

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惠斯根通过双峰[6 + 4] / [4 + 2]过渡态进行的1,3偶极环加成反应。

Huisgen在1960年宣布1，3-偶极环加成的概念时发表于Alder研究重氮甲烷与二甲基富勒烯反应的前一年。Houk等在1970年再次研究了重氮甲烷反应。并显示出[6 + 4]加合物。Padwa的腈基内酯环加成到二甲基富勒烯中（1978）得到[6 + 4]和[4 + 2]加合物。我们使用密度泛函理论（DFT）对这些反应进行了计算研究，结果表明它们涉及双峰[6 + 4] / [4 + 2]过渡态，可导致从一个过渡态产生任何类型的环加合物。我们将本文致力于Rolf Huisgen的非凡生活和人性化，以及他的发现对化学的不朽影响。