The 1,3-dipolarcycloaddition of nitrile oxides to 2-X-bicyclo[2.2.2]oct-5-enes (X=O, NMe, S, SO2) were investigated together with acyclic and alicyclic analogues. The regioselectivity in an exo-attack was controlled by the heteroatom present at an allylic position —a remote attack was predominant in the cases of O and SO2 but a vicinal attack in those of NMe and S— and the results were rationalized
与无环和脂环类似物一起研究了腈氧化物与 2-X-双环 [2.2.2] oct-5-烯(X=O、NMe、S、SO2)的 1,3-偶极环加成反应。外向攻击中的区域选择性受烯丙基位置上的杂原子控制——远程攻击在 O 和 SO2 的情况下占主导地位,但在 NMe 和 S 的情况下是邻位攻击——结果从电子性质中得到了合理化杂原子 X。在内向攻击中,在每种情况下都观察到远程攻击,并且 X 与氧化腈的氧之间的偶极-偶极排斥被认为是主要因素。杂原子周围的空间环境控制着面部选择性。