cavity. Lewis acid activation of the double bond causes it to react with an incoming "stoppered" diene, affording the [2]rotaxane in up to 91% yield. Unusually for an active-template synthesis, the metal binding site "lives on" in these rotaxanes. This was exploited in the synthesis of a molecular shuttle containing two different ligating sites in which the position of the macrocycle could be switched
描述了 [2] 轮烷的合成,其中 Zn(II) 或 Cu(II)
路易斯酸催化狄尔斯-阿尔德环加成形成轴,同时作为组装互锁分子的模板。
路易斯酸与多齿内位 2,6-二(亚甲氧基甲基)
吡啶基或联
吡啶类大环的配位使螯合亲二烯体通过大环腔定向。双键的
路易斯酸活化导致它与传入的“封闭”二烯反应,以高达 91% 的产率提供 [2] 轮烷。与活性模板合成不同的是,
金属结合位点在这些轮烷中“存在”。