Department of Chemistry, Northwestern University, Evanston, IL 60208.
Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
Proc Natl Acad Sci U S A. 2022 Mar 22;119(12):e2118573119. doi: 10.1073/pnas.2118573119. Epub 2022 Mar 15.
Although catenanes comprising two ring-shaped components can be made in large quantities by templation, the preparation of three-dimensional (3D) catenanes with cage-shaped components is still in its infancy. Here, we report the design and syntheses of two 3D catenanes by a sequence of SN2 reactions in one pot. The resulting triply mechanically interlocked molecules were fully characterized in both the solution and solid states. Mechanistic studies have revealed that a suit[3]ane, which contains a threefold symmetric cage component as the suit and a tribromide component as the body, is formed at elevated temperatures. This suit[3]ane was identified as the key reactive intermediate for the selective formation of the two 3D catenanes which do not represent thermodynamic minima. We foresee a future in which this particular synthetic strategy guides the rational design and production of mechanically interlocked molecules under kinetic control.
虽然可以通过模板大量制备由两个环形组件组成的轮烷，但具有笼状组件的三维（3D）轮烷的制备仍处于起步阶段。在这里，我们通过一锅法中的一系列 SN2 反应报告了两种 3D 轮烷的设计和合成。所得的三重机械互锁分子在溶液和固态中都得到了充分的表征。机理研究表明，在较高温度下形成了一种含有三倍对称笼状组件作为套件和三溴化物组件作为主体的 suit[3]ane。这种 suit[3]ane 被确定为选择性形成两种 3D 轮烷的关键反应中间体，而这两种 3D 轮烷并不代表热力学最小值。我们预计，在未来，这种特殊的合成策略将指导在动力学控制下对机械互锁分子进行合理设计和生产。
