Syntheses of three-dimensional catenanes under kinetic control
Yong Wu, Qing‐Hui Guo, Yunyan Qiu, Jacob A. Weber, Ryan M. Young, Laura Bancroft, Yang Jiao, Hongliang Chen, Bo Song, Wenqi Liu, Yuanning Feng, Xingang Zhao, Xuesong Li, Long Zhang, Xiao‐Yang Chen, Hao Li, Michael R. Wasielewski, J. Fraser Stoddart
Abstract
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.