Stereoprogrammed direct synthesis of calixarene-based [3]rotaxanes

Org Lett. 2012 Jun 15;14(12):3104-7. doi: 10.1021/ol3011997. Epub 2012 Jun 5.

Abstract

Directional calixarene wheels were threaded along a bis(benzylalkylammonium) axle in a stereoprogrammed way to obtain the first examples of calixarene-based [3]rotaxanes. The base/acid treatment demonstrated that these systems act as nanosized molecular shuttles. An unprecedented switching between the tail-to-tail and head-to-head relative orientation of the calix-wheels was observed.