Rotaxane Synthesis by an End-Capping Strategy via Swelling Axle-Phenols

A method for rotaxane synthesis by enlargement of the size of the terminal phenol group of the axle component by aromatic bromination has been developed. This method may be regarded as an end-capping strategy involving the swelling of the phenol group at the axle terminal. The advantages of the present strategy include: ready availability of axle components with a variety of swelling precursors, wide product scope (19 examples given including a [3]rotaxane), mild conditions for the swelling process, rich potential for the derivatization of the brominated rotaxanes, and possible release of the axle component by degradative dethreading of the thermally stable brominated rotaxanes under the basic conditions.

Automated summary

A method for rotaxane synthesis by enlarging the terminal phenol group of the axle component through aromatic bromination has been developed. This method involves an end-capping strategy by swelling the phenol group at the axle terminal. The advantages of this strategy include easy availability of axle components with various swelling precursors, a wide range of products (including a [3]rotaxane), mild conditions for the swelling process, rich potential for derivatizing the brominated rotaxanes, and the possibility of releasing the axle component by degradative dethreading of the thermally stable brominated rotaxanes under basic conditions.