Copillar[5]arene Chemistry: Synthesis and Applications

Research on pillar[n]arenes has witnessed a very quick expansion. This emerging class of functionalized macrocyclic oligoarenes not only offers host–guest properties due to the presence of the central cavity, but also presents a wide variety of covalent functionalization possibilities. This short review focuses on copillararenes, a subfamily of pillar[n]arenes. In copillararenes, at least one of the hydroquinone units bears different functional groups compared to the others. After having defined the particular features of copillararenes, this short review compares the different synthetic strategies allowing their construction. Some key applications and future perspectives are also described.

1 Introduction

2 General Features of Pillar[5]arenes

3 Synthesis of Functionalized Copillar[4+1]arenes

4 Concluding Remarks

Enantiopure pillar[5]arene active domains within a homochiral metal-organic framework

Enantiopure struts containing pillar[5]arenes incorporating planar chirality have been linked together with Zn4O clusters in order to create metal-organic frameworks that include homochiral active domains and so have the potential to act as a solid support in chiral chromatography.

A cationic water-soluble pillar[5]arene: synthesis and host–guest complexation with long linear acids

A cationic water-soluble pillar[5]arene has been synthesized and revealed to encapsulate linear acids in neutral, alkaline, and acidic conditions, driven by the hydrophobic and hydrogen bond interactions.