A metal-carbene template approach enables efficient synthesis of a functionalized cage-annulated crown ether

A facile synthetic method to form cage-annulated crown ether with anchored imidazolium units was developed. The present work verified the potential application of the metal-carbene template approach (MCTA) in the preparation of novel flexible polyimidazolium cages by photochemical [2+2] cycloaddition reactions and may provide a new method for the preparation of flexible pure organic cages with incorporation of a variety of functional sites. A novel flexible intramolecular cage-annulated crown ether organic imidazolium cation with potentially large cavities was constructed through a kind of post-assembly modification strategy, photochemical [2+2] cycloaddition reaction.