Synthesis of coprism[4+1]arene macrocycles via selective co-macrocyclization of 2,6-dialkoxynaphthalene monomers

Prismarenes are macrocycles composed of 2,6-dialkoxynaphthalene units connected via methylene bridges at positions 1 and 5, featuring deep, electron-rich cavities that can be exploited for molecular recognition. Their synthesis typically occurs by a templated process under thermodynamic control.¹,² Recently, the synthesis of prism[5]arene has been optimized by introducing a new templating agent with higher affinity for the macrocyclic cavity, resulting in improved yield and selectivity.³ The formation of functional macrocyclic hosts, such as copillararenes obtained through co-macrocyclization of different aromatic units has also been reported in the literature.⁴ Inspired by these developments, the present study aims to synthesize coprism[4+1]arenes using functionalized naphthalene monomers (see Figure 1). The goal is to develop new macrocyclic systems with enhanced supramolecular properties, applicable in fields such as drug delivery, supramolecular polymeric materials, and fluorescence sensors.