Cyanostar synthesis on large or rapid scales †

This is the authors' abstract. We don't add key points for this paper.

Cyanostar is a pentagonal macrocycle that is selective for polyatomic anions. Use of cyanostar in research and technology has grown since its debut in 2013 with more than 40 publications and 5 patents spanning recognition, sensing, dynamic polymers, reversible adhesives, semi-conductor dopants, and programmable optical materials. However, the optimised synthesis and purification of cyanostar has yet to be published. From commercially available 5-tert-butylisophthalic acid, cyanostar can be synthesised in six steps on large scales or in just five steps on expedited smaller scales. On large scales, column chromatography ensures high yields at each step and cyanostar is produced in 50% yield in 2 weeks. The small-scale synthesis produces cyanostar in 3% yield but can be completed in just 2 days. Herein, we present a step-by-step guide towards easy and reliable syntheses of cyanostar at both scales and provide a comparison of hazards, reaction times, and overall yields for these methods.