Ester-Bearing Calix[ n]phenoxazines: Side Chain Enhanced Recognition and Redox-Responsive Reversible Host-Guest System

J Org Chem. 2025 Jan 22. doi: 10.1021/acs.joc.4c02864. Online ahead of print.

Abstract

We report an enhanced recognition and redox-responsive reversible host-guest system based on ester-bearing calix[n]phenoxazines. The carbonyl groups, oriented toward the cavity, act as the extra binding sites to enhance the binding affinity, which is confirmed by NMR and FTIR experiments and single-crystal structure analysis. Due to the oxidizable nature of calix[n]phenoxazine, a redox-controlled reversible response is established. This research not only provides a strategy to enhance the binding affinity in calix-like macrocyclic arenes but also marks a major advance in the development of a macrocyclic arene-based reversibly responsive system.