Function‐Oriented Synthesis of a Didesmethyl Triazacryptand Analogue for Fluorescent Potassium Ion Sensing

Abstract

Triazacryptand (TAC)-based fluorescent K⁺ sensors have broad biomedical utility, yet their advancement has been hindered because of their challenging synthesis. Herein, an efficient synthesis is reported that delivers a didesmethyl tri-azacryptand (ddTAC) K⁺ sensor in twofold fewer steps and ninefold higher overall yield than the original TAC synthesis. Our synthesis utilizes a C-O dianionic oxidative macrocyclization and reports new examples of aminoarylations and a microwave route to xanthythilium chromophores. The K⁺ sensitivity and selectivity of the ddTAC-based sensor are comparable to the TAC-based sensor.