Electrochemically Generated Copper(I)-Catalyzed Click Chemistry: Triazole Synthesis and Insights into Their Photophysical Properties

Herein, we report the electro-click (e-CLICK) reaction via electrochemically generated copper(I) catalytic species. The reaction worked under constant potential electrolysis (?0.25 V) with copper(II) nitrate and 2,2′-bipyridine serving as pre-catalyst and ligand respectively. The reaction accommodates electronically different organic azides and terminal alkynes to afford 1,2,3-triazoles in good synthetic yields with excellent 1,4-regioselectivity. Compared to traditional click chemistry, the developed e-CLICK methodology avoids the use of external reducing agents such as sodium ascorbate. Absorptive properties of selected triazole products were assessed by UV-visible electronic spectra. Triazole ( 3 e ) was further applied for the spectrophotometric detection of Co²⁺ and Cu²⁺ species.