Rapid synthesis and antimicrobial evaluation of triazole-modified calix[4]arenes via click chemistry

The current study comprises the synthesis of para-tert-butylcalix[4]arene 2 bearing a terminal alkyne group via alkylation of para-tert-butylcalix[4]arene (1) with 4-bromo-1-butyne in the presence of K2CO3. A series of aryl azides, namely benzyl azide (3a), pentafluorobenzyl azide (3b), 4-nitrobenzyl azide (3c), and 2-(azidomethyl)naphthalene (3d), were prepared through the reaction of the corresponding aryl halides with NaN3. Compound 2 was then subjected to a Cu(I)-catalyzed click reaction with these azides to afford novel triazole derivatives 4a-d. The antimicrobial activities of compounds 4a-d were evaluated against Pseudomonas aeruginosa ATCC 11778, Escherichia coli ATCC 35213, Staphylococcus aureus ATCC 12600, and Streptococcus mutans ATCC 10449. Experimental results demonstrated that compounds 4a, 4c, and 4d exhibited strong activity comparable to ofloxacin, highlighting their potential as candidate molecules for antibiotic development.