Bismuth(III) Chloride Mediated Michaelis–Arbuzov Reaction: A Facile Synthesis of Substituted Arylphosphonates/Phosphinates and Bioactivity Evaluation

GRAPHICAL ABSTRACT

Abstract

BiCl₃ is economically affordable, less toxic and eco-friendly catalyst. A facile synthesis of substituted arylphosphonates/phosphinates in good yields was achieved using BiCl₃ catalyzed via Michaelis-Arbuzov reaction. 5-Iodovanillin/3,5-difluorobenzylbromide was reacted with various phosphites and dimethyl phenylphosphonite in the presence of Lewis acid catalyst BiCl₃, under N₂ atmosphere at 40°C to produce the corresponding arylphosphonates/phosphinates. They were characterized by ³¹P, ¹H, and ¹³C NMR spectroscopy, IR, mass spectrometry, and elemental analysis. All title compounds were screened for their in vitro antibacterial and antifungal activity. The compounds 5d, 3b, 5e, and 5b exhibited good antibacterial activity and the compounds 3a, 3b, 5a, and 5d exhibited significant antifungal activity compared to the standard bactericide Norfloxacin and fungicide Griseofulvin.

Keywords:

• Michaelis–Arbuzov reaction
• BiCl₃, 5-iodovanillin
• 3,5-difluorobenzylbromide
• arylphosphonates/phosphinates
• antibacterial activity
• antifungal activity

ACKNOWLEDGMENTS

The authors express their thanks to Hyderabad Central University and Osmania University for providing instrumentation facilities for recording the spectra.