CeCl₃.7H₂O-SiO₂ Catalyzed Ultrasonicated Solvent-Free Synthesis of Carbamoyl/Carbamothioyl Phosphonates and Antimicrobial Activity Evaluation

GRAPHICAL ABSTRACT

Abstract

an expeditious and green method has been developed for the synthesis of a series of P‒C bond derivatives, diethyl substituted phenylcarbamoylphosphonates 6(a–e)/phenylcarbamothioylphosphonates 7(a–f) in high yields via simple addition reaction of isocyanates/isothiocyanates with diethyl phosphite in the presence of silica supported Lewis acid catalyst, SiO₂-CeCl₃.7H₂O under solvent-free and sonication conditions. The advantages of this method are high yields, avoiding of harmful solvents, operational simplicity, shorter reaction time, and recoverability and recyclability of the catalyst. Antimicrobial activity was assayed for the title compounds, whereas the compounds 6c, 7b, and 7e against bacteria, and 6a, 7b, 7c, and 7e against fungi exhibited potential growth of inhibition.

Keywords:

• SiO₂-CeCl₃.7H₂O catalyst
• solvent-free synthesis
• ultrasonication
• carbamoyl/carbamothioylphosphonates
• antimicrobial activity