Expeditious, Nano-BF₃ · SiO₂-Catalyzed Michaelis–Arbuzov Reaction in an Ionic Liquid: Synthesis of Privileged Aryl/Heterocyclic Phosphonates

Abstract

An expeditious, simple, and green method was developed for the synthesis of privileged aryl/heterocyclicphosphonates, 8(a–c) to 13(a–c) through Michaelis–Arbuzov reaction of aryl/heterocyclic halides (Br), 1–6, and trialkylphosphites, 7(a–c), in room-temperature ionic liquid [bbim]Br using heterogeneous Lewis catalyst, nano-silica-supported boron trifluoride (BF₃-SiO₂). The advantages of this protocol are simplicity, good yield of the products, less reaction time (20–38 min), mild reaction conditions, easy workup, and reusability of the catalyst and ionic liquid. It is demonstrated that nano-BF₃-SiO₂ is a recoverable and easy accessible catalyst for the formation of C(sp²)-P bond in an ionic liquid.

GRAPHICAL ABSTRACT

Keywords:

• [bbim]Br ionic liquid
• green synthesis
• Michaelis–Arbuzov reaction
• nano-BF₃-SiO₂
• phosphonates

Notes

^a 1-Bromo-4-methyl-2-nitrobenzene (2) (1 mmol, 215 mg) and triethylphosphite (7b) (1 mmol, 0.18 mL) were selected as models for the optimization of reaction conditions.

**Boiling point.

^a 1-Bromo-4-methyl-2-nitrobenzene (2) (1 mmol, 215 mg) and triethylphosphite (7b) (1 mmol, 0.18 mL) were selected as models for the optimization of reaction conditions and the model reaction was progressed at 50–60 °C.

^a 1-Bromo-4-methyl-2-nitrobenzene (2) (1 mmol, 215 mg) and triethylphosphite (7b) (1 mmol, 0.18 mL) were selected as models for the optimization of reaction conditions and the reaction was conducted at 50–60 °C.

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