Task-Specific Ionic Liquid as Reagent and Reaction Medium for the One-Pot Horner–Wadsworth–Emmons–Type Reaction Under Microwave Irradiation

Abstract

A task-specific imidazolium-based phosphinite ionic liquid (IL-OPPh₂) was used as the dual solvent–reagent for the synthesis of E-cinamates and coumarin derivatives via the one-pot Horner–Wadsworth–Emmons–type reaction. The ionic liquid containing its corresponding phosphinite moiety was reacted with α-chloro esters and benzaldehyde or salicylaldehyde derivatives in the presence of sodium methoxide under microwave irradiation to produce the related E-cinamates or coumarins, respectively. The satisfactory results were obtained with good yields, short reaction time, and simple experimental procedure.

Keywords:

• Coumarin
• Horner–Wadsworth–Emmons reaction
• microwave
• task-specific ionic liquid

ACKNOWLEDGMENTS

We thank Azarbaijan University of Tarbiat Moallem for financial support of this work. We are also grateful to Prof. Majid M. Heravi for helpful discussions and to Miss Roya Kabiri at the Tabriz University for running the NMR spectra.

Notes

^a All the products have been characterized by ¹H NMR, ¹³C NMR (300 MHz, CDCl₃), and IR spectral analysis (spectroscopic data of well-known products are not reported here).

^b Isolated yields.

^a All the coumarins have been characterized by ¹H NMR, ¹³C NMR (300 MHz, CDCl₃), and IR spectral analysis. ^{[ 39 ]}

^b Isolated yields.