A Facial Route for the Preparation of Dialkyl 2-(Dicyanomethyl)-3-(triphenyl-λ⁵-phosphoranylidene)succinates from Triphenylphosphine, Acetylenic Esters and Malononitrile

Abstract

A one-pot synthesis of dialkyl 2-(dicyanomethyl)-3-(triphenyl-λ⁵-phosphoranylidene)succinates in fairly high yields by the reaction of malononitrile, dialkyl acetylenedicarboxylates and triphenylphosphine are reported. The formulas of these compounds were confirmed by IR, ¹ H,³¹ P, and ¹³ C NMR spectroscopy. The NMR spectra indicated that solutions of the phosphorus ylides (CDCl₃ as solvent) contain two rotamers (E and Z). The relative percentages of rotamers in CDCl₃ for each phosphorus ylide were determined from the ¹H NMR spectra.

Keywords:

• Acetylenic esters
• malononitrile
• Michael addition
• phosphorus ylide
• vinyltriphenylphosphonium salt

Acknowledgments

This work was supported by the Islamic Azad University-Zanjan Branch.