Abstract
Protonation of the reactive 1:1 intermediate produced in the reaction between dialkyl acetylenedicarboxylates and triphenylphosphine by 4-amino-5-alkyl-2,4-dihydro-1,2,4-triazole-3-thione leads to vinylphosphonium salts which undergo Michael addition with the conjugate base of the NH-acid to produce highly functionalized, salt-free phosphorus ylides in excellent yields.
Acknowledgements
We gratefully acknowledge the financial support from the Research Council of Islamic Azad University of Yazd and The Islamic Azad University of Zahedan of Iran.