Three-component One-pot Synthesis and Multinuclear NMR Study of Some β-phosphorus Ylides

Abstract

A one-step synthesis of sterically congested phosphorus ylides in moderate to good yields by the reaction of dialkyl acetylenedicarboxylates, NH-acids, dialkyl acetylene dicarboxylates and triphenylphosphine or tri-p-tolylphosphine are reported. The characterisation of these compounds were confirmed by IR, 1H, 31P, and 13C NMR spectroscopy and elemental analysis. NMR spectra showed that some of these compounds (in CDCl3 as solvent) contained two rotamers with unequal populations that equilibrate rapidly at higher temperatures.