A. Shaabani et al., One-pot synthesis and dynamic studies of stable dialkyl-2-(1H-isoindol-1,3(2H)-dione-2-yl)-3-(triphenylphosphoranylidene) butanedioate ylides, J CHEM R-S, (5), 2001, pp. 192-194
The title compounds were prepared in high yield by protonation of the react
ive 1:1 intermediates produced in the reaction between triphenylphosphine a
nd dialkyl acetylenedicarboxylate by phthalimide, followed by nucleophilic
addition of the imidic nitrogen anion to the vinyl phosphonium salts. A dyn
amic NMR study was also performed.