Abstract

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates by diphenylacetonitril, leads to the vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce the corresponding stabilized phosphorus ylides. Dipotassium hydrogen phosphate powder was found to catalyze the conversion of the stabilized phosphorus ylides to dialkyl(Z)-2-[cyano (diphenyl)methyl]-2-butenedioates under thermal and microwave conditions in a solventless system.