Theoretical Study of the Kinetics and Mechanism of the Reactions between triphenylphosphine,dialkylacetylenedicarboxylate and N-H acid Imidazole

Phosphorus ylides are reactive systems which have a role in many valuable reactions of organic synthesis [1-2]. These are most often obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine, dialkyl acetylendicarboxylates, in the presence of CH, SH or NH-compounds [3-4]. A facile synthesis of the reaction between triphenylphosphine 1, dialkyl acetylendicarboxylates 2 and imidazole 3 for generation of stable phosphorus ylides 4 has been reported earlier [5]. Previously,experimental kinetics study of these types reactions have been reportedaccompanied by obtained useful information from studies of the effect of solvents, structure of reactants (different alkyl groups within the dialkyl acetylenedicarboxylates and various heterocyclic compounds) and also concentration of reactants on the rate of reactions. Mechanism, rate determining and fast steps of the ylides reaction were recognized as a result of our previous experimental works [6-10].