Theoretical study on the mechanism of stable phosphorus ylides derived from 5-nitroindazole in the presence of dimetyl acetyelenedicarboxylates

Mechanism investigation of the reaction between triphenylphosphine1, dimetyl acetylenedicarboxylates 2 in the presence of NH-acid, such as 5-nitroindazole 3 was undertaken theoretically. Theoretical studies were performed for evaluation of potential energy surfaces of all structures participated in the reaction mechanism. The first step of all reactions was recognized as a rate determining step in the reaction mechanism. Quantum mechanical calculations were clarified how the ylides exist in solution as a mixture of two geometrical isomers (Z- and E-) as a minor or major forms.

Keywords:

Theoretical study , NH-acid , Z- and E-rotamers , 5-nitroindazole , Triphenylphosphine