Mechanistic investigation of the reactions between aminoguanidine derivatives and acetylenedicarboxylate derivatives

In this study, Density Functional Theory (DFT), which takes into consideration electron density and produces desired data over this electron density, has been used in order to determine the reaction mechanism and electronic properties of AG derivatives and acetylenedicarboxylate derivatives. With this theory, electronic, geometric structure and related properties of the species in the reaction medium were calculated. Transition states were determined when the reaction mechanisms were examined. The determination of the transition states was confirmed by IRC calculations. The theoretical calculations were performed in gas phase using the Gaussian 09 package program using the B3LYP method and the 6-31G basis set. While the enthalpy change of the first of the two mechanisms given in the literaute is endothermic, the formation of the transition state in the first step of the second mechanism is exothermic. Therefore, the second mechanism has been emphasized since the energy required to start the reaction in the first mechanism is higher than the second mechanism. Methanol was used as solvent in the reaction, but calculations were carried out in the gas phase. As the next steps of this study, performing the calculations in the solvent environment, comparing the experimental and theoretical reaction mechanism, the theoretical suitability of the proposed experimental mechanism was evaluated.