Theoretical Study of 1,3-Dipolar Reactions of Myrcene and Trimethylsilylazide

Background: Triazoline derivatives are important group of the heterocycle compounds possessing interesting medicinal and biological properties. Triazoline compounds can be applied in medicine because of their pharmaceutical properties as antiviral, antibacterial, anti-cancerous, antiasthmatic, analgesic and anti-inflammatory medicines. The essential oil of many plants contains Myrcene. The 1,3-cycloaddition reaction pathways of Myrcene with trimethylsilylazide were investigated to obtain the theoretical possibilities of the interesting varieties of its 1,2,3-triazoline derivatives. Methods: In this study, the 1,3-dipolar reactions of Myrcene (1) with trimethylsilylazide (TMS-N3; 2), the comparison of the three C=C of 1 in the kinetic and thermodynamic aspects, the structural studies of the 1,2,3-triazoline products and the transition states were investigated. The modeling of the reaction was performed by DFT-B3LYP/6-31G* method. This method was applied on the main configurations with less steric restraint effects. The experimental results of FT-IR were just carried out in this study to pursue the course of the reaction pathways. Results: The HOMO and LUMO orbital levels, ΔHOMO-LUMO gaps, dipole moments, the appropriate atoms Mulliken charges, thermodynamic and kinetic stabilities in vacuum were investigated for the components, transition states and the products (P1-P6) by the DFT method. The four important aspects about determination of the combining a dipolarophile (1) with a 1,3-dipole agents (TMS-N3(2)) to produce P1-P3 were determined. Conclusion: The kinetic and thermodynamic products of the 1,3-dipolar reactions were determined. The final result is that P4 is the kinetic and P6 is the thermodynamic product of the 1,3-dipolar cycloaddition reaction between Myrcene (1) and TMS-N3(2) during the two explained steps. The experimental results confirm the theoretical achievements.