THEORETICAL STUDY OF CONCERTED DIELS-ALDER REACTIONS BETWEEN DIMETHYL 1,2,4,5-TETRAZINE-3,6-DICARBOXYLATE AND DIENOPHILES

Authors

  • Jewad Kadhum Shneine Al-Nahrain University, College of Science, Department of Chemistry, Al-Jadrya, Baghdad-Iraq.
  • Shaima Mohamad Ali Mahmood Al-Nahrain University, College of Science, Department of Chemistry, Al-Jadrya, Baghdad-Iraq.
  • Mehdi Salih Shihab Al-Nahrain University, College of Science, Department of Chemistry, Al-Jadrya, Baghdad-Iraq.

Keywords:

NON

Abstract

Computational study at different levels of quantum calculations (AM1, PM3 and ab initio (HF/3-21G)) where preformed on the inverse-demand synchronous concerted Diels-Alder reactions between dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate as a diene and a variety of dienophiles (ethylene, cyclopentadiene, 1-hexene, cyclohexene). All the molecular structures (reactants, transition states, intermediates and adducts) were optimized by AM1 method. The calculated energies and volumes showed that the cycloaddition systems followed a mechanism by formation an intermediate and proceed to eject N2 molecule and ended by 1,2-hydrogen shift adduct. The prediction of the reaction energies of modeling of the cycloaddition reactions under-study by semiempirical AM1 method showed a good agreement with the experimental data comparing with PM3 and HF/3-21G. whereas, the prediction of activation energies by (AM1, PM3 and ab initio (HF/3-21G)) showed overestimated values comparing with experimental data.

Published

2009-03-01

Issue

Section

Articles

How to Cite

[1]
“THEORETICAL STUDY OF CONCERTED DIELS-ALDER REACTIONS BETWEEN DIMETHYL 1,2,4,5-TETRAZINE-3,6-DICARBOXYLATE AND DIENOPHILES”, ANJS, vol. 12, no. 1, pp. 14–23, Mar. 2009, Accessed: Mar. 28, 2024. [Online]. Available: https://anjs.edu.iq/index.php/anjs/article/view/1257