A THEORETICAL INVESTIGATION OF THE RELATIVE STABILITY OF ISOMERIC DIHYDROPYRIDINES

Abstract

The molecular structure and relative stability of isomeric dihydropyridines have been calculated using the density  functional theory and the Møller–Plesset second order  perturbation theory. The results of the calculations  demonstrate that 3,4- and 2,3-dihydropyridines are the most  stable species despite the presence of a 4π-electron  conjugated system within the ring. A comparison of the relative energy of acyclic analogs of dihydropyridines indicates that this is caused by the internal properties of the conjugated system.  The remaining dihydropyridines are strongly destabilized by  the formation of antiaromatic conjugated (or quasi-conjugated) systems due to the interaction of pz atomic orbitals of the  carbon and nitrogen atoms with the pseudo-π fragment orbital of the methylene group. Application of the more accurate  CCSD(T)/CBS method results in considerable stabilization of 1,4-dihydropyridine. However, the order of stability of other isomers remains the same as it was found at the MP2 level of theory.

How to Cite
Shishkin, O. V.; Zubatyuk, R. I.; Desenko, S. M.; Leszczynski, J. Chem. Heterocycl. Compd. 2014, 50, 327. [Khim. Geterotsikl. Soedin. 2014, 357.]

For this article in the English edition see DOI 10.1007/s10593-014-1480-9