Abstract
Structural characteristics of 1,4-dihydropyridines influencing the nonequivalence of the diastereotopic methylene protons in substituents at positions 2 and 6 were studied. The combined effect of magnetically anisotropic groups and intramolecular hydrogen bonds leads to a considerable difference in the chemical shifts of the methylene protons of the AB system. The unusual reversible temperature evolution of these proton signals in monocyclic 1,4-dihydropyridines is associated with two simultaneous conformational processes. It was estimated that the energetically most favorable conformations are stabilized by an intramolecular CH...O hydrogen bond.
Original language | English |
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Pages (from-to) | 1631-1639 |
Number of pages | 9 |
Journal | Chemistry of Heterocyclic Compounds |
Volume | 49 |
Issue number | 11 |
DOIs | |
Publication status | Published - Feb 2014 |
Externally published | Yes |
Keywords*
- 1,4-dihydropyridines
- NMR spectroscopy
- hydrogen bond
- nonequivalence of methylene protons
- quantum-chemical calculations
Field of Science*
- 1.4 Chemical sciences
Publication Type*
- 1.1. Scientific article indexed in Web of Science and/or Scopus database