TITLE:
Substituent, Temperature and Solvent Effects on the Keto-Enol EQUILIBRIUM in β-Ketoamides: A Nuclear Magnetic Resonance Study
AUTHORS:
Sergio L. Laurella, Manuel González Sierra, Jorge J. P. Furlong, Patricia E. Allegretti
KEYWORDS:
β-Ketoamides; Keto-Enol Equilibrium; Nuclear Magnetic Resonance Spectroscopy
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.3 No.4,
October
25,
2013
ABSTRACT:
Substituent, temperature and solvent effects on tautomeric
equilibria in several β-ketoamides
have been investigated by means of nuclear magnetic resonance spectroscopy
(NMR). Keto-enol equilibrium predominates over the amide-imidol one. The
relative stability of the individual tautomers and the corresponding
equilibrium shifts are explained considering electronic and steric effects and
tautomer stabilization via internal
hydrogen bonds. In solution, these compounds exist mainly as ketoamide and Z-enolamide tautomers, both presenting intramolecular hydrogen bonds.