Electronic effects on keto–enol tautomerism of p-substituted aryl-1,3-diketone malonates

1,1‐Ethenediol: The Long Elusive Enol of Acetic Acid

“…More generally speaking, most enols are short-lived reactive species and they readily isomerize to their ketoforms; enols can be stabilized through resonance, [23] steric factors, [1] and electronic effects. [2,24] Experimental methods such as time-resolved spectroscopy, [5,25] neutralization-reionization mass spectrometry, [26,27] NMR as well as IR spectroscopy, [28] and other spectroscopic techniques [29] along with computational methods [30][31][32][33] have played a significant role in understanding the structures and reactivities of enols. The simplest enol, ethenol (vinyl alcohol), was generated in the gas phase through the pyrolysis of ethylene glycol.…”

Magnetic response and its relation to the keto‐enol tautomerism of 3,3′‐(1,4‐phenylene)bis(pentane‐2,4‐dione): Experimental and theoretical insights

“…[ 2,3,5,6 ] For example, for acetylacetone and dibenzoylacetone, the enol form constitutes 81% and 100%, respectively. [ 7 ] However, in some Schiff's bases, the opposite behavior is observed. In those cases, the keto form is dominant in nonpolar solvents, while the enol form is dominant in more polar solvents.…”

“…Several spectroscopic methods such as NMR, UV‐vis absorption, infrared spectroscopy, and high performance liquid chromatography (HPLC) have been used to investigate keto‐enol tautomerism in solutions. [ 7 ] NMR spectroscopy allows monitoring the keto‐enol equilibrium electronic effects, as in the study of the molecular structure of 1,3‐diketones. [ 7 ]…”

“…[ 7 ] NMR spectroscopy allows monitoring the keto‐enol equilibrium electronic effects, as in the study of the molecular structure of 1,3‐diketones. [ 7 ]…”

1,1‐Ethendiol – Das lange Zeit schwer fassbare Enol der Essigsäure

“…Generell handelt es sich bei den meisten Enolen um kurzlebige, reaktive Intermediate, welche leicht zu ihrer Keto-Form isomerisieren. Enole kçnnen durch Resonanz, [23] sterische Faktoren [1] und elektronische Effekte [2,24] stabilisiert werden. Experimentelle Methoden wie zeitaufgelçste Spektroskopien, [5,25] Neutralisations-Ionisations-Massenspektrometrie, [26,27] NMR-und IR-Spektroskopien, [28] als auch weitere spektroskopische Techniken [29] zusammen mit computerchemischen Berechnungen [30][31][32][33] spielen eine bedeutende Rolle im Verständnis der Struktur und Reaktivität von Enolen.…”