enolisierbares

Enolisierbares is a German term used in organic chemistry to describe molecules that can undergo enolization. In English, the corresponding term is enolizable. A compound is enolisierbar if it contains at least one hydrogen on a carbon atom adjacent to a carbonyl group (an alpha-hydrogen) and can form an enol or an enolate under suitable conditions. Enolization is driven by the acidity of the alpha-hydrogens and the resonance stabilization of the resulting enolate with the carbonyl group.

In practice, enolisierbare substrates include many ketones, aldehydes, esters, and amides that possess alpha-hydrogens. Under base catalysis, deprotonation at the alpha position forms an enolate anion that can act as a nucleophile in alkylation, acylation, and Michael-type reactions. Under acid catalysis, keto–enol tautomerism permits interconversion between keto and enol forms, influencing reactivity and spectroscopy.

Applications of enolizable substrates are central to aldol condensations, Michael additions, Robinson annulations, and various enolate alkylations. The outcome of reactions involving enolates is governed by the stability of the enolate and by competing deprotonation at other sites, as well as by solvent and temperature.

Identification hinges on examining the structure for alpha-carbons adjacent to carbonyl groups bearing hydrogens. If such hydrogens exist and are sufficiently acidic, the compound is considered enolisierbar. Substrates lacking alpha-hydrogens are generally not enolisierbar under ordinary conditions.