Metal Enolates - Enamines - Enol Ethers: How Do Enolate Equivalents Differ in Nucleophilic Reactivity?

Leonov, Artem I.; Timofeeva, Daria S.; Ofial, Armin R. und Mayr, Herbert (2019): Metal Enolates - Enamines - Enol Ethers: How Do Enolate Equivalents Differ in Nucleophilic Reactivity? In: Synthesis-Stuttgart, Bd. 51, Nr. 5: S. 1157-1170

Abstract

The kinetics of the reactions of trimethylsilyl enol ethers and enamines (derived from deoxybenzoin, indane-1-one, and alpha-tetralone) with reference electrophiles (p-quinone methides, benzhydrylium and indolylbenzylium ions) were measured by conventional and stopped-flow photometry in acetonitrile at 20 degrees C. The resulting second-order rate constants were subjected to a least-squares minimization based on the correlation equation lg k = s(N)(N + E) for determining the reactivity descriptors N and s(N) of the silyl enol ethers and enamines. The relative reactivities of structurally analogous silyl enol ethers, enamines, and enolate anions towards carbon-centered electrophiles are determined as 1, 107, and 1014, respectively. A survey of synthetic applications of enolate ions and their synthetic equivalents shows that their behavior can be properly described by their nucleophilicity parameters, which therefore can be used for designing novel synthetic transformations.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0039-7881
• Sprache: Englisch