Premium
Quantification of Ion‐Pairing Effects on the Nucleophilic Reactivities of Benzoyl‐ and Phenyl‐Substituted Carbanions in Dimethylsulfoxide
Author(s) -
CorralBautista Francisco,
Appel Roland,
Frickel Johanna S.,
Mayr Herbert
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201404500
Subject(s) - carbanion , chemistry , electrophile , reactivity (psychology) , reaction rate constant , medicinal chemistry , kinetics , organic chemistry , catalysis , medicine , physics , pathology , quantum mechanics , alternative medicine
Second‐order rate constants for the reactions of acceptor‐substituted phenacyl (PhCOCH − Acc) and benzyl anions (PhCH − Acc) with diarylcarbenium ions and quinone methides (reference electrophiles) have been determined in dimethylsulfoxide (DMSO) solution at 20 °C. By studying the kinetics in the presence of variable concentrations of potassium, sodium and lithium salts (up to 10 −2 mol L −1 ), the influence of ion‐pairing on the reaction rates was examined. As the concentration of K + did not have any influence on the rate constants at carbanion concentrations in the range of 10 −4 –10 −3 mol L −1 , the acquired rate constants could be assigned to the reactivities of the free carbanions. The counter ion effects increase, however, in the series K +