Nucleophilic reactivities of ketene acetals

Abstract

The kinetics of the reactions of ketene acetals with benzhydrylium ions have been followed photometrically. The reactions proceed with rate-determining C-C bond formation that is considerably faster than expected for outer-sphere electron transfer processes. Structure-reactivity relationships are discussed. The excellent correlations between the observed second-order rate constants (log k2) and the previously reported electrophilicity parameters (E) of benzhydrylium ions suggest that several of the compounds investigated in this work can be used as reference nucleophiles for the development of electrophilicity scales. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.