Elimination and addition reactions. Part XIX. Elimination of phenoxide from β-substituted ethyl phenyl ethers: the nature of activation in 1,2-elimination

Abstract

In an investigation of the nature of activation in elimination reactions, rates of elimination of phenoxide under basic conditions from a series of 17 phenyl ethers of the type X–CH₂·CH₂·OPh have been measured.

Second-order rate constants span a range of 10¹¹ according to the nature of X. Good correlation is obtained between log k_elimination and the parameter σ_R^–, but not with σ or σ*, indicating that resonance stabilisation of a carbanionic species is an important component of activation in this system.

Relative rates of elimination correlate well with relative rates of addition of oxygen and nitrogen nucleophiles to electrophilic olefins of the type X–CH:CH₂.