Deuterium kinetic isotope effects in β-elimination from phenethyl bromide promoted by para-substituted sodium phenoxides in dimethylformamide

Abstract

Deuterium kinetic isotope effects have been measured for elimination from phenethyl bromide promoted by para-substituted sodium phenoxides in dimethylformamide. Despite the large basicity range considered variations in the magnitude (in the range 7·6–9·0) of the isotope effects were practically within experimental error. Some evidence for proton tunnelling was obtained and this has made difficult a straightforward interpretation of the k₂^H/k₂^D values in terms of transition state geometry.