
%0 Journal Article
%A Muir, DM 
%A Parker, AJ 
%T The E<sub>2</sub>C mechanism in elimination reactions. IX. Re-examination of the olefin-like transition-state
%J Australian Journal of Chemistry
%D 1983/09/01
%V 36
%N 9
%P 1667-1673
%K 
%R https://doi.org/10.1071/CH9831667
%U https://www.publish.csiro.au/paper/CH9831667 
%X The kinetics and product olefins arising from E2C-like elimination reactions of secondary bromides and tosylates having various alkyl and conjugating substituents at C&#945; and C&#946; are re-examined in the light of the theoretical Pross-Shaik valence-bond model and the apparent lack of a &#946;-phenyl effect. Comparison of the effect of substituents at C&#945; and C&#946; shows that whilst there are differences in reactivity and products of E2C reactions there is also a large degree of double-bond character in the transition state. There is a good correlation between the kinetics of E2C reactions and the double-bond stabilization energy arising from both alkyl and conjugating substituents. Contributing valence-bond structures, giving asymmetry and partial charge at C&#945; and C&#946; appear to vary in importance according to leaving group and substituent type. 
