Primary and secondary kinetic isotope effects in E2 elimination reactions

Abstract

Primary and secondary deuterium kinetic isotope effects have been measured for elimination of LCl (L = H or D) from some substituted 1,2-diaryl-1-chloroethanes. Although changes in these effects are in agreement with theoretical predictions, the high values of (E H-E D) β and the significantly low A H/A D may suggest that either proton tunnelling or an internal return mechanism is complicating this E2 elimination.