Kinetic Study of the Homolytic Brominolysis of 1,2-Diarylcyclopropanes

Article abstract of DOI:10.1021/jo00325a014

The rate constants for the photolytic brominolysis of 22 trans-1,2-diarylcyclopropanes in carbon disulfide relative to an internal standard, p-chlorotoluene, have been determined.The products of the brominolysis are 1,3-dibromo-1,3-diarylpropanes.The rate constants range over 5 orders of magnitude, being enhanced by electrondonating substituents on one or both benzene rings.The quantitative size of the substituent effect (ρ) at either involved carbon center is a function of the substituent at the other center.This fact suggests a continuum of transition-state structures with varying degrees of bond breaking and charge separation.