187454-97-3Relevant academic research and scientific papers
Beta Secondary Deuterium Kinetic Isotope Effects on the Thermal Stereomutations of 1,2-Diphenylcyclopropanes
Asuncion, Lisa A.,Baldwin, John E.
, p. 1421 - 1436 (2007/10/03)
(+)-(1S,2S)-trans-1,2-Diphenylcyclopropane and (-)-(1R,2R)-trans-1,2-diphenyl-3,3-d2-cyclopropane at 234°C interconvert reversibly with the corresponding enantiomers and cis-1,2-diphenylcyclopropanes. For the unlabeled trans isomer, the ratio of rate constants for one-center epimerization (k1) and two-center turnover (k12) was found to be 1.1. A small normal kH/kD effect, 3% per deuterium, was observed for the rate constant for one-center epimerization (k1); a substantial normal kH/kD effect, 17% per deuterium, was observed for the rate constant for two-center turnover (k12). Thus different transition structures, presumably EF and EE 1,3-diphenyltrimethylene diradicals, dominate the two sorts of stereomutations.
