Table 8. Hammett Substrate Kinetics Data.

^aThe temperature was increased to 90 °C for the Hammett study substrates such that the study of slower-to-fragment substrates could be completed in overnight NMR experiments.

^bOur previous report²³ provided k_obs values from linear fits of the curved integrated rate data for the fragmentation of the mixture of diastereomers taken to 90% completion. Herein, we report more representative k_obs values obtained from the reaction taken to 50% completion.