Dynamic Effects May Affect Hammett Linear Free Energy Relationship

The aromatic nucleophilic substitution reaction in the Clayden rearrangement reaction has an abnormal Hammett linear free energy relationship1. Inspired by the concertedstepwise variation of the aromatic nucleophilic substitution reaction in 20182, we determined the mechanism of Clayden rearrangement reaction under several conditions by DFT calculation then explained the mechanism diversity. We also found that there is a significant dynamic effect in the system due to the emergence of dynamic intermediates, which may be one of the reasons for the Hammett linear free energy relationship.