Rationalization of regioselectivity of electrophilic substitution reaction for cyclic compounds in terms of Dpb values

Accepted theories predict that substitution reactions are controlled by the electronic nature of the attacked site for electrophilic aromatic substitution. Here it is shown that in addition the bond strength of the broken bond may also influence the regioselectivity of the substitution reaction, and that the Dpb is a good indicator of the strength of a chemical bond. The Dpb denotes the depth of the potential acting on one electron in a molecule at the bond center (bc). In this letter, the values of Dpb along the CH and NH bonds have been investigated, and it is demonstrated that for aromatic compounds, the regioselectivity of the electrophilic substitution can well be rationalized in terms of Dpb values.

The absolute value of the potential acting on one electron in a molecule at the bond center, Dpb, is used to predict regioselectivity of electrophilic substitution reaction for cyclic compounds in situ.Figure optionsDownload as PowerPoint slide