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4284577 
Journal Article 
The Bell-Evans-Polanyi Principle and the regioselectivity of electrophilic aromatic substitution reactions 
Wubbels, GG 
2015 
1 
Tetrahedron Letters
ISSN: 0040-4039
EISSN: 1873-3581 
56 
13 
1716-1719 
WOS:000352250000029 
Relative activation energies of competing electrophilic aromatic substitution transition states are shown to correlate precisely with computed relative enthalpy changes leading to the corresponding sigma complexes. The correlations manifest the Bell-Evans-Polanyi Principle, which may be summarized by the relationship, E-a = m(Delta H) + I. Close correlation occurs for a variety of reactions and reactivities, but correlation does not occur for nitration of toluene, a case known to be exceptional. The correlations imply that activation energies control regioselectivity, and that the properties of the competing transition states resemble those of the sigma complexes. (C) 2015 Elsevier Ltd. All rights reserved. 
Regioselectivity; Bell-Evans-Polanyi Principle; Electrophilic aromatic substitution; Computed enthalpy change; Relative activation energies