A Remarkable Difference of the Positional Selectivity in Electrophilic Aromatic Substitution of Dibenzofuran between the Classical σ-Complex and Charge-Transfer Mechanisms
Electrophilic nitration of dibenzofuran with nitric acid by a charge-transfer mechanism occurs exclusively at the 3-position and on the other hand, substitution at the 2-position predominates in the acylation, in which a classical σ-complex mechanism is important.