Meisenheimer Complexes (sigma Complexes)

摘要

Meisenheimer complexes are known to form in aromatic nucleophilic substitution reactions. The purpose of the present study is to collect as much information as possible in this important field of organic chemistry. The interaction of nitro aromatics with bases and nucleophiles has been included in the review. The formation of the sigma-complexes has been evidenced in the light of various spectroscopic techniques and relevant kinetic and thermodynamic data. The conditions required for the formation of the sigma-complex along with the change of Sp2 to Sp3 hybridized C1 on the aromatic ring is considered.