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El complejo de Meisenheimer es un intermediario de carga negativa formado durante la reacción de sustitución nucleofílica aromática. Su descubrimiento por el científico alemán Eberhard Meisenheimer ha desempeñado un papel fundamental en la comprensión de las reacciones químicas que ocurren en los compuestos orgánicos.
A Meisenheimer complex or Jackson–Meisenheimer complex in organic chemistry is a 1:1 reaction adduct between an arene carrying electron withdrawing groups and a nucleophile. These complexes are found as reactive intermediates in nucleophilic aromatic substitution but stable and isolated Meisenheimer salts are also known.
A Meisenheimer complex is a negatively charged intermediate formed by the attack of a nucleophile upon one of the aromatic-ring carbons during the course of a nucleophilic aromatic substitution reaction. A typical Meisenheimer complex is shown in the reaction scheme below.
1 de nov. de 2020 · Cuando el compuesto aromático contiene grupos aceptores de electrones y un halógeno con nucleófilo ataca el carbono unido al halógeno, forma un intermedio de carbanión que se estabiliza en estructuras de resonancia, conocido como complejo de Meisenheimer.
16 de jul. de 2018 · The Meisenheimer model for predicting the principal site of for nucleophilic substitution in aromatic perfluorocarbons—generalization to include ring-nitrogen atoms and non-fluorine ring ...
- Eugene E. Kwan, Yuwen Zeng, Harrison A. Besser, Eric N. Jacobsen
- 2018
Some of these spirocyclic Meisenheimer complexes, a type of σXcomplex, are exceptionally stable in solution and/or as solids. They can be isolated and characterized using X-ray, and various spectroscopic techniques such as NMR, UV-Vis, IR, and fluorescence.
This chapter discusses Meisenheimer complexes. Spectroscopic and crystallographic methods have largely confirmed Meisenheimer's formula for the stable adducts from alkyl picrates and alkoxides. Meisenheimer associated with the para-nitro group is delocalized about the ring and in the nitro-groups.
