Electrophilic aromatic substitution summary

Section 12 1 On reaction with electrophilic reagents compounds that contain a ben zene ring undergo electrophilic aromatic substitution Table 12 1 m Section 12 1 and Table 12 3 m this summary give examples... 

A Summary of Substituent Effects in Aromatic Substitution A summary of the activating and directing effects of substituents in electrophilic aromatic substitution is shown in Table 16.2. 

Substituent effect, additivity of, 570 electrophilic aromatic substitution and, 560-563 summary of. 569 Substitution reaction, 138 Substrate (enzyme), 1041 Succinic acid, structure of, 753 Sucralose, structure of. 1006 sweetness of, 1005 Sucrose, molecular model of. 999 specific rotation of, 296 structure of, 999 sweetness of, 1005 Sugar, complex, 974 d, 980 L, 980... 

Steric Control of the Inner/Outer-Sphere Electron Transfer 461 Thermal and Photochemical ET in Strongly Coupled CT Complexes 463 Electron-Transfer Paradigm for Arene Transformation via CT Complexes 465 Electron-Transfer Activation of Electrophilic Aromatic Substitution 469 Structural Pre-organization of the Reactants in CT Complexes 470 CT Complexes in Aromatic Nitration and Nitrosation 472 Concluding Summary 475 References 475... 

Summary of Substituent Effects in Electrophilic Aromatic Substitution (18.6-18.9)... 

In summary, we can say that both reactivity and orientation in electrophilic aromatic substitution are determined by the rates of formation of the intermediate carbonium ions concerned. These rates parallel the stabilities of the carbonium ions, which are determined by the electron-releasing or electron-withdrawing tendencies of the substituent groups. 

In summary, then, analysis of the structures of product alkyl-aromatics, patterns of substrate reactivity, and side reaction pathways in modified faujasite-catalyzed alkylations reveals great similarity to the corresponding features commonly reported for electrophilic aromatic substitutions in the presence of strong protonic acids or promoted Lewis acids. 

Substitution processes are diverse in both scope and mechanism. Upon detailed investigation, even those reactions that seem most familiar to us offer degrees of complexity that confound our attempts to fit all of organic chemistry into a few distinct compartments. As one author put it, "in summary, nitration—the classic example of electrophilic aromatic substitution—is not always an electrophilic aromatic substitution." ... 

Summary This is an example of electrophilic aromatic substitution ... 

In Summary The Friedel-Crafts alkylation produces carbocations (or their equivalents) capable of electrophilic aromatic substitution by formation of aryl-carbon bonds. Haloalkanes, alkenes, and alcohols can be used to achieve aromatic alkylation in the presence of a Lewis or mineral acid. 

In Summary The problems of Friedel-Crafts alkylation (multiple substitution and carboca-tion rearrangements) are avoided in Friedel-Crafts acylations, in which an acyl halide or carboxylic acid anhydride is the reaction partner, in the presence of a Lewis acid. The intermediate acylium cations undergo electrophilic aromatic substitution to yield the corresponding aromatic ketones. 

In Summary When considering the effect of substituents on the reactivity of the benzene nucleus, we have to analyze the contributions that occur by induction and resonance. We can group these substituents into two classes (1) electron donors, which accelerate electrophilic aromatic substitutions relative to benzene, and (2) electron acceptors, which retard them. 

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