Aromatics, substitution addition-elimination

Mechanism 17-7 Nucleophilic Aromatic Substitution (Addition-Elimination) 787... [Pg.17]

Nucleophilic Aromatic Substitution Addition-Elimination (Section 22.3B) The... [Pg.983]

NUCLEOPHILIC AROMATIC SUBSTITUTION Addition-Elimination Elimination-Addition... [Pg.1231]

Mechanism of nucleophilic aromatic substitution by elimination addition (the benzyne mechanism). [Pg.707]

Pertinent examples of zeolite-catalyzed reactions in organic synthesis include Friedel-Crafts alkylations and acylations and other electrophilic aromatic substitutions, additions and eliminations, cyclizations, rearrangements and isomeriza-tions, and condensations. [Pg.59]

Because the elementary reactions of cationic alkene polymerizations are directly related to the organic chemistry of carbocations, Chapter 2 will investigate electrophilic additions to double bonds, nucleophilic substitution, electrophilic aromatic substitution, and elimination reactions. [Pg.23]

The author believes that students are well aware of the basic reaction pathways such as substitutions, additions, eliminations, aromatic substitutions, aliphatic nucleophilic substitutions and electrophilic substitutions. Students may follow undergraduate books on reaction mechanisms for basic knowledge of reactive intermediates and oxidation and reduction processes. Reaction Mechanisms in Organic Synthesis provides extensive coverage of various carbon-carbon bond forming reactions such as transition metal catalyzed reactions use of stabilized carbanions, ylides and enamines for the carbon-carbon bond forming reactions and advance level use of oxidation and reduction reagents in synthesis. [Pg.385]

The Addition-Elimination Mechanism of Nucleophilic Aromatic Substitution... [Pg.977]

THE ADDITION-ELIMINATION MECHANISM OF NUCLEOPHILIC AROMATIC SUBSTITUTION... [Pg.977]

The generally accepted mechanism for nucleophilic aromatic substitution m nitro substituted aryl halides illustrated for the reaction of p fluoromtrobenzene with sodium methoxide is outlined m Figure 23 3 It is a two step addition-elimination mechanism, m which addition of the nucleophile to the aryl halide is followed by elimination of the halide leaving group Figure 23 4 shows the structure of the key intermediate The mech anism is consistent with the following experimental observations... [Pg.977]

Although nucleophilic aromatic substitution by the elimination-addition mecha nism IS most commonly seen with very strong amide bases it also occurs with bases such as hydroxide ion at high temperatures A labeling study revealed that hydroly SIS of chlorobenzene proceeds by way of a benzyne intermediate... [Pg.985]

Section 23 6 Nucleophilic aromatic substitutions of the type just shown follow an addition—elimination mechanism... [Pg.987]

Other aryl halides that give stabilized anions can undergo nucleophilic aromatic substitution by the addition-elimination mechanism Two exam pies are hexafluorobenzene and 2 chloropyridme... [Pg.987]

Nucleophilic aromatic substitution can also occur by an elimination-addition mechanism This pathway is followed when the nucleophile is an exceptionally strong base such as amide ion m the form of sodium amide (NaNH2) or potassium amide (KNH2) Benzyne and related arynes are intermediates m nucleophilic aromatic substitutions that pro ceed by the elimination-addition mechanism... [Pg.987]