Electrophilic Aromatic Substitution Reactions of Benzene Review

Electrophilic Aromatic Substition: This video provides an overview of both nucleophilic and electrophilic aromatic substitution reactions. First, it provides a list of ortho, para, and meta directors as well as activating and deactivating groups. For electrophilic aromatic substitution reactions - most of the ortho para directing groups are electron donating activating groups and the meta directing groups are electron withdrawing deactivating groups. The reverse is true for nucleophilic aromatic substitution reactions. It list which groups are strongly, moderately and weakly activating and deactivating so you can be able to rank a list of compounds in order of increasing reactivity toward EAS and NAS. The video also provides a list of named reactions shown below:

Benzene Reactions:
Nitration - HNO3 & H2SO4
Sulfonation - SO3 & H2SO4
Bromination - Br2 + FeBr3
Chlorination - Cl2 + AlCl3
Iodination - I2 + HNO3
Friedel Crafts Alkylation - CH3Cl, CH3CH2Cl, CH3CH2CH2Cl, (CH3)3CCl + AlCl3
Friedel Crafts Acylation - CH3COCl + AlCl3
Permanganate Oxidation - KMnO4 + H3O+
Side Chain Halogenation - NBS
Gatterman Koch Reaction - CO, HCl, AlCl3, CuCl
Grignard Reaction - Mg, CO2, H2O, & direct alkylation
Sandmeyer Reaction - CuCl, CuBr, & CuCN
Reductive Amination - NO2 to NH2 using NaNO2 & HCl, or HONO, HNO2
-NH2 protecting groups - amine to amide

Products formed in this reaction include nitrobenzene, aniline, anisole, benzoic acid, benzaldehyde, styrene, alkyne, benzyl alcohol, benzenesulfonic acid, bromobenzene, iodobenzene, chlorobenzene, toluene, ethylbenzene, propylbenzene, isopropylbenzene, tert butyl benzene, m-nitrobenzoic acid, fluorobenzene, phenol, 1,3,5-tribromobenzene, dibenzene, methylaniline.

For the nucleophilic aromatic substitution portion of the video, the addition elimination reaction mechanism and the formation of the meisenheimer complex was discussed whenever an electron withdrawing group was present. The benzyne intermediate was obtained using NaNH2 when no electron withdrawing group is present. In addition, the diazo coupling of two benzene rings was discussed as well.

Other reactions include the friedel crafts acylation of nitrobenzene, bromination of phenyl benzoate, sulfonation of toluene, nitration of chlorobenzene, reduction of nitrobenzene, fluorination of benzene, fischer esterification of hydroxybenzoate and acetic acid, and synthesis of aspirin from acetylsalicyclic acid using salicyclic acid.