CHEM102 Lecture Notes - Lecture 11: Pi Bond, Benzene, Addition Reaction
Document Summary
10: this special stability lowers the reactivity of aromatic compounds, aromatic rings do not undergo addition reactions as this breaks apart the aromatic compounds. Naming of di-substituted aromatic compounds and their isomers: e. g. Electrophilic aromatic substitution: stability of aromatic compounds means that they tend to undergo substitution rather than elimination reactions, a range of electrophilic groups can be added to aromatic rings, all requiring the formation of a powerful, cationic, electrophile: Systems are stable therefore a electrophile is needed. Hence substitution occurs instead of addition reaction: mechanism: involves 2 steps the initial attack of the electrophile is rate determining and leads to a resonance stabilised intermediate (wheland intermediate, see lecture problem. Electrophilic aromatic substitution for aromatic rings with existing groups. If an aromatic ring has an existing group (substituent) then this can alter the reactivity of the ring towards electrophilic aromatic substitution and brings up the issue of isomers (regioisomers): e. g. nitration of toluene.
