Summary of Activators Groups: R -:>-N-R>-9-H>-0-R>-N-C-R>-R (no lone pairs) Compounds: R H :0: :OH :O-R :N-C-R phenoxides anilines phenols phenyl ethers anilides alkylbenzenes Chapter 17 16=>
Chapter 17 16 Summary of Activators =>
Deactivating Meta- Directing Substituents Electrophilic substitution reactions for nitrobenzene are 100,000 times slower than for benzene. The product mix contains mostly the meta isomer,only small amounts of the ortho and para isomers. Meta-directors deactivate all positions on the ring,but the meta position is less deactivated. Chapter 17 17
Chapter 17 17 Deactivating MetaDirecting Substituents • Electrophilic substitution reactions for nitrobenzene are 100,000 times slower than for benzene. • The product mix contains mostly the meta isomer, only small amounts of the ortho and para isomers. • Meta-directors deactivate all positions on the ring, but the meta position is less deactivated. =>
Ortho Substitution on Nitrobenzene Ortho attack charges adjacent ortho especially unstable => Chapter 17 18
Chapter 17 18 Ortho Substitution on Nitrobenzene =>