Friedel-Crafts reactions require an aromatic compound and an electrophile, facilitated by a Lewis acid catalyst (e.g., AlCl$_3$). However,
certain compounds cannot undergo Friedel-Crafts reactions due to deactivating groups or coordination issues with the catalyst.
Toluene, xylene, and cumene: These are activated aromatic compounds and can undergo Friedel-Crafts reactions.
Chlorobenzene: Chlorine is an electron-withdrawing group but is ortho/para-directing; hence it can still undergo Friedel-Crafts reactions.
Nitrobenzene, m-nitroaniline, m-dinitrobenzene: Nitro groups are strongly deactivating, making the aromatic ring unreactive for Friedel-Crafts reactions.
Aniline: The amino group ($-\text{NH}_2$) coordinates with the Lewis acid catalyst (AlCl$_3$), deactivating the ring.
Compounds that cannot undergo Friedel-Crafts reactions:
Nitrobenzene, aniline, m-nitroaniline, m-dinitrobenzene (4 compounds).
Final Answer: (4)
Identify the suitable reagent for the following conversion: $Ph-C(=O)-OCH_3$ $\longrightarrow$ $Ph-CHO$
Why is chlorobenzene resistant to nucleophilic substitution reactions?
If the system of equations \[ x + 2y - 3z = 2, \quad 2x + \lambda y + 5z = 5, \quad 14x + 3y + \mu z = 33 \] has infinitely many solutions, then \( \lambda + \mu \) is equal to:}
The equilibrium constant for decomposition of $ H_2O $ (g) $ H_2O(g) \rightleftharpoons H_2(g) + \frac{1}{2} O_2(g) \quad (\Delta G^\circ = 92.34 \, \text{kJ mol}^{-1}) $ is $ 8.0 \times 10^{-3} $ at 2300 K and total pressure at equilibrium is 1 bar. Under this condition, the degree of dissociation ($ \alpha $) of water is _____ $\times 10^{-2}$ (nearest integer value). [Assume $ \alpha $ is negligible with respect to 1]