Which one of the following is most reactive towards electrophilic attack?
Which one of the following is most reactive towards electrophilic attack?
Solution
Key Idea: Electron releasing groups stabilise the intermediate cation whereas electron withdrawing groups destabilise it.
The order of electron withdrawing group is :
$\mathrm{NO}_2 > \mathrm{Cl} > \mathrm{OH} > \mathrm{C}_6 \mathrm{H}_5$
electrophilic substitution because $-\mathrm{OH}$ group least destabilise the carbocation. Further $-\mathrm{OH}$ group is strongly activating group while $-\mathrm{NO}_2$ and $-\mathrm{Cl}$ are deactivating group.
electrophilic substitution because $-\mathrm{OH}$ group least destabilise the carbocation. Further $-\mathrm{OH}$ group is strongly activating group while $-\mathrm{NO}_2$ and $-\mathrm{Cl}$ are deactivating group.