Comparing reactivity of alkenes with arenes Flashcards
1
Q
Why do alkenes undergo electrophillic addition?
A
High e- density due to localised electrons in pi bonds. Able to induce dipole in non-polar molecules like Br2. Slightly positive bromine atom means Br2 acts as an electrophile
2
Q
Why does benzene react by electrophilic substitution?
A
Pi electrons are delocalised, low electron density. Cannot induce dipole in non-polar Br2 molecule. So halogen carrier catalyst needed to generate electrophile.
