Explain why no addition reaction occurs.
$\text{AlBr}_3$ reacts with bromine to produce the electrophile, $\text{Br}^+$. Draw the mechanism for the reaction between benzene and $\text{Br}^+$ ions. Include all the relevant arrows and charges.
Write an equation to show how the $\text{AlBr}_3$ catalyst is regenerated.
Suggest why bromination of phenol happens more readily than bromination of benzene.
Four different carbocations have the same formula, $\text{C}_4\text{H}_9^+$. One structure is already given in the table. Suggest the structural formulae of the other three carbocations.
Benzene reacts with each of these carbocations in separate Friedel-Crafts alkylation reactions. In each case, an organic compound with formula $\text{C}_{10}\text{H}_{14}$ is formed. The number of peaks in the carbon-13 NMR spectrum of each compound is given. Suggest the structures of the other three compounds.