Explain why an addition reaction does not occur.
AlBr$_3$ reacts with bromine to generate the electrophile, Br$^+$. Draw the mechanism for the reaction of benzene with Br$^+$ ions. Include all relevant arrows and charges.
Write an equation to show the catalyst AlBr$_3$ is reformed.
Suggest why phenol is brominated more readily than benzene.
There are four different carbocations that share the formula, $\text{C}_4\text{H}_9^+$. One is already shown in the table. Suggest the structural formulae for the other three carbocations.
Benzene reacts separately with each of these carbocations in Friedel-Crafts alkylation reactions. In every case, an organic compound with formula $\text{C}_{10}\text{H}_{14}$ is produced. The number of peaks in the carbon-13 NMR spectrum of each compound is given. Suggest the structures of the three other compounds.