Gold(III) bromide is used as a catalyst in a variety of reactions, but one of its most interesting uses is found in the Diels-Alder reaction. Specifically, the compound catalyzes the reaction between an enynal unit and carbonyl compounds to form a six-membered cyclic compound.
Another catalytic use of gold tribromide is in the nucleophilic substitution reaction of propargylic alcohols. In this reaction, the gold complex acts as an alcohol-activating agent to facilitate the substitution.