By appropriate choice of solid catalyst and stoichiometric reagent it is possible to develop alternative procedures for many electrophilic aromatic substitution reactions that avoid the need for Lewis acid catalysts such as aluminium chloride. Furthermore, the catalysts may be regenerated, the reactions may be more controlled, corrosive by-products may be avoided and the structural features of the solid may lead to much greater regioselectivity than with traditional Lewis acids. Examples where such benefits are found include nitration, chlorination, bromination and acylation.