Relatively long chain alkyl aromatic compounds are prepared by alkylating an alkylatable aromatic compound with a relatively long chain alkylating agent under alkylation reaction conditions in the presence of a layered material as an alkylation catalyst. The layered material contains titanate in the layers and oxide pillars separating the layers. The layers also contain vacancies and/or metals incorporated therein. The degree of alkylation is a function of the interplanar d-spacing of the pillared material, which is, in turn a function of the chain length of the swelling agent used to prepare the layered material.