Heterogeneous catalysts have been prepared by crosslinking the polyisoprene block of a microphase-separated poly(vinylferrocenium triflate-block-isoprene) copolymer. The poly(vinylferrocenium triflate) moieties provide catalytic activity while the polyisoprene block provides the support structure. Reaction rates obtained with the self-assembled heterogeneous catalyst are within experimental error of those obtained with (monomeric) ferrocenium triflate as a homogeneous catalyst.