Heterogenized versions of the second generation MacMillan imidazolidin-4-one are
described for the first time. This versatile organocatalyst has been supported onto 1% DVB Merrifield
resin and Fe3O4 magnetic nanoparticles through copper-catalyzed alkyne-azide cycloaddition (CuAAC)
reaction. The resulting catalytic materials have been successfully applied to the asymmetric Friedel-
Crafts alkylation of indoles with α,β-unsaturated aldehydes. While both catalytic systems can be easily
recovered and admit repeated recycling, the polystyrene-based catalyst shows higher stability and
provides better stereoselectivities.