Polymer-supported chloroaluminate catalysts for the Diels–Alder reaction of cyclopentadiene with methyl methacrylate Original Research Article

Polymer-supported chloroaluminates, poly(1-butyl-4-vinylpyridinium) chloroaluminate (p([BVPy]AlCl4)), poly(1-butyl-3-vinylimidazolium) chloroaluminate (p([BVIm]AlCl4)), and poly(1-ethyl-3-vinylimidazolium) chloroaluminate (p([EVIm]AlCl4)), were synthesized and tested for their activities in the Diels–Alder reaction of cyclopentadiene (CPD) with methyl methacrylate (MMA). These polymer-supported heterogeneous catalysts exhibited activities comparable to their corresponding monomeric homogeneous analogues, 1-butyl-4-vinylpyridinium chloroaluminate ([BVPy]AlCl4) and 1-butyl-3-vinylimidazolium chloroaluminate ([BVIm]AlCl4). The catalyst recycle tests showed that the supported catalysts can be reused with a moderate loss of initial activity at least up to five times.