N-Cyclohexylmaleimide (CHMI, NCMI) is a cyclic imide. Diels-Alder reactions of 9-hydroxymethylanthracene with CHMI catalyzed by hydrophobic nanospace confined within the self-assembled Pd6 open cage bearing triimidazole walls have been reported. It undergoes Diels-Alder reactions with various aromatic hydrocarbons promoted by self-assembled coordination cage. This cage acts as nanometer-sized molecular flask and hence promotes this reaction. CHMI is reported to undergo radical polymerization readily under various polymerization conditions to afford poly(CHMI), having excellent thermal stability.