Synthesis of [60]fullerene-functionalized rotaxanes

Synthesis of [60]fullerene (C60)-functionalized rotaxanes via Diels–Alder reactions with C60 is described. Diels–Alder reaction of C60 and sulfolene moiety as masked diene attached on the wheels of rotaxanes results in high yields of C60 incorporation. Rotaxanes are prepared by tin-catalyzed urethane-forming end-capping reaction with isocyanate of pseudorotaxane having the wheel carrying C60 functionality as introduced by the Diels–Alder reaction. The Diels–Alder reaction was accomplished as end-capping reaction between C60 and pseudorotaxane bearing sultine moiety as masked diene on the axle terminal. A variety of C60-containing [2]rotaxanes was prepared in moderate to good yields by these Diels–Alder protocols.