Synthesis of [60]fullerene-functionalized rotaxanes

Synthesis of [60]fullerene (C-60)-functionalized rotaxanes via Diels-Alder reactions with C-60 is described. Diels-Alder reaction of C-60 and sulfolene moiety as masked diene attached on the wheels of rotaxanes results in high yields of C-60 incorporation. Rotaxanes are prepared by tin-catalyzed urethane-forming end-capping reaction with isocyanate of pseudorotaxane having the wheel carrying C-60 functionality as introduced by the Diels-Alder reaction. The Diels-Alder reaction was accomplished as end-capping reaction between C-60 and pseudorotaxane bearing sultine moiety as masked diene on the axle terminal. A variety of C-60-containing [2]rotaxanes was prepared in moderate to good yields by these Diels-Alder protocols. (c) 2005 Elsevier Ltd. All rights reserved.