Regio- and Stereoselective Synthesis of a trans-4-[60]Fullerenobisacetic Acid Derivative by a Tether-Directed Biscyclopropanation: A Diacid Component Applicable for the Synthesis of Regio- and Stereo-regular [60]Fullerene Pearl-Necklace Polyamides

A trans-4-[60]fullerenobisacetic acid derivative was easily obtained from its diethyl ester, which was regio- and stereoselectively prepared by the biscyclopropanation of [60]fullerene with a tethered bis(α-bromophenylacetate) derivative. The polycondensation of the resultant fullerenobisacetic acid with aromatic diamines proceeded smoothly to give the corresponding regio- and stereo-regular [60]fullerene pearl-necklace polyamides in excellent yields.