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 stereo-selectively 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.