Macrocyclic malonates. A new family of tethers for the regio- and diastereoselective functionalization of [60]fullerene

The tether-directed remote functionalization of C60 has been investigated by using cyclic bis- and trismalonate tethers. The reactive malonate groups are connected with alkyl spacers and their synthesis was performed in one step by the condensation reaction of malonyl dichloride with an appropriate diol. Macrocycles containing identical alkyl spacers afforded bis- and triadducts of C60 with rotational symmetry in a regioselective manner and in remarkable yields. In contrast, macrocycles bearing different alkyl spacers led to the formation of Cs-symmetrical bisadducts. Tuning of the spacer’s length gave access to different addition patterns of C60 while, the synthesis of enantiomerically pure trisadducts of C60 with an e,e,e-addition pattern was achieved via cyclopropanation with chiral D3-symmetrical cyclo-tris-malonate tethers. To cite this article: N. Chronakis et A. Hirsch.C. R. Chimie 8 (2005).