Regioselective electrosynthesis of tetra- and hexa-functionalized fullerene derivatives with unprecedented addition patterns†
The efficient and regioselective electrosynthesis of tetra- and hexa-functionalized fullerene derivatives with unprecedented addition patterns has been achieved. The tetra-functionalized fullerene derivative with an intriguing 1,2,4,17-addition pattern is regioselectively obtained by cyclization reaction of the dianionic species generated electrochemically from a fulleroindoline with 1,2-bis(bromomethyl)benzene at 0 °C, and can be converted to the more stable 1,2,3,4-adduct at 25 °C. Furthermore, the hexa-functionalized fullerene derivative with the 1,2,3,4,9,10-addition pattern displaying a unique “S”-shaped configuration can be synthesized by protonation of the electrochemically generated dianion of the obtained tetra-functionalized 1,2,4,17-adduct. The structures of the tetra- and hexa-functionalized products have been determined by spectroscopic data and single-crystal X-ray analysis.