USE OF ANIONS OF C-60 AS ELECTROGENERATED BASES

C-60 was reduced in the mixed solvent acetonitrile-toluene (2:3) to fo rm a series of three electrogenerated bases of successively increasing basicity. These were the radical anion, the dianion, and the radical trianion of the fullerene. Cyclic voltammograms indicated that the rad ical anion was capable of deprotonating the relatively strong C-H acid , ethyl nitroacetate. The weaker acid, diethyl malonate, required the stronger base C-60(2-) in order to observe deprotonation on the voltam metric time scale. Other weak acids that react with C-60(2-), include diethyl methylmalonate, 2-nitropropane, and n-octanethiol. The anionic electrogenerated bases were used to carry out efficient base-catalyze d synthetic reactions. These included the C60(-.)-catalyzed reaction o f ethyl nitroacetate with ethyl acrylate and acrylonitrile to form the double addition products, 3b and 3c. The dianion promoted reaction of nitromethane with ethyl acrylate to form triple addition product 4 in good yield, as well as the reaction of diethyl malonate with acryloni trile to give double addition product 3c. In this case it was demonstr ated that the fullerene probase may be recycled at least two times. Th e dianion was also used to catalyze the addition of n-octanethiol to s tyrene oxide. The reactions of still weaker acids could be promoted by the highly basic C-60(3-). These included the addition of pyrrole to acrylonitrile and the Wittig-Horner reaction of diethyl benzylphosphon ate with benzaldehyde.