Roland Kessinger

Preparation of enantiomerically pure C76 with a general electrochemical method for the removal of Di(alkoxycarbonyl)methano bridges from methanofullerenes: The retro-bingel reaction

Serendipitously discovered during electrochemical investigations on the stability of anion 1, a preparatively useful electrochemical procedure, the retro-Bingel reaction, has been identified as a method for removing di(alkoxycarbonyl)methano bridges from methanofullerenes. This procedure was applied to prepare the first samples of enantiomerically pure D2-C76 with unambiguous optical purity.

Herstellung von enantiomerenreinem C76 durch Retro-Bingel-Reaktion

Zufallig entdeckt wurde bei elektrochemischen Untersuchungen zur Stabilitat von Anionen von 1 eine praparativ nutzliche Methode: die Retro-Bingel-Reaktion, eine elektrochemische Methode zur Entfernung der Bis(alkoxycarbonyl)methano-Bucken von Methanofullerenen. Sie wurde dazu verwendet, um die ersten Proben von enantiomerenreinem D2-C76 mit gesicherter optischer Reinheit herzustellen.

Electrochemical Transformations of Methanofullerenes

The synthesis of fullerene derivatives started almost as soon as the parent compounds were first isolated in large quantities in 1990, after extraction from the soot produced by arching graphite rods under a helium atmosphere [1]. A wide variety of reactions have been developed to prepare fullerene derivatives, mainly from C60 and C70, since these are the most abundant carbon allotropes produced in the soot. Given the spherical symmetry of C60, along with its unique and interesting electronic properties, it has been used extensively as the core from which well-defined three-dimensional architectures containing specific functional groups have been built [2,3]. Single as well as multiple adducts can be easily attached to C60 using a variety of protocols, but the persistent challenge is to prepare the multiple adducts in a regioselective way [4].