Fullerene derivatives hexakis-adducts

Ortiz AL, Echegoyen L (2010) Unexpected and selective formation of an (e, e, e, e)-tetrakis-[60]fullerene derivative via electrolytic retro-cyclopropanation of a D2h-hexakis-[60]fuller-ene adduct. J Mater Chem 21 1362-1364... 

A Ci-symmetric hexakis-adduct of C6o including an azahomofullerene substructure (addition pattern analogue of homo[60]fullerene derivative ( )-26, Scheme 1.2) was obtained as a side product upon nitrogen extrusion from a fullerene derivative bearing five Bingel type addends and a fused triazoline arranged in a pseudo-octahedral manner.120... 

Hirsch and co-workers subsequently discovered that the yield of hexakis-adducts such as 8 or 9 can be greatly increased and their separation from side products substantially facilitated, if 9,10-dimethylanthracene (DMA) is used as a template (Scheme 7-2) [14, 15]. Anthracene derivatives such as DMA are well known to undergo reversible Diels-Alder additions with fullerenes at ambient temperamre [16-18]. After addition to the fullerene, the template directs diethyl malonate addends in the Bingel addition tegio-selectively into e positions, ultimately yielding the hexakis-adducts with a pseudo-octahedral, all-e addition pattern. The templated activation of e 6-6 bonds (bonds between two six-membered rings) is also efficient starting from C o mono-adducts, and several examples are shown in Scheme 7-2. Thus, bis(alkynyl)methanofullerene 10 [19] reacted with diethyl 2-bromomalonate/DBU (8 equiv) and DMA (12 equiv) to provide hexakis-... 

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