Cobalt-Catalyzed Hydroalkylation of [60]Fullerene with Active Alkyl Bromides: Selective Synthesis of Monoalkylated Fullerenes

The Co-catalyzed hydroalkylation of C-60 with reactive alkyl bromides 1 (RBr) in the presence of Mn reductant and H2O at ambient temperature gave the monoalkylated C60 (2) in good to high yields. The use of CoLn/Mn/H2O under Ar atmosphere is crucial for the success of the present transformation. The reaction most probably proceeds through the Co (0 or I) complex-promoted generation of a radical (R-center dot) followed by addition to C-60. This hydroalkylation method was applied to the synthesis of zinc porphyrin attached C-60 (2l), dendrimer attached C-60 (2m), and fullerene dimer (2n), which were not easily available through the previously known methods.