Tunable Copper-Catalyzed Reaction of C60 with 2-Ethoxycarbonylacetamides and Subsequent BF3·Et2O-Mediated Isomerization of the Generated Dihydrofuran-Fused Fullerenes to Fulleropyrrolidinones.

A tunable copper-catalyzed reaction of C60 with 2-ethoxycarbonylacetamides using air as the oxidant has been explored, which selectively affords methanofullerenes (2) and dihydrofuran-fused fullerenes (3) under the CuI/DMAP and CuCl/NMI catalytic systems, respectively. Furthermore, the generated dihydrofuran-fused fullerenes could be transformed to fulleropyrrolidinones (4 and 5) upon treatment with BF3·Et2O.