Regioselectivity of Bingel–Hirsch Cycloadditions on IPR Metallofullerenes

In this work, the Bingel–Hirsch addition of diethylbromomalonate to all non-equivalent bonds of Sc3N@D3h-C78 was studied using density functional theory calculations. The regioselectivities observed computationally allowed the proposal of a set of rules, the predictive aromaticity criteria (PAC), to identify the most reactive bonds of a given endohedral metallofullerene based on a simple evaluation of the cage structure. The predictions based on the PAC are fully confirmed by both the computational and experimental exploration of the Bingel–Hirsch reaction of Sc3N@D5h-C80, thus indicating that these rules are rather general and applicable to other isolated pentagon rule endohedral metallofullerenes.

The results were published today in Angewandte Chemie – International Edition:
M. Garcia-Borràs, M.R. Cerón, S. Osuna, M. Izquierdo, J.M. Luis, L. Echegoyen, and M. Solà
“The Regioselectivity of Bingel-Hirsch Cycloadditions on Isolated Pentagon Rule Endohedral Metallofullerenes”
Angew. Chem. Int. Ed. 2016, 55, 2374-2377
DOI: 10.1002/anie.201509057