The Regioselectivity of Bingel-Hirsch Cycloadditions on Isolated Pentagon Rule Endohedral Metallofullerenes

Abstract

Aquest mateix article està publicat a l'edició alemanya d''Angewandte Chemie' (ISSN 0044-8249, EISSN 1521-3757), 2016, vol. 128, núm. 7, p. 2420-2423. DOI http://dx.doi.org/10.1002/ange.201509057

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

We are grateful to the Spanish MINECO (CTQ2014-54306-P, CTQ2014-52525-P, CTQ2014-59212-P, and JdlC contract to S.O.), the Catalan DIUE (2014SGR931, ICREA Academia 2014 Award to M.S. and XRQTC), and the FEDER fund (UNGI10-4E-801) for financial support. M.G.-B. thanks the Spanish MECD for a PhD grant (AP2010-2517) and S.O. the European Commission for CIG project (FP7-PEOPLE-2013- CIG-630978). CESCA and BSC-CNS are acknowledged. M.R.C, M.I. and L.E. thanks the NSF for generous support of this work under grant (CHE-1408865) and to the NSFPREM program (DMR-1205302). The Robert A. Welch Foundation is also gratefully acknowledged for an endowed chair to L.E. (grant AH-0033)