Two of the most important reactions in fullerene chemistry are the Diels-Alder and the Bingel-Hirsch additions. In this work, we have quantum chemically explored all possible mechanistic pathways of the Diels-Alder cycloaddition of (1,2,3,4,5-pentamethyl)cyclopentadiene and the Bingel-Hirsch addition of dimethyl bromomalonate to La@C_2v-C₈₂ using dispersion-corrected DFT. La@C_2v-C₈₂ has 24 nonequivalent carbon atoms and 35 different bonds (see Figure 1). Our calculations show that the Diels-Alder reaction to La@C_2v-C₈₂ is very regioselective and occurs exclusively on bond o [1]. On the other hand, La@C_2v-C₈₂ is not particularly regioselective under Bingel-Hirsch conditions. Still, from the obtained results one can make a tentative assignment of the products experimentally observed [2]. According to our calculations [3], the observed fulleroid adduct results from the attack to bond 19 and the singly-bonded derivatives correspond to the C2, C19, C21, and C23 initial attacks. However, other possibilities cannot be ruled out completely.

 

References

1. M. Garcia-Borràs, J. M. Luis, M. Swart, M. Solà, Chem. Eur. J. 2013, 19, 4468–4479.

2. L. Feng, T. Wakahara, T. Nakahodo, T. Tsuchiya, Q. Piao, Y. Maeda, Y. Lian, T. Akasaka, E. Horn, K. Yoza, T. Kato, N. Mizorogi, S. Nagase, Chem. Eur. J. 2006, 12, 5578–5586.

3. J. P. Martínez, M. Garcia-Borràs, S. Osuna, J. Poater, F. M. Bickelhaupt, M. Solà, submitted for publication.