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Aquest mateix article està publicat a l'edició alemanya de la revista 'Angewandte Chemie' (ISSN 0044-8249, EISSN 1521-3757), vol. 127, núm. 9, p. 2767-2771. DOI http://dx.doi.org/10.1002/ange.201410557 Highly enantioselective epoxidation of -substituted styrenes with aqueous H2O2 is described by using a chiral iron complex as the catalyst and N-protected amino acids (AAs) as coligands. The amino acids synergistically cooperate with the iron center in promoting an efficient activation of H2O2 to catalyze epoxidation of this challenging class of substrates with good yields and stereoselectivities (up to 97%ee) in short reaction times We acknowledge group LIPPSO from UdG for providing amino acid samples and A. Riera (IRB) for access to a polarimeter. We acknowledge financial support from the European Research Council (ERC-2009-StG-239910), MINECO of Spain (CTQ2012-37420-C02-01/BQU, CSD2010-00065), and Generalitat de Catalunya (2009SGR637). J.L.-F. thanks MICINN for a RyC contract. X.R. and M.C. thank ICREA-Academia awards

Encapsulation of metal clusters in endohedral metallofullerenes takes place in cages that in most cases are far from being the most stable isomer in the corresponding hollow fullerenes. In large metal clusters and small fullerene cages, the election is mainly driven by the need to reduce strain. For the not so large metal clusters, it is usually said that the cage is chosen to minimize the electrostatic repulsion between charged five-membered rings.1 We have proved that maximizing the aromaticity is the main driving force that determines the most suitable hosting carbon cage for a given metallic cluster.2 This simple rule, the so-called Maximum ARomaticity Criterion (MARC), allow us to directly compare IPR (isolated pentagon rule) and non-IPR anionic isomers regardless the number of adjacent pentagon pairs (APP) they have. We have tested the MARC for the majority of endohedral metallofullerenes from C66 to C104 reported to date and the results show that MARC successfully predicts the most suitable C2n cage for hosting a given metal cluster among the manifold existing C2n isomers. In addition, using the Maximum ARomaticity Criterion, one can justify why the IPR rule is not always fulfilled when EMFs are considered. [Figure 1 here] Figure 1. Classification in terms of the ALA index of the anionic IPR and non-IPR fullerene isomers with 1-3 Adjacent Pentagon Pairs (APPs) for the most common C2 n (2n = 66–104) EMFs reported to date. Isomers experimentally observed are marked using black dots, and their corresponding isomer numbers are indicated. The ALA prediction ordering for the experimentally observed isomers are given in parentheses. A. Rodríguez-Fortea, N. Alegret, A.L. Balch, J.M. Poblet, Nat. Chem. 2010, 2, 955. M. Garcia-Borràs, S. Osuna, M. Swart, J.M. Luis, and M. Solà, Angew. Chem. Int. Ed. 2013, 52, 9275.

Aquest mateix article està publicat a l'edició alemanya d''Angewandte Chemie' (ISSN 0044-8249, EISSN 1521-3757), 2011, vol.123, núm. 25, p. 5766-5771. DOI http://dx.doi.org/10.1002/ange.201100907 HAT trick: [MnIV(OH)2(H,MePytacn)]2+ (A) and [MnIV(O)(OH)(H,MePytacn)]+ (B) differ in their reactions with CH bonds: compound A engages in typical single-step hydrogen atom transfer (HAT) reactions, whereas B first forms a substrate–B encounter complex (C; see scheme). This equilibrium alters the relative CH reactivity from that expected from CH bond dissociation energies We thank Prof. Jim Mayer and Dr. Julio Lloret for reading this work and for helpful comments. M. C. thanks MICINN (CTQ2009-08464/BQU and PhD grants to I.G.-B) and the European Research Council (ERC-StG-239910). M. C. and X. R. acknowledge ICREA-Academia Awards, and SGR 2009-SGR637. S. S. thanks the Swedish Energy Agency, The K&A Wallenberg Foundation, and the EU/Energy project "SOLAR-H2". W. R. B. thanks Netherlands Technology Foundation STW grant no. 11059