74967 20210111082904.0 doi 10.3390/catal8080305 sideral 107612 ART-2018-107612 eng (orcid)0000-0001-9988-0287 Giménez Sonsona, I. Urea activation by an external brønsted acid: Breaking self-association and tuning catalytic performance 2018 Access copy available to the general public Unrestricted In this work, we hypothesize that Brønsted acids can activate urea-based catalysts by diminishing its self-assembly tendency. As a proof of concept, we used the asymmetric Friedel–Crafts alkylation of indoles with nitroalkenes as a benchmark reaction. The resulting 3-substituted indole derivatives were obtained with better results due to cooperative effects of the chiral urea and a Brønsted acid additive. Such synergy has been rationalized in terms of disassembly of the supramolecular catalyst aggregates, affording a more acidic and rigid catalytic complex. info:eu-repo/grantAgreement/ES/DGA/E07-17R info:eu-repo/grantAgreement/ES/MINECO/CTQ2017-88091-P info:eu-repo/grantAgreement/ES/UZ/JIUZ-2017-CIE-05 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 3.444 2018 CHEMISTRY, PHYSICAL 57 / 148 = 0.385 2018 Q2 T2 0.853 2018 Physical and Theoretical Chemistry 2018 Q2 Catalysis 2018 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion (orcid)0000-0001-6832-8983 Marqués-López, E. Universidad de Zaragoza Häring, M. (orcid)0000-0002-0557-3364 Díaz, D. (orcid)0000-0002-5244-9569 Pérez Herrera, R. Universidad de Zaragoza 2013 765 Universidad de Zaragoza Dpto. Química Orgánica Área Química Orgánica 8, 8 (2018), 305 [21 pp] Catalysts CATALYSTS 2073-4344 10938078 http://zaguan.unizar.es/record/74967/files/texto_completo.pdf Versión publicada 104637 http://zaguan.unizar.es/record/74967/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:74967 articulos driver 2021-01-11-07:55:19 ARTICLE