{ "dc.contributor.author": "Masferrer Rius, Eduard" , "dc.contributor.author": "Borrell Recasens, Margarida" , "dc.contributor.author": "Lutz, Martin" , "dc.contributor.author": "Costas Salgueiro, Miquel" , "dc.contributor.author": "Gebbink, Robertus J. M. Klein" , "dc.date.accessioned": "2021-05-13T08:14:32Z" , "dc.date.available": "2021-05-13T08:14:32Z" , "dc.date.issued": "2021-08-03" , "dc.identifier.issn": "1615-4150" , "dc.identifier.uri": "http://hdl.handle.net/10256/19491" , "dc.description.abstract": "The oxidation of aromatic substrates to phenols with H2O2 as a benign oxidant remains an ongoing challenge in synthetic chemistry. Herein, we successfully achieved to catalyze aromatic C−H bond oxidations using a series of biologically inspired manganese catalysts in fluorinated alcohol solvents. While introduction of bulky substituents into the ligand structure of the catalyst favors aromatic C−H oxidations in alkylbenzenes, oxidation occurs at the benzylic position with ligands bearing electron‐rich substituents. Therefore, the nature of the ligand is key in controlling the chemoselectivity of these Mn‐catalyzed C−H oxidations. We show that introduction of bulky groups into the ligand prevents catalyst inhibition through phenolate‐binding, consequently providing higher catalytic turnover numbers for phenol formation. Furthermore, employing halogenated carboxylic acids in the presence of bulky catalysts provides enhanced catalytic activities, which can be attributed to their low pKa values that reduces catalyst inhibition by phenolate protonation as well as to their electron‐withdrawing character that makes the manganese oxo species a more electrophilic oxidant. Moreover, to the best of our knowledge, the new system can accomplish the oxidation of alkylbenzenes with the highest yields so far reported for homogeneous arene hydroxylation catalysts. Overall our data provide a proof‐of‐concept of how Mn(II)/H2O2/RCO2H oxidation systems are easily tunable by means of the solvent, carboxylic acid additive, and steric demand of the ligand. The chemo‐ and site‐selectivity patterns of the current system, a negligible KIE, the observation of an NIH‐shift, and the effectiveness of using tBuOOH as oxidant overall suggest that hydroxylation of aromatic C−H bonds proceeds through a metal‐based mechanism, with no significant involvement of hydroxyl radicals, and via an arene oxide intermediate" , "dc.description.sponsorship": "The European Commission is acknowledged for financial support through the NoNoMeCat project (675020- MSCA-ITN-2015-ETN). We also thank Utrecht University. Support by the Spanish Ministry of Science (PGC2018-101737- B-I00 to M.C. and PhD grant to M.B. BES-2016-076349), and Generalitat de Catalunya (ICREA Academia Award to M.C. and 2017 SGR 00264) is acknowledged" , "dc.format.mimetype": "application/pdf" , "dc.language.iso": "eng" , "dc.publisher": "Wiley" , "dc.relation": "info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-101737-B-I00/ES/CATALISIS DE OXIDACION BIOINSPIRADA MEDIANTE DISEÑO RACIONAL DE CATALIZADORES/" , "dc.relation.isformatof": "Reproducció digital del document publicat a: https://doi.org/10.1002/adsc.202001590" , "dc.relation.ispartof": "Advanced Synthesis and Catalysis, 2021, vol. 363, núm. 15, p. 3783-3795" , "dc.relation.ispartofseries": "Articles publicats (D-Q)" , "dc.rights": "Attribution-NonCommercial 4.0 International" , "dc.rights.uri": "http://creativecommons.org/licenses/by-nc/4.0/" , "dc.subject": "Compostos orgànics -- Síntesi" , "dc.subject": "Organic compounds -- Synthesis" , "dc.subject": "Catalitzadors" , "dc.subject": "Catalysts" , "dc.title": "Aromatic C−H Hydroxylation Reactions with Hydrogen Peroxide Catalyzed by Bulky Manganese Complexes" , "dc.type": "info:eu-repo/semantics/article" , "dc.rights.accessRights": "info:eu-repo/semantics/openAccess" , "dc.relation.projectID": "info:eu-repo/grantAgreement/EC/H2020/675020/EU/Non-Noble Metal Catalysis/NoNoMeCat" , "dc.type.version": "info:eu-repo/semantics/publishedVersion" , "dc.identifier.doi": "https://doi.org/10.1002/adsc.202001590" , "dc.contributor.funder": "Agencia Estatal de Investigación" , "dc.type.peerreviewed": "peer-reviewed" , "dc.relation.FundingProgramme": "H2020" , "dc.relation.FundingProgramme": "Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020" , "dc.relation.ProjectAcronym": "NoNoMeCat" , "dc.relation.ProjectAcronym": "CATALISIS DE OXIDACION BIOINSPIRADA MEDIANTE DISEÑO RACIONAL DE CATALIZADORES" , "dc.identifier.eissn": "1615-4169" }