Počet záznamů: 1
Chemoselectivity in the Oxidation of Cycloalkenes with a Non-Heme Iron(IV)-Oxo-Chloride Complex: Epoxidation vs. Hydroxylation Selectivity
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SYSNO ASEP 0507769 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Chemoselectivity in the Oxidation of Cycloalkenes with a Non-Heme Iron(IV)-Oxo-Chloride Complex: Epoxidation vs. Hydroxylation Selectivity Tvůrce(i) Terencio, T. (CZ)
Andris, E. (CZ)
Gamba, I. (ES)
Srnec, Martin (UFCH-W) RID, ORCID
Costas, M. (ES)
Roithová, J. (CZ)Zdroj.dok. Journal of the American Society for Mass Spectrometry. - : American Chemical Society - ISSN 1044-0305
Roč. 30, č. 10 (2019), s. 1923-1933Poč.str. 11 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova C–H activation ; DFT calculations ; Epoxidation ; Gas-phase reactions ; Iron complexes Vědní obor RIV CF - Fyzikální chemie a teoretická chemie Obor OECD Physical chemistry CEP GA18-13093S GA ČR - Grantová agentura ČR Způsob publikování Omezený přístup Institucionální podpora UFCH-W - RVO:61388955 UT WOS 000491555700011 EID SCOPUS 85070377151 DOI 10.1007/s13361-019-02251-1 Anotace We report and analyze chemoselectivity in the gas phase reactions of cycloalkenes (cyclohexene, cycloheptene, cis-cyclooctene, 1,4-cyclohexadiene) with a non-heme iron(IV)-oxo complex [(PyTACN)Fe(O)(Cl)]+, which models the active species in iron-dependent halogenases. Unlike in the halogenases, we did not observe any chlorination of the substrate. However, we observed two other reaction pathways: allylic hydrogen atom transfer (HAT) and alkene epoxidation. The HAT is clearly preferred in the case of 1,4-cyclohexadiene, both pathways have comparable reaction rates in reaction with cyclohexene, and epoxidation is strongly favored in reactions with cycloheptene and cis-cyclooctene. This preference for epoxidation differs from the reactivity of iron(IV)-oxo complexes in the condensed phase, where HAT usually prevails. To understand the observed selectivity, we analyze effects of the substrate, spin state, and solvation. Our DFT and CASPT2 calculations suggest that all the reactions occur on the quintet potential energy surface. The DFT-calculated energies of the transition states for the epoxidation and hydroxylation pathways explain the observed chemoselectivity. The SMD implicit solvation model predicts the relative increase of the epoxidation barriers with solvent polarity, which explains the clear preference of HAT in the condensed phase. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2020 Elektronická adresa http://hdl.handle.net/11104/0298739
Počet záznamů: 1