Nucleophilic versus Electrophilic Reactivity of Bioinspired Superoxido Nickel(II) Complexes.

Autor: Panda C; Department of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany., Chandra A; Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany., Corona T; Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany., Andris E; Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic., Pandey B; Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400 076, India., Garai S; Department of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany., Lindenmaier N; Department of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany., Künstner S; Berlin Joint EPR lab, Institute Nanospectroscopy, Helmholtz-, Zentrum Berlin für Materialien und Energie, Berlin, Germany., Farquhar ER; CWRU Center for Synchrotron Biosciences, NSLS-II, Brookhaven National Laboratory, Upton, NY, 11973, USA., Roithová J; Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic.; Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, The Netherlands., Rajaraman G; Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400 076, India., Driess M; Department of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, Germany., Ray K; Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2018 Nov 05; Vol. 57 (45), pp. 14883-14887. Date of Electronic Publication: 2018 Oct 17.
DOI: 10.1002/anie.201808085
Abstrakt: The formation and detailed spectroscopic characterization of the first biuret-containing monoanionic superoxido-Ni II intermediate [LNiO 2 ] - as the Li salt [2; L=MeN[C(=O)NAr) 2 ; Ar=2,6-iPr 2 C 6 H 3 )] is reported. It results from oxidation of the corresponding [Li(thf) 3 ] 2 [LNi II Br 2 ] complex M with excess H 2 O 2 in the presence of Et 3 N. The [LNiO 2 ] - core of 2 shows an unprecedented nucleophilic reactivity in the oxidative deformylation of aldehydes, in stark contrast to the electrophilic character of the previously reported neutral Nacnac-containing superoxido-Ni II complex 1, [L'NiO 2 ] (L'=CH(CMeNAr) 2 ). According to density-functional theory (DFT) calculations, the remarkably different behaviour of 1 versus 2 can be attributed to their different charges and a two-state reactivity, in which a doublet ground state and a nearby spin-polarized doublet excited-state both contribute in 1 but not in 2. The unexpected nucleophilicity of the superoxido-Ni II core of 2 suggests that such a reactivity may also play a role in catalytic cycles of Ni-containing oxygenases and oxidases.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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