0000000000059910
AUTHOR
Jana Leppin
ChemInform Abstract: Powerful Fluoroalkoxy Molybdenum(V) Reagent for Selective Oxidative Arene Coupling Reaction.
A novel dinuclear fluoroalkoxy Mo(V)-complex is efficient as reagent for the oxidative arene coupling of electron-rich arenes with superior reactivity compared to MoCl5 and MoCl5/TiCl4.
Leistungsstarkes Fluoralkoxy-Molybdän(V)-Reagens für die selektive oxidative Arenkupplung
Wir stellen ein neues Fluoralkoxy-Molybdan(V)-Reagens 1, mit im Vergleich zu MoCl5 oder MoCl5/TiCl4 hoherer Reaktivitat und Selektivitat in der oxidativen Kupplung von Arenen vor. Haufige Nebenreaktionen wie Chlorierung und/oder Oligomerenbildung werden erheblich reduziert, sodass ein leistungsstarkes und nutzliches Reagens fur die oxidative Kupplung erhalten wird. Theoretische Untersuchungen der Wechselwirkung des Reagens mit 1,2-Dimethoxybenzol-artigen Substraten deuten auf einen Innenspharen-Elektronentransfer gefolgt von einem radikalkationischen Reaktionspfad fur den oxidativen Kupplungsprozess hin. ESR-spektroskopische und elektrochemische Untersuchungen, Rontgenkristallstrukturanalys…
Photochemistry and Redox Chemistry of an Unsymmetrical Bimetallic Copper(I) Complex
The bimetallic copper(I) complex Cu2L2 (cis-1) is formed with high diasteroselectivity from [Cu(NCCH3)4][BF4] and HL (4-tert-butyl phenyl(pyrrolato-2-yl-methylene)amine) in a kinetically controlled reaction. cis-1 features a rather short Cu···Cu distance of 2.4756(6) A and is weakly emissive at room temperature in solution. Oxidatively triggered disproportionation of cis-1 yields elemental copper and the mononuclear copper(II) complex CuL2 (trans-2). One-electron reduction of trans-2 gives cuprate [2]– with a bent bis(pyrrolato) coordinated copper(I) entity. The imine donor atoms of [2]– can insert an additional copper(I) ion giving exclusively the bimetallic complex cis-1 closing the oxida…
Ligand dynamics of tert-butyl isocyanide oxido complexes of molybdenum(IV).
The six-coordinate molybdenum(IV) oxido isocyanide complex 1 [Δ,Λ-OC-6-2-3-[MoO(N(p)∩N(i))2(CN(t)Bu)]; N(p)∩N(i) = 4-tert-butylphenyl(pyrrolato-2-ylmethylene)amine] is obtained in diastereomerically pure form in the solid state, as revealed by single-crystal X-ray diffraction. In solution, this stereoisomer equilibrates with the Δ,Λ-OC-6-2-4 diastereomer 2 at ambient temperature. The stereochemistry of both isomers has been elucidated by NMR, IR, and UV/vis spectroscopy in combination with density functional theory (DFT)/polarizable continuum model and time-dependent DFT calculations. The isomerization 1 → 2 is suggested to proceed via a dissociative trigonal twist with dissociation of the …
Powerful Fluoroalkoxy Molybdenum(V) Reagent for Selective Oxidative Arene Coupling Reaction
We introduce the novel fluoroalkoxy molybdenum(V) reagent 1 which has superior reactivity and selectivity in comparison to MoCl5 or the MoCl5 /TiCl4 reagent mixture in the oxidative coupling reactions of aryls. Common side reactions, such as chlorination and/or oligomer formation, are drastically diminished creating a powerful and useful reagent for oxidative coupling. Theoretical treatment of the reagent interaction with 1,2-dimethoxybenzene-type substrates indicates an inner-sphere electron transfer followed by a radical cationic reaction pathway for the oxidative-coupling process. EPR spectroscopic and electrochemical studies, X-ray analyses, computational investigations, and the experim…
V2O5 nanowires with an intrinsic peroxidase-like activity
V2O5 nanowires exhibit an intrinsic catalytic activity towards classical peroxidase substrates such as 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 3,3,5,5,-tetramethylbenzdine (TMB) in the presence of H2O2. These V2O5 nanowires show an optimum reactivity at a pH of 4.0 and the catalytic activity is dependent on the concentration. The Michaelis-Menten kinetics of the ABTS oxidation over these nanowires reveals a behavior similar to that of their natural vanadium-dependent haloperoxidase (V-HPO) counterparts. The V2O5 nanowires mediate the oxidation of ABTS in the presence of H2O2 with a turnover frequency (k(cat)) of 2.5 x 10(3) s(-1). The K-M values of the V2O5 nanowire…
Molybdenum Complex with Bulky Chelates as a Functional Model for Molybdenum Oxidases
The novel bulky Schiff base chelate ligand [(4,5-diisopropyl-1H-pyrrole-2-yl)methylene]-4-(tert-butyl)aniline ((iPr2)HL) bearing two isopropyl groups close to the pyrrole nitrogen atom reacts with MoCl2(dme)O2 (dme = 1,2-dimethoxyethane) to give the sterically congested complex Mo(VI)((iPr2)L)2O2 ((iPr2)1; OC-6-4-4 configuration). In spite of the increased steric shielding of the [MoO2] unit (iPr2)1 is active in oxygen-atom transfer to PMe3 and PPh3 to give OPMe3 and OPPh3, respectively. Because of the increased steric bulk of the chelate ligand, formation of dinuclear complexes [Mo(V)((iPr2)L)2O]2(μ-O) ((iPr2)3) by comportionation is effectively prevented in contrast to the highly favored …
Initial Radical Cation Pathway in the Mo2Cl10-Mediated Dehydrogenative Arene Coupling
Experimental (EPR) and theoretical (DFT) evidence is provided for radical cation formation as initial step in the Mo2Cl10-mediated dehydrogenative arene coupling. The initial electron transfer from methoxyarenes to molybdenum proceeds via an inner sphere mechanism.
CCDC 965850: Experimental Crystal Structure Determination
Related Article: Jana Leppin, Christoph Förster, Katja Heinze|2014|Inorg.Chem.|53|12416|doi:10.1021/ic501751p
CCDC 965852: Experimental Crystal Structure Determination
Related Article: Jana Leppin, Christoph Förster, Katja Heinze|2014|Inorg.Chem.|53|12416|doi:10.1021/ic501751p
CCDC 966311: Experimental Crystal Structure Determination
Related Article: Moritz Schubert, Jana Leppin, Kathrin Wehming, Dieter Schollmeyer, Katja Heinze and Siegfried R. Waldvogel|2014|Angew.Chem.,Int.Ed.|53|2494|doi:10.1002/anie.201309287
CCDC 952600: Experimental Crystal Structure Determination
Related Article: Jana Leppin, Christoph Förster, and Katja Heinze|2014|Inorg.Chem.|53|1039|doi:10.1021/ic4025102
CCDC 965851: Experimental Crystal Structure Determination
Related Article: Jana Leppin, Christoph Förster, Katja Heinze|2014|Inorg.Chem.|53|12416|doi:10.1021/ic501751p
CCDC 984218: Experimental Crystal Structure Determination
Related Article: Jana Leppin, Christoph Förster, Katja Heinze|2014|Inorg.Chem.|53|12416|doi:10.1021/ic501751p
CCDC 1458703: Experimental Crystal Structure Determination
Related Article: Oliver Back, Jana Leppin, Christoph Förster, and Katja Heinze|2016|Inorg.Chem.|55|9653|doi:10.1021/acs.inorgchem.6b01400
CCDC 1044691: Experimental Crystal Structure Determination
Related Article: Oliver Back, Jana Leppin, Christoph Förster, and Katja Heinze|2016|Inorg.Chem.|55|9653|doi:10.1021/acs.inorgchem.6b01400
CCDC 966309: Experimental Crystal Structure Determination
Related Article: Moritz Schubert, Jana Leppin, Kathrin Wehming, Dieter Schollmeyer, Katja Heinze and Siegfried R. Waldvogel|2014|Angew.Chem.,Int.Ed.|53|2494|doi:10.1002/anie.201309287
CCDC 966310: Experimental Crystal Structure Determination
Related Article: Moritz Schubert, Jana Leppin, Kathrin Wehming, Dieter Schollmeyer, Katja Heinze and Siegfried R. Waldvogel|2014|Angew.Chem.,Int.Ed.|53|2494|doi:10.1002/anie.201309287