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6月, 2015の投稿を表示しています
Powerful Bis-facially Pyrazolate-Bridged Dinuclear Ruthenium Epoxidation Catalyst Joan Aguiló   † ‡ ,  Laia Francàs   ‡ ,  Roger Bofill   † ,  Marcos Gil-Sepulcre   † ,  Jordi García-Antón   † ,  Albert Poater   ∥ ,  Antoni Llobet   † ‡ ,  Lluís Escriche   * † ,  Franc Meyer   ⊥ , and  Xavier Sala   * † †  Departament de Química, Facultat de Ciències,  Universitat Autònoma de Barcelona , Cerdanyola del Vallès, 08193 Barcelona,  Spain ‡   Institute of Chemical Research of Catalonia (ICIQ) , Av. Països Catalans 16, 43007 Tarragona,  Spain ∥  Institut de Química Computacional i Catàlisi and Departament de Química,  Universitat de Girona , Campus de Montilivi, 17071 Girona,  Spain ⊥  Institut für Anorganische Chemie,  Georg-August-Universität , Tammannstrasse 4, 37077 Göttingen, Germany Inorg. Chem. , Article ASAP DOI:  10.10...

Mechanism of Oxygen Atom Transfer from FeV(O) to Olefins at Room Temperature

Kundan K. Singh   † ,  Mrityunjay k. Tiwari   ‡ ,  Basab B. Dhar   † ,  Kumar Vanka   * ‡ , and  Sayam Sen Gupta * † † Chemical Engineering Division and  ‡ Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory,  CSIR-National Chemical Laboratory , Pune 411008,  India Inorg. Chem. , Article ASAP DOI:  10.1021/ic503053q Publication Date (Web): June 8, 2015 Copyright © 2015 American Chemical Society Abstract In biological oxidations, the intermediate Fe V (O)(OH) has been proposed to be the active species for catalyzing the epoxidation of alkenes by nonheme iron complexes. However, no study has been reported yet that elucidates the mechanism of direct O-atom transfer during the reaction of Fe V (O) with alkenes to form the corresponding epoxide. For the first time, we study the mechanism of O-atom transfer to alkenes using the Fe V (O) complex of biuret-modified Fe–TAML at room temp...

Acetate anion-triggered peroxygenation of non-native substrates by wild-type cytochrome P450s

Hiroki Onoda ,     Osami Shoji  and     Yoshihito Watanabe    Dalton Trans. , 2015, Accepted Manuscript Cytochrome P450SPα (P450SPα) and cytochrome P450BSβ (P450BSβ) belonging to the CYP152 family of enzymes (CYP152s), which can utilize H2O2 efficiently as an oxidant for the generation of Compound I. Although P450SPα and P450BSβ have very high substrate specificity and catalyse hydroxylation of long-alkyl-chain fatty acids exclusively, we found that they can oxidize non-native substrates such as styrene simply by including medium chain length n-alkyl carboxylic acids as “decoy molecules.” Although we had assumed that acetic acid did not serve as a decoy molecule, P450SPα and P450BSβ efficiently catalysed oxidation of non-native substrates when the reaction was carried out under high concentration of acetate anion. The turnover rate for epoxidation of styrene catalysed by P450BSβ in the presence of 1 M acetate anion reached 590 ± 30/min....

Single-site trinuclear copper oxygen clusters in mordenite for selective conversion of methane to methanol

Sebastian Grundner 1 , Monica A.C. Markovits 1 , Guanna Li 2 , Moniek Tromp 3 , Evgeny A. Pidko 2 , 4 , Emiel J.M. Hensen 2 , Andreas Jentys 1 , Maricruz Sanchez-Sanchez 1 , Johannes A. Lercher 1 , 5 , Affiliations Contributions Corresponding author doi:10.1038/ncomms8546 Received 19 December 2014 Accepted 19 May 2015 Published 25 June 2015    http://www.nature.com/ncomms/2015/150625/ncomms8546/full/ncomms8546.html   Abstract Copper-exchanged zeolites with mordenite structure mimic the nuclearity and reactivit...

An Iron Reservoir to the Catalytic Metal THE RUBREDOXIN IRON IN AN EXTRADIOL DIOXYGENASE

Receivedforpublication,March8,2015,andinrevisedform,April10,2015 Published,JBCPapersinPress,April27,2015,DOI10.1074/jbc.M115.650259 Fange Liu ‡§1,2 , Jiafeng Geng ‡¶1,2,3,4 , Ryan H. Gumpper ‡ , Arghya Barman ‡ , Ian Davis ‡¶ , Andrew Ozarowski 􏰀 , Donald Hamelberg ‡§¶ , and X Aimin Liu ‡§¶5 From the ‡ Department of Chemistry, § Center for Diagnostics and Therapeutics, and ¶ Molecular Basis of Disease Program, Georgia State University, Atlanta, Georgia 30303 and the 􏰀 National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 http://www.jbc.org/content/290/25/15621.full?sid=a5ac4e07-0089-43df-9404-976daf368631 Abstract The rubredoxin motif is present in over 74,000 protein sequences and 2,000 structures, but few have known functions. A secondary, non-catalytic, rubredoxin-like iron site is conserved in 3-hydroxyanthranilate 3,4-dioxygenase (HAO), from single cellular sources but not multicell...

Proton-Induced, Reversible Interconversion of a μ-1,2-Peroxo and a μ-1,1-Hydroperoxo Dicopper(II) Complex

Nicole Kindermann   ,  Sebastian Dechert   ,  Serhiy Demeshko   , and  Franc Meyer   * Institut für Anorganische Chemie,  Georg-August-Universität Göttingen , Tammannstraße 4, 37077 Göttingen, Germany J. Am. Chem. Soc. , Article ASAP DOI:  10.1021/jacs.5b04361 Publication Date (Web): June 10, 2015 Copyright © 2015 American Chemical Society * franc.meyer@chemie.uni-goettingen.de http://pubs.acs.org/doi/abs/10.1021/jacs.5b04361 Abstract The μ-1,2-peroxo dicopper(II) complex ( 2 ) of a compartmental bis(tetradentate) pyrazolate-based ligand is shown to convert, upon protonation, to the corresponding μ-1,1-hydroperoxo dicopper(II) complex ( 3 ). The transformation is cleanly reversed with base, and an apparent p K a = 22.2 ± 0.3 for the Cu 2 OOH unit in MeCN has been determined. The unprecedented stability of 3  ( t 1/2  = 9 h in nitrile solvents at room temperature, giving the hydroxo-bridged dicopper com...

Controlled nitrene transfer from a tyrosinase-like arylnitroso–copper complex

  Mohammad S. Askari , a      Maylis Orio b c  and     Xavier Ottenwaelder * a    Show Affiliations Chem. Commun. , 2015, Advance Article DOI:  10.1039/C5CC02806J Received 03 Apr 2015, Accepted 09 Jun 2015 First published online 09 Jun 2015 http://pubs.rsc.org/en/Content/ArticleLanding/2015/CC/C5CC02806J#!divAbstract Abstract Cited by Related Content   The reaction between  p -nitrosonitrobenzene and the tetramethylpropylenediamine–copper( I ) complex yields a dinuclear complex that is structurally and electronically similar to side-on peroxo species known in Cu/O 2  chemistry. The complex reacts with di- tert -butylphenolate  via  nitrene transfer, as observed through an intermediate and the aminophenol product obtained upon reductive work-up.

Developing Mononuclear Copper–Active-Oxygen Complexes Relevant to Reactive Intermediates of Biological Oxidation Reactions

Shinobu Itoh   * Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering,  Osaka University , 2-1 Yamada-oka, Suita, Osaka 565-0871,  Japan Acc. Chem. Res. , Article ASAP DOI:  10.1021/acs.accounts.5b00140 Publication Date (Web): June 18, 2015 Copyright © 2015 American Chemical Society http://pubs.acs.org/doi/abs/10.1021/acs.accounts.5b00140 *E-mail:  shinobu@mls.eng.osaka-u.ac.jp .  Special Issue Published as part of the  Accounts of Chemical Research  special issue “ Synthesis in Biological Inorganic Chemistry ”. Biography Shinobu Itoh  received his doctor’s degree in engineering from Osaka University in 1986. He joined the Department of Applied Chemistry of Osaka University as an Assistant Professor (1986–1994) and an Associate Professor (1994–1999). During that period, he spent a year (1987–1988) as a postdoctoral fellow in Professor Teddy G. T...

Oxidation of Ni(II) to Ni(IV) with Aryl Electrophiles Enables Ni-Mediated Aryl–CF3 Coupling

James R. Bour , Nicole M. Camasso , and Melanie S. Sanford * University of Michigan , Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b04892 Publication Date (Web): June 16, 2015 Copyright © 2015 American Chemical Society http://pubs.acs.org/doi/abs/10.1021/jacs.5b04892 Abstract This communication describes the synthesis and reactivity of Ni IV (aryl)(CF 3 ) 2 complexes supported by trispyrazolylborate and 4,4′-di- tert -butylbipyridine ligands. We demonstrate that isolable Ni IV complexes can be accessed under mild conditions via the oxidation of Ni II precursors with S -(trifluoromethyl)dibenzothiophenium triflate as well as with diaryliodonium and aryl diazonium reagents. The Ni IV intermediates undergo high yielding aryl–CF 3 bond-forming reductive elimination. These studies support the potential viability of Ni IV intermediates in nickel-catalyzed co...

Incorporation of Pendant Bases into Rh(diphosphine)2 Complexes: Synthesis, Thermodynamic Studies, And Catalytic CO2 Hydrogenation Activity of [Rh(P2N2)2]+ Complexes

Journal of the American Chemical Society by Alyssia M. Lilio, Mark H. Reineke, Curtis E. Moore, Arnold L. Rheingold, Michael K. Takase and Clifford P. Kubiak  /  13h  //  keep unread  //  hide  //  preview http://pubs.acs.org/doi/abs/10.1021/jacs.5b04291 Journal of the American Chemical Society DOI: 10.1021/jacs.5b04291

Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O2

Angela Gonzalez-de-Castro   and  Jianliang Xiao   * Department of Chemistry,  University of Liverpool , Liverpool L69 7ZD,  U.K. J. Am. Chem. Soc. , Article ASAP DOI:  10.1021/jacs.5b03956 Publication Date (Web): June 1, 2015 Copyright © 2015 American Chemical Society http://pubs.acs.org/doi/abs/10.1021/jacs.5b03956 * jxiao@liv.ac.uk Abstract A mild and operationally simple iron-catalyzed protocol for the selective aerobic oxidation of aromatic olefins to carbonyl compounds is described. Catalyzed by a Fe(III) species bearing a pyridine bisimidazoline ligand at 1 atm of O 2 , α- and β-substituted styrenes were cleaved to afford benzaldehydes and aromatic ketones generally in high yields with excellent chemoselectivity and very good functional group tolerance, including those containing radical-sensitive groups. With α-halo-substituted styrenes, the oxidation took place with concomitant halide migration to afford α-halo acetop...
Steric Effect on the Nucleophilic Reactivity of Nickel(III) Peroxo Complexes Jalee Kim † , Bongki Shin † , Hyunjeong Kim † , Junhyung Lee † , Joongoo Kang † , Sachiko Yanagisawa § , Takashi Ogura § , Hideki Masuda ⊥ , Tomohiro Ozawa ⊥ , and Jaeheung Cho * † † Department of Emerging Materials Science, DGIST , Daegu 711-873, Korea § Picobiology Institute, Graduate School of Life Science, University of Hyogo , Hyogo 678-1297, Japan ⊥ Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology , Nagoya 466-8555, Japan Inorg. Chem. , Article ASAP DOI: 10.1021/acs.inorgchem.5b00294 Publication Date (Web): June 12, 2015 Copyright © 2015 American Chemical Society *E-mail: jaeheung@dgist.ac.kr . http://pubs.acs.org/doi/pdf/10.1021/acs.inorgchem.5b00294   Synopsis A set of nickel(III) peroxo complexes, [Ni III (TBDAP)(O 2 )] + and [Ni III (CHDAP)(O 2 )] + , were prepared. The spectroscopic characterization cl...

[CuO]+ and [CuOH]2+ Complexes: Intermediates in Oxidation Catalysis?

Accounts of Chemical Research  by Nicole Gagnon and William B. Tolman Accounts of Chemical Research DOI: 10.1021/acs.accounts.5b00169 Visit Website
Water-Soluble Iron(IV)-Oxo Complexes Supported by Pentapyridine Ligands: Axial Ligand Effects on Hydrogen Atom and Oxygen Atom Transfer Reactivity Teera Chantarojsiri   † ,  Yujie Sun   † ∥ # ,  Jeffrey R. Long   * † ⊥ , and  Christopher J. Chang   * † ‡ § ∥ † Departments of Chemistry and  ‡ Molecular and Cell Biology and the  § Howard Hughes Medical Institute, University of California , Berkeley, California 94720,  United States ∥ Chemical Sciences and  ⊥ Materials Sciences Divisions,  Lawrence Berkeley National Laboratory , Berkeley, California 94720,  United States #  Department of Chemistry and Biochemistry,  Utah State University , Logan, Utah 84322,  United States Inorg. Chem. ,  2015 ,  54  (12), pp 5879–5887 DOI:  10.1021/acs.inorgchem.5b00658 Publication Date (Web): June 3, 2015 Copyright © 2015 American Chemical Society *E-mail:  jrlong@berkeley.edu ...

A Ruthenium(II)–Copper(II) Dyad for the Photocatalytic Oxygenation of Organic Substrates Mediated by Dioxygen Activation

酸素を活性化する銅錯体と、光を吸収して銅錯体に電子を供給できるRu錯体の連結分子で、酸化反応を行ったという論文です。 犠牲的還元剤として、トリエタノールアミンを使っていることや、基質がチオアニソール類なところはいまいちですが、この触媒では、インデンのシスジオール化が進行するそうです。また、環状アルケンの酸化では、環状エノンが生成するようです。 Dr. Wissam Iali, Dr. Pierre-Henri Lanoe, Dr. Stéphane Torelli, Dr. Damien Jouvenot, Prof. Frédérique Loiseau, Colette Lebrun, Dr. Olivier Hamelin and Dr. Stéphane Ménage Article first published online: 27 MAY 2015 | DOI: 10.1002/anie.201501180 O 2 activation oxidation : A new Ru-Cu dyad has been isolated and confirmed to be efficient for the photocatalytic oxygenation of organic substrates. Mechanistic investigations confirmed a photoinduced electron transfer from the photosensitizer to the copper catalytic center prior to O 2  activation. X=substrate (sulfides, alkenes, phosphines). Abstract Full Article (HTML) Enhanced Article (HTML) PDF(759K) References Supporting Information