Itoh Group Literature Review

Article | Published: 24 July 2019 Kazunari Nakajima, Hiroki Toda, Ken Sakata & Yoshiaki Nishibayashi  Nature Chemistryvolume 11, pages702–709 (2019)  窒素還元をやっている、東大西林研の研究で、 ルテニウム錯体を触媒として アンモニアを窒素へと酸化した研究です。酸化剤はマジックブルー、錯体は、水の酸化で一斉を風靡したチュンメルの錯体です。 活性種の観測こそありませんが、ニトリド錯体がカップリングすることでN–N結合が生成すると提唱しています。窒素錯体は、結晶も取れています。 ピリジンの６位のカルボン酸のヘミレイバビリティがいい仕事してるんでしょうね。きれいな研究です。

Summer A. Baker Dockrey 1,2 , April L. Lukowski 2,3 , Marc R. Becker 1 and Alison R. H. Narayan 1,2,3 * 1 Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA. 2 Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA. 3 Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, USA. doi :10.1038/nchem.2879      https://www.nature.com/articles/nchem.2879 酵素触媒によるフェノールの酸化反応についてです。 選択性、基質適合性、合成スケールが合成化学的にも有用なほど優れているようです。

Asim Maity, Sung-Min Hyun and David C. Powers *  PUBLISHED ONLINE: 16 OCTOBER 2017 | DOI: 10.1038/NCHEM.2873  https://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2873.html 酸素分子を酸素源とした超原子価ヨウソ試薬を生成し、様々な酸化反応に適用しています。 理想の酸化剤である酸素分子を酸素源に用いている点と、錯体を用いない酸化反応の論文という点で、参考になると思いました。

Bin Wang 1 , Yong-Min Lee 1 , Woon-Young Tcho 1 , Samat Tussupbayev 2,3 , Seoung-Tae Kim 2,3 , Yujeong Kim 4 , Mi Sook Seo 1 , Kyung-Bin Cho 1 , Yavuz Dede 5 , Brenna C. Keegan 6 , Takashi Ogura 7 , Sun Hee Kim 4 , Takehiro Ohta 7 , Mu-Hyun Baik 2,3 , Kallol Ray 8 , Jason Shearer 6 & Wonwoo Nam 1,9  DOI: 10.1038/ncomms14839 概要 Co(IV)オキソ錯体の単離し、その反応性について報告しています。 水素原子引き抜き反応、酸素原子挿入反応に対して活性を有することが明らかになりました。 abstract Co(II)錯体とヨードソベンゼンの反応から、Co(IV)錯体を生成しています。 UV、EPR、質量分析、ラマンからCo(IV)オキソの同定を行っており、EXAFSなどからその構造情報についても考察しました。一般に 後周期遷移金属錯体では、オキソとの結合を考えた際に反結合性軌道に電子が格納されるため、二重結合性を有するオキソ錯体の生成は困難となります。一方今回の錯体では、非結合性の軌道に電子が格納されるため、結合次数を保ちつつオキソ錯体を形成しています。 雑誌会質問　回答 質問 Co(IV)錯体をデカメチルフェロセンを用いて還元した際のEPRの帰属について。 Co(IV) g  = 6.5, 4.4, 2.02 Co(III) EPR scilent g = 4.4, 2.00 はデカメチルフェロセニウム由来のシグナル Co(II) g  = 6.0, 3.2, 1.85 EPRは不対電子を検出する分光手法です。 磁場中の不対電子はゼーマン分裂により、電子間にエネルギー順位差が生じます。 このエネルギー差に対応したマイクロ波を吸収することで、シグナルが観測されます。 生じるエネルギー差ΔEの比例定数gをg値といい、シグナルが観測された時のg値を知ることでその...

Ambika Bhagi-Damodaran 1 , Matthew A. Michael 2 , Qianhong Zhu 3 , Julian Reed 4 , Braddock A. Sandoval 1 , Evan N. Mirts 5 , Saumen Chakraborty 1 , Pierre Moënne-Loccoz 3 * , Yong Zhang 2 * and Yi Lu 1,4,5 *    Nature Chemistry (2016)       doi:10.1038/nchem.2643 Received              05 April 2016 Accepted             09 September 2016 Published online   07 November 2016   http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.2643.pdf Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA. 2 Department of Biomedical Engineering, Chemistry, and Biological Sciences, Stevens Institute of Technology, Hoboken, New Jersey, USA. 3 Division of Environmental & Biomolecular Systems, Institute o...

Shiliang Tian , Jing Liu , Ryan E. Cowley , Parisa Hosseinzadeh , Nicholas M. Marshall , Yang Yu , Howard Robinson , Mark J. Nilges , Ninian J. Blackburn , Edward I. Solomon &  Yi Lu http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2489.html Abstract Abstract •   Main •   Results •   Discussion •   Conclusions •   Methods •   Accession codes •   References • Acknowledgements •   Author information •   Supplementary information S-Nitrosothiols are known as reagents for NO storage and transportation and as regulators in many physiological processes. Although the  S -nitrosylation catalysed by haem proteins is well known, no direct evidence of  S -nitrosylation in copper proteins has been reported. Here, we report reversible insertion of NO into a copper–thiolate bond in an engineered copper centre in Pseudomonas aeruginosa  azurin by rational design of the primary coor...

Nature Chemistry. doi:10.1038/nchem.2503 Authors: Marcus Schulze, Valentin Kunz, Peter D. Frischmann & Frank Würthner   http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2503.html http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.2503.pdf Designing improved catalysts is predicated on understanding how they work. Now, by positioning three ruthenium centres in a macrocyclic framework, a remarkable acceleration of catalytic water oxidation has been achieved. Detailed mechanistic studies revealed that the catalyst operates through the ‘water nucleophilic attack’ pathway—similar to the natural oxygen-evolving cluster of photosystem II.    

Shiyu Zhang , Marie M. Melzer , S. Nermin Sen , Nihan Çelebi-Ölçüm &  Timothy H. Warren Nature Chemistry (2016),  doi:10.1038/nchem.2502 1 Department of Chemistry, Georgetown University, Box 571227, Washington, DC 20057, USA. 2 Department of Chemical Engineering, Yeditepe University, Istanbul 34755, Turkey. 3 Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA. http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2502.html Abstract Nitric oxide ( NO ) participates in numerous biological processes, such as signalling in the respiratory system and vasodilation in the cardiovascular system. Many metal-mediated processes involve direct reaction of  NO  to form a metal–nitrosyl (M–NO), as occurs at the Fe 2+ centres of soluble guanylate cyclase or cytochrome  c  oxidase. However, some copper electron-transfer proteins that bear a type 1 Cu site (His 2 Cu–Cys) reversibly bind  N...

Reconstitution of [Fe]-hydrogenase using model complexes 23 Nature Chemistry by Seigo Shima  Nature Chemistry. doi:10.1038/nchem.2382 Authors: Seigo Shima, Dafa Chen, Tao Xu, Matthew D. Wodrich, Takashi Fujishiro, Katherine M. Schultz, Jörg Kahnt, Kenichi Ataka & Xile Hu [Fe]-hydrogenase has an iron-guanylylpyridinol cofactor and catalyses the reversible hydrogenation of a methenyl-tetrahydromethanopterin. Now, [Fe]-hydrogenase has been reconstituted using synthetic cofactor mimics. The enzyme containing a mimic with a 2-hydroxy-pyridine group was active, whereas one containing a 2-methoxy-pyridine group was inactive. This result, together with DFT computations, supports a catalytic mechanism involving the deprotonated pyridinol hydroxy group as a proton acceptor.

Nature Chemistry 7, 871–878 ( 2015 ) doi:10.1038/nchem.2353 Received 06 March 2015 Accepted 19 August 2015 Published online 28 September 2015 Author Gavin W. Collie, Karolina Pulka-Ziach, Caterina M. Lombardo, Juliette Fremaux, Frédéric Rosu, Marion Decossas, Laura Mauran, Olivier Lambert, Valérie Gabelica, Cameron D. Mackereth & Gilles Guichard Affiliations Université de Bordeaux, CNRS, and etc. Abstract The design and construction of biomimetic self-assembling systems is a challenging yet potentially highly rewarding endeavour that contributes to the development of new biomaterials, catalysts, drug-delivery systems and tools for the manipulation of biological processes. Significant progress has been achieved by engineering self-assembling DNA-, protein- and peptide-based building units. However, the design of entirely new, completely non-natural folded architectures that resemble biopolymers (‘foldamers’) and have the ability to self-assemble...

Nature Chemistry. doi:10.1038/nchem.2366 Authors: Shauna M. Paradine, Jennifer R. Griffin, Jinpeng Zhao, Aaron L. Petronico, Shannon M. Miller & M. Christina White http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2366.html http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.2366.pdf C–H bond oxidation reactions underscore the existing paradigm wherein high reactivity and high selectivity are inversely correlated. The development of catalysts capable of oxidizing strong aliphatic C( sp 3 )–H bonds while displaying chemoselectivity (that is, tolerance of more oxidizable functionality) remains an unsolved problem. Here, we describe a catalyst, manganese tert -butylphthalocyanine [Mn( t BuPc)], that is an outlier to the reactivity–selectivity paradigm. It is unique in its capacity to functionalize all types of C( sp 3 )–H bond intramolecularly, while displaying excellent chemoselectivity in the presence of π functionality. Mechanistic studies indicat...

Nature Chemistry by Courtney M. Krest  /  20h  //  keep unread  //  hide  //  preview http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.2306.pdf Nature Chemistry. doi:10.1038/nchem.2306 Authors: Courtney M. Krest, Alexey Silakov, Jonathan Rittle, Timothy H. Yosca, Elizabeth L. Onderko, Julio C. Calixto & Michael T. Green Cytochrome P450 (P450) and chloroperoxidase (CPO) are both thiolate-ligated haem proteins that form a ferryl radical species called compound I. P450-I is, however, significantly more reactive than CPO-I. Variable-temperature Mössbauer and X-ray absorption measurements have now shown that increased electron donation from the axial thiolate ligand in P450-I may explain its greater propensity for C–H bond activation. Visit Website

Nature Chemistry 7, 653 (2015).  doi:10.1038/nchem.2285 Authors: Alison R. H. Narayan, Gonzalo Jiménez-Osés, Peng Liu, Solymar Negretti, Wanxiang Zhao, Michael M. Gilbert, Raghunath O. Ramabhadran, Yun-Fang Yang, Lawrence R. Furan, Zhe Li, Larissa M. Podust, John Montgomery, K. N. Houk & David H. Sherman The reactivity of a monooxygenase (P450 PikC) has been modified through protein and substrate engineering, and applied to the oxidation of unactivated methylene C–H bonds. The protein engineering was guided by using molecular dynamics and quantum mechanical calculations to develop a predictive model for substrate scope, site selectivity and stereoselectivity of the C–H hydroxylation. 過去にC. White らは、基質の立体的な込み具合と、１級か２級かなど電子的な要因を注意深く検討することで、複雑な化合物でも位置特異的な水酸化反応がおこなえる事を示しました(Science, 2010, 327, 566)。触媒としてcis-4配位の鉄錯体を、酸化剤として過酸化水素を用いて用いています。 この研究では、そのような先例をふまえ、錯体触媒では酸化が難しい位置の水酸化が、タンパク質という土台を使う事で可能になるというコンセプトです（下図 Figure 1、赤色領域）。 とはいえ、無置換アルキルではさすがに無理です。カルボン酸を配向基として用いて...

Nature Chemistry. doi:10.1038/nchem.2285 Authors: Alison R. H. Narayan, Gonzalo Jiménez-Osés, Peng Liu, Solymar Negretti, Wanxiang Zhao, Michael M. Gilbert, Raghunath O. Ramabhadran, Yun-Fang Yang, Lawrence R. Furan, Zhe Li, Larissa M. Podust, John Montgomery, K. N. Houk & David H. Sherman   http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2285.html The reactivity of a monooxygenase (P450 PikC) has been modified through protein and substrate engineering, and applied to the oxidation of unactivated methylene C–H bonds. The protein engineering was guided by using molecular dynamics and quantum mechanical calculations to develop a predictive model for substrate scope, site selectivity and stereoselectivity of the C–H hydroxylation.

Nature Chemistry  by Suhee Bang   Nature Chemistry.  doi:10.1038/nchem.2055 Authors: Suhee Bang, Yong-Min Lee, Seungwoo Hong, Kyung-Bin Cho, Yusuke Nishida, Mi Sook Seo, Ritimukta Sarangi, Shunichi Fukuzumi & Wonwoo Nam Non-haem iron(III)-peroxo complexes that bind redox-inactive metal ions are synthesized to investigate the role of the Ca2+ ion in the oxidation of water to dioxygen in Photosystem II. The electrochemical properties and reactions of these compounds with an electron donor and an acceptor are found to be markedly dependent on the Lewis acidity of redox-inactive metal ions. Visit Website

NATURE CHEMISTRY  |  ARTICLE Print Email Share/bookmark Time-resolved observations of water oxidation intermediates on a cobalt oxide nanoparticle catalyst Miao Zhang , Moreno de Respinis &  Heinz Frei Affiliations Contributions Corresponding author Nature Chemistry   6 ,   362–367   (2014)   doi:10.1038/nchem.1874 Received   16 November 2013  Accepted   14 January 2014  Published online   23 February 2014 Article tools PDF Citation Reprints Rights & permissions Article metrics Abstract Abstract •   Main •   Results and discussion •   Conclusions •   Methods •   References •   Acknowledgements •   Author information •   Supplementary information In any artificial photosynthetic system, the oxidation of  water  to molecular  oxygen  provides the electrons needed for the r...