Yumiko Nakajima

Verified email at aist.go.jp

National Institute of Advanced Industrial Science and Technology (AIST)




organometallics coordination chemistry silicon chemistry


Scopus Publications

Scopus Publications

  • End-Groups of Poly(p-phenylene sulfide) Characterized by DNP NMR Spectroscopy
    Shinji Tanaka, Shingo Takada, Tohru Suzuki, Yumiko Nakajima, and Kazuhiko Sato

    Macromolecules, ISSN: 00249297, eISSN: 15205835, Pages: 2806-2812, Published: 12 April 2022 American Chemical Society (ACS)

  • Radical Hydrodehalogenation of Aryl Halides with H<inf>2</inf>Catalyzed by a Phenanthroline-Based PNNP Cobalt(I) Complex
    Nai-Yuan Jheng, Yusuke Ishizaka, Yuki Naganawa, Yasunori Minami, Akira Sekiguchi, Kosuke Iizuka, and Yumiko Nakajima

    ACS Catalysis, eISSN: 21555435, Pages: 2320-2329, Published: 18 February 2022 American Chemical Society (ACS)

  • Theoretical Study on Si−Cl Bond Activation in Pd-Catalyzed Cross-Coupling of Chlorosilanes with Organoaluminum
    Yuki Naganawa, Yumiko Nakajima, Shigeyoshi Sakaki, and Hajime Kameo

    European Journal of Organic Chemistry, ISSN: 1434193X, eISSN: 10990690, Volume: 2022, Published: 11 February 2022 Wiley

  • DNP NMR spectroscopy enabled direct characterization of polystyrene-supported catalyst species for synthesis of glycidyl esters by transesterification
    Shinji Tanaka, Yumiko Nakajima, Atsuko Ogawa, Takashi Kuragano, Yoshihiro Kon, Masanori Tamura, Kazuhiko Sato, and Christophe Copéret

    Chemical Science, ISSN: 20416520, eISSN: 20416539, Published: 2022 Royal Society of Chemistry (RSC)
    We demonstrated that DNP-enhanced NMR spectroscopy enables the direct and detailed characterization of polymer-supported alkylammonium catalysts.

  • Capturing ethylene glycol with dimethyl carbonate towards depolymerisation of polyethylene terephthalate at ambient temperature
    Shinji Tanaka, Junichi Sato, and Yumiko Nakajima

    Green Chemistry, ISSN: 14639262, eISSN: 14639270, Pages: 9412-9416, Published: 7 December 2021 Royal Society of Chemistry (RSC)
    A strategy of capturing ethylene glycol with dimethyl carbonate in the catalytic methanolysis of polyethylene terephthalate enabled depolymerization at ambient temperature.

  • Selective hydrosilylation of allyl chloride with trichlorosilane
    Koya Inomata, Yuki Naganawa, Zhi An Wang, Kei Sakamoto, Kazuhiro Matsumoto, Kazuhiko Sato, and Yumiko Nakajima

    Communications Chemistry, eISSN: 23993669, Published: December 2021 Springer Science and Business Media LLC
    AbstractThe transition-metal-catalysed hydrosilylation reaction of alkenes is one of the most important catalytic reactions in the silicon industry. In this field, intensive studies have been thus far performed in the development of base-metal catalysts due to increased emphasis on environmental sustainability. However, one big drawback remains to be overcome in this field: the limited functional group compatibility of the currently available Pt hydrosilylation catalysts in the silicon industry. This is a serious issue in the production of trichloro(3-chloropropyl)silane, which is industrially synthesized on the order of several thousand tons per year as a key intermediate to access various silane coupling agents. In the present study, an efficient hydrosilylation reaction of allyl chloride with trichlorosilane is achieved using the Rh(I) catalyst [RhCl(dppbzF)]2 (dppbzF = 1,2-bis(diphenylphosphino)-3,4,5,6-tetrafluorobenzene) to selectively form trichloro(3-chloropropyl)silane. The catalyst enables drastically improved efficiency (turnover number, TON, 140,000) and selectivity (&gt;99%) to be achieved compared to conventional Pt catalysts.

  • Long-Range Metal-Ligand Cooperation by Iron Hydride Complexes Bearing a Phenanthroline-Based Tetradentate PNNP Ligand
    Monika Gautam, Shinji Tanaka, Akira Sekiguchi, and Yumiko Nakajima

    Organometallics, ISSN: 02767333, eISSN: 15206041, Pages: 3697-3702, Published: 22 November 2021 American Chemical Society (ACS)

  • Catalytic Reductive Cleavage of Poly(phenylene sulfide) Using a Hydrosilane
    Yasunori Minami, Yumiko Nakajima, Nao Matsuyama, Yasuaki Matsuo, Masanori Tamura, and Kazuhiko Sato

    Synthesis (Germany), ISSN: 00397881, eISSN: 1437210X, Pages: 3351-3354, Published: 16 September 2021 Georg Thieme Verlag KG
    AbstractThe solvent-insoluble poly(phenylene sulfide) main chain was reductively cleaved by using triethylsilane as a hydrogen source under palladium/IcHex catalytic conditions. After the reaction, benzene and bis(triethylsilyl) sulfide as a sulfide source were formed efficiently. This method could be operated on a gram scale.

  • Metal-ligand cooperation behaviour of Fe and Co complexes bearing a tetradentate phenanthroline-based PNNP ligand
    Yumiko Nakajima, Tomohiro Takeshita, and Nai-Yuan Jheng

    Dalton Transactions, ISSN: 14779226, eISSN: 14779234, Pages: 7532-7536, Published: 14 June 2021 Royal Society of Chemistry (RSC)
    A metal–ligand cooperation (MLC) behavior was investigated using Iron and cobalt complexes bearing a phenanthroline-based meridional PNNP ligand, demonstrating a unique long-range MLC, where the phenanthroline backbone behaves as a H2 reservoir.

  • Palladium/Carboxylic Acid-catalyzed Alkenylation of Furfural and its Derivatives Using Alkynes
    Yasunori Minami, Hitomi Miyamoto, and Yumiko Nakajima

    ChemCatChem, ISSN: 18673880, eISSN: 18673899, Pages: 855-858, Published: 5 February 2021 Wiley
    Furfural and its derivatives underwent alkenylation with alkynes via α‐C−H activation in the presence of a palladium/carboxylic acid catalyst to give the corresponding single and double alkenylated products. The reactive aldehyde group remained intact during this reaction. This catalytic system allowed selective alkenylation of furan substrates having electron‐withdrawing substituents.

  • A General and Selective Synthesis of Methylmonochlorosilanes from Di-, Tri-, and Tetrachlorosilanes
    Yuki Naganawa, Kei Sakamoto, and Yumiko Nakajima

    Organic Letters, ISSN: 15237060, eISSN: 15237052, Pages: 601-606, Published: 15 January 2021 American Chemical Society (ACS)
    Direct catalytic transformation of chlorosilanes into organosilicon compounds remains challenging due to difficulty in cleaving the strong Si-Cl bond(s). We herein report the palladium-catalyzed cross-coupling reaction of chlorosilanes with organoaluminum reagents. A combination of [Pd(C3H5)Cl]2 and DavePhos ligand catalyzed the selective methylation of various dichlorosilanes 1, trichlorosilanes 5, and tetrachlorosilane 6 to give the corresponding monochlorosilanes.

  • Co(i) complexes with a tetradentate phenanthroline-based PNNP ligand as a potent new metal-ligand cooperation platform
    Nai-Yuan Jheng, Yusuke Ishizaka, Yuki Naganawa, Akira Sekiguchi, and Yumiko Nakajima

    Dalton Transactions, ISSN: 14779226, eISSN: 14779234, Pages: 14592-14597, Published: 7 November 2020 Royal Society of Chemistry (RSC)
    A cobalt(i) alkyl complex bearing a tetradentate phenanthroline-based PNNP ligand undergoes dearomatization of the ligand backbone skeleton upon heating and furthermore achieves H–H bond cleavage.

  • Selective C-P(O) Bond Cleavage of Organophosphine Oxides by Sodium
    Jian-Qiu Zhang, Eiichi Ikawa, Hiroyoshi Fujino, Yuki Naganawa, Yumiko Nakajima, and Li-Biao Han

    Journal of Organic Chemistry, ISSN: 00223263, eISSN: 15206904, Pages: 14166-14173, Published: 6 November 2020 American Chemical Society (ACS)
    Sodium exhibits better efficacy and selectivity than Li and K for converting Ph3P(O) to Ph2P(OM). The destiny of PhNa co-generated is disclosed. A series of alkyl halides R4X and aryl halides ArX all react with Ph2P(ONa) to produce the corresponding phosphine oxides in good to excellent yields.

  • Catalytic Decarboxylation of Silyl Alkynoates to Alkynylsilanes
    Takahiro Kawatsu, Keiya Aoyagi, Yumiko Nakajima, Jun-Chul Choi, Kazuhiko Sato, and Kazuhiro Matsumoto

    Organometallics, ISSN: 02767333, eISSN: 15206041, Pages: 2947-2950, Published: 24 August 2020 American Chemical Society (ACS)
    Herein, we describe a decarboxylative approach to the preparation of alkynylsilanes. Treatment of a silyl alkynoate in N,N-dimethylformamide (DMF) at 80 °C in the presence of catalytic amounts of C...

  • Polypropylene-Based Nanocomposite with Enhanced Aging Stability by Surface Grafting of Silica Nanofillers with a Silane Coupling Agent Containing an Antioxidant
    Ryota Watanabe, Aki Sugahara, Hideaki Hagihara, Kei Sakamoto, Yumiko Nakajima, and Yuki Naganawa

    ACS Omega, eISSN: 24701343, Pages: 12431-12439, Published: 2 June 2020 American Chemical Society (ACS)
    Simultaneous improvement in the mechanical properties and lifetime of polymer nanocomposites is crucially significant to further extend the versatility of polymer materials and reduce environmental impact. In this study, we fabricated reinforced polypropylene (PP)-based nanocomposites with improved aging stability by the addition of surface-modified well-ordered silica nanospheres with a silane coupling agent (SCA) containing hindered phenol antioxidant as a filler. Uniform grafting of the SCA on the filler surface contributed to homogeneous dispersion of the filler into the matrix, leading to improved properties (e.g., stiffness and ductility) and uniform distribution of the antioxidant component into the entire nanocomposite by filler dispersion. The grafting of SCA also likely provides an inhibitory effect on antioxidant migration, which leads to loss of polymer stability during the aging process. This novel idea for the material design of PP-based nanocomposites, which simultaneously enhances their mechanical properties and lifetime, is promising for application in the fabrication of various types of polymer nanocomposites.

  • Hydrosilylation reactions of functionalized alkenes
    Yuki Naganawa, Koya Inomata, Kazuhiko Sato, and Yumiko Nakajima

    Tetrahedron Letters, ISSN: 00404039, eISSN: 18733581, Published: 12 March 2020 Elsevier BV
    Abstract Hydrosilylation of alkenes is an important reaction for the production of organosilicon compounds such as industrially important silicones and silane coupling agents. To synthesize highly sophisticated organosilicon materials, it is of great importance to develop novel hydrosilylation catalysts with good compatibility towards a wide range of functional groups. This review highlights the main advances made in this area. Efforts to develop Pt catalysis systems as well as environmentally benign base-metal catalyst systems have been collected with the aim of providing a comprehensive overview of the subject from the viewpoint of both academia and industry.

  • Oxidative Addition of C–X Bonds and H–H Activation Using PNNP-Iron Complexes
    Monika Gautam, Takafumi Yatabe, Shinji Tanaka, Naoto Satou, Tomohiro Takeshita, Kazuya Yamaguchi, and Yumiko Nakajima

    ChemistrySelect, eISSN: 23656549, Pages: 15-17, Published: 9 January 2020 Wiley

  • 4,4′-Bipyridyl-Catalyzed Reduction of Nitroarenes by Bis(neopentylglycolato)diboron
    Hiromu Hosoya, Luis C. Misal Castro, Ibrahim Sultan, Yumiko Nakajima, Toshimichi Ohmura, Kazuhiko Sato, Hayato Tsurugi, Michinori Suginome, and Kazushi Mashima

    Organic Letters, ISSN: 15237060, eISSN: 15237052, Pages: 9812-9817, Published: 20 December 2019 American Chemical Society (ACS)
    4,4'-Bipyridyl worked as an organocatalyst for the reduction of nitroarenes by bis(neopentylglycolato)diboron (B2nep2), followed by hydrolysis to give the corresponding anilines. This reduction proceeded under aerobic conditions without any prepurification of substrates and reagents. We found broad functional group tolerance and compatibility for O- and N-protecting groups under the reaction conditions. The key in this catalytic system was the addition of B2nep2 to 4,4'-bipyridyl to form N,N'-bis[(neopentylglycolato)boryl]-4,4'-bipyridinylidene as a deoxygenating reagent of nitroarenes.

  • Ruthenium-catalyzed selective hydrosilylation reaction of allyl-functionalized PEG derivatives
    Koya Inomata, Yuki Naganawa, Haiqing Guo, Kazuhiko Sato, and Yumiko Nakajima

    Tetrahedron Letters, ISSN: 00404039, eISSN: 18733581, Published: 10 October 2019 Elsevier BV
    Abstract Reactions of allyl-functionalized poly(ethylene glycol) (PEG) derivatives with alkoxysilanes proceeded efficiently to furnish the corresponding hydrosilylated products in good to excellent yields using a ruthenium catalyst, [RuCl2(nbd)]n. A preliminary mechanistic study supported the pivotal role of the PEG moiety, which coordinated to the ruthenium atom during the reaction to achieve high reaction selectivity. This method may be applicable to the synthesis of various PEGs with a silyl terminus, which is useful as biocompatible and low toxic silane coupling agents. .

  • Nickel-Catalyzed Selective Cross-Coupling of Chlorosilanes with Organoaluminum Reagents
    Yuki Naganawa, Haiqing Guo, Kei Sakamoto, and Yumiko Nakajima

    ChemCatChem, ISSN: 18673880, eISSN: 18673899, Pages: 3756-3759, Published: 21 August 2019 Wiley
    Nickel‐catalyzed cross‐coupling reactions of chlorosilanes with organoaluminum reagents were developed. An electron‐rich Ni(0)/PCy3 complex was found to be an effective catalyst for the desired transformation. The reaction of dichlorosilanes 1 proceeded to give the corresponding monosubstituted products 2. Trichlorosilanes 4 underwent selective double substitution to furnish the corresponding monochlorosilanes 2. Overall, the selective synthesis of a series of alkylmonochlorosilanes 2 from di‐ and trichlorosilanes was achieved using the present catalytic systems.

  • Synthesis and Characterization of Silyl-Bridged Dinuclear Cobalt Complexes Supported by an N-Heterocyclic Carbene
    Yusuke Ishizaka and Yumiko Nakajima

    Organometallics, ISSN: 02767333, eISSN: 15206041, Pages: 888-893, Published: 25 February 2019 American Chemical Society (ACS)
    A cobalt dialkyl with an N-heterocyclic carbene [Co(CH2SiMe3)2(IPr)] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene) underwent successive Si–H bond cleavage of hydrosilanes. The reaction paths were highly dependent on the bulkiness of the hydrosilanes, which led to the formation of various μ-silyl-bridged dicobalt complexes, [{Co(IPr)}2(μ-SiH2Hex)4], [{Co(IPr)}2(μ-SiH2Ph)3(H)3], and [{Co(IPr)}2(μ-SiHPh2)(μ-H)2].

  • Catalytic Reduction of Alkoxysilanes with Borane Using a Metallocene-Type Yttrium Complex
    Keiya Aoyagi, Kazuhiro Matsumoto, Shigeru Shimada, Kazuhiko Sato, and Yumiko Nakajima

    Organometallics, ISSN: 02767333, eISSN: 15206041, Pages: 210-212, Published: 28 January 2019 American Chemical Society (ACS)
    The catalytic reduction of alkoxysilanes with the borane HBpin (pin = pinacolato) was achieved using a metallocene-type yttrium complex as a catalyst precursor. Mechanistic study supported the pivotal role of the rigid metallocene structure of the catalyst, which bears two bulky η5-C5Me4SiMe3 ligands, in suppressing the coordination of the side product MeOBpin that is generated during the reaction.

  • Synthesis of hydrosilanes: Via Lewis-base-catalysed reduction of alkoxy silanes with NaBH<inf>4</inf>
    Keiya Aoyagi, Yu Ohmori, Koya Inomata, Kazuhiro Matsumoto, Shigeru Shimada, Kazuhiko Sato, and Yumiko Nakajima

    Chemical Communications, ISSN: 13597345, eISSN: 1364548X, Pages: 5859-5862, Published: 2019 Royal Society of Chemistry (RSC)
    Hydrosilanes were synthesized by reduction of alkoxysilanes with BH3 in the presence of hexamethylphosphoric triamide (HMPA) as a Lewis-base catalyst. The reaction was also achieved using an inexpensive and easy-to-handle handled hydride source NaBH4, which reacted with EtBr as a sacrificial reagent to form BH3in situ.

  • Deprotonation of a PNNP-Iron Complex: Expanding the concept of metal-ligand cooperation to the PNNP-iron system
    Chemistry Letters, ISSN: 03667022, eISSN: 13480715, Pages: 364-366, Published: 2019

  • Heterogeneous hydrosilylation reaction catalysed by platinum complexes immobilized on bipyridine-periodic mesoporous organosilicas
    Yuki Naganawa, Yoshifumi Maegawa, Haiqing Guo, Sandeep Suryabhan Gholap, Shinji Tanaka, Kazuhiko Sato, Shinji Inagaki, and Yumiko Nakajima

    Dalton Transactions, ISSN: 14779226, eISSN: 14779234, Pages: 5534-5540, Published: 2019 Royal Society of Chemistry (RSC)
    A platinum complex immobilized on a bipyridine-periodic mesoporous organosilica (BPy-PMO) effectively catalysed the hydrosilylation reaction and showed good reusability without the loss of the product yield.