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TATSUYA UCHIDA Last modified date：2022.06.07

Associate Professor / Division for Arts and Science
Division for Experimental Natural Science
Faculty of Arts and Science


Graduate School
Department of Chemistry
Graduate School of Sciences
Undergraduate School
Department of Chemistry
School of Sciences
Other Organization
International Institute for Carbon-Neutral Energy Research


Homepage
https://kyushu-u.pure.elsevier.com/en/persons/tatsuya-uchida
　Reseacher Profiling Tool　Kyushu University Pure
http://www.science.scc.kyushu-u.ac.jp/index.html
Phone
092-802-6022
Fax
092-802-6022
Academic Degree
Dr. of Sci.
Country of degree conferring institution (Overseas)
No
Field of Specialization
organic synthesis
Total Priod of education and research career in the foreign country
00years00months
Research
Research Interests
  • the development of environment friendly asymmetric reaction using transition metal complexes as catalysts
    keyword : Catalytic asymmetric reaction
    2013.10～2013.10.
Academic Activities
Reports
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1. Daiki Doiuchi, Tatsuya Uchida, Recent Strategies in Non-Heme-Type Metal Complexes-Catalyzed Site-, Chemo-, and Enantioselective C–H Oxygenations, Synthesis, 2021.06, C–H bonds are ubiquitous and abundant in organic molecules. If such C–H bonds can be converted to the desired functional groups in a site-, chemo-, diastereo-, and enantio-selective manner, the functionalization of C–H bonds would be an efficient tool for the step-, atom- and redox-economic organic synthesis. C–H oxidation is one of a typical C–H functionalization, to afford hydroxy and carbonyl groups, which are essential key functional groups in organic synthesis and biological chemistry, directly. Recently, significant developments have been made using non-heme-type transition metal catalysts. Oxygen functional groups can be introduced to not only simple hydrocarbons but also complicated natural products. In this paper, the recent developments, during the last fourteen years, of non-heme-type complex-catalyzed C–H oxidations are reviewed. .
2. Hayashi, Hiroki; Uchida, Tatsuya, Nitrene Transfer Reactions for Asymmetric C-H Amination: Recent Development, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 10.1002/ejoc.201901562, 2020.02, [URL], C-H bonds are ubiquitous and abundant in organic molecules. If C-H bonds could be directly converted to desired functional groups in a chemo-, site-, and stereoselective manner, C-H functionalization would be a strong and useful tool for organic synthesis. Recent developments in catalytic and enzymatic chemistry have achieved highly sustainable and selective nitrene C-H insertion. Initially, C-H amination was inspired by model studies on enzymatic oxidation and used iminoiodinanes, nitrogen analogs of iodosobenzene, as nitrene precursors. Transition-metal/iminoiodinane systems are well studied and established. These systems can directly introduce sulfonamide groups with excellent stereoselectivity, albeit with co-production of iodobenzene as waste material. Fortunately, the atom economics of this methodology were improved by introducing highly sustainable nitrene sources such as azide compounds and 1,2,4-dioxazol-5-one derivatives. In this review, we present the details of these developments with respect to their catalysts and nitrene sources..
3. RYO IRIE, TATSUYA UCHIDA, KAZUHIRO MATSUMOTO, Katsuki Catalysts for Asymmetric Oxidation: Design Concepts, Serendipities for Breakthroughs, and Applications, Chemical Letters, 2015.08.
4. TATSUYA UCHIDA, Tsutomu Katsuki, Asymmetric nitrene transfer reactions: sulfimidation, aziridination and C-h amination using azide compounds as nitrene precursors, The Chemical Record, 2014.02, Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-produces iodobenzene, as a nitrene precursor and have a low atom economy. Azide compounds, which give nitrene species by releasing nitrogen, are ideal precursors but rather stable. Their decomposition needs UV irradiation, heating in the presence of a metal complex, or Lewis acid treatment. The examples of previous azide decomposition prompted us to examine Lewis acid and low-valent transition-metal complexes as catalysts for azide decomposition. Thus, we designed new ruthenium complexes that are composed of a low-valent Ru(II) ion, apical CO ligand, and an asymmetry-inducing salen ligand. With these ruthenium complexes and azides, we have achieved highly enantioselective nitrene transfer reactions under mild conditions. Recently, iridium-salen complexes were added to our toolbox..
5. TATSUYA UCHIDA, Tsutomu Katsuki, Green Asymmetric Oxidation Using Air as Oxidant, Synthetic Organic Chemistry Japan, 2013.11, Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-produces iodobenzene, as a nitrene precursor and have a low atom economy. Azide compounds, which give We found that (NO)- and (aqua)ruthenium-salen complexes are efficient catalysts for the asymmetric aerobic oxygen atom transfer reactions such as epoxidation and sulfoxidation at ambient temperature. (NO)ruthenium-salen complexes 2 and 3 could catalyze oxidation of sulfides and the epoxidation of conjugated olefins with good to high enantioselectivity using dioxygen as oxidant, albeit under visible light-irradiation, respectively. On the other hand, (aqua)ruthenium-salen complex 5 was found to catalyze highly enantioselective epoxidation in air even without irradiation. Although the mechanism of this ruthenium-catalyzed aerobic oxidation has not been completely elucidated, water that is bound to the ruthenium ion has been considered to play a critical role in proton coupled electron transfer, a key step for oxygen activation, and to be regenerated via oxo-hydroxo tautomerization. We also found that (di-μ-hydroxo)iron-salan complexes catalyzes asymmetric dehydrogenative oxidation reactions such as 2-naphthol coupling, alcohol oxidation, and dearomatization, using air as oxidant..
Papers
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1. Yuki Yamakawa, Takashi Ikuta, Hiroki Hayashi, Keigo Hashimoto, Ryoma Fujii, Kyohei Kawashima, Seiji Mori, Tatsuya Uchida, Tsutomu Katsuki, Iridium(III)-Catalyzed Asymmetric Site-Selective Carbene C–H Insertion during Late-Stage Transformation, The Journal of Organic Chemistry, 10.1021/acs.joc.2c00470, 87, 10, 6769-6780, 2022.05, C–H functionalization has recently received considerable attention because C–H functionalization during the late-stage transformation is a strong and useful tool for the modification of the bioactive compounds and the creation of new active molecules. Although a carbene transfer reaction can directly convert a C–H bond to the desired C–C bond in a stereoselective manner, its application in late-stage material transformation is limited. Here, we observed that the iridium–salen complex 6 exhibited efficient catalysis in asymmetric carbene C–H insertion reactions. Under optimized conditions, benzylic, allylic, and propargylic C–H bonds were converted to desired C–C bonds in an excellent stereoselective manner. Excellent regioselectivity was demonstrated in the reaction using not only simple substrate but also natural products, bearing multiple reaction sites. Moreover, based on the mechanistic studies, the iridium-catalyzed unique C–H insertion reaction involved rate-determining asynchronous concerted processes..
2. Doiuchi, Daiki; Uchida, Tatsuya, Catalytic Highly Regioselective C–H Oxygenation Using Water as the Oxygen Source: Preparation of 17O/18O-Isotope-Labeled Compounds, Organic Letters, 10.1021/acs.orglett.1c02812, 23, 7301-7305, 2021.09, A water molecule is one of the ideal oxygen sources in organic synthesis. If a theoretical stoichiometric amount of water can be activated to the reactive intermediates such as metal(oxo) species and inserted to C–H bond, the C¬–H oxidation would be an efficient and useful tool for the oxygen functionalization, especially isotopically oxygen-labeled functional groups. Herein, we found that the oxygen atom of water is activated to iodosylbenzene derivatives via reversible hydrolysis of iodobenzene(dicarboxylate) and can be used to the oxygen source for non-heme-type ruthenium(bpga)-catalyzed site-selective C–H oxygenation. Under that Ru(bpga)/PhI(OOCR)2/H2O system, sterically less bulky methinic and methylenic C–H bonds in various compounds, even complicated natural products, can be converted to desired oxygen functional groups in a site-selective manner. Using this method, oxygen-isotope labeled compounds such as D-[3-17O/18O]-mannose can be prepared in a multi-gram scale..
3. Masaki Yoshitake, Hiroki Hayashi, Tatsuya Uchida*, Ruthenium-Catalyzed Asymmetric N-Acyl Nitrene Transfer Reaction: Imidation of Sulfide, Organic letters, 10.1021/acs.orglett.0c01373, 22, 10, 4021-4025, 2020.05, (Aqua)ruthenium(salen) complex 1c achieved good to high chemo- and enantioselective oxidative cross-coupling of arenols. The catalytic system can be used to selectively produce C1-symmetric bis(arenol)s from the combination of C3- and C7-substituted 2-naphthols or phenols even when there is no significant difference in oxidation potential between the cross-coupling partners. This unique cross-selectivity is dominated by steric rather than electronic effects of the arenols and can be controlled by chemoselective single-electron oxidation and oxidative carbon-carbon bond formation..
4. Takuya Oguma, Daiki Doiuchi, Chisaki Fujitomo, Chungsik Kim, Hiroki Hayashi, Tatsuya Uchida, Tsutomu Katsuki, Iron-Catalyzed Asymmetric Inter- and Intramolecular Aerobic Oxidative Dearomatizing Spirocyclization of 2-Naphthols, Asian Journal of Organic Chemistry, 10.1002/ajoc.201900602, 9, 3, 404-415, 2020.03, Highly chemo- and enantioselective inter- and intra-molecular oxidative dearomatizing spirocyclization of 1-alkyl-2-naphthols with O2 as the hydrogen acceptor was achieved using an iron catalyst. In the iron complex 1-catalyzed reaction, 1-methyl-2-naphthols 2 in the presence of phenol derivatives as the nucleophile was selectively oxidized, producing the spirocyclic ketones with good to high enantioselectivities via a tandem strategy. Pre-synthesized 1,1′-methylbis(arenol)s 6 and 7, intermediates of the tandem strategy were also converted to the desired products with chemo- and enantioselectivity..
5. Hiroki Hayashi, Takamasa Ueno, Chungsik Kim, Tatsuya Uchida, Ruthenium-Catalyzed Cross-Selective Asymmetric Oxidative Coupling of Arenols, Organic letters, 10.1021/acs.orglett.0c00048, 22, 4, 1469-1474, 2020.02, (Aqua)ruthenium(salen) complex 1c achieved good to high chemo- and enantioselective oxidative cross-coupling of arenols. The catalytic system can be used to selectively produce C1-symmetric bis(arenol)s from the combination of C3- and C7-substituted 2-naphthols or phenols even when there is no significant difference in oxidation potential between the cross-coupling partners. This unique cross-selectivity is dominated by steric rather than electronic effects of the arenols and can be controlled by chemoselective single-electron oxidation and oxidative carbon-carbon bond formation..
6. Daiki Doiuchi, Tatsuya Nakamura, Hiroki Hayashi, Tatsuya Uchida, Non-Heme-Type Ruthenium Catalyzed Chemo- and Site-Selective C−H Oxidation, Chemistry - An Asian Journal, 10.1002/asia.202000134, 2020.01, Herein, we developed a Ru(II)(BPGA) complex that could be used to catalyze chemo- and site-selective C−H oxidation. The described ruthenium complex was designed by replacing one pyridyl group on tris(2-pyridylmethyl)amine with an electron-donating amide ligand that was critical for promoting this type of reaction. More importantly, higher reactivities and better chemo-, and site-selectivities were observed for reactions using the cis-ruthenium complex rather than the trans-one. This reaction could be used to convert sterically less hindered methyne and/or methylene C−H bonds of a various organic substrates, including natural products, into valuable alcohol or ketone products..
7. KIM CHUNG SIK, Takuya Oguma, Chisaki Fujitomo, TATSUYA UCHIDA, Tsutomu Katsuki, Iron-Catalyzed Asymmetric Aerobic Oxidative Dearomatizing Spirocyclization of Methylenebis(arenol)s, Chemistry Letters, 10.1246/cl.160680, 45, 1262-1264, 2016.08, Iron(salan) complexes are efficient catalysis in intramolecular aerobic oxidative dearomatizing spirocyclization of methylenebis(arenol)s, which was prepared from salicyl akdehydes and phenols with simple microwave irradiation. Under the iron-catalyzed aerobic oxidation conditions, methylenebis(arenol)s converted to the corresponding spirocyclic compounds with good to high enantioselectivity (up to 87% ee)..
8. Hirotaka Mizoguchi, TATSUYA UCHIDA, Tsutomu Katsuki, Ruthenium-Catalyzed Oxidative Kinetic Resolution of Unactivated and Activated Secondary Alcohols with Air as the Hydrogen Acceptor at Room Temperature., ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201310426, 53, 3178-3182, 2014.02, Enantiopure alcohols are versatile building blocks for asymmetric synthesis and the kinetic resolution (KR) of racemic alcohols is a reliable method for preparing them. Although many KR methods have been developed, oxidative kinetic resolution (OKR), in which dioxygen is used as the hydrogen acceptor, is the most atom-efficient. Dioxygen is ubiquitous in air, which is abundant and safe to handle. Therefore, OKR with air has been intensively investigated and the OKR of benzylic alcohols was recently achieved by using an Ir catalyst without any adjuvant. However, the OKR of unactivated alcohols remains a challenge. An [(aqua)Ru- (salen)] catalyzed OKR with air as the hydrogen acceptor was developed, in which the aqua ligand is exchanged with alcohol and the Ru complex undergoes single electron transfer to dioxygen and subsequent alcohol oxidation. This OKR can be applied without any adjuvant to activated and unactivated alcohols with good to high enantioselectivity. The unique influence of substrate inhibition on the enantioselectivity of the OKR is also described..
9. Yota Nishioka, TATSUYA UCHIDA, Tsutomu Katsuki, Enantio- and Regioselective Intermolecular Benzylic and Allylic C-H Bond Amination, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201208906, 52, 6, 1739-1742, 2013.01, We designed new ruthenium catalysts that were composed of ruthenium(II) ion, apical CO ligand, and highly enantioselective salen ligand and could for the first time achieve highly enantioselective sulfimidation, aziridination, and C-H amination using azide compounds as the nitrene precursors. Catalytic activity, stereoselectivity, and regioselectivity of the ruthenium catalysts were remarkably improved by an appropriate tuning of salen ligand..
10. Yasuaki Fukunaga, TATSUYA UCHIDA, Yutaro Ito, Tsutomu Katsuki, Ru(CO)-salen-Catalyzed Synthesis of Enantiopure Aziridinyl Ketones and Formal Asymmetric Synthesis of (+)-PD 128907, ORGANIC LETTERS, 10.1021/ol302095r, 14, 17, 4658-4661, 2012.09, Aziridination of vinyl ketones using SESN3 in the presence Ru(CO)-salen complex 1 provides the enantiopure aziridinyl ketones that can serve as useful chiral building blocks. A formal asymmetric synthesis of (þ)-PD 128907 was achieved in an eight-step sequence via aziridination..
11. Shota Koya, Yota Nishioka, Hirotaka Mizoguchi, Tatsuya Uchida, Tsutomu Katsuki, Asymmetric Epoxidation of Conjugated Olefins with Dioxygen, Angew. Chem. Int. Ed., 10.1002/anie.201201848, 51, 33, 8243-8246, 2012.07, A complex situation: Asymmetric epoxidation of conjugated olefins was achieved at room temperature using ruthenium complex 1 as the catalyst and air as the oxidant to give epoxides in up to 95 % ee. When the product was acid sensitive, the reaction was carried out at 0 °C under oxygen..
12. Chungsik Kim, Tatsuya Uchida, Tsutomu Katsuki, Asymmetric olefin aziridination using a newly designed Ru(CO)(salen) complex as the catalyst, Chem. Commun, 10.1039/c2cc32997b, 48, 7188–7190, 2012.04, Highly enantioselective and good to high-yielding aziridination of conjugated and non-conjugated terminal olefins and cyclic olefins was achieved using a newly designed Ru(CO)(salen) complex as the catalyst in the presence of SESN3 under mild conditions..
13. Masami Ichinose, Hidehiro Suematsu, Yoichi Yasutomi, Yota Nishioka, Tatsuya Uchida, and Tsutomu Katsuki, Enantioselective Intramolecular Benzylic CーH Bond Amination:
Efficient Synthesis of Optically Active Benzosultams, Angew. Chem. Int. Ed, 10.1002/anie.201101801, 50, 9884-9887, 2011.09.
14. Tanaka, H., Nishikawa, H., Uchida, T. & Katsuki, T., , Photopromoted Ru-Catalyzed Asymmetric Aerobic Sulfide Oxidation and Epoxidation Using Water as a Proton Transfer Mediator., J. Am. Chem. Soc, 10.1021/ja104184r, 132, 34, 12034-12041, 2010.05, 著者等は、光学活性なルテニウム（ニトロシル）サレン錯体が、室温、常圧の温和な条件下で還元剤を用いること無しに、分子状酸素を酸化剤とするオレフィンの不斉エポキシ化、スルフィドの不斉スルホキシ化に成功した。可視光照射条件下において、錯体２を触媒とすることで不斉スルホキシ化が最高98% eeのエナンチオ選択性にて、また錯体３を用いることにて不斉エポキシ化が76-92% eeの不斉収率にて目的とする酸化生成物が得られた。
本反応では、反応系中に存在する水分子が、ルテニウムイオンに配位し、プロトン供給源として分子状酸素活性化の一翼を担い、また、消費された水は反応サイクル中で再生するものと考えられる。.
15. Mizoguchi Takahiro, Ishida Koichi, Uchida Tatsuya, Katsuki Tsutomu , Ru-salen complex catalyzed chemoselective aerobic oxidation of primary alcohols to aldehydes, Tetrahedron Letters, 2009.06.
16. Tatsuya Uchida, Tstomu Katsuki, Construction of a new type of chiral bidentate NHC ligands: copper-catalyzed asymmetric conjugate alkylation, Tetrahedron Letters, 2009.06.
17. Hidehiro Suematsu, Shigefumi Kanchiku, Tatsuya Uchida, Tsutomu Katsuki, Construction of aryliridium-salen complexes
Enantio- and cis-selective cyclopropanation of conjugated and nonconjugated olefins, Journal of the American Chemical Society, 10.1021/ja802561t, 130, 31, 10327-10337, 2008.08, Two stable and optically active iridium-salen complexes were synthesized by introducing a tolyl or phenyl ligand at the apical position, respectively, via the SEAr mechanism, and they were found to be efficient catalysts for cis-selective asymmetric cyclopropanation. The scope of the cyclopropanation was wide, and the reactions of not only conjugated mono-, di-, and trisubstituted olefins but also nonconjugated terminal olefins proceeded with high enantio- and cis-selectivity, even in the presence of a functional group such as an ether or ester. The utility of this cyclopropanation was demonstrated by a short step synthesis of 8-[(1R,2S)-2-hexylcyclopropyl]octanoate, isolated from Escherichia coli B-ATCC 11303, using the reaction as the key step..
18. Shigefumi Kanchiku, Hidehiro Suematsu, Kazuhiro Matsumoto, Tatsuya Uchida, Tsutomu Katsuki, Construction of an aryliridium-salen complex for highly cis- and enantioselective cyclopropanations, Angewandte Chemie - International Edition, 10.1002/anie.200604385, 46, 21, 3889-3891, 2007.06, (Chemical Equation Presented) Ringing the changes: Iridium(lll)-salen complexes 1 bearing a σ-coordinated aryl ligand (L = CH3C 6H4, C6H5) at the apical position are found to efficiently catalyze the cis- and enantioselective cyclopropanation of mono- and disubstituted olefins (see scheme)..
19. Omura Kazuhumi, Murakami Masakazu, Uchida Tatsuya, Katsuki Tsutomu, Enantioselective aziridination and amination using p-toluenesulfonyl azide in the presence of Ru(salen)(CO) complex, CHEMISTRY LETTERS, 32, 4, 354-355, ３２巻４号、p. 354-355, 2003.04.
Presentations
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1. Tatsuya Uchida, Ruthenium-Catalyzed Asymmetric Nitrene Transfer Reactions, 5th International Conference on Catalysis and Chemical Engineering (CCE-2021), 2021.02.
2. Late-stage functionalization of organic molecules are powerful tools for reforming functional molecules. However, catalytic late-stage transformations were still challenging due to the complexity of the target molecules. Herein, we found that newly synthesized heme-type ruthenium complex is an efficient catalyst for the C–H oxidation. Ruthenium-catalyzed C–H oxidation could obtain the desired product in the presence of iodobenzene(dicarboxylate) with slightly excess amount of water, which is the highly sustainable and clean oxygen resource, as the oxygen source with excellent regio-selective manner even highly complicated natural products. .
3. Daiki Doiuchi, Hiroki Hayashi, Tatsuya Uchida, Ruthenium-Catalyzed 3° C–H Bond Selective Hydroxylation, 6th Japan–UK Symposium on Asymmetric Catalysis, 2018.11.
4. Tatsuya Uchida, Asymmetric C–H Functionalization, 6th Japan–UK Symposium on Asymmetric Catalysis, 2018.11, Carbon–hydrogen bonds are ubiquitous and abundant in organic molecule. If that C–H bond can be directly converted to desired function group with stereo- and site-selective manner, C– H bond functionalization would really strong and efficient tool in organic synthesis. Recently, we found that ruthenium-salen complexes are efficient catalyst for nitrene and oxo transfer reactions using highly atom-economic oxidants such as azide and dioxygen.
(OC)ruthenium(II)-salen complex decompose azide compounds to corresponding nitrene intermediates with co-producing nitrogen gas as the by-product. Obtained ruthenium-nitrene can insert benzylic and allylic C–H bond with excellent site- and stereo-selective manner. Interestingly, ruthenium-catalysed C–H amination undergoes exclusively at methylene C–H bond on ethyl group. 1
On the other hand, (aqua)ruthenium(III) complex can activate dioxygen to superoxide intermediate via single electron transfer (SET). Obtained superoxide delocalized radical cation intermediate.2 This mechanism suggests that, arenols could be oxidized to the electrophilic radical intermediate and then converted to the desired bis(arenol)s. Based on this suggestion, we conducted the oxidative coupling of arenols using dioxygen as a hydrogen accepter. Under ruthenium-catalyzed aerobic conditions, arenols can converted to bis(arenol)s with good to high enantioselectivity. Under that conditions, C3-substituted 2-naphthols using C7-substituted 2-naphthols or phenol derivatives gave the cross-coupling products with good to high chemoselectivity, irrespective with electron nature of each arenols..
5. Hiroki Hayashi, Takamasa Ueno, Tatsuya Uchida, Ruthenium-Catalyzed Enanatioselective Oxidative Cross-Coupling of 2-Naphthols, The Fourth International Symposium On C–H Activation, 2018.08.
6. Yuki Yamakawa, Takashi Ikuta, Hiroki Hayashi, Tatsuya Uchida, Highly Site-selective C–H Insertion via Iridium-Carbene Intermediate, The Fourth International Symposium on C–H Activation, 2018.08.
7. Tatsuya Uchida, Asymmetric Oxidative Cross-Coupling of Arenols, The 13th International Symposium on Activation of Dioxygen and Homogeneous Oxidation Catalysis, 2018.06.
8. 内田 竜也, Site-selective Asymmetric C−H Bond Functionalization, The 1st Sino-Japanese Symposium on Catalysis for Precision Synthesis, 2018.05.
9. 内田　竜也, Activation of Molecular Oxygen and Catalytic Asymmetric Aerobic Oxidation, 第1回精密制御反応場国際シンポジウム, 2016.07, Molecular oxygen (O2) is an ubiquitous, abundant, and highly atom economic oxidant on the earth. However, most of O2 activation required heating and/or pressurizing conditions or the addition of co-reductant, unfortunately. Stereoselectivities of these oxidations are insufficient. On the other hand, typical biological oxidation proceeded with complete stereoselectivity albeit with consuming 2H+ and 2e- and producing water as a waste material. Thus, development of new methodology for O2 activation has been strongly required. Herein, we presented ruthenium-catalyzed highly enantioselective aerobic oxidation such as epoxidation and oxidative kinetic resolution of alcohol.Under aqueous conditions, ruthenium-salen complexes can activate O2 to active oxygen spices such as corresponding superoxide and oxo spices via single-electron-transfer (SET) and proton-coupled- electron-transfer (PCET) with water mediation, and catalyze epoxidation of trans- -methylstyrene derivatives with good to high enantioselectivity (up to 95% ee).1b On the other hand, under alcoholic conditions, racemic sec-alcohol was oxidized with high enantiomer differentiation (krel = up to 60).1a It was noteworthy that ruthenium-salen complexes catalyzed aerobic oxidations are proceed under ambient conditions without any activation methods..
10. 内田　竜也, Development of Catalytic C-C Bond Formation, I2CNER International Workshop -Natural and Chemical Catalysts for Technology-, 2017.02, C-H bond functionalization via carbene transfer reaction is one of strong and useful tool for the construction of carbon framework and has garner much attention. However, C-H bond, which is ubiquitous and abundant in organic molecule, is still difficult to convert desired function group at well. Herein, we found that (aryl)iridium(salen) complexes are efficient catalysis in C-H functionalization.1 (Aryl)iridium complex can decompose -aryl- -dizaoacetates to desired carbene intermediates and convert benzylic, allylic, and propargylic C-H bond to the corresponding C-C bond with excellent diastereo- and enantio-selectivities. Furthermore, iridium-catalyzed C-H insertion reactions showed interesting site-selectivity. That reaction carried out at only methylene C-H bond on ethyl group..
11. , [URL].
12. Asymmetric Baeyer-Villiger Oxidation Using Metallosalen Complex as Catalyst.
13. Asymmetric Aziridination Using Azide Compounds as Nitrene Precursor in the Presence of Robust Ru(salen) Complex.
Membership in Academic Society
  • American Chemical Society


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