| 1. |
Hidetoshi Ohta, Kanako Tobayashi, Akihiro Kuroo, Mao Nakatsuka, Hirokazu Kobayashi, Atsushi Fukuoka, Go Hamasaka, Yasuhiro Uozumi, Haruno Murayama, Makoto Tokunaga, Minoru Hayashi, Surface Modification of a Supported Pt Catalyst Using Ionic Liquids for Selective Hydrodeoxygenation of Phenols into Arenes under Mild Conditions, Chemistry - A European Journal, 10.1002/chem.201902668, 25, 65, 14762-14766, 2019.11. |
| 2. |
Study for practical application of supported gold nanoparticles for removal of DMTS responsible for hineka in sake. |
| 3. |
Zhenzhong Zhang, Taishin Hashiguchi, Tamao Ishida, Akiyuki Hamasaki, Tetsuo Honma, Hironori Ohashi, Takushi Yokoyama, Makoto Tokunaga, Aerobic oxidation of cyclohexanones to phenols and aryl ethers over supported Pd catalysts, Organic Chemistry Frontiers, 10.1039/c4qo00354c, 2, 6, 654-660, 2015.06, Transformation of cyclohexanones to phenols and aryl ethers over supported Pd catalysts using molecular oxygen as the sole oxidant is developed. Several metal oxide supported Pd catalysts were used to activate the C-H bond in cyclohexanones to produce cyclohexenones and phenols through oxidation. Although the selectivity of cyclohexenones was difficult to control, phenols were obtained in excellent yield with a broad substrate scope. A novel catalytic system, using ZrO2 supported Pd(OH)2, was proposed for the synthesis of aryl ethers, and the products were obtained in moderate to excellent yields. Orthoesters, such as trimethyl orthoformate (TMOF), triethyl orthoformate (TEOF), and triisopropyl orthoformate (TIPOF), enabled nucleophilic addition and elimination after activation of cyclohexanones over a Pd catalyst to produce the corresponding aryl ethers. TIPOF was also used as the dehydrating reagent to promote the reaction of cyclohexanones with alcohols for the preparation of versatile aryl ethers.. |
| 4. |
Asymmetric Basic Hydrolysis with Chiral Quaternary Ammonium Salts. |
| 5. |
Joe P. Richmond, Martin Banwell, Daniel Bellus, Kilian Muniz, Koichi Narasaka, Yoshio Okamoto, Jun Okuda, Manfred Schlosser, Ichiro Shinkai, Kuniaki Tatsuta, Gerard van Koten, Xiao-Zeng You, Varinder K. Aggarwal, Takuzo Aida, Howard Alper, Chunli Bai, Kankan Bhattacharyya, Hans-Ulrich Blaser, Benoit Pugin, Felix Spindler, John M. Brown, Stephen L. Buchwald, Albert S. C. Chan, Naoto Chatani, Scott E. Denmark, Francois Diederich, Michael P. Doyle, Greg Fu, Akira Fujishima, Stephen Hanessian, Shunichi Hashimoto, Masahiko Hayashi, Tamejiro Hiyama, Peter Hofmann, Zhaomin Hou, Tsuneo Imamoto, Kunisuke Izawa, Eric Jacobsen, Tsutomu Katsuki, Sunggak Kim, Shu Kobayashi, Koichi Komatsu, Hidenori Kumobayashi, E. Peter Kuendig, Eun Lee, Walter Leitner, Steven V. Ley, Bruce Lipshutz, Lu Yixin, Keiji Maruoka, Shun-Ichi Murahashi, Shinji Murai, K. C. Nicolaou, Hisao Nishiyama, Takeshi Ohkuma, Tetsuo Ohta, Koichiro Oshima, Junzo Otera, Andreas Pfaltz, Manfred T. Reetz, Alfredo Ricci, Mitsuo Sawamoto, Michelangelo Scalone, K. Barry Sharpless, Roger Sheldon, Victor Snieckus, Mikiko Sodeoka, Makoto Tokunaga, Kiyoshi Tomioka, Yoshio Umezawa, Yasuhiro Uozumi, Chi-Huey Wong, Henry N. C. Wong, Yoshinori Yamamoto, Daoben Zhu, A tribute to Professor Ryoji Noyori on the occasion of his 70(th) birthday, ADVANCED SYNTHESIS & CATALYSIS, 350, 13, 1925-1941, 2008.09. |
| 6. |
Aki Nakamura, Makoto Tokunaga, Au(I) complexes-catalyzed transfer vinylation of alcohols and carboxylic acids, TETRAHEDRON LETTERS, 10.1016/j.tetlet.2008.04.037, 49, 23, 3729-3732, 2008.06, Au(I) complexes-catalyzed transfer vinylation of alcohols and carboxylic acids has been achieved. The catalyst system consists of 2 mol % AuClPPh(3) and 2 mol % AgOAc. Primary alcohols and secondary alcohols were converted into corresponding vinyl ethers in good yield (64-93%); however, tertiary alcohols showed poor reactivities. Carboxylic acids were also transformed into corresponding vinyl esters in good yield (78-96%). (C) 2008 Elsevier Ltd. All rights reserved.. |
| 7. |
Naoya Ohmura, Asami Nakamura, Akiyuki Hamasaki, Makoto Tokunaga, Hydrolytic Deallylation of N-Allyl Amides Catalyzed by Pd-II Complexes, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 10.1002/ejoc.200800771, 30, 5042-5045, 2008.10, Hydrolytic deallylation of N-allyl amides to give amides and propanal can be achieved with Pd-II catalysts. The optimized catalyst consists of Pd(OCOCF3)(2) and 1,3-bis(diphenylphosphanyl)propane (DPPP). Several kinds of open-chain N-allyl amides and N-allyl lactams undergo hydrolytic deallylation to give the corresponding amides and lactams in good to high yield. A mechanism which includes isomerization to enamides and subsequent hydrolysis is proposed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008). |
| 8. |
Takeshi Sakuma, Eiji Yamamoto, Hiroshi Aoyama, Yasushi Obora, Yasushi Tsuji, Makoto Tokunaga, Kinetic resolution of phosphoryl and sulfonyl esters of 1,1 '-bi-2-naphthol via Pd-catalyzed alcoholysis of their vinyl ethers, TETRAHEDRON-ASYMMETRY, 10.1016/j.tetasy.2008.06.034, 19, 13, 1593-1599, 2008.07, Kinetic resolution of phosphoryl and sulfonyl esters of 1,1'-bi-2-naphthol has been achieved via the Pd-catalyzed alcoholysis of their vinyl ethers. The highest k(rel) value reached 36.8 with substrate 3c. and (R)-3c 99.0% ee was obtained in 43% isolated yield. (C) 2008 Elsevier Ltd. All rights reserved.. |
| 9. |
Makoto Tokunaga, Saki Harada, Tetsuo Iwasawa, Yasushi Obora, Yasushi Tsuji, Palladium-catalyzed oxidation of cyclohexanones to conjugated enones using molecular oxygen, TETRAHEDRON LETTERS, 10.1016/j.tetlet.2007.07.181, 48, 39, 6860-6862, 2007.09, Oxidation of cyclohexanones into conjugated enones with molecular oxygen as oxidant was achieved by palladium catalysts. A catalyst system consists of I mol % Pd(OCOCF3)(2) and 5,5'-dimethyl-2,2'-bipyridine accomplished maximum 84% yield for the oxidation of cyclohexanone and 51-78% yields for 4-SLibstituted-cyclohexanones. (C) 2007 Elsevier Ltd. All rights reserved.. |
| 10. |
Yuji Ohashi, Makoto Tokunaga, Naoki Taketomo, Kazunari Ushida, Stimulation of indigenous lactobacilli by fermented milk prepared with Probiotic bacterium, Lactobacillus delbrueckii subsp bulgaricus strain 2038, in the pigs, JOURNAL OF NUTRITIONAL SCIENCE AND VITAMINOLOGY, 10.3177/jnsv.53.82, 53, 1, 82-86, 2007.02, The aim of this study was to evaluate the effect of feeding yoghurt, prepared with Lactobacillus delbrueckii subsp. bulgaricus strain 2038, on indigenous lactobacilli in the pig cecum. Three female pigs fistulated at the cecum were,fed 2 50 g of this yoghurt that contained over 10(11) colony-forming units of L. delbrueckii subsp. bulgaricus strain 2038 with their daily meal for 2 wk. The relative abundance and the composition of cecal lactobacilli was monitored by analysis of bacterial 16S rDNA with real time PCR and amplified bacterial rDNA restriction analysis using Lactobacillus-group specific primers, respectively, for 2 wk prior to, at the end of 2 wk of and 2 wk after the administration of this yoghurt. The relative abundance of lactobacilli was significantly increased by feeding yoghurt (p |
| 11. |
Toshiaki Murai, Shinsuke Inaji, Ken Morishita, Fumitoshi Shibahara, Makoto Tokunaga, Yasushi Obora, Yasushi Tsuji, Synthesis of 1,1 '-binaphthyl-2,2 '-diyl phosphoroselenoic amides and their conversion to optically pure phosphoramidites, CHEMISTRY LETTERS, 10.1246/cl.2006.1424, 35, 12, 1424-1425, 2006.12, Optically pure phosphoroselenoyl chloride was reacted with racemic amines to give phosphoroselenoic amides as two diastereomeric mixtures in high yields. The diastereomeric mixtures were separated by fractional recrystallization or by chromatography. Extrusion of the selenium atom from the separated amides led to diastercomerically pure phosphoramidites. The ability of the obtained amidites to act as optically active ligands was tested in the hydrogenation of an imine.. |
| 12. |
Hidetoshi Ohta, Kanako Tobayashi, Akihiro Kuroo, Mao Nakatsuka, Hirokazu Kobayashi, Atsushi Fukuoka, Go Hamasaka, Yasuhiro Uozumi, Haruno Murayama, Makoto Tokunaga, Minoru Hayashi, Surface Modification of a Supported Pt Catalyst Using Ionic Liquids for Selective Hydrodeoxygenation of Phenols into Arenes under Mild Conditions, Chemistry - A European Journal, 10.1002/chem.201902668, 25, 65, 14762-14766, 2019.11, The selective and efficient removal of oxygenated groups from lignin-derived phenols is a critical challenge to utilize lignin as a source for renewable aromatic chemicals. This report describes how surface modification of a zeolite-supported Pt catalyst using ionic liquids (ILs) remarkably increases selectivity for the hydrodeoxygenation (HDO) of phenols into arenes under mild reaction conditions using atmospheric pressure H2. Unmodified Pt/H-ZSM-5 converts phenols into aliphatic species as the major products along with a slight amount of arenes (10 % selectivity). In contrast, the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate, keeps up to 76 % selectivity for arenes even at a nearly complete conversion of phenols. The IL on the surface of Pt catalyst may offer the adsorption of phenols in an edge-to-face manner onto the surface, thus accelerating the HDO without the ring hydrogenation.. |
| 13. |
Zhenzhong Zhang, Tetsuya Mamba, Qi An Huang, Haruno Murayama, Eiji Yamamoto, Tetsuo Honma, Makoto Tokunaga, The additive effect of amines on the dihydroxylation of buta-1,3-diene into butenediols by supported Pd catalysts, Molecular Catalysis, 10.1016/j.mcat.2019.110502, 475, 2019.10, The additive effect of amines on the supported PdO catalyzed-dihydroxylation of buta-1,3-diene is first examined. The significant enhancement of the synthetic efficiency for the diol products is achieved by the addition of less hindered strong bases, such as morpholines and N-methylimidazole. Notably, we found that the amine additive is indispensable to keep the catalytic activity during the recycling test, which is never mentioned in previous reports. Furthermore, both the fresh and spent catalysts are characterized by attenuated total reflection infrared (ATR-IR) observation and X-ray absorption fine structure (XAFS) measurements.. |
| 14. |
Zhenzhong Zhang, Tetsuya Mamba, Eiji Yamamoto, Haruno Murayama, Tamao Ishida, Tetsuo Honma, Tadahiro Fujitani, Makoto Tokunaga, Direct transformation of terminal alkenes with H2O into primary alcohols over metal oxide-supported Pd catalysts, Applied Catalysis B: Environmental, 10.1016/j.apcatb.2019.01.031, 246, 100-110, 2019.06, The anti-Markovnikov addition of H2O to alkenes to directly bring in primary alcohols has been considered one of the “10 challenges in catalysis” in the 1990s, but the challenging issue has still remained unsolved over the past few decades, particularly in terms of developing an atom-efficient synthetic strategy. In this context, we introduce a novel access for the transformation of terminal alkenes with H2O into the corresponding primary alcohols over metal oxide-supported Pd catalysts, employing O2 as the sole oxidant. Direct and efficient synthesis of cinnamyl alcohol from allylbenzene and H2O was initially achieved as a fine chemical example over Pd(NO3)2/CeO2-ZrO2, and the target saturated alcohol (3-phenylpropan-1-ol) was obtained as the anti-Markovnikov selective product from a “one-pot” process using H2 as the reductant. The Pd(NO3)2/CeO2-ZrO2 was characterized by HAADF-STEM, XRD and X-ray absorption fine structure (XAFS) analyses, indicating that the molecular Pd(NO3)2 is probably deposited as it is on the support, which likely plays an important role to promote this reaction. In the second part, Pd(NO3)2/CeO2-ZrO2 and other supported Pd catalysts were applied for the transformation of 1,3-butadiene into 2-butene-1,4-diol in a batch reactor. Besides, butane-1,4-diol, which is an important industrial material, was efficiently produced by the simple hydrogenation of 2-butene-1,4-diol in a “one-pot” manner. Significantly, the development of the reaction catalyzed by supported Pd in a gas flow reactor bestows great potential to further industrial applications. Additionally, the adsorption structure of 1,3-butadiene on Pd(111) was confirmed as the s-trans form by infrared reflection absorption spectroscopy (IRAS) measurements. The change in the electronic states of surface Pd atoms upon oxygen adsorption was observed by X-ray photoelectron spectroscopy (XPS).. |
| 15. |
Eiji Yamamoto, Kodai Wakafuji, Yusuke Mori, Gaku Teshima, Yuki Hidani, Makoto Tokunaga, Enantioselective Protonation of Enol Esters with Bifunctional Phosphonium/Thiourea Catalysts, Organic letters, 10.1021/acs.orglett.9b01216, 21, 11, 4030-4034, 2019.06, Bifunctional phosphonium/thioureas derived from tert-leucine behaved as highly selective catalysts for enantioselective protonation of enol esters, providing α-chiral ketones in yields of up to 99% with high enantioselectivities (up to 98.5:1.5 er). Control experiments clarified that a bulky tert-butyl group and phosphonium and thiourea moieties were necessary to achieve such high stereoselectivity. In addition, mechanistic investigations indicated the catalyst was converted to the corresponding betaine species, which served as a monomolecular catalyst.. |
| 16. |
Tamao Ishida, Tetsuo Honma, Kengo Nakada, Haruno Murayama, Tetsuya Mamba, Kurumi Kume, Yusuke Izawa, Masaru Utsunomiya, Makoto Tokunaga, Pd-catalyzed decarbonylation of furfural
Elucidation of support effect on Pd size and catalytic activity using in-situ XAFS, Journal of Catalysis, 10.1016/j.jcat.2019.04.041, 374, 320-327, 2019.06, Palladium (Pd) clusters on zirconia (ZrO2) and single Pd atoms on ceria (CeO2) exhibited high catalytic activity and selectivity for decarbonylation of furfural to furan without additives in the liquid phase. To study the active size of Pd and changes in chemical states or structures during the reaction, in-situ X-ray absorption fine structure (XAFS) measurements were conducted. The size of Pd clusters consisting of less than 10 Pd atoms was maintained on ZrO2 during the reaction. In contrast, single Pd atoms were aggregated during heating and only Pd clusters consisting of 13 atoms were present after the reaction. According to the in-situ XAFS results, the size of Pd particles did not gradually increase to Pd13 clusters. Instead, Pd13 clusters were partly formed from the beginning of the reaction, and the proportion of Pd13 clusters increased with time while keeping the size of Pd13 clusters. This result suggests that a single Pd atom is inactive, but Pd clusters are active for decarbonylation. Ab-initio calculation revealed that ZrO2 (1 1 1) surface had lower adsorption and migration energies than CeO2 (1 1 1), implying that Pd was easily diffused on the surface and stabilized as small Pd clusters.. |
| 17. |
Zhihao Fang, Haruno Murayama, Qi Zhao, Bing Liu, Feng Jiang, Yuebing Xu, Makoto Tokunaga, Xiaohao Liu, Selective mild oxidation of methane to methanol or formic acid on Fe-MOR catalysts, Catalysis Science and Technology, 10.1039/c9cy01640f, 9, 24, 6946-6956, 2019.01, Controllable methane oxidation directly into value-added products under mild conditions remains a challenge. Herein, an active Fe/MOR catalyst was synthesized via simple solid-state ion exchange, and its activity in the selective oxidation of methane with H2O2 in the aqueous phase was intensively investigated. The octahedral dimeric Fe3+ species [Fe2(μ-O)2] in the extra framework was confirmed as the initial active site by X-ray photoelectron spectroscopy, X-ray absorption near-edge structure and extended X-ray absorption fine structure, UV-vis diffuse-reflectance spectroscopy, and high-angle annular dark-field scanning transmission electron microscopy in combination with DFT calculations. The DFT calculations indicated that methanol formation via methyl peroxide (CH3OOH∗) on [Fe2(μ-OH)2O2] is the most favorable pathway compared to the direct formation of methanol via CH3O∗. The formed CH3OH is easily further oxidized by hydroxyl radicals (OH) resulting in non-selective methane oxidation. In contrast, the Fe/MOR catalyst could lead to a high methanol selectivity of 71.3% in the presence of homogeneous Cu2+ precursor, which efficiently suppressed the over-oxidation of methanol, and a high formic acid selectivity up to 81-82% at a slightly higher reaction temperature by mildly shifting the oxidation of methanol and formaldehyde to the target product.. |
| 18. |
Makoto Tokunaga, Selective mild oxidation of methane to methanol or formic acid on Fe-MOR catalysts, Catalysis Science and Technology, 9, 10.1039/C9CY01640F, 2019. |
| 19. |
Hidetoshi Ohta, Kanako Tobayashi, Akihiro Kuroo, Mao Nakatsuka, Hirokazu Kobayashi, Atsushi Fukuoka, Go Hamasaka, Yasuhiro Uozumi, Haruno Murayama, Makoto Tokunaga, Minoru Hayashi, Surface Modification of a Supported Pt Catalyst Using Ionic Liquids for Selective Hydrodeoxygenation of Phenols into Arenes under Mild Conditions, Chemistry - A European Journal, 10.1002/chem.201902668, 25, 65, 14762-14766, 2019.11, The selective and efficient removal of oxygenated groups from lignin-derived phenols is a critical challenge to utilize lignin as a source for renewable aromatic chemicals. This report describes how surface modification of a zeolite-supported Pt catalyst using ionic liquids (ILs) remarkably increases selectivity for the hydrodeoxygenation (HDO) of phenols into arenes under mild reaction conditions using atmospheric pressure H2. Unmodified Pt/H-ZSM-5 converts phenols into aliphatic species as the major products along with a slight amount of arenes (10 % selectivity). In contrast, the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate, keeps up to 76 % selectivity for arenes even at a nearly complete conversion of phenols. The IL on the surface of Pt catalyst may offer the adsorption of phenols in an edge-to-face manner onto the surface, thus accelerating the HDO without the ring hydrogenation.. |
| 20. |
Zhenzhong Zhang, Tetsuya Mamba, Qi An Huang, Haruno Murayama, Eiji Yamamoto, Tetsuo Honma, Makoto Tokunaga, The additive effect of amines on the dihydroxylation of buta-1,3-diene into butenediols by supported Pd catalysts, Molecular Catalysis, 10.1016/j.mcat.2019.110502, 475, 2019.10, The additive effect of amines on the supported PdO catalyzed-dihydroxylation of buta-1,3-diene is first examined. The significant enhancement of the synthetic efficiency for the diol products is achieved by the addition of less hindered strong bases, such as morpholines and N-methylimidazole. Notably, we found that the amine additive is indispensable to keep the catalytic activity during the recycling test, which is never mentioned in previous reports. Furthermore, both the fresh and spent catalysts are characterized by attenuated total reflection infrared (ATR-IR) observation and X-ray absorption fine structure (XAFS) measurements.. |
| 21. |
Zhenzhong Zhang, Tetsuya Mamba, Eiji Yamamoto, Haruno Murayama, Tamao Ishida, Tetsuo Honma, Tadahiro Fujitani, Makoto Tokunaga, Direct transformation of terminal alkenes with H2O into primary alcohols over metal oxide-supported Pd catalysts, Applied Catalysis B: Environmental, 10.1016/j.apcatb.2019.01.031, 246, 100-110, 2019.06, The anti-Markovnikov addition of H2O to alkenes to directly bring in primary alcohols has been considered one of the “10 challenges in catalysis” in the 1990s, but the challenging issue has still remained unsolved over the past few decades, particularly in terms of developing an atom-efficient synthetic strategy. In this context, we introduce a novel access for the transformation of terminal alkenes with H2O into the corresponding primary alcohols over metal oxide-supported Pd catalysts, employing O2 as the sole oxidant. Direct and efficient synthesis of cinnamyl alcohol from allylbenzene and H2O was initially achieved as a fine chemical example over Pd(NO3)2/CeO2-ZrO2, and the target saturated alcohol (3-phenylpropan-1-ol) was obtained as the anti-Markovnikov selective product from a “one-pot” process using H2 as the reductant. The Pd(NO3)2/CeO2-ZrO2 was characterized by HAADF-STEM, XRD and X-ray absorption fine structure (XAFS) analyses, indicating that the molecular Pd(NO3)2 is probably deposited as it is on the support, which likely plays an important role to promote this reaction. In the second part, Pd(NO3)2/CeO2-ZrO2 and other supported Pd catalysts were applied for the transformation of 1,3-butadiene into 2-butene-1,4-diol in a batch reactor. Besides, butane-1,4-diol, which is an important industrial material, was efficiently produced by the simple hydrogenation of 2-butene-1,4-diol in a “one-pot” manner. Significantly, the development of the reaction catalyzed by supported Pd in a gas flow reactor bestows great potential to further industrial applications. Additionally, the adsorption structure of 1,3-butadiene on Pd(111) was confirmed as the s-trans form by infrared reflection absorption spectroscopy (IRAS) measurements. The change in the electronic states of surface Pd atoms upon oxygen adsorption was observed by X-ray photoelectron spectroscopy (XPS).. |
| 22. |
Eiji Yamamoto, Kodai Wakafuji, Yusuke Mori, Gaku Teshima, Yuki Hidani, Makoto Tokunaga, Enantioselective Protonation of Enol Esters with Bifunctional Phosphonium/Thiourea Catalysts, Organic letters, 10.1021/acs.orglett.9b01216, 21, 11, 4030-4034, 2019.06, Bifunctional phosphonium/thioureas derived from tert-leucine behaved as highly selective catalysts for enantioselective protonation of enol esters, providing α-chiral ketones in yields of up to 99% with high enantioselectivities (up to 98.5:1.5 er). Control experiments clarified that a bulky tert-butyl group and phosphonium and thiourea moieties were necessary to achieve such high stereoselectivity. In addition, mechanistic investigations indicated the catalyst was converted to the corresponding betaine species, which served as a monomolecular catalyst.. |
| 23. |
Tamao Ishida, Tetsuo Honma, Kengo Nakada, Haruno Murayama, Tetsuya Mamba, Kurumi Kume, Yusuke Izawa, Masaru Utsunomiya, Makoto Tokunaga, Pd-catalyzed decarbonylation of furfural
Elucidation of support effect on Pd size and catalytic activity using in-situ XAFS, Journal of Catalysis, 10.1016/j.jcat.2019.04.041, 374, 320-327, 2019.06, Palladium (Pd) clusters on zirconia (ZrO2) and single Pd atoms on ceria (CeO2) exhibited high catalytic activity and selectivity for decarbonylation of furfural to furan without additives in the liquid phase. To study the active size of Pd and changes in chemical states or structures during the reaction, in-situ X-ray absorption fine structure (XAFS) measurements were conducted. The size of Pd clusters consisting of less than 10 Pd atoms was maintained on ZrO2 during the reaction. In contrast, single Pd atoms were aggregated during heating and only Pd clusters consisting of 13 atoms were present after the reaction. According to the in-situ XAFS results, the size of Pd particles did not gradually increase to Pd13 clusters. Instead, Pd13 clusters were partly formed from the beginning of the reaction, and the proportion of Pd13 clusters increased with time while keeping the size of Pd13 clusters. This result suggests that a single Pd atom is inactive, but Pd clusters are active for decarbonylation. Ab-initio calculation revealed that ZrO2 (1 1 1) surface had lower adsorption and migration energies than CeO2 (1 1 1), implying that Pd was easily diffused on the surface and stabilized as small Pd clusters.. |
| 24. |
Zhihao Fang, Haruno Murayama, Qi Zhao, Bing Liu, Feng Jiang, Yuebing Xu, Makoto Tokunaga, Xiaohao Liu, Selective mild oxidation of methane to methanol or formic acid on Fe-MOR catalysts, Catalysis Science and Technology, 10.1039/c9cy01640f, 9, 24, 6946-6956, 2019.01, Controllable methane oxidation directly into value-added products under mild conditions remains a challenge. Herein, an active Fe/MOR catalyst was synthesized via simple solid-state ion exchange, and its activity in the selective oxidation of methane with H2O2 in the aqueous phase was intensively investigated. The octahedral dimeric Fe3+ species [Fe2(μ-O)2] in the extra framework was confirmed as the initial active site by X-ray photoelectron spectroscopy, X-ray absorption near-edge structure and extended X-ray absorption fine structure, UV-vis diffuse-reflectance spectroscopy, and high-angle annular dark-field scanning transmission electron microscopy in combination with DFT calculations. The DFT calculations indicated that methanol formation via methyl peroxide (CH3OOH∗) on [Fe2(μ-OH)2O2] is the most favorable pathway compared to the direct formation of methanol via CH3O∗. The formed CH3OH is easily further oxidized by hydroxyl radicals (OH) resulting in non-selective methane oxidation. In contrast, the Fe/MOR catalyst could lead to a high methanol selectivity of 71.3% in the presence of homogeneous Cu2+ precursor, which efficiently suppressed the over-oxidation of methanol, and a high formic acid selectivity up to 81-82% at a slightly higher reaction temperature by mildly shifting the oxidation of methanol and formaldehyde to the target product.. |
| 25. |
Makoto Tokunaga, Selective mild oxidation of methane to methanol or formic acid on Fe-MOR catalysts, Catalysis Science and Technology, 9, 10.1039/C9CY01640F, 2019. |
| 26. |
Haruno Murayama, Yusuke Yamamoto, Misaki Tone, Takayuki Hasegawa, Moemi Kimura, Tamao Ishida, Atsuko Isogai, Tsutomu Fujii, Mitsutaka Okumura, Makoto Tokunaga, Selective adsorption of 1,3-dimethyltrisulfane (DMTS) responsible for aged odour in Japanese sake using supported gold nanoparticles, Scientific reports, 10.1038/s41598-018-34217-w, 8, 1, 2018.12, Gold (Au) nanoparticles (NPs) supported on SiO2 (Au/SiO2) were prepared by a practical impregnation method and applied as an adsorbent for 1,3-dimethyltrisulfane (DMTS), which is responsible for an unpleasant odour in drinks, especially Japanese sake. Compared with a conventional adsorbent, activated carbon, Au/SiO2 selectively reduced the DMTS concentration in Japanese sake without decreasing the concentrations of other aromatic components. DFT calculations revealed that the selective adsorption of DMTS occurred through the formation of a stable intermediate. The size of the supported Au NPs was controlled by the preparation conditions and determined from TEM observations and XRD measurements, and the size was ranged from 2.4 nm to 30 nm. Au/SiO2 having Au NPs with a diameter of 2.4 nm adsorbed DMTS the most efficiently. Smaller Au NPs showed better DMTS adsorption capabilities because larger amounts of Au atoms were exposed on their surfaces in the size range of this study. Langmuir-type monolayer adsorption and one-to-one binding of Au–S are proposed to occur based on an adsorption isotherm experiment. Even though significant differences of the fruity aroma score were not observed in the sensory evaluation between Au/SiO2 and activated carbon for this less aromatic Japanese sake, Au/SiO2 selectively decreased the DMTS concentration in the instrumental analysis.. |
| 27. |
Isao Nakamura, Haruno Murayama, Makoto Tokunaga, Mitsutaka Okumura, Tadahiro Fujitani, Adsorption and thermal reactivity of dimethyl trisulfide on a Au(111) single-crystal surface, Surface Science, 10.1016/j.susc.2018.07.012, 677, 186-192, 2018.11, We investigated the adsorption and thermal reactivity of dimethyl trisulfide (DMTS, CH3SSSCH3) on a Au(111) single-crystal surface. X-ray photoelectron spectroscopy results indicated that at exposure temperatures of 100–300 K, DMTS dissociatively adsorbed as CH3S and CH3SS. That the dissociative adsorption rate was independent of exposure temperature suggested that DMTS dissociation on Au proceeded without an energy barrier at >100 K. In contrast, the thermal reactions of the adsorbed CH3S and CH3SS varied strongly with formation temperature. Specifically, after CH3S and CH3SS formed on Au(111) at 100 K, increasing the temperature resulted in associative desorption of CH3S as dimethyl disulfide (CH3SSCH3) and coupling reaction of CH3SS to ethane and atomic sulfur. In contrast, after CH3S and CH3SS formed at 150 K, increasing the temperature resulted not only in these two reactions but also in production of dimethyl disulfide and atomic sulfur by reaction between CH3S and CH3SS. At formation temperatures of 200 and 300 K, the only reaction observed was that between CH3S and CH3SS. These results suggest that the surface structure of the adsorbed species formed by DMTS dissociation on Au(111) depended on formation temperature. Specifically, at 100 K, dissociation of DMTS resulted in formation of CH3S and CH3SS islands on the Au(111) surface, whereas the two species were randomly adsorbed at higher formation temperatures.. |
| 28. |
Eiji Yamamoto, Kodai Wakafuji, Yuho Furutachi, Kaoru Kobayashi, Takashi Kamachi, Makoto Tokunaga, Dynamic Kinetic Resolution of N-Protected Amino Acid Esters via Phase-Transfer Catalytic Base Hydrolysis, ACS Catalysis, 10.1021/acscatal.8b00693, 8, 7, 5708-5713, 2018.07, Asymmetric base hydrolysis of α-chiral esters with synthetic small-molecule catalysts is described. Quaternary ammonium salts derived from quinine were used as chiral phase-transfer catalysts to promote the base hydrolysis of N-protected amino acid hexafluoroisopropyl esters in a CHCl3/NaOH (aq) via dynamic kinetic resolution, providing the corresponding products in moderate to good yields (up to 99%) with up to 96:4 er. Experimental and computational mechanistic studies using DFT calculation and pseudotransition state (pseudo-TS) conformational search afforded a TS model accounting for the origin of the stereoselectivity. The model suggested π-stacking and H-bonding interactions play essential roles in stabilizing the TS structures.. |
| 29. |
Makoto Tokunaga, A. Hamasaki, 5.18 Addition Reaction
Kinetic Resolution, Comprehensive Chirality, 10.1016/B978-0-08-095167-6.00520-6, 5, 421-435, 2012.09. |
| 30. |
Masato Kitamura, Makoto Tokunaga, Trang Pham, William D. Lubell, Ryoji Noyori, Asymmetric synthesis of α-amino β-hydroxy phosphonic acids via BINAP-ruthenium catalyzed hydrogenation, Tetrahedron Letters, 10.1016/00404-0399(50)11355-, 36, 32, 5769-5772, 1995.08, BINAP-Ru catalyzed hydrogenation of configurationally labile α-amido β-keto phosphonic esters gives the (R,R)- or (S,S)-α-amido β-hydroxy phosphonic esters in a highly enantio- and diastereoselective manner.. |
| 31. |
Yamamoto, E.;Gokuden, D.; Nagai, A. Kamachi, T.; Yoshizawa, K.; Hamasaki, A.; Ishida, T.;Tokunaga, M. , Hydrolytic Enantioselective Protonation of Cyclic Dienyl Esters and a -diketone with Chiral Phase-transfer Catalysts , Org. Lett., 14, 61787-6181, 2012.12. |
| 32. |
Hamasaki, A.; Maruta, S.; Nakamura, A.; Tokunaga, M. , Palladium-catalyzed 1,4-Addition of Carboxylic Acids to Butadiene Monoxide , Adv. Synth. Catal., 354, 11-12, 2129-2134, 2012.08. |
| 33. |
Ishida, T.; Watanabe, H.; Takei, T.; Hamasaki, A.; Tokunaga, M.; Haruta, M. , Metal Oxide-Catalyzed Ammoxidation of Alcohols to Nitriles and Promotion
Effect of Gold Nanoparticles for One-Pot Amide Synthesis , Appl. Catal. A Gen., 2012, , 425-426, 85-90, 2012.04. |
| 34. |
Hamasaki, A.; Kuwada, H.; Tokunaga, M. , tert-Butylnitrite as a convenient and easy-removable oxidant for the
conversion of benzylic alcohols to ketones and aldehydes
, Tetrahedron Lett., 53, 811-814, 2012.03. |
| 35. |
Hamasaki, A.; Muto, A.; Haraguchi, S.; Liu, X.; Sakakibara, T.;
Yokoyama, T.; Tokunaga, M.
, Cobalt oxide supported gold nanoparticles as a stable and
readily-prepared precursor for the in situ generation of cobalt carbonyl
like species , Tetrahedron Lett. , 52, 6869-6872, 2011.03. |
| 36. |
Yamamoto, E.; Nagai, A. Hamasaki, A.; Tokunaga, M., Catalytic Asymmetric Hydrolysis: Asymmetric Hydrolytic Protonation of Enolesters Catalyzed by Phase Transfer Catalysts, Chem. Eur. J., 2011.05. |
| 37. |
Liu, X.; Hamasaki, A.; Honma, T.; Tokunaga, M., Anti-ASF distribution in Fischer-Tropsch Synthesis over Unsupported Cobalt Catalysts in a Batch Slurry Phase Reactor, Catal. Today,, 2011.05. |
| 38. |
Nakamura, A.; Hamasaki, A.; Goto, S.; Utsunomiya, M.; Tokunaga, M., Irreversible Catalytic Ester Hydrolysis of Allyl Esters to Give Acids and Aldehydes by Homogeneous Ruthenium and Ruthenium/Palladium Dual Catalyst Systems, Adv. Synth. Catal., 353, 973-984, 2011.02. |
| 39. |
Liu, X., Tokunaga, M., Controllable Fischer-Tropsch Synthesis by in situ Produced 1-Olefins, ChemCatChem, 2, 1569-1572, 2010.11. |
| 40. |
Hamasaki, A.; Yamamoto, A.; Ito, H, Tokunaga, M., Highly Atom Efficient Catalytic Reactions Utilizing Water and
Alcohols as Reagents, J. Organomet. Chem, 696, 202-210., 2010.10. |
| 41. |
ang, L.; Kinoshita, S.; Yamada, T.; Kanda, S.; Kitagawa, H.; Tokunaga,
M.; Ishimoto , T.; Ogura, T.; Nagumo, R.; Miyamoto, A.; Koyama, M., A Metal-Organic Framework as An Electrocatalyst for Ethanol Oxidation, Angew. Chem. Int Ed., 49, 5348-5351, 2010.07. |
| 42. |
Sakuma, T.; Yamamoto, E.; Aoyama, H.; Obora, Y.; Tsuji, Y.; Tokunaga, M., Kinetic resolution of phosphoryl and sulfonyl esters of 1,10-bi-2-naphthol via Pd-catalyzed alcoholysis of their vinyl ethers., Tetrahedron: Asymmetry, 2008,19,1593-1599.
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| 43. |
Hirai, T.; Hamasaki, A.; Nakamura, A.; Tokunaga, M., Enhancement of Reaction Efficiency by Functionalyzed Alcohols on Gold(I)
Catalyzed Intermolecular Hydroalkoxylation of Unactivated Olefins, Org. Lett., 2009.11. |
| 44. |
Yamane, Y.; Liu, X.; Hamasaki, A.; Ishida, T.; Haruta, M.; Yokoyama, T.;
Tokunaga, M., One-Pot Synthesis of Indoles and Aniline Derivatives from
Nitroarenes under Hydrogenation Condition with Supported Gold Nanoparticles, Org. Lett., 2009, 11, 5162-5165, 2009.11. |
| 45. |
Liu, X.; Hu, B.; Fujimoto, K.; Haruta, M.; Tokunaga, M., Hydroformylation of Olefins by Au/Co3O4 Catalysts., Appl. Catal. B, 2009, 92, 411-421., 2009.10. |
| 46. |
Fujihara, T.; Kubouchi, S.; Obora, Y.; Tokunaga, M.; Takenaka, K.; Tsuji, Y., ynthesis and Structural Characterization of a Series of
Mono-O-(diphenylphosphinobenzyl)calix[6]arenes with and without
tert-Butyl Moieties at the Upper Rim., Bull. Chem. Soc. Jpn., 2009, 82, 1187-1193., 2009.09. |
| 47. |
Itoh, H.; Yamamoto, E.; Masaoka, S.; Sakai, K.; Tokunaga, M., Kinetic Resolution of P-Chirogenic Compounds by Pd-catalyzed Alcoholysis
of Vinyl Ethers, Adv. Synth. Cat.,, 351, 1796-1800., 2009.08. |
| 48. |
Hamasaki, A.; Liu, X.; Tokunaga, M., Amidocarbonylation of Aldehydes Utilizing Cobalt Oxide Supported-Gold Nanoparticles as a Heterogeneous Catalyst., Chem. Lett,, 37, 1292-1293., 2008.12. |
| 49. |
Liu, X.; Haruta, M.; Tokunaga, M., Coprecipitated Gold-Tricobalt Tetraoxide Catalyst for Heterogeneous Hydroformylation of Olefins., Chem. Lett,, 37, 1290-1291., 2008.12. |
| 50. |
Ohmura, N.; Nakamura, A.; Hamasaki, A.; Tokunaga, M., Hydrolytic deallylation from N-allyl amides catalyzed by Pd(II) complexes., Eur. J. Org. Chem., 5042-5045, 2008.10. |
| 51. |
Tokunaga, M.; Harada, S.; Iwasawa, T.; Obora, Y.; Tsuji, Y.
, Palladium-catalyzed oxidation ofcyclohexanone to conjugated onones using molecular oxygen., Tetrahedron Lett., 2007, 48, 6860-6862, 2007.08. |
| 52. |
Nakamura A.; Tokunaga, M., Au(I) complexes-catalyzed transfer vinylation of alcohols and carboxylic
acids., Tetrahedron Lett., 2008, 49, 3729-3732, 2008.06. |
| 53. |
Fujihara, T.; Obora, Y.; Tokunaga, M.; Tsuji, Y., Rhodium(III) complexes with a bidentate N-heterocyclic carbene ligand bearing flexible dendritic frameworks, Dalton Trans., 1567-1569, 2007.04. |
| 54. |
Kitamura, M.; Ohkuma, T.; Tokunaga, M.; Noyori, R., Dynamic Kinetic Resolution in BINAP-Ruthenium(II) Catalyzed Hydrogenation of 2-Substituted 3-Oxo Carboxylic Esters., Tetrahedron: Asymmetry, 1990, 1, 1-4., 1990.01. |
| 55. |
Kitamura, M.; Tokunaga, M.; Ohkuma, T.; Noyori, R., Convenient Preparation of BINAP-Ruthenium(II) Complexes Catalyzing Asymmetric Hydrogenation of Functionalized Ketones., Tetrahedron Lett., 1991, 32, 4163-4166., 1991.01. |
| 56. |
Kitamura, M.; Tokunaga, M.; Ohkuma, T.; Noyori, R., Asymmetric Hydrogenation of 3-Oxo Carboxylates Using BINAP-Ruthenium Complexes: (R)-Methyl 3-Hydroxybutanoate., Org. Syntheses, 1992, 71, 1-13. (Published in Collective Volume 9 p. 589), 1992.01. |
| 57. |
Kitamura, M.; Tokunaga, M.; Noyori, R., Practical Synthesis of BINAP-Ruthenium(II) Dicarboxylate Complexes., J. Org. Chem., 1992, 57, 4053-4054., 1992.01. |
| 58. |
Takaya, H.; Ohta, T.; Inoue, S.; Tokunaga, M.; Kitamura, M.; Noyori, R., Asymmetric Hydrogenation of Allylic Alcohols Using BINAP-Ruthenium Complexes: (S)-Citronellol., Org. Syntheses, 1993, 72, 74-85. (Published in Collective Volume 9 p. 169), 1993.01. |
| 59. |
Kitamura, M.; Tokunaga, M.; Noyori, R., Quantitative Expression of Dynamic Kinetic Resolution of Chirally Labile Enantiomers: Stereoselective Hydrogenation of 2-Substituted 3-Oxo Carboxylic Esters Catalyzed by BINAP-Ruthenium(II) Complexes., J. Am. Chem. Soc., 1993, 115, 144-152.. |
| 60. |
Kitamura, M.; Tokunaga, M.; Noyori, R., Mathematical Treatment of Kinetic Resolution of Chirally Labile Substrates., Tetrahedron, 1993, 49, 1853-1866., 1993.01. |
| 61. |
Faller, J. W.; Tokunaga, M., Chiral Poisoning in the Kinetic Resolution of Allylic Alcohols., Tetrahedron Lett., 1993, 34, 7359-7362., 1993.01. |
| 62. |
Faller, J. W.; Mazzieri, M. R.; Nguyen, J. T.; Parr , J.; Tokunaga, M., Controlling Stereochemistry in C-C and C-H Bond Formation with Electronically Asymmetric Organometallics and Chiral Poisons., Pure Appl. Chem., 1994, 66, 1463-1469., 1994.01. |
| 63. |
Noyori, R.; Tokunaga, M.; Kitamura, M., Stereoselective Organic Synthesis via Dynamic Kinetic Resolution., Bull. Chem. Soc. Jpn., 1995, 68, 36-55., 1995.01. |
| 64. |
Kitamura, M.; Tokunaga, M.; Pham, T.; Lubell, W. D.; Noyori, R., Asymmetric Synthesis of -Amino -Hydroxy Phosphonic Acids via BINAP-Ruthenium Catalyzed Hydrogenation., Tetrahedron Lett., 1995, 36, 5769-5772., 1995.01. |
| 65. |
Kitamura, M.; Tokunaga, M.; Noyori, R., Asymmetric Hydrogenation of -Keto Phosphonates: A Practical Way to Fosfomycin., J. Am. Chem. Soc., 1995, 117, 2931-2932., 1995.01. |
| 66. |
Jacobsen, E. N.; Kakiuchi, F.; Konsler, R. G.; Larrow, J. F.; Tokunaga, M., Enantioselective Catalytic Ring Opening of Epoxide with Carboxylic Acids., Tetrahedron Lett., 1997, 38, 773-776., 1997.01. |
| 67. |
Tokunaga, M.; Larrow, J. F.; Kakiuchi, F.; Jacobsen, E. N., Asymmetric Catalysis with Water: Efficient Kinetic Resolution of Terminal Epoxides by Means of Catalytic Hydrolysis., Science, 1997, 277, 936-938., 1997.08. |
| 68. |
Tokunaga, M.; Wakatsuki, Y., The First Anti-Markovnikov Hydration of Terminal Alkynes: Formation of Aldehydes Catalyzed by a Ruthenium(II)/Phosphane Mixture., Angew. Chem., Int. Ed., 1998, 37, 2867-2869, 1998.11. |
| 69. |
Tokunaga, M.; Suzuki, T.; Koga, N.; Fukushima, T.; Horiuchi, A.; Wakatsuki, Y., Ruthenium Catalyzed Hydration of 1-Alkynes to Give Aldehydes: The insight into the anti-Markovnikov Regiochemistry., J. Am. Chem. Soc., 2001, 123, 11917-11924, 2001.01. |
| 70. |
Suzuki, T.; Tokunaga, M.; Wakatsuki, Y, Ruthenium Complex-Catalyzed anti-Markovnikov Hydration of Terminal Alkynes., Org. Lett.,, 2001, 3, 735-737., 2001.01. |
| 71. |
Tokunaga, M.; Ota, M.; Haga, M.; Wakatsuki, Y., A Practical One-pot Synthesis of 2,3-Disubstituted Indoles from Unactivated Anilines, Tetrahedron Lett.,, 2001, 42, 3865-3868, 2001.01. |
| 72. |
Obora, Y.; Baleta, A. S.; Tokunaga, M.; Tsuji, Y, Platinum Complex Catalyzed Reaction of Tributyltin Cyanide with alkynes, J. Organomet. Chem., 2002, 660, 173-177, 2002.01. |
| 73. |
Schaus, S. E.; Brandes, B. D.; Larrow, J. F.; Tokunaga, M.; Hansen, K. B.; Gould, A. E.; Furrow, M. E.; Jacobsen,, Highly Selective Hydrolytic Kinetic Resolution of Terminal Epoxides Catalyzed by Chiral (salen)Cobalt(III)-Complexes. Practical Synthesis of Enantioenriched Terminal Epoxides and 1,2-Diols., E. N. J. Am. Chem. Soc, 2002、124、1307-1315, 2002.01. |
| 74. |
Suzuki, T.; Tokunaga, M.; Wakatsuki, Y., Efficient Transformation of Propargylic Alcohols to ,-Unsaturated Aldehydes Catalyzed by Ruthenium/water under Neutral Conditions., Tetrahedron Lett.,, 2002, 42, 7531-7533., 2002.01. |
| 75. |
Obora, Y.; Nakanishi, M.; Tokunaga, M.; Tsuji, Y, Palladium Complex Catalyzed Acylation of Allylic Esters with Acylstannanes: Complementary Method to the Acylation with Acylsilanes, J. Org. Chem, 2002.01. |
| 76. |
Niyomura, O.; Tokunaga, M.; Obora, Y.; Iwasawa, T.; Tsuji, Y, Rate Enhancement with a Bowl-Shaped Phosphane in the Rhodium-Catalyzed Hydrosilylation of Ketones, Angew. Chem., Int. Ed, 2003, 42, 1287-1289
2003, 115, 1325-1327, 2003.01. |
| 77. |
Wakatsuki, Y.; Hou, Z.; Tokunaga, M., New Reactions of 1-Alkynes Catalyzed by Transition Metal Complexes, The Chemical Record, 2003, 3, 144-157, 2003.01. |
| 78. |
Obora, Y.; Moriya, H.; Tokunaga, M.; Tsuji, Y, Cross-coupling Reaction of Thermally Stable Titanium(II)-alkyne Complexes with Aryl Halides Catalysed by a Nickel Complex, ChemComm., 2003.01. |
| 79. |
Iwasawa, T.; Tokunaga, M.; Obora, Y.; Tsuji, Y, Homogeneous Palladium Catalyst Suppressing Pd Black Formation in Air Oxidation of Alcohols, J. Am. Chem. Soc, 2004, 126, 6554-6555, 2004.01. |
| 80. |
Aoyama, H.; Tokunaga, M.; Hiraiwa S.; Shirogane, Y.; Obora, Y.; Tsuji, Y, Hydrolysis of Alkenyl Esters and Ethers Catalyzed by Metal Complexes, Org. Lett, 2004, 6, 509-512, 2004.01. |
| 81. |
Obora, Y.; Kimura, M.; Tokunaga, M.; Tsuji, Y, Low-valent Nb(III)-mediated synthesis of 1,1,2-trisubstituted-1H-indenes from aliphatic ketones and aryl-substituted alkynes, ChemComm, 2005, 901 - 902, 2005.01. |
| 82. |
Obora, Y.; Liu, Y.- K.; Jiang, L.-H.; Takenaka, K.; Tokunaga, M.; Tsuji, Y, Iridium(I) and Rhodium(I) Cationic Complexes with Triphosphinocalix[6]arene Ligands: Dynamic Motion with Size-Selective Molecular Encapsulation, Organometallics, 2005, 24, 4-6, 2005.01. |
| 83. |
Komano, T.; Iwasawa, T.; Tokunaga, M.; Obora, Y.; Tsuji, Y, MALDI TOF Mass Study on Oligomerization of Pd(OAc)2(L)2 (L=Pyridine Derivatives):Relevance to Pd Black Formation in Pd-catalyzed Air Oxidation of Alcohols, Org. Lett, 2005, 7, 4677-4679, 2005.01. |
| 84. |
Fujihara, T.; Obora, Y.; Tokunaga, M.; Sato, H.; Tsuji, Y, Dendrimer N-Heterocyclic Carbene Complexes with Rhodium(I) at the Core, ChemComm., 2005, 4526 - 4528, 2005.01. |
| 85. |
Aoyama, H.; Tokunaga, M.; Kiyosu, J.; Iwasawa, T.; Obora, Y.; Tsuji, Y, Kinetic Resolution of Axially Chiral 2,2’-Dihydroxy-1,1’-biaryls by Palladium Catalyzed Alcoholysis, J. Am. Chem. Soc, 2005, 127, 10474-10475, 2005.01. |
| 86. |
Niyomura, O.; Iwasawa, T.; Sawada, N.; Tokunaga, M.; Obora, Y.; Tsuji, Y, A Bowl-Shaped Phosphine as a Ligand in the Rhodium-Catalyzed Hydrosilylation — Rate Enhancement by a Mono-phosphine Rhodium Species, Organometallics, 2005, 24, 3468-3475, 2005.01. |
| 87. |
Tokunaga, M.; Shirogane, Y.; Aoyama, H.; Obora, Y.; Tsuji, Y, Copper-catalyzed oxidative cleavage of carbon-carbon double bond of enol ethers with molecular oxygen, J. Organomet. Chem, 2005, 690, 5378-5382. (special issue, Organometallic Chemistry - The Next Generation), 2005.01. |
| 88. |
Obora, Y.; Tokunaga, M.; Tsuji, Y, Transition–metal Complexes with Nano–sized Phosphine and Pyridine Ligands–Catalysis, Fluxional Behavior and Molecular Recognition, Catalysis Survey from Asia, 2005, 9, 259-268, 2005.01. |
| 89. |
Obora, Y.; Kimura, M.; Ohtake, T.; Tokunaga, M.; Tsuji, Y, Nickel–Catalyzed Cross–Coupling Reaction of Niobium(III)–Alkyne Complexes with Aryl Iodides, Organometallics, 2006, 25, 2097-2100, 2006.03. |
| 90. |
Tokunaga, M.; Kiyosu, J.; Obora, Y.; Tsuji, Y, Kinetic Resolution Displaying Zeroth Order Dependence on Substrate Consumption: Copper-catalyzed Asymmetric Alcoholysis of Azlactones, J. Am. Chem. Soc, 2006, 128, 4481-4486, 2006.04. |
| 91. |
Obora, Y.; Liu, Y.- K.; Kubouchi, S.; Tokunaga, M.; Tsuji, Y, Monophosphinocalix[6]arene Ligands—Synthesis, Characterization, Complexation, and Their Use in Catalysis, Eur. J. Inorg. Chem, 2006, 222-230, 2006.04. |
| 92. |
Iwasawa, T.; Komano, T.; Tajima, A.; Tokunaga, M.; Obora, Y.; Fujihara, T.; Tsuji Y., Phosphines having a 2,3,4,5-tetraphenylphenyl moiety: effective ligands in palladium-catalyzed transformations of aryl chlorides, Organometallic, 2006.06. |
| 93. |
Tokunaga, M.; Aoyama, H.; Shirogane, Y.; Obora, Y.; Tsuji, Y., Oxidative cleavage of C–C bond of 2-phenylpropionaldehyde using molecular oxygen., Catalysis Today, 2006, 117, 138-140, 2006.07. |
| 94. |
Murai, T.; Inaji, S.; Morishita, K.; Shibahara, F.; Tokunaga, M.; Obora,Y.; Tsuji Y., Synthesis of 1,1'-Binaphthyl-2,2'-diyl Phosphoroselenoic Amides and
Their Conversion to Optically Pure Phosphoramidites, Chem. Lett.,, 35, 1424-1425., 2006.12. |
| 95. |
Ohta, H.; Tokunaga, M.; Obora, Y.; Iwai, T.; Iwasawa, T.; Fujihara,, A Bowl-Shaped Phosphine as a Ligand in Palladium-Catalyzed
Suzuki-Miyaura Coupling of Aryl Chlorides: Effect of a Depth of the Bowl, Org. Lett.,2007, 9, 89-92, 2007.04. |
| 96. |
Sato, H.; Fujihara, T.; Obora, Y.; Tokunaga, M.; Kiyosu, J.; Tsuji Y., Rhodium(I) complexes with N-heterocyclic carbenes bearing a
2,3,4,5-tetraphenyl-phenyl and its higher dendritic frameworks, ChemComm.,, ChemComm.,, 2007.04. |
| 97. |
Tokunaga, M.; Aoyama, H.; Kiyosu, J; Shirogane, Y.; Iwasawa, T.; Obora,, Metal complexes-catalyzed hydrolysis and alcoholysis of organic
substrates and their application to kinetic resolution, J. Organomet. Chem., 692, 472-480., 2007.01. |
