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213 results on '"Shimada, Toyoshi"'

1. Prognostic impact of concomitant pH-regulating drugs in patients with non-small cell lung cancer receiving epidermal growth factor receptor tyrosine kinase inhibitors: the Tokushukai REAl-world Data project 01-S1

Author

Uryu, Kiyoaki, Imamura, Yoshinori, Shimoyama, Rai, Mase, Takahiro, Fujimura, Yoshiaki, Hayashi, Maki, Ohtaki, Megu, Otani, Keiko, Hibino, Makoto, Horiuchi, Shigeto, Fukui, Tomoya, Fukai, Ryuta, Chihara, Yusuke, Iwase, Akihiko, Yamada, Noriko, Tamura, Yukihiro, Harada, Hiromasa, Shinozaki, Nobuaki, Shimada, Toyoshi, Tsuya, Asuka, Fukuoka, Masahiro, and Minami, Hironobu

Published
2024
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7. Facile preparation of a new BINAP-based building block, 5,5'-diiodoBINAP, and its synthetic application

Author

Shimada, Toyoshi, Suda, Masahiko, Nagano, Toyohiro, and Kakiuchi, Kiyomi

Subjects
Iodine compounds -- Chemical properties, Oxides -- Chemical properties, Borates -- Chemical properties, Chlorides -- Chemical properties, Dichloropropane -- Chemical properties, Biological sciences, Chemistry
Abstract

Direct iodination of 2,2'-bis(diphenylphosphino)-1-1'-binaphthyl (BINAP) dioxide with iodine monochloride and N-iodosucinimide in the presence of trifluoroacetic acid is discussed. Derivatization at the 5,5'-positions to BINAP does not influence enantioselectivities or yields in rhodium-catalyzed asymmetric 1,4-additions.

Published
2005

8. The regiochemistry of cyclization of alpha-sulfenyl-, alpha sulfinyl-, and alpha-sulfonyl1-5-hexenyl radicals: procedures leading to regioselective syntheses of cyclic sulfones and sulfoxides

Author

Della, Ernest W., Graney, Sean D., Shimada, Toyoshi, Hayashi, Tamio, and Hongjun Zhang

Subjects
Chemistry, Organic -- Research, Sulfones -- Research, Sulfones -- Chemical properties, Biological sciences, Chemistry
Abstract

A unique contrast was found in the mode of ring closure of radicals on studying the cyclization of alpha-sulfenyl-, alpha-sulfinyl-, and alpha-sulfonyl-5-hexenyl radicals. The 5-hexenyl radicals' sulfinyl-substituted species displayed unexpected regioselectivity relative to its analogues.

Published
2004

9. Asymmetric synthesis of axially chiral biaryls by nickel-catalyzed grignard cross-coupling of dibenzothiophenes

Author

Yong-Hwan Cho, Asato Kina, Shimada, Toyoshi, Hayashi, Tamio, and Hongjun Zhang

Subjects
Nickel compounds -- Research, Nickel compounds -- Chemical properties, Chemistry, Organic -- Research, Biological sciences, Chemistry
Abstract

A full description of catalytic asymmetric Grignard cross-coupling and its reaction of 1,9-disubstituted dibenzothiophenes and dinaphthothiophene are reported. The cross-coupling products are converted into useful axially chiral compounds.

Published
2004

10. Preparation of enantiomerically pure 2'-substituted 2-diphenylphosphino-1,1'-binaphthyls by reductive cleavage of the carbon-phosphorus bond in a borane complex of 2-diphenylphosphino-2'-diphenylphosphinyl-1,1'-binaphthyl

Author

Shimada, Toyoshi, Kurushima, Hiroaki, Yong-Hwan Cho, and Hayashi, Tamio

Subjects
Chemistry, Organic -- Research, Carbon -- Physiological aspects, Phosphorus -- Physiological aspects, Enantiomers -- Physiological aspects, Borane -- Physiological aspects, Coordination compounds -- Physiological aspects, Tetrahydrofuran -- Physiological aspects, Biological sciences, Chemistry
Abstract

Research has been conducted on the (S)-2'-boranatophenylphosphino-2-diphenylphosphinyl-1,1'-binaphthyl. The reaction of this borane complex with the excess of n-butyllithium in tetrahydrofuran has been carried out and the results indicate that it has brought the carbon-phosphorus selective cleavage between the binaphthyl and diphenylphosphinyl.

Published
2001

17. Theoretical studies on Si-C bond cleavage in organosilane precursors during polycondensation to organosilica hybrids

Author

Shirai, Soichi, Goto, Yasutomo, Mizoshita, Norihiro, Ohashi, Masataka, Tani, Takao, Shimada, Toyoshi, Hyodo, Shi-aki, and Inagaki, Shinji

Subjects
Benzene -- Structure, Benzene -- Chemical properties, Density functionals -- Usage, Molecular orbitals -- Analysis, Organosilicon compounds -- Chemical properties, Organosilicon compounds -- Structure, Chemicals, plastics and rubber industries
Published
2010

18. Rhodium-catalyzed asymmetric synthesis of indanones: Development of a new 'axially chiral' bisphosphine ligand

Author

Shintani, Ryo, Yashio, Keiji, Nakamura, Tomoaki, Okamoto, Kazuhiro, Shimada, Toyoshi, and Hayashi, Tarnio

Subjects
Rhodium -- Chemical properties, Chirality -- Research, Catalysis -- Research, Chemistry
Abstract

The development of a rhodium-catalyzed asymmetric isomerization of racemic alpha-arylpropargyl alcohols to beta-chiral indanones and the achievement of high enantioselectivity through optimization of axial chiral of bisphosphine ligands are described. The ligand's axial chirality is fixed to a single configuration upon complexation to a transition metal due to the chiral axes existing at other positions within the molecule.

Published
2006

19. An alternate route for the synthesis of hybrid mesoporous organosilica with crystal-like pore walls from allylorganosilane precursors

Author

Kapoor, Mahendra P., Inagaki, Shinji, Ikeda, Shushiro, Kakiuchi, Kiyomi, Suda, Masahiko, and Shimada, Toyoshi

Subjects
Benzene -- Chemical properties, Organosilicon compounds -- Chemical properties, Organosilicon compounds -- Research, Chemical synthesis, Chemistry
Abstract

The bridged allylorganosilanes 1,4-bis(diallylethoxysilyl)benzene and 1,4-bis(triallylsilyl)benzene are the new precursors for the surfactant-assisted synthesis of ordered mesoporous organosilica with pore walls having crystal-like molecular-scale periodicity. The findings indicate that this synthesis method is applicable for the preparation of mesoporous organosilica with bulky organic groups.

Published
2005

21. A new synthetic route to enantiomerically pure axially chiral 2,2'-bipyridine N,N'-dioxides. Highly efficient catalysts for asymmetric allylation of aldehydes with allyl(trichloro)silanes

Author

Shimada, Toyoshi, Kina, Asato, and Hayashi, Tamio

Subjects
Cyclic compounds -- Composition, Glycols, Esters, Optical isomers, Enantiomers, Silane, Aldehydes, Pyridine, Catalysts -- Composition, Oxides, Chirality, Organic compounds -- Composition, Chemistry, Organic -- Research, Biological sciences, Chemistry
Abstract

Research has been conducted on axialy chiral 2,2'-bipyridine N,N'-dioxides. The authors report that these compounds have been produced in an enantiomerically pure form from cyclic diesters formed vie diaesterification of diols.

Published
2003

23. Grafted Polymethylhydrosiloxane on Hierarchically Porous Silica Monoliths: A New Path to Monolith-Supported Palladium Nanoparticles for Continuous Flow Catalysis Applications

Author

Pélisson, Carl-Hugo, primary, Nakanishi, Takahiro, additional, Zhu, Yang, additional, Morisato, Kei, additional, Kamei, Toshiyuki, additional, Maeno, Ayaka, additional, Kaji, Hironori, additional, Muroyama, Shunki, additional, Tafu, Masamoto, additional, Kanamori, Kazuyoshi, additional, Shimada, Toyoshi, additional, and Nakanishi, Kazuki, additional

Published
2016
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24. Amine/Hydrido Bifunctional Nanoporous Silica with Small Metal Nanoparticles Made Onsite: Efficient Dehydrogenation Catalyst

Author

Zhu, Yang, primary, Nakanishi, Takahiro, additional, Kanamori, Kazuyoshi, additional, Nakanishi, Kazuki, additional, Ichii, Shun, additional, Iwaida, Kohji, additional, Masui, Yu, additional, Kamei, Toshiyuki, additional, Shimada, Toyoshi, additional, Kumamoto, Akihito, additional, Ikuhara, Yumi H., additional, Jeon, Mina, additional, Hasegawa, George, additional, Tafu, Masamoto, additional, Yoon, Chang Won, additional, and Asefa, Tewodros, additional

Published
2016
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28. A new hierarchically porous Pd@HSQ monolithic catalyst for Mizoroki–Heck cross-coupling reactions

Author

60452265, 20379308, 00188989, Moitra, Nirmalya, Matsushima, Ayumi, Kamei, Toshiyuki, Kanamori, Kazuyoshi, Ikuhara, Yumi H., Gao, Xiang, Takeda, Kazuyuki, Zhu, Yang, Nakanishi, Kazuki, Shimada, Toyoshi, 60452265, 20379308, 00188989, Moitra, Nirmalya, Matsushima, Ayumi, Kamei, Toshiyuki, Kanamori, Kazuyoshi, Ikuhara, Yumi H., Gao, Xiang, Takeda, Kazuyuki, Zhu, Yang, Nakanishi, Kazuki, and Shimada, Toyoshi

Abstract

Pore architecture of catalyst supports is an important factor facilitating accessibility of reactants to catalytic sites. This holds the key to improving catalytic activities. Amongst various catalytic reactions, supported Pd nanoparticles-catalyzed C–C cross-coupling reactions have been attracting a great deal of attention in the last decade. Although various supports have been examined, applications of hierarchically porous monolithic materials have never been reported, mainly because of difficulties in multistep synthesis of catalysts. We herein report a novel on-site reduction-based methodology using hierarchically porous hydrogen silsesquioxane (HSQ) monoliths for one-step synthesis of Pd nanoparticles-embedded monoliths (Pd@HSQ). Characterization of these monoliths evidences the on-site reduction, i.e. formation of Pd nanoparticles and conversion of Si–H present in the monolith to Si–O . Fast, quantitative reduction of Pd[2+] to Pd(0) to form supported Pd nanoparticles is achieved with preservation of the porous structure of the original monolith, which makes this material attractive as a catalyst for C–C cross-coupling reactions. The obtained Pd@HSQ catalyst has been employed in the Mizoroki–Heck cross-coupling reaction. High accessibility of reactant molecules, undetectable leaching of Pd nanoparticles and easy separation of the monolith from liquid media provide high catalytic activity, reusability and easy handling.

Published
2014

29. Functionalization on silica gel with allylsilanes. A new method of covalent attachment of organic functional groups on silica gel

Author

Shimada, Toyoshi, Aoki, Kazuko, Nakamura, Tomoaki, Tokunaga, Norihito, Inagaki, Shinji, and Hayashi, Tamio

Subjects
Chemical bonds -- Research, Silane -- Chemical properties, Silica gel -- Chemical properties, Chemistry
Abstract

A new method for the modification of the silica gel surface by use of (allyl)organosilanes is found. The method finds its application in the surface-modifying technology on the silica gel as a reliable functionalization method.

Published
2003

30. Nickel-catalyzed asymmetric Grignard cross-coupling of dinaphthothiophene giving axially chiral 1,1'-binaphthyls

Author

Shimada, Toyoshi, Yong-Hwan Cho, and Hayashi, Tamio

Subjects
Racemization -- Methods, Grignard reagents -- Usage, Nickel -- Research, Chemistry
Abstract

A new efficient route to axially chiral 1,1'-binaphthyls, which is realized by nickel-catalyzed asymmetric cross-coupling of dinaphthothiphene with the Grignard reagents is described. The dinaphthothiophene is a chiral molecule but undergoes racemization much faster than the catalytic cross-coupling reaction.

Published
2002

31. Asymmetric synthesis of 1-aryl-1,2-ethanediols from arylacetylenes by palladium-catalyzed asymmetric hydrosilylation as a key step

Author

Shimada, Toyoshi, Mukaide, Kotaro, Shinohara, Akihiro, Han, Jin Wook, and Hayashi, Tamio

Subjects
Glycols -- Chemical properties, Glycols -- Research, Rhodium -- Usage, Acetylene -- Chemical properties, Acetylene -- Research, Palladium -- Usage, Chemistry
Abstract

A study reports on asymmetric synthesis of 1,2-diols from arylacetylenes by use of the palladium-catalyzed asymmetric hydrosilylation as a key step. This method gives a new efficient and practical route to enantiomerically enriched 1,2 diols prepared from alkenes.

Published
2002

45. Amine/Hydrido Bifunctional Nanoporous Silica with Small Metal Nanoparticles Made Onsite: Efficient Dehydrogenation Catalyst

Author

Zhu, Yang, Nakanishi, Takahiro, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Ichii, Shun, Iwaida, Kohji, Masui, Yu, Kamei, Toshiyuki, Shimada, Toyoshi, Kumamoto, Akihito, Ikuhara, Yumi H., Jeon, Mina, Hasegawa, George, Tafu, Masamoto, Yoon, Chang Won, and Asefa, Tewodros

Abstract

Multifunctional catalysts are of great interest in catalysis because their multiple types of catalytic or functional groups can cooperatively promote catalytic transformations better than their constituents do individually. Herein we report a new synthetic route involving the surface functionalization of nanoporous silica with a rationally designed and synthesized dihydrosilane (3-aminopropylmethylsilane) that leads to the introduction of catalytically active grafted organoamine as well as single metal atoms and ultrasmall Pd or Ag-doped Pd nanoparticles via on-site reduction of metal ions. The resulting nanomaterials serve as highly effective bifunctional dehydrogenative catalysts for generation of H2from formic acid.

Published
2017
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46. Grafted Polymethylhydrosiloxane on Hierarchically Porous Silica Monoliths: A New Path to Monolith-Supported Palladium Nanoparticles for Continuous Flow Catalysis Applications

Author

Pélisson, Carl-Hugo, Nakanishi, Takahiro, Zhu, Yang, Morisato, Kei, Kamei, Toshiyuki, Maeno, Ayaka, Kaji, Hironori, Muroyama, Shunki, Tafu, Masamoto, Kanamori, Kazuyoshi, Shimada, Toyoshi, and Nakanishi, Kazuki

Abstract

Polymethylhydrosiloxane has been grafted on the surface of a hierarchically porous silica monolith using a facile catalytic reaction between Si–H and silanol to anchor the polymer. This easy methodology leads to the functionalization of the surface of a silica monolith, where a large amount of free Si–H bonds remain available for reducing metal ions in solution. Palladium nanoparticles of 15 nm have been synthesized homogeneously inside the mesopores of the monolith without any stabilizers, using a flow of a solution containing Pd2+. This monolith was used as column-type fixed bed catalyst for continuous flow hydrogenation of styrene and selective hydrogenation of 3-hexyn-1-ol, in each case without a significant decrease of the catalytic activity after several hours or days. Conversion, selectivity, and stereoselectivity of the alkyne hydrogenation can be tuned by flow rates of hydrogen and the substrate solution, leading to high productivity (1.57 mol g(Pd)−1h–1) of the corresponding cis-alkene.

Published
2017
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