Search results for: Shuichi Nakamura

Items from 1 to 20 out of 109 results

article

Organocatalysis for Enantioselective Decarboxylative Nucleophilic Addition Reactions

Naoki Yasukawa, Shuichi Nakamura

European Journal of Organic Chemistry > 27 > 35 > n/a - n/a

The catalytic decarboxylation of malonic acid half oxy‐ and thioesters, β‐ketocarboxylic acids, and their related compounds is a straightforward, powerful, and atom‐economical strategy for the in‐situ formation of enolates, which are important and well‐studied synthons for various functional materials and natural products. This strategy, inspired by the biosynthesis of polyketides and fatty acids,...

article

Organocatalytic Stereoselective Decarboxylative Addition of α‐Amido Malonic Acid Half Oxyesters to Isatins

Kazuki Fujita, Ibuki Kumazawa, Jyunpei Yokoi, Kazuki Abe, more

Advanced Synthesis & Catalysis > 366 > 3 > 438 - 443

The stereoselective reaction of α‐amido‐substituted malonic acid half oxyesters (α‐amido‐MAHOs) with isatins was developed. A cinchona alkaloid thiourea catalyst gave products bearing a tetrasubstituted stereogenic centre in high yields with high diastereo‐ and enantioselectivities (75–99% yield, 83:17–97:3 dr, 92:8–99:1 er). The obtained products can be converted into some chiral compounds without...

article

Enantioselective Synthesis of Benzothiazolines from Fluoroalkyl Ketones Using Chiral Imidazoline−Phosphoric Acid Catalysts

Yuka Iizuka, Tatsumi Wada, Kazuki Ogura, Tsunayoshi Takehara, more

Advanced Synthesis & Catalysis > 364 > 24 > 4271 - 4274

The first enantioselective synthesis of cyclic N,S‐ketals having tetrasubstituted chiral center through intramolecular cyclization between carbonyl compounds and aminothiols has been developed. The reaction of fluoroalkyl ketones with aminobenzenethiols using a chiral imidazoline−phosphoric acid catalyst afforded products in high yields with high enantioselectivity. The observed enantioselectivity...

article

Enantioselective Allenylation of Ketimines Derived from Isatins Using Chiral Bis(imidazoline)‐Palladium Catalysts

Yusuke Oyamada, Shintaro Yamasaki, Mika Tsuzuki, Takumi Kitagawa, more

Advanced Synthesis & Catalysis > 364 > 24 > 4255 - 4259

The catalytic enantioselective allenylation of ketimines derived from isatins is described. Products with high regio‐ and enantioselectivities were obtained in the presence of a bis(imidazoline)‐palladium catalyst. The obtained products were then converted into various chiral amines. The stereoselectivity origin was revealed by DFT calculations of the transition state.

article

Aligned Porous Structure of (Ba,Ca)(Ti,Zr)O₃ Piezoelectric Ceramics for Enhanced Catalytic Activity

Takahiro Samma, Teruaki Fuchigami, Shuichi Nakamura, Tobias Fey, more

physica status solidi (b) > 259 > 9 > n/a - n/a

The effect of pore orientation and pore volume on the dielectric and piezoelectric properties as well as the piezocatalytic activity of lead‐free porous (Ba,Ca)(Ti,Zr)O₃ (BCTZ) are investigated. The pore orientation in BCTZ is controlled using a freeze‐casting method. Two types of porous BCTZ samples, i.e., A‐BCTZ and B‐BCTZ, are prepared by cutting them in parallel and perpendicular directions,...

article

Synthesis and Acid Catalytic Activity of Al‐Doped Spiky‐Shaped Niobium Pentoxide

Teruaki Fuchigami, Yusuke Oyamada, Masaaki Haneda, Shuichi Nakamura, more

physica status solidi (b) > 259 > 9 > n/a - n/a

Niobium pentoxide (Nb₂O₅) is a promising heterogeneous acid catalyst because of its water‐tolerant acidity. However, the reactivity of Nb₂O₅ is limited to the surface of a bulk material; thus, its catalytic activity is generally lower than homogeneous catalysts. Nano‐sized Nb₂O₅ shows superior activity but has low stability and recoverability. We develop spiky‐shaped Nb₂O₅ composed of radially grown...

article

Enantiodivergent Reaction of Ketimines with Malononitriles Using Single Cinchona Alkaloid Sulfonamide Catalysts

Shuichi Nakamura, Natsuki Matsumoto, Masato Kibe, Kazuki Abe, more

Advanced Synthesis & Catalysis > 364 > 4 > 781 - 786

We report the enantiodivergent reaction of ketimines derived from α‐ketoesters with malononitriles using a single chiral source. The reactions using an 8‐quinolinesulfonyl cinchona alkaloid catalyst in the presence and absence of Et₂Zn gave both enantiomers in high yields with high enantioselectivities (53∼99% yield, 99:1∼3:97 er). The obtained malononitrile‐derived α‐amino acids were converted into...

article

Crawling motility of Treponema denticola modulated by outer sheath protein

Eitoyo Kokubu, Yuichiro Kikuchi, Kazuko Okamoto‐Shibayama, Shuichi Nakamura, more

Microbiology and Immunology > 65 > 12 > 551 - 558

Treponema denticola, a helically shaped motile microorganism, is a major pathogen of chronic periodontitis. Major surface protein (Msp) and dentilisin are virulence factors of T. denticola that are located on the outer sheath. The motility of T. denticola is deeply involved in colonization on and invasion into the host tissue. The outer sheath is located at the interface between the environment and...

article

Enantioselective Vinylogous Mannich Reaction of Acyclic Vinylketene Silyl Acetals with Acyclic Ketimines

Kazuki Ogura, Tsunayoshi Takehara, Takeyuki Suzuki, Shuichi Nakamura

Advanced Synthesis & Catalysis > 363 > 19 > 4544 - 4548

The first enantioselective vinylogous Mannich reaction of acyclic vinylketene silyl acetals with acyclic ketimines derived from alkynyl ketoesters was developed. Excellent yields and enantioselectivities were obtained from the reaction using bis(imidazoline)‐Zn(II) catalyst. Based on experiments and MO calculation, a plausible transition state was proposed to explain the stereoselectivity of the reaction...

article

Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells

Isabel Sebastián, Nobuhiko Okura, Bruno M. Humbel, Jun Xu, more

Cellular Microbiology > 23 > 9 > n/a - n/a

Bacterial pathogens have evolved multiple strategies to disassemble epithelial cell apical junctional complexes (AJCs) and infect epithelial cells. Leptospirosis is a widespread zoonotic infection, mainly caused by Leptospira interrogans, and its dissemination across host cell barriers is essential for its pathogenesis. However, the mechanism of bacterial dissemination across epithelial cell barriers...

article

Cover Image: Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells (Cellular Microbiology 09/2021)

Isabel Sebastián, Nobuhiko Okura, Bruno M. Humbel, Jun Xu, more

Cellular Microbiology > 23 > 9 > n/a - n/a

Focused ion beam‐scanning electron microscopy image of renal proximal tubule epithelial cells infected for 24 hrs with Leptospira interrogans. Leptospires localized in the gap between two adjacent cells (red and blue). For further details, readers are referred to the article by Sebastián et al. on p. e13343 of this issue.

article

Catalytic Enantioselective Synthesis of N,N‐Acetals from α‐Dicarbonyl Compounds Using Chiral Imidazoline‐Phosphoric Acid Catalysts

Shuichi Nakamura, Tatsumi Wada, Tsunayoshi Takehara, Takeyuki Suzuki

Advanced Synthesis & Catalysis > 362 > 23 > 5374 - 5379

The enantioselective synthesis of chiral N,N‐acetals derived from α‐dicarbonyl compounds has been achieved. Good yields and enantioselectivities were observed for the reaction with various α‐dicarbonyl compounds with 2‐aminobenzamides using chiral bis(imidazoline)‐phosphoric acid catalysts. Based on these experimental investigations, a possible transition state is proposed to explain the origin of...

article

Direct observation of speed fluctuations of flagellar motor rotation at extremely low load close to zero

Shuichi Nakamura, Yuta Hanaizumi, Yusuke V. Morimoto, Yumi Inoue, more

Molecular Microbiology > 113 > 4 > 755 - 765

The bacterial flagellar motor accommodates ten stator units around the rotor to produce large torque at high load. But when external load is low, some previous studies showed that a single stator unit can spin the rotor at the maximum speed, suggesting that the maximum speed does not depend on the number of active stator units, whereas others reported that the speed is also dependent on the stator...

article

Tree of motility – A proposed history of motility systems in the tree of life

Makoto Miyata, Robert C. Robinson, Taro Q. P. Uyeda, Yoshihiro Fukumori, more

Genes to Cells > 25 > 1 > 6 - 21

Motility often plays a decisive role in the survival of species. Five systems of motility have been studied in depth: those propelled by bacterial flagella, eukaryotic actin polymerization and the eukaryotic motor proteins myosin, kinesin and dynein. However, many organisms exhibit surprisingly diverse motilities, and advances in genomics, molecular biology and imaging have showed that those motilities...

article

Effects of fermentation products of the commensal bacterium Clostridium ramosum on motility, intracellular pH, and flagellar synthesis of enterohemorrhagic Escherichia coli

Jun Xu, Yukako Koyanagi, Emiko Isogai, Shuichi Nakamura

Archives of Microbiology > 2019 > 201 > 6 > 841-846

The flagellum and motility are crucial virulence factors for many pathogenic bacteria. In general, pathogens invade and translocate through motility and adhere to specific tissue via flagella. Therefore, the motility and flagella of pathogens are effectual targets for attenuation. Here, we show that the fermentation products of Clostridium ramosum, a commensal intestinal bacterium, decrease the intracellular...

article

Recipient sepsis caused by Lactococcus garvieae contamination of platelets from a donor with colon cancer

Shuichi Nakamura, Kenji Nakai, Momoko Sakata, Yoshio Nagaoka, more

Vox Sanguinis > 114 > 2 > 182 - 184

Lactococcus garvieae is a well‐known fish pathogen that has low virulence in humans and is rarely isolated from the blood cultures of endocarditis patients. We describe herein the first reported case of transfusion‐transmitted L. garvieae sepsis caused by a contaminated platelet concentrate from a donor who consumed raw octopus before blood donation. Retrospective examination of the laboratory results...

article

Salmonella Typhimurium is Attracted to Egg Yolk and Repelled by Albumen

Katsuya Okuno, Jun Xu, Emiko Isogai, Shuichi Nakamura

Current Microbiology > 2019 > 76 > 4 > 393-397

Salmonella Typhimurium is the causative agent of non-typhoidal, foodborne salmonellosis. Contamination of hen eggs by the bacterium is a common source of S. Typhimurium infection. S. Typhimurium is peritrichous, and flagellum-dependent motility and chemotaxis are believed to facilitate egg contamination despite the presence of many antimicrobial egg components. We performed motility and chemotaxis...

article

Implications of coordinated cell-body rotations for Leptospira motility

Kyosuke Takabe, Akihiro Kawamoto, Hajime Tahara, Seishi Kudo, more

Biochemical and Biophysical Research Communications > 2017 > 491 > 4 > 1040-1046

The spirochete Leptospira has a coiled cell body and two periplasmic flagella (PFs) that reside beneath the outer sheath. PFs extend from each end of the cell body and are attached to the right-handed spiral protoplasmic cylinder (PC) via a connection with the flagellar motor embedded in the inner membrane. PFs bend each end of the cell body into left-handed spiral (S) or planar hook (H) shapes, allowing...

article

Enantioselective Reaction of 2H‐Azirines with Phosphite Using Chiral Bis(imidazoline)/Zinc(II) Catalysts

Shuichi Nakamura, Daiki Hayama

Angewandte Chemie International Edition > 56 > 30 > 8785 - 8789

The first highly enantioselective nucleophilic addition reaction of phosphites with 2H‐azirines has been developed. The reaction was applied to various 3‐substituted 2H‐azirines using novel chiral bis(imidazoline)/Zn^II catalysts to afford products in good yield with high enantioselectivity. The transformation of the obtained optically active aziridines showed that 2H‐azirines act as either α,β‐ or...

article

Catalytic Enantioselective Reaction of Allenylnitriles with Imines Using Chiral Bis(imidazoline)s Palladium(II) Pincer Complexes

Masaru Kondo, Masashi Omori, Tsubasa Hatanaka, Yasuhiro Funahashi, more

Angewandte Chemie International Edition > 56 > 30 > 8677 - 8680

The first highly enantioselective reaction of allenylnitriles with imines has been developed. Excellent yields and enantioselectivities were observed for the reaction with various imines using chiral Phebim‐Pd^II complexes. This process offers a simple and efficient synthetic route for various functionalized α‐vinylidene‐β‐aminonitriles and their derivatives.

Publication date

Last 3 months (1)
Last year (2)
Last 3 years (8)

Close

Date range setting

Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.

From:

To:
Set your own date range

Content availability

Available (108)
None (1)

Publication type

article (108)
book (1)

Keywords

Data set

Wiley (52)
Elsevier (37)
ACS (12)
Springer (5)
ieee (3)

Journal

Chemistry – A European Journal (11)
Tetrahedron Letters (11)
Angewandte Chemie (10)
Angewandte Chemie International Edition (10)
Advanced Synthesis & Catalysis (7)
Journal of Fluorine Chemistry (7)
Journal of the American Chemical Society (5)
The Journal of Organic Chemistry (5)
Tetrahedron (4)
Tetrahedron: Asymmetry (4)
Biochemical and Biophysical Research Communications (3)
Current Microbiology (3)
IEEE Transactions on Applied Superconductivity (3)
Molecular Microbiology (3)
Biophysical Journal (2)
Cellular Microbiology (2)
Journal of Molecular Biology (2)
Microbiology and Immunology (2)
Organic Letters (2)
physica status solidi (b) (2)
Animal Science Journal (1)
Archives of Microbiology (1)
Bioorganic & Medicinal Chemistry Letters (1)
European Journal of Organic Chemistry (1)
FEMS Microbiology Letters (1)
General Pharmacology (1)
Genes to Cells (1)
Microbiological Research (1)
Thin Solid Films (1)
Vox Sanguinis (1)
more

INFONA - science communication portal

Search results for: Shuichi Nakamura

Organocatalysis for Enantioselective Decarboxylative Nucleophilic Addition Reactions

Organocatalytic Stereoselective Decarboxylative Addition of α‐Amido Malonic Acid Half Oxyesters to Isatins

Enantioselective Synthesis of Benzothiazolines from Fluoroalkyl Ketones Using Chiral Imidazoline−Phosphoric Acid Catalysts

Enantioselective Allenylation of Ketimines Derived from Isatins Using Chiral Bis(imidazoline)‐Palladium Catalysts

Aligned Porous Structure of (Ba,Ca)(Ti,Zr)O₃ Piezoelectric Ceramics for Enhanced Catalytic Activity

Synthesis and Acid Catalytic Activity of Al‐Doped Spiky‐Shaped Niobium Pentoxide

Enantiodivergent Reaction of Ketimines with Malononitriles Using Single Cinchona Alkaloid Sulfonamide Catalysts

Crawling motility of Treponema denticola modulated by outer sheath protein

Enantioselective Vinylogous Mannich Reaction of Acyclic Vinylketene Silyl Acetals with Acyclic Ketimines

Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells

Cover Image: Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells (Cellular Microbiology 09/2021)

Catalytic Enantioselective Synthesis of N,N‐Acetals from α‐Dicarbonyl Compounds Using Chiral Imidazoline‐Phosphoric Acid Catalysts

Direct observation of speed fluctuations of flagellar motor rotation at extremely low load close to zero

Tree of motility – A proposed history of motility systems in the tree of life

Effects of fermentation products of the commensal bacterium Clostridium ramosum on motility, intracellular pH, and flagellar synthesis of enterohemorrhagic Escherichia coli

Recipient sepsis caused by Lactococcus garvieae contamination of platelets from a donor with colon cancer

Salmonella Typhimurium is Attracted to Egg Yolk and Repelled by Albumen

Implications of coordinated cell-body rotations for Leptospira motility

Enantioselective Reaction of 2H‐Azirines with Phosphite Using Chiral Bis(imidazoline)/Zinc(II) Catalysts

Catalytic Enantioselective Reaction of Allenylnitriles with Imines Using Chiral Bis(imidazoline)s Palladium(II) Pincer Complexes

Filter options

Publication date

Content availability

Publication type

Keywords

Data set

Journal

INFONA - science communication portal

Search results for: Shuichi Nakamura

Add recipient

Sending message cancelled

Are you sure you want to cancel sending this message?

Send message

Filter options

Publication date

Date range setting

Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.

Content availability

Publication type

Keywords

Data set

Journal

Reporting an error / abuse

Sending the report failed

Accessibility options