Kobayashi, Toi

写真a

Affiliation

Faculty of Pharmacy, Department of Pharmaceutical Sciences (Shiba-Kyoritsu)

Position

Research Associate/Assistant Professor/Instructor
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Papers 【 Display / hide 】

  • iso-TEtraQuinoline (i-TEQ): an inherently chiral N4 macrocyclic quinoline tetramer

    Yagami R., Xu W., Kobayashi T., Nagata Y., Kumagai N.

    Chemical Science 16 ( 24 ) 10714 - 10721 2025.05

    ISSN  20416520

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    Chiral macrocycles are attracting growing interest due to their broad applicability as ligands in asymmetric catalysis and as host molecules for chiral recognition. Robustness and high thermodynamic stability can be effectively achieved by strategically linking aromatic panels to construct an axially chiral macrocyclic framework. Cyclic concatenation of four quinoline units affords a fully sp<sup>2</sup>-hybridized, non-planar macrocycle featuring four inwardly oriented, coordinatively active pyridyl nitrogen atoms. The previously reported tetramer TEtraQuinoline (TEQ) exhibits head-to-tail connectivity of its quinoline units, affording an achiral architecture possessing S<inf>4</inf> symmetry. Herein, we report the design and synthesis of iso-TEtraQuinoline (i-TEQ), an inherently chiral analogue featuring head-to-head connectivity at the 2,2′- and 8,8′-positions, which gives rise to a D<inf>2</inf>-symmetric architecture. Detailed comparative investigations of the connectivity isomers i-TEQ and TEQ revealed an array of distinct characteristics, including the overall architecture, intrinsic macrocyclic strain, spatial orientation of nitrogen lone pairs, thermodynamic stability, racemisation behaviour, metal complex stability, and circularly polarised luminescence.

  • Enlarged-TriQuinoline (Enl-TQ): Disparity in Chemical Behaviors by Geometric Scaling of the Trimeric Quinoline Ring System

    Yamashita M., Tsutsumi R., Kobayashi T., Kumagai N.

    Chemistry an Asian Journal  2025

    ISSN  18614728

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    TriQuinoline (TQ), a quasi-planar cyclic quinoline trimer concatenated at the 2,8-positions in a head-to-tail arrangement, strongly captures a proton at the 12-membered inner cycle and exhibits unusual physicochemical properties, including unexpected water solubility and the ability to engage in complexation with other π-conjugated molecules. In this study, we designed and synthesized its expanded analog, coined Enlarged-TriQuinoline (Enl-TQ), in which three alkyne units are embedded between three quinoline units to acquire an expanded planar 18-membered ring system. DFT calculations and X-ray crystallographic analysis revealed its planar architecture with three inwardly facing pyridinic nitrogen atoms. Despite its structural similarity to TQ, Enl-TQ displayed distinct host capability and photophysical characteristics.

  • Development of Unique Quinoline-Based Macrocyclic Systems and Strategic Applications in Versatile Chemistry

    Kobayashi T., Xu W., Kumagai N.

    Yuki Gosei Kagaku Kyokaishi Journal of Synthetic Organic Chemistry 83 ( 5 ) 386 - 394 2025

    ISSN  00379980

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    Macrocyclic compounds exhibit unique properties due to their large ring─shaped structures, which have captivated chemists in recent decades. These molecules exert specific functions in a multidisciplinary basis, e.g. chemistry, materials science, and biology. Crown ethers, calix [n] arenes, and porphyrinoids, which contain several ether／phenol／pyrrole subunits, represent milestones in these molecular categories with unparalleled functional diversity. In contrast, macrocycles exploiting quinoline as a key unitary element to construct specific macrocyclic architecture have received limited attention and been barely explored. In this report, we summarize the recent advances in oligo─ quinoline macrocycles TriQuinoline (TQ), oxa─TriQuinoline (o─TQ), TEtraQuinoline (TEQ), and indole／quinoline hybrid macrocycle In2Q2. Particular emphasis is placed on the synthesis, structure, and application of these molecules in organometallic and supramolecular chemistry, which may guide new molecular designs in the heterocycle─based macrocycle family.

  • In2Q2: A New Entry of 16-Membered Tetraazamacrocycle Concatenating Indole and Quinoline Units

    Kihara K., Kobayashi T., Xu W., Kumagai N.

    Chemistry - A European Journal 30 ( 25 )  2024.05

    ISSN  09476539

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    A new family of 16-membered macrocycles comprising two indole (In) and two quinoline (Q) units, coined In2Q2, was synthesized. Each unit is diagonally located and concatenated in a head-to-tail fashion, furnishing a non-flat saddle-shaped architecture with C2 symmetry. The synthetic protocol utilizing macrocyclic diamide as a pivotal precursor allowed us to access a series of In2Q2 derivatives bearing various substituents on the periphery. The In2Q2 derivatives and their Zn2+ complexes were emissive in both solution phase and solid state. While the entire architecture of In2Q2 is similar to that of quinoline tetramer TEtraQuinoline, a couple of contrasting physicochemical properties were revealed.

  • Oxa-TriQuinoline: A New Entry to Aza-Oxa-Crown Architectures**

    Kobayashi T., Kumagai N.

    Angewandte Chemie - International Edition 62 ( 32 )  2023.08

    ISSN  14337851

    　View Summary

    A new 15-membered-macrocyclic molecular entity, oxa-TriQuinoline (o-TQ), was designed and synthesized. In o-TQ, three oxygen atoms were joined onto three quinoline units at the 2- and 8-positions in a head-to-tail fashion by three-fold SNAr reactions, giving rise to the characteristic N3O3 aza-oxa-crown architecture. o-TQ can serve as a new tridentate nitrogen ligand to capture a CuI cation and adopt a bowl shape, before supramolecular complexation with corannulene and [12]cycloparaphenylene (CPP) occurs through π–π and CH–π interactions. In the presence of the CuI cation, the non-emissive o-TQ becomes a highly emissive material in the solid state, whereby the emission wavelengths depend on the ancillary ligand on the CuI cation. The o-TQ/CuI complex is able to promote carbene catalysis to provide a range of enamines with a gem-difluorinated terminus.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Courses Taught 【 Display / hide 】

  • STUDY OF MAJOR FIELD (MOLECULAR DESIGN)

    2025

  • SEMINAR (MOLECULAR DESIGN)

    2025

  • RESEARCH FOR BACHELOR'S THESIS 1

    2025

  • PHARMACEUTICAL-ENGLISH SEMINAR

    2025

  • MOLECULAR DESIGN OF MEDICINE

    2025

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