KEIO RESEARCHERS INFORMATION SYSTEM

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• 博士（工学）, Nagoya University, Coursework, 2014.03

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Nanotechnology/Materials / Structural organic chemistry and physical organic chemistry (有機分子触媒、反応開発)

• Nanotechnology/Materials / Structural organic chemistry and physical organic chemistry

Research Keywords 【 Display / hide 】

Research Keywords 【 Display / hide 】

• Organic chemistry

• Organic synthesis

• 反応開発

• 有機分子触媒

• 有機化学

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Books 【 Display / hide 】

Books 【 Display / hide 】

• Trichloroperoxyacetamidic Acid

  Robert D Bach, Ryosuke Tsutsumi, Daisuke Uraguchi, Takashi Ooi, Wiley, 2018.03

  • Access to Document (DOI)

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Catalyst-Controlled Chemoselective Transformation of Cyanopyridines over Cyanoarenes Enabled by a DATB–Phenothiazine Hybrid Photocatalyst

  Kinase Y., Tsutsumi R., Kumagai N.

  Synlett  2026.08

  ISSN  09365214

  　View Summary

  A catalyst-dependent chemoselective photoredox reaction of cyanopyridines and cyanoarenes with N-aryl tertiary amines is described. In competitive reactions under visible-light irradiation, a conventional iridium photocatalyst preferentially promoted coupling of the cyanoarene component, whereas phenothiazine-based catalyst systems, including a DATB–phenothiazine hybrid, favored formation of cyanopyridine-derived products. The cyanopyridine-selective product distribution was observed across several combinations of amines, cyanopyridines, and competing cyanoarenes. These results show that the identity of the photocatalyst can govern the relative substrate preference of closely related cyano(hetero)arene acceptors in photoredox catalysis.

  • Access to Document (DOI)

• TriQuinazoline and Related Quinoline/Quinazoline Cyclic Trimers: Unified Synthesis, Planar Discotic Architecture, and Proton Dynamics in an Atomic-Scale Cavity

  Takuya Sakurai, Ryosuke Tsutsumi, Naoya Kumagai

  Chemistry of Materials 38 ( 5 ) 2453 - 2463 2026.02

  Accepted,  ISSN  08974756

  　View Summary

  Heteroatom-doped graphitic materials, particularly those bearing nitrogen, have attracted considerable attention because of their unique physicochemical properties, which are unattainable in pristine carbon frameworks. To rigorously investigate the effects of doping and to enable fine-tuning of their functions at the atomic scale, bottom-up synthesis of well-defined molecular surrogates provides a powerful approach. Herein, we report the design, synthesis, and physicochemical characterization of a series of quinoline/quinazoline cyclic trimers, TriQuinoline (TQ, Q3), Q2Qz1, Q1Qz2, and TriQuinazoline (TQz, Qz3), featuring an atomic-sized central cavity surrounded by three pyridinic nitrogens that mirrors the local topology of nitrogen-doped graphene defects. A modular synthetic strategy enabled facile access to all of the quinazoline-containing congeners. Systematic X-ray analysis and computational studies revealed increasing molecular planarity with increasing quinazoline incorporation, arising from stepwise elimination of destabilizing CH···HC contacts and the emergence of favorable CH···N interactions. Spectroscopic and theoretical studies demonstrated that quinazoline substitution progressively decreases the proton affinity at the central cavity owing to the electron-withdrawing nature of the quinazoline units, which markedly accelerates proton exchange. Even with these electronic modifications, supramolecular association with polycyclic aromatics, such as coronene and [12]cycloparaphenylene ([12]CPP), substantially remained preserved upon quinazoline incorporation. These findings highlight the cooperative interplay of structural planarity and heteroatom substitution in dictating the properties of discotic heteroaromatics, offering a versatile platform for material design.

  • Access to Document (DOI)

• Intramolecular hydrogen bonding topology modulates fluorescence in C4N4 fluorophores

  Kohei M., Niimura M., Tsutsumi R., Kumagai N.

  Organic & Biomolecular Chemistry  2026

  ISSN  14770520

  　View Summary

  Systematic comparison of hydroxy-, amino-, amide-, sulfonamide-, and phosphinamide-substituted C4N4 fluorophores revealed that fluorescence is modulated not simply by hydrogen-bond donor strength, but by positional, geometrical, and conformational accessibility of intramolecular hydrogen bonding to the pyrimidine core. This insight was translated into an acetylation-responsive turn-on probe, providing a design basis for responsive C4N4 fluorophores.

  • Access to Document (DOI)

• DiazaChrysenes (DC): Nitrogen-Containing π-Extended Molecules for Photocatalytic C–H Amination

  Wei Xu, Atsushi Iwai, Itsuki Nagasaka, Satsuki Watanabe, Ryosuke Tsutsumi, Naoya Kumagai

  Organic Letters 27 ( 39 ) 10937 - 10942 2025.10

  Research paper (scientific journal), Accepted,  ISSN  15237060

  　View Summary

  We report a new class of nitrogen-containing π-extended heterocycles, DiazaChrysenes (DCs), and their dimeric analogues (dDCs) as metal-free photocatalysts for C–H amination. DCs featuring a quinolino[1,2-c]quinazolin-5-ium core were synthesized via electrophilic amide activation and arylation. The resulting compounds displayed tunable photophysical and redox properties, with CF<inf>3</inf>-substituted DCs enabling the C–H amination of arenes with azoles under visible light and aerobic conditions, achieving yields up to 85%. The reaction tolerated a range of arene and azole substrates without requiring metal salts or additives. In contrast, dDCs exhibited diminished activity, likely due to their extended π-curvature. Computational studies, including NCI, ACID, and NICS analyses, revealed locally aromatic but electronically isolated π-systems and deshielded central 8-membered cores. This work highlights the utility of DC scaffolds as synthetically accessible and redox-tunable organic photocatalysts.

  • Access to Document (DOI)

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

  Mai Yamashita, Ryosuke Tsutsumi, Toi Kobayashi, Naoya Kumagai

  Chemistry – An Asian Journal 20 ( 17 )  2025.09

  Research paper (scientific journal), Accepted,  ISSN  18614728

  　View Summary

  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.

  • Access to Document (DOI)

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

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

• Development of highly active amidation catalyst

  Tsutsumi, Ryosuke

  学事振興資金研究成果実績報告書 (慶應義塾大学)  2022

Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• Catalytic asymmetric fluorination using CSF sparingly soluble in organic solvent

  Tsutsumi R.

  Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry (Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry)  78 ( 2 ) 158 - 159 2020

  Article, review, commentary, editorial, etc. (scientific journal), Single Work,  ISSN  00379980

  　View Summary

  Metal fluorides such as KF and CsF are inexpensive and easy-to-handle nucleophilic fluorinating reagents while their insolubility in most organic solvents often causes a problem in their synthetic use. In this review, examples of nucleophilic fluorination promoted by a hydrogen-bonding donor are described. Moreover, a recent research on asymmetric nucleophilic fluorination using a chiral hydrogen-bond donor catalyst is introduced.

  • Access to Document (DOI)

• Cover Feature: Enantioselective Electrophilic Cyanation of Boron Enolates: Scope and Mechanistic Studies (Chem. Eur. J. 64/2018)

  Takaya Nagata, Atsuko Tamaki, Kensuke Kiyokawa, Ryosuke Tsutsumi, Masahiro Yamanaka, Satoshi Minakata

  Chemistry – A European Journal (Wiley)  24 ( 64 ) 16926 - 16926 2018.11

  • Access to Document (DOI)

• 忘れられた反応剤Davis’オキサジリジン

  堤 亮祐, 浦口大輔, 大井貴史

  月刊化学 2013 ( 10 ) 66 - 67 2013.10

  Article, review, commentary, editorial, etc. (scientific journal), Joint Work

Presentations 【 Display / hide 】

Presentations 【 Display / hide 】

• 光触媒機能統合型DATBを用いる化学選択的シアノピリジン変換反応

  木名瀬佑亮、堤亮祐、熊谷直哉

  [Domestic presentation]  日本化学会第106春季年会 (千葉) , 

  2026.03

  , 

  Poster presentation

• TriQuinazoline：1原子欠損型平⾯芳⾹族分⼦群の平面性・電子特性精査

  櫻井拓也, 堤亮祐, 熊谷直哉

  [Domestic presentation]  日本化学会第106春季年会 (千葉) , 

  2026.03

  , 

  Oral presentation (general)

• 特異ヘテロ六員環を擁する協奏機能型触媒を用いたカルボン酸変換反応の開拓

  田井喜輝、堤亮祐、近藤樹、原渕祐、前田理、熊谷直哉

  [Domestic presentation]  日本化学会第106春季年会 (千葉) , 

  2026.03

  , 

  Poster presentation

• １原子欠損型完全平面芳香族化合物TriQuinazolineの合成と物理化学的特性精査

  櫻井拓也, 堤亮祐, 熊谷直哉

  [Domestic presentation]  第52回有機典型元素化学討論会 (茨城) , 

  2025.12

  , 

  Oral presentation (general)

• 環状キノリン3量体の幾何学的スケーリングによる物理化学的特性の変化

  山下舞，堤亮祐，小林透威，熊谷直哉

  [Domestic presentation]  第54回複素環化学討論会 (東京) , 

  2025.10

  , 

  Poster presentation

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• 異種触媒機能の協奏が拓くカルボン酸の直接的化学変換

  2026.04

  -

  2029.03

  基盤研究(C), Principal investigator

• 特殊ヘテロ環の複合機能化を鍵とするカルボン酸原料を用いる多様な触媒的分子変換

  2023.04

  -

  2026.03

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), Principal investigator

  　View Summary

  現在、アミドは専らカルボン酸とアミンに対し縮合剤を作用させて合成されるが、カルボン酸に対して量論量以上の縮合剤を投入する必要がある点、付随して縮合剤に由来する量論量以上の廃棄物が生成する点が大きな問題となる。そのためグリーンケミストリーの観点から、量論量の試薬を排したカルボン酸とアミンの触媒的脱水縮合が古くから研究されている。本研究では、B3NO2型ヘテロ6員環を有する1,3-Dioxa-5-Aza-2,4,6-TriBorinane (DATB) のアミド結合形成触媒能に着目し、本年度は工業的応用を視野に入れた触媒活性のさらなる向上とDATBの触媒機構に着目した新規触媒反応の開発に取り組んだ。具体的には、DATB分子内に基質であるカルボン酸またはアミンの認識部位を組み込んだ新規基質認識型DATBの開発を目指した。最近開発したDATBの改良合成法を駆使することで設計した触媒の多くは実際に合成可能であり、モデル基質を用いた触媒活性評価を実施した。現在のところ、オリジナルのDATBを凌駕する活性を有する誘導体は見出していないが、今後さらなる誘導体化により構造活性相関を精査することで、高活性触媒の導出を目指す。また、これまで未開拓であったDATBを用いるアミド化以外の触媒的合成法の開発を志向し、本年度は遷移金属触媒との協働を念頭に、金属配位部位を導入した複合機能型DATBの創出に取り組んだ。これまでに、遷移金属に配位可能な官能基を有するいくつかの誘導体を合成しており、一部については数種の金属塩との錯形成を示唆する実験結果が得られた。今後金属錯体を用いた新規触媒的分子変換の開拓を目指す。

• Expeditious Sophistication of Seed Molecular Entities Aided by Theory and Machine Learning

  2023.04

  -

  2026.03

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Transformative Research Areas (B), Coinvestigator(s)

• Development of Catalytic Amidation Technology for Sustainable Material Production

  2022.04

  -

  2023.03

  The Hitachi Global Foundation, The Kurata Grants, Principal investigator

• N/A

  2020.04

  -

  2021.03

  Fukuoka Naohiko Memorial Foundation, Principal investigator

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Intellectual Property Rights, etc. 【 Display / hide 】

Intellectual Property Rights, etc. 【 Display / hide 】

• DOCK1阻害化合物およびその用途

  Date applied： 特願2018-225753  2018.11 

  Patent

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• DRUG SYNTHESIS LABORATORY COURSE

  2026

• CHEMISTRY OF BIOACTIVE SUBSTANCES

  2026

• RESEARCH FOR BACHELOR'S THESIS 1

  2026

• SEMINAR (MOLECULAR DESIGN)

  2026

• PHARMACEUTICAL-ENGLISH SEMINAR

  2026

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Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• The Pharmaceutical Society of Japan, 

  2021.04

  -

  Present

• The Society of Synthetic Organic Chemistry, Japan, 

  2016.09

  -

  Present

• The Chemical Society of Japan, 

  2009.12

  -

  Present