Details of a Researcher - Tsutsumi, Ryosuke

Tsutsumi, Ryosuke

写真a

Affiliation: Faculty of Pharmacy, Department of Pharmaceutical Sciences 分子創成化学講座 ( Shiba-Kyoritsu )

Position: Research Associate/Assistant Professor/Instructor

Contact Address: 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512

External Links

Page Top ▲

Academic Degrees 【 Display / hide 】

博士（工学）, Nagoya University, Coursework, 2014.03

Page Top ▲

Books 【 Display / hide 】

Trichloroperoxyacetamidic Acid

Robert D Bach, Ryosuke Tsutsumi, Daisuke Uraguchi, Takashi Ooi, Wiley, 2018.03
- Access to Document (DOI)

Page Top ▲

Papers 【 Display / hide 】

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

Xu W., Iwai A., Nagasaka I., Watanabe S., Tsutsumi R., Kumagai N.

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

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

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)
Expeditious Access to the B3NO2 Heterocycle Enabling Modular Derivatization.

Ryosuke Tsutsumi, Nobuaki Kashiwagi, Naoya Kumagai

The Journal of organic chemistry (Journal of Organic Chemistry) 88 ( 9 ) 6247 - 6251 2023.05

Research paper (scientific journal), Joint Work, Lead author, Accepted, ISSN 00223263

　View Summary

DATB (1,3-dioxa-5-aza-2,4,6-triborinane) is a unique six-membered heterocycle exhibiting proficient catalytic activity in direct dehydrative amidation. Reported herein is an improved synthetic protocol for DATB derivatives featuring a concise two-step chromatography-free process. Suzuki-Miyaura coupling assembled 2,6-dibromoaniline derivatives and 1,2-phenylenediboronic acid to afford dimeric B-spiroborate salts. Acidic untying of the spiroborates gave rise to the DATB ring system with various substituents.
- Access to Document (DOI)
Azo-tagged C4N4 fluorophores: unusual overcrowded structures and their application to fluorescent imaging.

Miki Kohei, Naoki Takizawa, Ryosuke Tsutsumi, Wei Xu, Naoya Kumagai

Organic & biomolecular chemistry (Organic and Biomolecular Chemistry) 21 ( 14 ) 2889 - 2893 2023

Research paper (scientific journal), Joint Work, Accepted, ISSN 14770520

　View Summary

The C4N4 fluorophore is an intense fluorescence emitter featuring a 2,5-diaminopyrimidine core comprising four carbon and four nitrogen atoms. A series of C4N4 derivatives was photochemically dimerized at the 5-amino group, furnishing overcrowded ortho-tetraaryl-substituted diaryl azo compounds with a characteristic skewed structure revealed by X-ray crystallography. The photoquenched azo-C4N4s are useful for fluorescently visualizing cells under hypoxic conditions.
- Access to Document (DOI)
Chiral Bipyridine Ligand with Flexible Molecular Recognition Site: Development and Application to Copper‐Catalyzed Asymmetric Borylation of α,β‐Unsaturated Ketones

Ryosuke Tsutsumi, Rika Taguchi, Masahiro Yamanaka

ChemCatChem (Wiley) 14 ( 2 ) e202101278 2021.10

Research paper (scientific journal), Joint Work, Lead author, Accepted, ISSN 1867-3880
- Access to Document (DOI)

display all >>

Page Top ▲

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

Page Top ▲

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’オキサジリジン

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

Page Top ▲

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