Zwitterionic Open-Shell Singlet Diradical with Solvent-Dependent Singlet–Triplet Energy Gap
Shimizu, A.; Hayashida, M.; Ochi, Y.; Shiomi, D.; Sato, K.; Takui, T.; Shintani, R.
Asian J. Org. Chem. 2023, 12, e202300224 (1–5).
DOI: 10.1002/ajoc.202300224
Special Collections on Keiji Maruoka's 70th birthday

A Kinetically Stabilized Nitrogen-Doped Triangulene Cation: Stable and NIR Fluorescent Diradical Cation with Triplet Ground State
Arikawa, S.; Shimizu, A.; Shiomi, D.; Sato, K.; Takui, T.; Sotome, H.; Miyasaka, H.; Murai, M.; Yamaguchi, S.; Shintani, R.
Angew. Chem., Int. Ed. 2023, 62, e202302714 (1–8).
DOI: 10.1002/anie.202302714

Synthesis and Isolation of a Kekulé Hydrocarbon with a Triplet Ground State
Shimizu, A.; Morikoshi, T.; Sugisaki, K.; Shiomi, D.; Sato, K.; Takui, T.; Shintani, R.
Angew. Chem., Int. Ed. 2022, 61, e202205729 (1–5).
DOI: 10.1002/anie.202205729
Highlighted in Synfacts (DOI: 10.1055/s-0042-1751762)

Synthesis and Isolation of a Kinetically Stabilized Crystalline Triangulene
Arikawa, S.; Shimizu, A.; Shiomi, D.; Sato, K.; Shintani, R.
J. Am. Chem. Soc. 2021, 143, 19599–19605.
DOI: 10.1021/jacs.1c10151
Press Release from Osaka University
Highlighted in JACS Spotlights (DOI: 10.1021/jacs.1c12518)

Anthracene-Based Zwitterion with a Small HOMO–LUMO Energy Gap
Kayama, A.; Shimizu, A.; Shintani, R.
Synthesis 2021, 53, 4042–4047.
DOI: 10.1055/a-1543-4018

HOMO–LUMO Energy-Gap Tuning of π-Conjugated Zwitterions Composed of Electron-Donating Anion and Electron-Accepting Cation
Shimizu, A.; Ishizaki, Y.; Horiuchi, S.; Hirose, T.; Matsuda, K.; Sato, H.; Yoshida, J.
J. Org. Chem. 2021, 86, 770–781.
DOI: 10.1021/acs.joc.0c02343

Metal-free Twofold Electrochemical C-H Amination of Activated Arenes: Application to Medicinally Relevant Precursor Synthesis
Wesenberg, L. J.; Diehl, E.; Zähringer, T. J. B.; Dörr, C.; Schollmeyer, D.; Shimizu, A.; Yoshida, J.; Hellmich, U. A.; Waldvogel, S. R.
Chem. Eur. J. 2020, 26, 17574-17580.
DOI: 10.1002/chem.202003852

Azoniadibenzo[a,j]phenalenide: A Polycyclic Zwitterion with Singlet Biradical Character
Arikawa, S.; Shimizu, A.; Shintani, R.
Angew. Chem., Int. Ed. 2019, 58, 6415–6419.
DOI: 10.1002/anie.201902006
Highlighted in Synfacts (DOI: 10.1055/s-0037-1612563)

Metal- and Oxidant-Free Alkenyl C−H/Aromatic C−H Cross-Coupling Using Electrochemically Generated Iodosulfonium Ions
Hayashi, R.; Shimizu, A.; Davies, J. A.; Ishizaki, Y.; Willis, C.; Yoshida, J.
Angew. Chem. Int. Ed. 2018, 57, 12891–12895.
DOI: 10.1002/anie.201807592

Generation and Reactions of Thiirenium Ions by the Cation Pool Method
Shimizu A.; Horiuchi S.; Hayashi R.; Matsumoto K.; Miyamoto Y.; Morisawa Y.; Wakabayashi T.; Yoshida J.
Arkivoc 2018, 97-113.
DOI: 10.24820/ark.5550190.p010.302

Liquid Quinones for Solvent-Free Redox Flow Batteries
Shimizu, A.; Takenaka, K.; Handa, N.; Nokami, T.; Itoh, T.; Yoshida, J.
Adv. Mater. 2017, 29, 1606592.
DOI: 10.1002/adma.201606592

New Approach to 1,4-Benzoxazin-3-ones by Electrochemical C−H Amination
Wesenberg, L. J.; Herold, S.; Shimizu, A.; Yoshida, J.; Waldvogel, S. R.
Chem. Eur. J. 2017, 23, 12096–12099.
DOI: 10.1002/chem.201701979
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Fluoreno[2,3-b]fluorene vs. Indeno[2,1-b]fluorene: Unusual Relationship Between the Number of π Electrons and Excitation Energy in meta-Quinodimethane Type Singlet Diradicaloids
Miyoshi, H.; Miki, M.; Hirano, S.; Shimizu, A.; Kishi, R.; Fukuda, K.; Shiomi, D.; Sato, K.; Takui, T.; Hisaki, I.; Nakano, M.; Yoshito Tobe, Y.
J. Org. Chem. 2017, 82, 1380–1388.
DOI: 10.1021/acs.joc.6b02500

Metal-Free Benzylic C−H Amination via Electrochemically Generated Benzylaminosulfonium Ions
Hayashi, R.; Shimizu, A.; Song, Y.; Ashikari, Y.; Nokami, T.; Yoshida, J.
Chem. Eur. J. 2017, 23, 61–64.
DOI: 10.1002/chem.201604484

The Stabilized Cation Pool Method: Metal- and Oxidant-Free Benzylic C−H/Aromatic C−H Cross-Coupling
Hayashi, R.; Shimizu, A.; Yoshida, J.
J. Am. Chem. Soc. 2016, 138, 8400–8403.
DOI: 10.1021/jacs.6b05273

Generation, Characterization, and Reactions of Thionium Ions Based on the Indirect Cation Pool Method
Shimizu, A.; Takeda, K.; Mishima, S.; Saito, K.; Kim, S.; Nokami, T.; Yoshida, J.
Bull. Chem. Soc. Jpn. 2016, 89, 61–66.
DOI: 10.1246/bcsj.20150323

PPV Polymerization via the Gilch Route: Diradical Character of Monomers
Nikolić, J. Đ.; Sebastian Wouters, S.; Romanova, J.; Shimizu, A.; Champagne, B.; Junkers, T.; Vanderzande, D.; Neck, D. V.; Waroquier, M.; Speybroeck, V. V.; Catak, S.
Chem. Eur. J. 2015, 21, 19176–19185.
DOI: 10.1002/chem.201501900

Heterocyclization Approach for Electrooxidative Coupling of Functional Primary Alkylamines with Aromatics
Morofuji, T.; Shimizu, A.; Yoshida, J.
J. Am. Chem. Soc. 2015, 137, 9816–9819.
DOI: 10.1021/jacs.5b06526
Highlighted in JACS Spotlights (DOI: 10.1021/jacs.5b08475)

Automated Electrochemical Assembly of the Protected Potential TMG-Chitotriomycin Precursor Based on Rational Optimization of the Carbohydrate Building Block
Nokami, T.; Isoda, Y.; Sasaki, N.; Takaiso, A.; Hayase, S.; Itoh, T.; Shimizu, A.; Hayashi, R.; Yoshida, J.
Org. Lett. 2015, 17, 1525–1528.
DOI: 10.1021/acs.orglett.5b00406

Switching the Reaction Pathways of Electrochemically Generated β-Haloalkoxysulfonium Ions - Synthesis of Halohydrins and Epoxides
Shimizu, A.; Hayashi, R.; Ashikari, Y.; Nokami, T.; Yoshida, J.
Beilstein J. Org. Chem. 2015, 11, 242–248.
DOI: 10.3762/bjoc.11.27

Electrochemical Intramolecular C−H Amination: Synthesis of Benzoxazoles and Benzothiazoles
Morofuji, T.; Shimizu, A.; Yoshida, J.
Chem. Eur. J. 2015, 21, 3211–3214.
DOI: 10.1002/chem.201406398
Highlighted in ACIE (DOI: 10.1002/anie.201502638)

Tetracyclopenta[def,jkl,pqr,vwx]tetraphenylene: A Potential Tetraradicaloid Hydrocarbon
Nobusue, S.; Miyoshi, H.; Shimizu, A.; Hisaki, I.; Fukuda, K.; Nakano, M.; Tobe, Y.
Angew. Chem. Int. Ed. 2015, 54, 2090–2094.
DOI: 10.1002/anie.201410791
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Redox Active Dendronized Polystyrenes Equipped with Peripheral Triarylamines
Nokami, T.; Musya, N.; Morofuji, T.; Takeda, K.; Takumi, M.; Shimizu, A.; Yoshida, J.
Beilstein J. Org. Chem. 2014, 10, 3097–3103.
DOI: 10.3762/bjoc.10.326

Transformation of Octadehydrodibenzo[12]annulene to Benzonaphthopentalene by Successive Nucleophilic and Electrophilic Transannular Cyclizations
Nobusue, S.; Yoshizaki, A.; Miki, M.; Miyoshi, H.; Shimizu, A.; Tobe, Y.
Tetrahedron 2014, 70, 8474–8479.
DOI: 10.1016/j.tet.2014.09.079

Introduction of Two Lithiooxycarbonyl Groups Enhances Cyclability of Lithium Batteries with Organic Cathode Materials
Shimizu, A.; Kuramoto, H.; Tsujii, Y.; Nokami, T.; Inatomi, Y.; Hojo, N.; Suzuki, H.; Yoshida, J.
J. Power Sources 2014, 260, 211–217.
DOI: 10.1016/j.jpowsour.2014.03.027

Direct C−N Coupling of Imidazoles with Aromatic and Benzylic Compounds via Electrooxidative C−H Functionalization
Morofuji, T.; Shimizu, A.; Yoshida, J.
J. Am. Chem. Soc. 2014, 136, 4496–4499.
DOI: 10.1021/ja501093m
Highlighted in JACS Spotlights (DOI: 10.1021/ja503143p)

Nitrogen-Containing Polycyclic Quinones as Cathode Materials for LIB with Improved Voltage
Shimizu, A.; Tsujii, Y.; Kuramoto, H.; Nokami, T.; Inatomi, Y.; Hojo, N.; Yoshida, J.
Energy Technol. 2014, 2, 155–158.
DOI: 10.1002/ente.201300148

Benz[c]indeno[2,1-a]fluorene: A 2,3-Naphthoquinodimethane Incorporated into an Indenofluorene Frame
Miyoshi, H.; Nobusue, S.; Shimizu, A.; Hisaki, I.; Miyata, M.; Tobe, Y.
Chem. Sci. 2014, 5, 163–168.
DOI: 10.1039/C3SC52622D
Highlighted in Synfacts (DOI: 10.1055/s-0033-1340612)

Synthesis and Physical Properties of Zethrene Derivatives Bearing Donor/Acceptor Substituents at 7,14-Positions
Hibi, D.; Kitabayashi, K.; Shimizu, A.; Umeda, R.; Tobe, Y.
Org. Biomol. Chem. 2013, 11, 8256–8261.
DOI: 10.1039/C3OB41674G

Halogen and Chalcogen Cation Pools Stabilized by DMSO. Versatile Reagents for Alkene Difunctionalization
Ashikari, Y.; Shimizu, A.; Nokami, T.; Yoshida, J.
J. Am. Chem. Soc. 2013, 135, 16070–16073.
DOI: 10.1021/ja4092648

Automated Solution-Phase Synthesis of Oligosaccharides via Iterative Electrochemical Assembly of Thioglycosides
Nokami, T.; Hayashi, R.; Saigusa, Y.; Shimizu, A.; Liu, C.-Y.; Mong, K.-K. T.; Yoshida, J.
Org. Lett. 2013, 15, 4520–4523.
DOI: 10.1021/ol402034g

Indeno[2,1-b]fluorene: A 20-π-Electron Hydrocarbon with Very Low-Energy Light Absorption
Shimizu, A.; Kishi, R.; Nakano, M.; Shiomi, D.; Sato, K.; Takui, T.; Hisaki, I.; Miyata, M.; Tobe, Y.
Angew. Chem. Int. Ed. 2013, 52, 6076–6079.
DOI: 10.1002/anie.201302091
Selected as Back Cover (DOI: 10.1002/anie.201303391)

Electrochemical C−H Amination: Synthesis of Aromatic Primary Amines via N-Arylpyridinium Ions
Morofuji, T.; Shimizu, A.; Yoshida, J.
J. Am. Chem. Soc. 2013, 135, 5000–5003.
DOI: 10.1021/ja402083e
Highlighted in Synfacts (DOI: 10.1055/s-0033-1338914)

Oxidative Cyclodimerization After Tandem Cyclization of Dehydrobenzo[14]annulenes Induced by Alkyllithium
Nobusue, S.; Shimizu, A.; Hori, K.; Hisaki, I.; Miyata, M.; Tobe, Y.
Angew. Chem. Int. Ed. 2013, 52, 4184–4188.
DOI: 10.1002/anie.201210233
Selected as Inside Cover (DOI: 10.1002/anie.201301655)
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Polymer-Bound Pyrene-4,5,9,10-tetraone for Fast-Charge and-Discharge Lithium-Ion Batteries with High Capacity
Nokami, T.; Matsuo, T.; Inatomi, Y.; Hojo, N.; Tsukagoshi, T.; Yoshizawa, H.; Shimizu, A.; Kuramoto, H.; Komae, K.; Tsuyama, H.; Yoshida, J.
J. Am. Chem. Soc. 2012, 134, 19694–19700.
DOI: 10.1021/ja306663g

Metal- and Chemical-Oxidant-Free C−H/C−H Cross-Coupling of Aromatic Compounds: The Use of Radical-Cation Pools
Morofuji, T.; Shimizu, A.; Yoshida, J.
Angew. Chem. Int. Ed. 2012, 51, 7259–7262.
DOI: 10.1002/anie.201202788

Aromaticity and π-Bond Covalency: Prominent Intermolecular Covalent Bonding Interaction of a Kekulé Hydrocarbon with Very Significant Singlet Biradical Character
Shimizu, A.; Hirao, Y.; Matsumoto, K.; Kurata, H.; Kubo, T.; Uruichi, M.; Yakushi, K.
Chem. Commun. 2012, 48, 5629–5631.
DOI: 10.1039/C2CC31955A

Singlet Open-Shell Character of Conjugated Kekulé Molecules
Kubo, T.; Aoba, M.; Shimizu, A.; Hirao, Y.; Matsumoto, K.; Kurata, H.; Nakano, M.
AIP Conf. Proc. 2012, 1504, 883–886.
DOI: 10.1063/1.4771836

Theoretical Aspects on the Evaluation and Interpretation of the Third-Order Nonlinear Optical Properties of Diradical Compounds
Champagne, B.; Botek, E.; Shimizu, A.; Kubo, T.; Kamada, K.; Ohta, K.; Kishi, R.; Fukui, H.; Takahashi, H.; Nakano, M.
AIP Conf. Proc. 2012, 1504, 844–847.
DOI: 10.1063/1.4771826

Theoretical Consideration of Singlet Open-Shell Character of Polyperiacenes Using Clar's Aromatic Sextet Valence Bond Model and Quantum Chemical Calculations
Shimizu, A.; Hirao, Y.; Kubo, T.; Nakano, M.; Botek, E.; Champagne, B.
AIP Conf. Proc. 2012, 1504, 399–405.
DOI: 10.1063/1.4771733

Synthesis, Crystal Structure, and Physical Properties of Sterically Unprotected Hydrocarbon Radicals
Kubo, T.; Katada, Y.; Shimizu, A.; Hirao, Y.; Sato, K.; Takui, T.; Uruichi, M.; Yakushi, K.; Haddon, R. C.
J. Am. Chem. Soc. 2011, 133, 14240–14243.
DOI: 10.1021/ja2065768
Highlighted in Synfacts (DOI: 10.1055/s-0031-1289391)

Indeno[2,1-a]fluorene: An Air-Stable o-Quinodimethane Derivative
Shimizu, A.; Tobe, Y.
Angew. Chem. Int. Ed. 2011, 50, 6906–6910.
DOI: 10.1002/anie.201101950

Electronic Structure of Delocalized Singlet Biradical Ph2-IDPL Solid Film
Kanai, K.; Noda, Y.; Kato, K.; Kubo, T.; Iketaki, K.; Shimizu, A.; Ouchi, Y.; Nakasuji, K.; Seki, K.
Phys. Chem. Chem. Phys. 2010, 12, 12570–12577.
DOI: 10.1039/C0CP00178C

Alternating Covalent Bonding Interactions in a One-Dimensional Chain of a Phenalenyl-Based Singlet Biradical Molecule Having Kekulé Structures
Shimizu, A.; Kubo, T.; Uruichi, M.; Yakushi, K.; Nakano, M.; Shiomi, D.; Sato, K.; Takui, T.; Hirao, Y.; Matsumoto, K.; Kurata, H.; Morita, Y.; Nakasuji, K.
J. Am. Chem. Soc. 2010, 132, 14421–14428.
DOI: 10.1021/ja1037287

Synthesis, Structure, and Photophysical Properties of Dibenzo[de,mn]naphthacenes
Wu, T.-C.; Chen, C.-H.; Hibi, D.; Shimizu, A.; Tobe, Y.; Wu, Y.-T.
Angew. Chem. Int. Ed. 2010, 49, 7059–7062.
DOI: 10.1002/anie.201001929

Synthesis and Characterization of Teranthene: A Singlet Biradical Polycyclic Aromatic Hydrocarbon Having Kekulé Structures
Konishi, A.; Hirao, Y.; Nakano, M.; Shimizu, A.; Botek, E.; Champagne, B.; Shiomi, D.; Sato, K.; Takui, T.; Matsumoto, K.; Kurata, H.; Kubo, T.
J. Am. Chem. Soc. 2010, 132, 11021–11023.
DOI: 10.1021/ja1049737
Highlighted in Synfacts (DOI: 10.1055/s-0030-1258739)
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Signature of Multiradical Character in Second Hyperpolarizabilities of Rectangular Graphene Nanoflakes
Nagai, H.; Nakano, M.; Yoneda, K.; Kishi, R.; Takahashi, H.; Shimizu, A.; Kubo, T.; Kamada, K.; Ohta, K.; Botek, E.; Champagne, B.
Chem. Phys. Lett. 2010, 489, 212–218.
DOI: 10.1016/j.cplett.2010.03.013

Singlet Diradical Character from Experiment
Kamada, K.; Ohta, K.; Shimizu, A.; Kubo, T.; Kishi, R.; Takahashi, H.; Botek, E.; Champagne, B.; Nakano, M.
J. Phys. Chem. Lett. 2010, 1, 937–940.
DOI: 10.1021/jz100155s

Third-Order Nonlinear Optical Properties of Trigonal, Rhombic and Bow-Tie Graphene Nanoflakes with Strong Structural Dependence of Diradical Character
Yoneda, K.; Nakano, M.; Kishi, R.; Takahashi, H.; Shimizu, A.; Kubo, T.; Kamada, K.; Ohta, K.; Champagne, B.; Botek, E.
Chem. Phys. Lett. 2009, 480, 278–283.
DOI: 10.1016/j.cplett.2009.09.047

Resonance Balance Shift in Stacks of Delocalized Singlet Biradical
Shimizu, A.; Uruichi, M.; Yakushi, K.; Matsuzaki, H.; Okamoto, H.; Nakano, M.; Hirao, Y.; Matsumoto, K.; Kurata, H.; Kubo, T.
Angew. Chem. Int. Ed. 2009, 48, 5482–5486.
DOI: 10.1002/anie.200901382

Scanning Tunneling Microscopy Study of a Phenalenyl-Based Singlet Biradical on Graphite
Iketaki, K.; Kanai, K.; Shimizu, A.; Kubo, T.; Wang, Z.-H.; Ouchi, Y.; Morita, Y.; Nakasuji, K.; Seki, K.
J. Phys. Chem. C 2009, 113, 1515–1519.
DOI: 10.1021/jp808686v

Theoretical Study of Third-Order Nonlinear Optical Properties in Square Nanographenes with Open-Shell Singlet Ground States
Nakano, M.; Nagai, H.; Fukui, H.; Yoneda, K.; Kishi, R.; Takahashi, H.; Shimizu, A.; Kubo, T.; Kamada, K.; Ohta, K.; Champagne, B.; Botek, E.
Chem. Phys. Lett. 2008, 467, 120–125.
DOI: 10.1016/j.cplett.2008.10.084

Ambipolar Organic Field-Effect Transistors Based on a Low Band Gap Semiconductor with Balanced Hole and Electron Mobilities
Chikamatsu, M.; Mikami, T.; Chisaka, J.; Yoshida, Y.; Azumi, R.; Yase, K.; Shimizu, A.; Kubo, T.; Morita, Y.; Nakasuji, K.
Appl. Phys. Lett. 2007, 91, 043506.
DOI: 10.1063/1.2766696

Strong Two-Photon Absorption of Singlet Diradical Hydrocarbons
Kamada, K.; Ohta, K.; Kubo, T.; Shimizu, A.; Morita, Y.; Nakasuji, K.; Kishi, R.; Ohta, S.; Furukawa, S.; Takahashi, H.; Nakano, M.
Angew. Chem. Int. Ed. 2007, 46, 3544–3546.
DOI: 10.1002/anie.200605061

Singlet Biradical Character of Phenalenyl-Based Kekulé Hydrocarbon with Naphthoquinoid Structure
Kubo, T.; Shimizu, A.; Uruichi, M.; Yakushi, K.; Nakano, M.; Shiomi, D.; Sato, K.; Takui, T.; Morita, Y.; Nakasuji, K.
Org. Lett. 2007, 9, 81–84.
DOI: 10.1021/ol062604z

Synthesis, Intermolecular Interaction, and Semiconductive Behavior of a Delocalized Singlet Biradical Hydrocarbon
Kubo, T.; Shimizu, A.; Sakamoto, M.; Uruichi, M.; Yakushi, K.; Nakano, M.; Shiomi, D.; Sato, K.; Takui, T.; Morita, Y.; Nakasuji, K.
Angew. Chem. Int. Ed. 2005, 44, 6564–6568.
DOI: 10.1002/anie.200502303

m-Quinodimethane-Based Fused-Ring Triplet Hydrocarbons
Shimizu, A.; Arikawa, S.; Morikoshi, T.; Shintani, R.
Pure Appl. Chem. 2023, 95, 401–412.
DOI: 10.1515/pac-2023-0208

Development of Electroorganic Reactions Utilizing Stabilized Reactive Species and Its Application to Organic Energy Storage Materials
Shimizu, A.
Electrochemistry 2018, 86, 298-302.
DOI: 10.5796/electrochemistry.18-6-E2671

Electrogenerated Cationic Reactive Intermediates: The Pool Method and Further Advances
Yoshida, J.; Shimizu, A.; Hayashi, R.
Chem. Rev. 2018, 118, 4702-4730.
DOI: 10.1021/acs.chemrev.7b00475

Reaction Integration Using Electrogenerated Cationic Intermediates
Yoshida, J.; Shimizu, A.; Ashikari, Y.; Morofuji, T.; Hayashi, R.; Nokami, T.; Nagaki, A.
Bull. Chem. Soc. Jpn. 2015, 88, 763–775.
DOI: 10.1246/bcsj.20150100

Non-Alternant Non-Benzenoid Kekulenes: Birth of a New Kekulene Family
Miyoshi, H.; Nobusue, S.; Shimizu, A.; Tobe, Y.
Chem. Soc. Rev. 2015, 44, 6560–6577.
DOI: 10.1039/c5cs00185d

Indenofluorene Congeners: Biradicaloids and Beyond
Shimizu, A.; Nobusue, S.; Miyoshi, H.; Tobe, Y.
Pure Appl. Chem. 2014, 86, 517–528.
DOI: 10.1515/pac-2014-5043

Experimental Consideration on Covalent Bonding Interactions in Stacks of Singlet Biradicals Having Kekulé Structures
Shimizu, A.; Nakano, M.; Hirao, Y.; Kubo, T.
J. Phys. Org. Chem. 2011, 24, 876–882.
DOI: 10.1002/poc.1873

Singlet Open-Shell Character of Polyperiacenes
Shimizu, A.; Konishi, A.; Hirao, Y.; Kubo, T.
In Graphene and its Fascinating Attributes; Swapan, P.; Enoki, T.; Rao, C. N. R., Eds., World Scientific Publishing: 2011