Article
Chemistry, Multidisciplinary
Martin Linden, Silja Hofmann, Antonia Herman, Nicole Ehler, Robin M. M. Baer, Siegfried R. R. Waldvogel
Summary: This study presents the first electrochemical approach for the direct synthesis of pyrazolines and pyrazoles from easily accessible hydrazones and dipolarophiles. The method allows for large-scale production and even conversion of highly sensitive alkenes. The use of a biphasic system with sodium iodide as a supporting electrolyte and mediator is cost-effective. Mechanistic insight is provided by the isolation of key intermediates, and the synthesis of a commercial herbicide safener further highlights the significance of this reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Subrata Patra, Ivan Mosiagin, Rahul Giri, Thomas Nauser, Dmitry Katayev
Summary: This paper introduces an electrochemically assisted method for generating nitryl radicals from ferric nitrate using inexpensive graphite and stainless-steel electrodes under mild reaction conditions. The reaction mechanism is supported by spectroscopic and experimental studies. The synthesis of diverse products is demonstrated through the development of highly efficient nitration protocols for various unsaturated hydrocarbons. These protocols have broad applications, are easily scalable for large quantities, and exhibit exceptional substrate generality and functional-group compatibility.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Guanqi Qiu, Chi-Li Ni, Robert R. Knowles
Summary: We report a diagnostic framework for elucidating the mechanisms of photoredox-based hydrogen isotope exchange (HIE) reactions based on hydrogen/deuterium (H/D) fractionation. The traditional thermal HIE methods proceed by reversible bond cleavage and bond reformation steps, while light-driven HIE reactions can proceed via multiple, non-degenerate sets of elementary steps. The fractionation method presented here extracts information regarding the nature of the key bond-forming and bond-breaking steps.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Alexander S. Harmata, B. J. Roldan, Corey R. J. Stephenson
Summary: The field of strain-driven, radical formal cycloadditions is undergoing a surge in activity, driven by the rise of photoredox catalysis and the demand for sp(3)-rich ring systems. This area has seen significant progress in recent years, with the development of various reactions and the generation of valuable sp(3)-rich ring systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Linbo Tan, Teling Xu, Xueyan Zhang, Juan Luo, Xiaoqin Xiao, Lian Li, Shanshan Huang, Qiang Tang
Summary: An efficient Friedel-Crafts-type reaction followed by electrocyclization cascade has been developed using readily available starting materials, ethanol as a solvent, and Bronsted acid as a catalyst under an air atmosphere. The strategy has been successfully applied to the synthesis of 2-(2-aminophenyl)-9H-carbazole with excellent regioselectivity, functional group tolerance, and scalability. Additionally, the one-pot synthesis of quino[3,4-a]carbazoles has been achieved, demonstrating the broad synthetic utility of this strategy for the synthesis of valuable heteroaryl-annulated [a]carbazoles.
Article
Chemistry, Multidisciplinary
Zhipeng Guan, Shuxiang Zhu, Siyuan Wang, Huamin Wang, Siyuan Wang, Xingxing Zhong, Faxiang Bu, Hengjiang Cong, Aiwen Lei
Summary: An unprecedented electrochemical oxidative carbon-atom difunctionalization of isocyanides has been developed, providing a series of novel multisubstituted imino sulfide ethers. This metal-free and external oxidant-free method shows high stereoselectivities, excellent functional-group tolerance, and good efficiency for large-scale synthesis, enabling further derivatization of the products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Qi Huang, Chuanjiang Xiong, Yungui Peng
Summary: A diastereoselective (3+3) cycloaddition of azomethine imines and in situ-generated azaoxyallyl cations from a-halohydroxamate promoted by a Bronsted base has been developed. A series of pyrazolo [1,2-a][1,2,4]triazin-6-ones were accessed with up to 95% yields and diastereoselectivities greater than 20:1. The asymmetric version of this reaction was explored and moderate enantioselectivity was achieved after screening a series of cinchonine-derived chiral catalysts.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Yan Zhang, Zhipeng Lin, Lutz Ackermann
Summary: The study developed a metal-free electrochemical oxidative dehydrogenative C-H amidation method for heteroarenes with N-alkylsulfonamides, and provided evidence for the generation of nitrogen-centered radicals through cyclic voltammetry studies.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Chu-Hong Ou, Ying-Ming Pan, Hai-Tao Tang
Summary: In this study, we designed and synthesized a porous organic polymer with NHC as the core structure, which exhibited higher catalytic activity and recyclability compared to homogeneous NHC. The polymer successfully catalyzed the cycloaddition reaction of aldehyde and ethyl isocyanoacetate under electro-oxidation conditions. This study provides a reference for the development of new green catalytic systems.
SCIENCE CHINA-CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Tsuyoshi Taniguchi
Summary: This review focuses on recent examples of tetracoordinate boryl groups influencing reactions in organic synthesis by stabilizing or activating reactive intermediates. The unique substituent effects of tetracoordinate boryl groups often promote desired reactions and impact the results of reactions, such as yield and selectivity of products.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Yuta Nishimura, Takashi Harimoto, Takanori Suzuki, Yusuke Ishigaki
Summary: A nitrogen-centered heptalene, azaheptalene, was designed as a representative of a new class of redox-responsive molecules with a large steric strain. The pentabenzo derivative of azaheptalene was efficiently synthesized by a palladium-catalyzed one-pot reaction. Bromination led to mono- and dibrominated derivatives, with the latter exhibiting near-infrared absorption as isolable radical cation species. Optically pure azaheptalenes with P- or M-helicity showed strong chiroptical properties, which could be changed by an electric potential.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Applied
Rongkang Wang, Fangming Chen, Lvqi Jiang, Wenbin Yi
Summary: An efficient electrochemical synthesis method has been developed for the production of various unsymmetrical thioethers and arylboronates. This approach utilizes stable arylazo sulfones as radical precursors for carbon-heteroatom bond formation under electrochemical conditions, and shows scalability for gram-scale reactions. The protocol avoids the use of stoichiometric oxidants, metal catalysts, activating agents, and added bases, while also demonstrating favorable functional group tolerance.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Liu-Liang Mao, An-Xi Zhou, Xian-Hong Zhu, Li-Xia Quan, Fayun Chen, Jie-Ping Wan, Yin-Long Lai
Summary: In this study, a visible-light-mediated tandem phosphorylation/cyclization reaction of N-arylacrylamides with H-phosphine oxides has been developed for the synthesis of phosphorylated oxindoles. This efficient and facile method allows for the construction of a C-P bond and triggers the formation of a C-C bond with good compatibility with functional groups under mild reaction conditions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jian Luo, Bo Hu, Wenda Wu, Maowei Hu, T. Leo Liu
Summary: This study reports a redox neutral electrochemical C(sp(2))-C(sp(3)) cross-coupling reaction conducted under ambient conditions using nonprecious metal catalysts. The reaction demonstrated good yields and a broad scope, with potential applications in pharmaceuticals and natural amino acid modification. The method, which proceeds through an unconventional radical transmetalation mechanism, is highly productive and expected to have widespread applications in organic synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Hayoung Song, Ewa Pietrasiak, Eunsung Lee
Summary: This Account describes the recent work on developing NHC-derived persistent radicals and their prospective applications. NHCs not only stabilize radicals but also interact reversibly with gas molecules. In medicine-related applications, NHC-NO radicals can serve as a platform for NO release in tumor treatment. In energy storage materials, NHC-supported radicals can be used as cathode active materials in batteries. Moreover, stable organic radicals derived from NHCs have potential applications in flexible devices and MRI contrasting agents.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Engineering, Chemical
Hiroshi Takezaki, Takahiko Otsubo, Yuji Echigo, Hidehiro Kamiya, Yohei Okada
Summary: Biocompatible polymer fine particles can be produced by oil in oil emulsion castings, which results in porous and spherical particles with narrow size distribution. The pore networks constructed throughout the particles provide large pore volumes.
Article
Chemistry, Organic
Yuma Kurose, Kazuhiro Okamoto, Yohei Okada, Yoshikazu Kitano, Kazuhiro Chiba
Summary: Ring oxygen-substituted artificial nucleosides, with furanose structure, exhibit unique pharmacological activities as anticancer and antiviral agents, even when not incorporated into oligonucleotides. Direct anodic N-alpha hydroxylation in aqueous media is demonstrated as a practical synthetic method for versatile intermediates in the preparation of azanucleoside derivatives.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Engineering, Chemical
Nanami Aoki, Genki Horiguchi, Hidehiro Kamiya, Yohei Okada
Summary: This study investigates the mechanisms of fly ash deposition in thermal power plants and reveals that fly ash deposition triggered by alkali metals can have different mechanisms. This finding is significant for improving heat transfer efficiency and fuel utilization.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Genki Horiguchi, Tsuyoshi Fujimoto, Kentaro Yoshinaga, Yohei Okada, Hidehiro Kamiya
Summary: The addition of calcium carbonate nanoparticles (CaCO3 NPs) can control particle adhesion at high temperatures. The size and amount of CaCO3 NPs are important factors that determine particle adhesion. Furthermore, the addition of alumina nanoparticles (Al2O3 NPs) can suppress the increase in adhesion caused by CaCO3 NPs at high temperatures.
Article
Chemistry, Organic
Haruka Morizumi, Kazuhiro Okamoto, Shinnosuke Akahane, Hitoshi Takemae, Mami Oba, Yohei Okada, Yoshikazu Kitano, Tetsuya Mizutani, Kazuhiro Chiba
Summary: In this study, we report a practical method for de novo preparation of imino-d-ribitol and C-azanucleosides. Diastereopure Imino-d-ribitol was synthesized on a multigram scale using simple manipulation. The efficient synthesis of corresponding C-azanucleosides with high beta-selectivity was achieved through late-stage anomeric derivatization by regio- and diastereoselective electrochemical C(sp(3))-H activation.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Aina Tanikawa, Takaya Fujihara, Natsumi Nakajima, Yuka Maeda, Yasuyuki Nogata, Erina Yoshimura, Yohei Okada, Kazuhiro Chiba, Yoshikazu Kitano
Summary: This study synthesized 15 isothiocyanates derived from beta-citronellol and evaluated their antifouling activities and toxicities. The synthesized isothiocyanates demonstrated effective antifouling properties with low toxicity, making them potential candidates for further development.
CHEMISTRY & BIODIVERSITY
(2023)
Article
Chemistry, Multidisciplinary
Tatsuya Sudo, Shohei Yamashita, Natsumi Koike, Hidehiro Kamiya, Yohei Okada
Summary: Nanoparticles are prone to aggregation, making it important to enhance their dispersibility for applications. Organic ligands with oleyl groups have been found to be good dispersants in less polar solvents due to their inefficient shell packing and inhibition of crystallization between particles. However, ligands with oleyl structures may contain impurities that could affect the properties of the nanoparticles. This study investigates the relationship between ligand structure and dispersibility using phosphonic acid ligands, revealing that the regio- and stereochemistries of the ligand's C=C double bond, as well as the choice of solvent, play a key role in enhancing dispersibility.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Zimo Wang, Genki Horiguchi, Hidehiro Kamiya, Yohei Okada
Summary: Using tetrahydrobenzodifuran as the core architecture, novel single-benzene fluorophores are created, which possess unique and powerful photophysical properties. These fluorophores can find extensive applications in both academic and industrial settings.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Kaii Nakayama, Yohei Okada
Summary: Arene C-H aminations were achieved using a catalytic amount of DDQ photocatalyst without the need for a co-oxidant. Various functional groups, such as pyrazoles, triazoles, tetrazoles, purines, and tert-butoxycarbonyl amine, were successfully attached to benzene via amination. The mechanism of this reaction, involving the reactivation of DDQH2 to DDQ under UV light irradiation, is still not fully understood, but the presence of O2 and/or a solvent as terminal oxidants is suggested.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sota Adachi, Naoya Maeta, Kaii Nakayama, Zimo Wang, Yasuhiro Hashimoto, Yohei Okada
Summary: Both intermolecular and intramolecular electron transfers play important roles in determining the synthetic outcomes of photochemical and electrochemical reactions. In this study, dispersed TiO2 nanoparticles in combination with methoxybenzene were found to be a unique heterogeneous photocatalyst for facilitating the formation of novel cyclobutanes. The results suggest that methoxybenzene is adsorbed onto the TiO2 surface, leading to a pseudo-intramolecular electron transfer with the forming cyclobutane radical cation.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Genki Horiguchi, Atsuko Uesaka, Tatsuya Sudo, Yukina Ito, Hidehiro Kamiya, Yohei Okada
Summary: Colloidal nanoparticles with unique properties can be stabilized by organic ligands. By functionalizing the surface of nanoparticles, we achieved successful dispersion of various nanoparticles in different solvents.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Review
Electrochemistry
Kazuhiro Okamoto, Kazuhiro Chiba
Summary: In this paper, we summarize the research progress in the application of electrochemical methodology for skeletal modification in synthetic chemistry. By using specific electrolyte systems, the reactivity of oxidative electrochemical reactions can be significantly enhanced.
Article
Food Science & Technology
Kazumi Ninomiya, Yusuke Yamaguchi, Hitoshi Kumagai, Hitomi Kumagai
Summary: Buckwheat albumin is a promising functional food material with high thermal resistance, solubility, and emulsifying and foaming properties. It can be widely used in various functional foods, even after undergoing protease hydrolysis.
Letter
Nutrition & Dietetics
Miwa YamaguchiL, Nobuo Nishil, Yusuke Yamaguchi, Hitomi Kumagai
JOURNAL OF NUTRITIONAL SCIENCE AND VITAMINOLOGY
(2022)
