Article
Chemistry, Multidisciplinary
Kaixue Xie, Martin Oestreich
Summary: Readily available cyclohexa-2,5-dien-1-ylcarbonyl chloride derivatives were used as stable HCl surrogates for transfer hydrochlorination of alkenes and alkynes. B(C6F5)(3) facilitated the stepwise fragmentation of acyl chlorides, allowing the addition of HCl across C-C double and triple bonds with Markovnikov selectivity at room temperature.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Katherine I. Burton, Iris Elser, Alexander E. Waked, Tobias Wagener, Ryan J. Andrews, Frank Glorius, Douglas W. Stephan
Summary: The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications has shown high carbon-based Lewis acidity, making them effective catalysts for hydrodefluorination reactions. These Lewis acids are capable of generating catalytically active silylium cations and have been successfully used for the initiation of deuterodefluorination reactions. Experimental and computational data support the role of these dications as initiators in the generation of silylium cations.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Alexandra Walter, Wolfgang Eisenreich, Golo Storch
Summary: This study reports a photochemical approach using flavin catalysts to oxidize silyl enol ethers to α,β-unsaturated ketones. The catalysts exhibit good stability throughout the reaction and can be successfully applied in subsequent aerobic epoxidation reactions. The sequential catalytic activity of flavin enables rapid diversification of substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Gilvan A. Correia, Marcos L. de Araujo, Wagner A. Carvalho, Mirela Sairre, Giselle Cerchiaro, Lidia S. Shul'pina, Yuriy N. Kozlov, Georgiy B. ShulPin, Alexander M. Kirillov, Dalmo Mandelli
Summary: In this study, the catalytic epoxidation of (R)-carvone by the Ga(NO3)3/H2O2 system was explored, along with the investigation of metal-ligand cooperation using 17 different ligands. The results show that different ligands exhibit different selectivities and efficiencies in the epoxidation reaction.
MOLECULAR CATALYSIS
(2022)
Review
Chemistry, Medicinal
Ivan A. Yaremenko, Peter S. Radulov, Yulia Yu. Belyakova, Dmitriy I. Fomenkov, Svetlana B. Tsogoeva, Alexander O. Terent'ev
Summary: This article summarizes the main achievements in the synthesis of organic peroxides using Lewis acids and heteropoly acids for the first time. It is divided into three parts: (1) the application of metal-based Lewis acids in the synthesis of organic peroxides; (2) the synthesis of organic peroxides promoted by non-metal-based Lewis acids; and (3) the application of heteropoly acids in the synthesis of organic peroxides. The information covered in this review will be useful for specialists in organic synthesis, reactions and processes of oxygen-containing compounds, catalysis, pharmaceuticals, and materials engineering.
Article
Chemistry, Physical
Jia Han, Lei Wang, Wenjin Cao, Qinqin Yuan, Xiaoguo Zhou, Shilin Liu, Xue-Bin Wang
Summary: Size-selective, negative ion photoelectron spectroscopy in conjunction with quantum chemical calculations is employed to investigate the geometric and electronic structures of a protype system in catalytic olefin epoxidation research. The study illustrates the prevalence of a high-lying isomer with asymmetric dual hydrogen-bonding configuration, which is formed by direction-specific electrostatic interactions between [HFIP-H](-) and H2O2. The occurrence of partial charge transfer and proton transfer is observed, and the produced hydroperoxyl radical HOO center dot offers a possible new pathway in olefin epoxidation chemistry.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Marcos Lopes de Araujo, Gilvan Aguiar Correia, Wagner Alves Carvalho, Lidia Sergeevna Shul'pina, Yuriy Nikitovich Kozlov, Georgiy Borisovich Shul'pina, Dalmo Mandelli
Summary: Ethanol and acetol can be oxidized in water at 60 degrees C by the Fe(ClO4)(3)-HClO4-H2O2 system with full conversions, producing formic acid and acetic acid. The oxidation of ethanol and acetol follows different mechanisms, with ethanol oxidation following a chain mechanism and acetol oxidation following a non-chain process. The activation energies for ethanol and acetol oxidation are 24.1 and 14.8 kcal/mol, respectively.
MOLECULAR CATALYSIS
(2021)
Article
Chemistry, Organic
Kellsie Jurkowski, Eike B. Bauer
Summary: Ferrocenium cations are used as catalysts in organic transformations, and their decomposition rate constants depend on the nature of the counterion, with oxidative process being the main decomposition pathway. The cosolvent and changes in counterions can influence the catalytic activity.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Applied
Roman Ottenbacher, Vladimir Kurganskiy, Evgenii P. Talsi, Konstantin P. Bryliakov
Summary: In this study, we reported the enantioselective epoxidation of electron-deficient cis- and trans-alpha,beta-unsaturated amides using the environmentally benign oxidant H2O2. The manganese complexes with bis-amino-bis-pyridine and related ligands as catalysts showed high efficiency and excellent chemo- and enantioselectivity. The presence of NH moiety was found to enhance the enantioselectivity and yield of cis-enamides epoxidation significantly.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Pooja Chaudhary, Geeta Devi Yadav, Krishna K. Damodaran, Surendra Singh
Summary: New chiral Mn(III)-salen complexes were synthesized and evaluated for the asymmetric epoxidation of styrene, showing high yields and promising catalytic activity; the recovered catalysts could be reused for multiple runs, demonstrating good stability and durability.
NEW JOURNAL OF CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Lionel Massi, Jean-Francois Gal, Elisabet Dunach
Summary: Metal triflates have demonstrated their applicability as catalysts in various organic reactions, primarily in C-O and C-C bond formation. Understanding the interaction between Lewis acids and organic functional groups as ligands helps in selecting suitable metal cations for specific reactions. Electrospray ionization mass spectrometry provides a means for characterizing and quantifying donor/acceptor interactions involved in catalytic processes. By using ligand displacement experiments, quantitative affinity scales of ligands towards metal centers can be established.
Article
Chemistry, Applied
Marcos Lopes Araujo, Gilvan Aguiar Correia, Wagner Alves Carvalho, Lidia Sergeevna Shul'pina, Yuriy Nikitovich Kozlov, Georgiy Borisovich Shul'pin, Dalmo Mandelli
Summary: This paper investigated the oxidation of 2-butanol using different ligands in aqueous solutions. It was found that the addition of PCA, 5MPCA, and 3TFMPZOLE improved the reaction performance, while other ligands led to lower accumulation of products. DFT studies suggested that metal-ligand pi-back-bonding could be responsible for the reaction activity increase.
Article
Chemistry, Multidisciplinary
Kai Dong, Yuanyuan Wang, Longcheng Zhang, Xiaoya Fan, Zerong Li, Donglin Zhao, Luchao Yue, Shengjun Sun, Yongsong Luo, Qian Liu, Abdulmohsen Ali Alshehri, Quan Li, Dongwei Ma, Xuping Sun
Summary: Renewable electricity-driven organic electrosynthesis processes using electrocatalytically generated H2O2 for olefin epoxidation can efficiently produce high-purity epoxide solutions, with only water and oxygen consumed at ambient conditions.
Article
Chemistry, Physical
Nataliya V. Maksimchuk, Vasilii Yu. Evtushok, Olga V. Zalomaeva, Gennadii M. Maksimov, Irina D. Ivanchikova, Yuriy A. Chesalov, Ilia V. Eltsov, Pavel A. Abramov, Tatyana S. Glazneva, Vadim V. Yanshole, Oxana A. Kholdeeva, R. John Errington, Albert Sole-Daura, Josep M. Poblet, Jorge J. Carbo
Summary: Zr-monosubstituted Lindqvist-type polyoxometalates have been used as molecular models to investigate the mechanism of hydrogen peroxide activation over Zr(IV) sites. These compounds catalyze the epoxidation of unfunctionalized alkenes and show increased activity with acid additives. The interaction with H2O2 results in the formation of various peroxo derivatives, with different species showing different reactivity towards oxygen transfer reactions.
Article
Chemistry, Multidisciplinary
Fabian Scharinger, Adam Mark Palvoelgyi, Melanie Weisz, Matthias Weil, Christian Stanetty, Michael Schnuerch, Katharina Bica-Schroeder
Summary: In this study, we propose a novel approach for various asymmetric transformations of cyclic enones. By optimizing the catalyst components, we have developed a particularly powerful and versatile organocatalyst that shows excellent stereocontrol. Furthermore, a simple change in the diamine's configuration allows access to both product antipodes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Nanoscience & Nanotechnology
Eri Hayashi, Takatoshi Tamura, Takeshi Aihara, Keigo Kamata, Michikazu Hara
Summary: Heterogeneously catalyzed aerobic oxidative C-H functionalization under mild conditions was achieved using nanosized murdochite-type oxide Mg6MnO8 (Mg6MnO8-MA) synthesized by the sol-gel method. The catalyst exhibited superior catalytic performance and could be reused several times without significant loss of activity. The mechanism of hydrogen atom transfer was found to be controlled by basicity, with O-2 activation playing a crucial role in the oxidation process.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Electrochemistry
Yuuki Sugawara, Satomi Ueno, Keigo Kamata, Takeo Yamaguchi
Summary: The physical and chemical properties of inorganic materials depend on their crystal structures, making precise structure design important for the development of efficient electrocatalysts. This study analyzed various iron-based oxides and found clear correlations between their oxygen evolution reaction (OER) activities and structural descriptors, with the Fe-O bond length identified as the most dominant descriptor for OER on iron-based oxides.
Editorial Material
Electrochemistry
Yuuki Sugawara, Satomi Ueno, Keigo Kamata, Takeo Yamaguchi
Article
Chemistry, Physical
Satomi Shibata, Keigo Kamata, Michikazu Hara
Summary: LaFeO3 nanoparticles synthesized using aspartic acid as a sol-gel method exhibit efficient and stable heterogeneous catalytic activity for the oxidative transformation of alpha-bromostyrene to phenacyl bromide under mild conditions without the need for additives and light irradiation. Changing the A-site metal cation from alkaline metals to lanthanum significantly improves the stability of Fe-containing perovskite oxides. LaFeO3 shows higher catalytic activity compared to other Fe3+/Fe2+-containing simple oxides, and the reaction proceeds through a radical-type mechanism involving surface adsorbed O-2 species over p-type LaFeO3.
Article
Chemistry, Multidisciplinary
Maki Koutani, Eri Hayashi, Keigo Kamata, Michikazu Hara
Summary: This study successfully synthesized mesoporous todorokite-type manganese oxide (OMS-1) nanoparticles with high specific surface areas using a new synthesis approach. It was found that there is a linear correlation between the catalytic performance and the surface area of the nanoparticles, without a trade-off relationship between particle size and catalytic activity. The OMS-1 nanoparticles exhibited high catalytic activity for the oxidation reactions and can be used as recyclable heterogeneous catalysts.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Takeshi Aihara, Wataru Aoki, Shin Kiyohara, Yu Kumagai, Keigo Kamata, Michikazu Hara
Summary: In this study, perovskite oxide nanoparticles were successfully synthesized using dicarboxylic acids as reagents. The resulting SrTiO3 nanoparticles showed high catalytic activity for the cyanosilylation of carbonyl compounds, even without a heat pretreatment.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Sosuke Takei, Ayumi Itoh, Yoshinao Kobayashi, Keigo Kamata, Shintaro Yasui
Summary: Li-B-O materials were used as binders for all solid-state lithium-ion batteries, and amorphous Li2B4O7 powder was obtained through heating treatment of precursor powder synthesized by solution method. The crystallization of the precursor powder occurred at around 500 degrees C, so the heating treatment was performed below 500 degrees C. The obtained amorphous powder was used to prepare dense pellets and can be applied as a new binder for all solid-state lithium-ion batteries.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Yuuki Sugawara, Keigo Kamata, Aoi Matsuda, Takeo Yamaguchi
Summary: Iron-based phosphates are efficient precatalysts for the anodic oxygen evolution reaction in water splitting. The electrochemically generated Fe-based compounds show significantly higher OER activity than the best conventional catalyst. Postcharacterization analysis reveals the transformation of Fe3O3(PO4) into Fe-based (oxyhydr)oxides with phosphorus dissolution.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Aoi Matsuda, Kazuhiko Obara, Atsushi Ishikawa, Meng-Hsuan Tsai, Chia-Hsin Wang, Yu-Chuan Lin, Michikazu Hara, Keigo Kamata
Summary: The direct oxidation of methane to formaldehyde using molecular oxygen as the sole oxidant was studied over different bismuth-based catalysts. Among the catalysts tested, monoclinic BiPO4 nanoparticles synthesized in a mixed solvent of diethylene glycol (DEG) and water showed the highest catalytic activity and selectivity for formaldehyde formation.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Nanako Tamai, Naoki Ogiwara, Eri Hayashi, Keigo Kamata, Toshiyuki Misawa, Takeru Ito, Tatsuhiro Kojima, Mireia Segado, Enric Petrus, Carles Bo, Sayaka Uchida
Summary: Cation-uptake has been extensively studied in materials science. In this study, the researchers focused on a molecular crystal composed of a charge-neutral polyoxometalate (POM) capsule and discovered the occurrence of cation-coupled electron-transfer reaction. The findings reveal the significance of the POM capsule in cation uptake.
Article
Nanoscience & Nanotechnology
Yusuke Kita, Kahoko Kato, Shun Takeuchi, Takaaki Oyoshi, Keigo Kamata, Michikazu Hara
Summary: The liquid-phase reduction method using hydrosilane as reducing and size-controlling agent is an effective way to prepare Ni nanoparticles with high catalytic activity. These nanoparticles exhibited excellent performance in various hydrogenation reactions and can be handled under air. The method allows for control over the size and crystal phase of Ni nanoparticles.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Applied
Takeshi Aihara, Wataru Aoki, Michikazu Hara, Keigo Kamata
Summary: The development of acid-base bifunctional catalysts is important for promoting specific chemical transformations. In this study, Ti-based perovskite oxides were synthesized and used as catalysts for two C-C bond-forming reactions (cyanosilylation and Knoevenagel condensation). The highly pure SrTiO3 nanoparticles with a high specific surface area exhibited the highest catalytic performance, and could be easily recovered and reused.
Article
Chemistry, Physical
Keigo Kamata, Nanami Kinoshita, Maki Koutani, Ryusei Aono, Eri Hayashi, Michikazu Hara
Summary: Beta-MnO2 nanoparticles with high specific surface areas were synthesized successfully and exhibited excellent catalytic activity and selectivity in the oxidation reaction of aromatic and heteroaromatic alcohols. The catalyst could also be used for the one-pot synthesis of nitriles and amides in the presence of ammonia, without the need for additional additives.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Kahoko Kato, Dian Deng, Yusuke Kita, Keigo Kamata, Michikazu Hara
Summary: Heterogeneous transition metal catalysts play an important role in the selective synthesis of primary amines. We have discovered a composite material composed of metallic cobalt and silica particles, which exhibits high catalytic performance under mild conditions and addresses the selectivity issues in the production of secondary and tertiary amines. Mechanistic studies revealed that the substrate nitrile and the product amine hinder the hydrogenation of secondary imine intermediates, resulting in a selective reaction. Additionally, the addition of coordinating organic molecules further improves the selectivity for primary amines.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Endah Suarsih, Yusuke Kita, Keigo Kamata, Michikazu Hara
Summary: A MgO-co-deposited Co catalyst is more efficient in promoting the alpha-alkylation of ketones with alcohols through a borrowing hydrogen mechanism compared to a Ru-based catalyst. Controlled experiments revealed that MgO promoted the hydrogenation step and the TiO2 support contributed to the condensation step in the reaction sequence.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
