Article
Chemistry, Physical
Ying Yang, Nan-Nan Hang, Hui-Yao Liu, Shufeng Chen, Jialin Ming
Summary: One-step asymmetric synthesis of metallocenes with planar and central chirality was achieved using rhodium catalysis. The reactions proceeded through a desymmetric conjugate addition-Michael cyclization sequence, allowing for the simultaneous construction of both planar and central chirality. The synthetic utility of this method was demonstrated by the asymmetric synthesis of a novel chiral chain diene ligand.
Article
Chemistry, Applied
Mikhail A. Arsenov, Yury V. Fedorov, Dmitry V. Muratov, Yulia V. Nelyubina, Dmitry A. Loginov
Summary: Efficient conditions for the catalytic oxidative coupling of electron-poor carboxylic acids with diphenylacetylene using rhodium have been optimized, leading to the formation of isocoumarins and polycyclic aromatic hydrocarbons. The photophysical properties of the products in solutions have been studied, showing interesting fluorescence emission and solvatochromic effects.
Article
Chemistry, Multidisciplinary
Tomoki Yoshida, Masaya Ohta, Tomoya Emmei, Takuya Kodama, Mamoru Tobisu
Summary: The C-F bond of acyl fluorides can be cleaved and added across tethered alkenes using a cationic rhodium(I) tetrafluoroborate catalyst. This 1,2-carbofluorination reaction provides a highly efficient method for the synthesis of tertiary alkyl fluoride derivatives with a 100% atom economy. Mechanistic studies demonstrate that the concerted action of a rhodium cation and a tetrafluoroborate anion is crucial for the controlled cleavage and formation of C-F bonds in this catalytic process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Christof Matt, Andreas Orthaber, Jan Streuff
Summary: A catalytic enantioselective beta-O-elimination reaction is reported, which involves a zirconium-catalyzed asymmetric opening reaction to achieve chiral beta-O-elimination. The reaction proceeds under mild conditions, with low catalyst loadings, and produces chiral monoprotected cis-1,2-diols in good yield and enantiomeric excess. Combination with other reactions also allows access to additional diol and aminoalcohol building blocks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Guangying Tan, Mowpriya Das, Ivan Maisuls, Cristian A. Strassert, Frank Glorius
Summary: The rhodium-catalyzed dealkenylative arylation of alkenes with arylboronic compounds provides an unconventional access to bi(hetero)aryls with excellent chemoselectivity. This method enables the cleavage of C(aryl)-C(alkenyl) and C(alkenyl)-C(alkenyl) bonds in various alkenes and 1,3-dienes, leading to the efficient construction of novel organic fluorescent molecules with excellent photophysical properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Liexin Wu, Huiying Xu, Hui Gao, Liping Li, Weijie Chen, Zhi Zhou, Wei Yi
Summary: The study presents a (CpRh)-Rh-X(III)-catalyzed enantioselective intermolecular carboamination of 1,3-dienes, allowing the direct synthesis of chiral allylic amines with phenol functionalities under mild conditions. The mechanistic pathway involves an unusual Rh(III)-Rh(I)-Rh(III) catalytic cycle and has shown potential in the derivation of natural products and bioactive complexes.
Article
Chemistry, Physical
Yasuharu Kanda, Ryo Saito, Taiki Ono, Kenichi Kon, Takashi Toyao, Shinya Furukawa, Yasushi Obora, Ken-ichi Shimizu
Summary: The addition of a second metal (Ru, Pt, and Ir) to SiO2-supported Rh phosphide catalysts enhances the hydrodesulfurization (HDS) activity. Among the Rh-M-P catalysts, Rh-Pt-P catalyst exhibits the highest HDS activity, where Pt and Rh cooperate as active sites to enhance the C-S bond cleavage.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Zhenming Cao, Huiqi Li, Qiyuan Fan, Zhantao Liu, Zitao Chen, Yunchao Sun, Jinyu Ye, Maofeng Cao, Cong Shen, Yaqi Jiang, Miaofang Chi, Jun Cheng, Hailong Chen, Zhaoxiong Xie, Younan Xia
Summary: Selective breaking of the C-C bond in ethanol is crucial for various industrial processes, and introducing C atoms into the interstitial sites of Rh nanosheets enhances this process. The insertion of C atoms changes the Rh lattice structure and promotes the exothermic cleavage of the C-C bond. Based on these findings, a new method is developed to enhance the selectivity and activity of commercial Rh black catalysts by introducing C atoms into their surface.
Article
Chemistry, Applied
Muhammad Aliyu Idris, Kwang Ho Song, Sunwoo Lee
Summary: This study presents a new method for synthesizing acyl fluorides under environmentally friendly conditions without the need for transition-metal catalysts or additives. The methodology demonstrates good functional group tolerance towards various groups.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Zhoulong Fan, Daniel A. Strassfeld, Han Seul Park, Kevin Wu, Jin-Quan Yu
Summary: The study presents a sequential C-H/C-C functionalization strategy for the stereospecific synthesis of cis-gamma-functionalized cyclobutyl ketones from readily available cyclobutyl aryl ketones. This strategy involves the generation of a bicyclo[1.1.1]pentan-2-ol intermediate from the parent cyclobutyl ketone via an optimized Norrish-Yang procedure, followed by a ligand-enabled, palladium-catalyzed C-C cleavage/functionalization to produce valuable cis-gamma-(hetero)arylated, alkenylated, and alkynylated cyclobutyl aryl ketones. The benzoyl moiety of these compounds can be further converted to a wide range of functional groups, including amides and esters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Jin Zhang, Pei Zhang, Yangmin Ma, Michal Szostak
Summary: This study reports a novel solvent-free method for synthesizing ketones with high selectivity from acyl chlorides and boronic acids. The reaction takes place in the solid state, without the use of solvents, and has a short reaction time, demonstrating excellent selectivity for C(acyl)-Cl bond cleavage.
Review
Chemistry, Multidisciplinary
Bo Su, John F. Hartwig
Summary: This review discusses the rapid development and significance of enantioselective silylation and borylation of C-H bonds, emphasizing the importance of designing and developing chiral ligands for these reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Stephanie H. Carpenter, Nikki J. Wolford, Brennan S. Billow, Taylor V. Fetrow, Nathalia Cajiao, Aleksa Radovic, Michael T. Janicke, Michael L. Neidig, Aaron M. Tondreau
Summary: The first uranium bis(acyl)phosphide (BAP) complexes were synthesized and characterized using single-crystal X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra revealed that the BAP ligands on the uranium center retained a significant amount of electron density.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Taeyang An, Yan Lee
Summary: A novel guanidine C-N bond substitution strategy involving the formation of guanidine cyclic diimide (GCDI) structures is proposed to destabilize the resonance structure of the guanidine group. In the presence of acid additives, the guanidine carbon center of GCDIs undergoes nucleophilic substitution reactions with various amines and alcohols.
Article
Chemistry, Organic
Jin Zhang, Hui Zhao, Guangchen Li, Xinhao Zhu, Linqin Shang, Yang He, Xin Liu, Yangmin Ma, Michal Szostak
Summary: This article presents a strategy for activation of N-C(S) thioamide bonds by ground-state-destabilization, which can be used in transamidation reactions and modify the properties of thioamide isosteres in organic synthesis. It is expected to find broad applications in various facets of chemical science, including metal-free, metal-catalyzed, and metal-promoted reaction pathways.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Takahiro Mido, Hiroaki Iitsuka, Miyuki Kobayashi, Keiichi Noguchi, Noriyuki Yonezawa, Akiko Okamoto
Article
Chemistry, Multidisciplinary
Suzuka Kinoshita, Ryota Yamano, Yu Shibata, Yusuke Tanaka, Kyoichi Hanada, Takashi Matsumoto, Kazunori Miyamoto, Atsuya Muranaka, Masanobu Uchiyama, Ken Tanaka
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Multidisciplinary
Masahiro Kubo, Keiichi Noguchi, Koji Nakano
Summary: Chiral spiro pi-conjugated compounds, including a chiral benzo[b]silole-fused SBF and a pi-extended spiro polycyclic arene, have been synthesized and studied for their optical properties. These compounds exhibit circularly polarized luminescence with dissymmetry factors up to 0.76x10(-3). Experimental and theoretical analyses show that the emission of these compounds occurs from specific subunits, with slightly different structures compared to the Frank-Condon state.
Article
Biochemistry & Molecular Biology
Yosuke Inoue, Yuya Hanazono, Kentaro Noi, Akihiro Kawamoto, Masato Kimatsuka, Ryuhei Harada, Kazuki Takeda, Ryoichi Kita, Natsuki Iwamasa, Kyoka Shibata, Keiichi Noguchi, Yasuteru Shigeta, Keiichi Namba, Teru Ogura, Kunio Miki, Kyosuke Shinohara, Masafumi Yohda
Summary: A study on CtHsp104 revealed that in the presence of ADP, it assembles into a left-handed spiral filament with a hexamer of split spiral structures. Staggered and split hexameric rings were observed in cryo-EM images, and substrate addition was found to enhance the conformational change and increase the frequency of the split structure.
Article
Soil Science
Akira Takamoto, Yohey Hashimoto, Maki Asano, Keiichi Noguchi, Rota Wagai
Summary: The study investigated the distribution and chemical species of phosphorus in relation to iron and aluminum phases in two Andisols, revealing a stronger control of aluminum phases over phosphorus compared to iron phases. Phosphorus was primarily associated with aluminum, with organic and inorganic phosphorus reservoirs being important in low- to meso-density fractions in Andisols.
Article
Crystallography
Hiroaki Litsuka, Kun Li, Miyuki Kobayashi, Kikuko Lida, Keiichi Noguchi, Noriyuki Yonezawa, Akiko Okamoto
Summary: The crystal of the compound has a monoclinic structure with cell parameters a=10.3707 angstrom, b=12.0232 angstrom, c=15.7744 angstrom, and β=90.907 degrees, at a temperature of 193.15K.
ZEITSCHRIFT FUR KRISTALLOGRAPHIE-NEW CRYSTAL STRUCTURES
(2021)
Article
Chemistry, Multidisciplinary
Naofumi Naga, Keiichi Noguchi, Tomoaki Kouya, Kei Nishii
Summary: Syndiotactic-polystyrene based porous polymers were successfully obtained by polymerizations of styrene, 4-methyl styrene, or 4-tert-butyl styrene and copolymerization of St/MeSt, St/BuSt, or St/DVB using a half metallocene catalyst and methylaluminoxane. The resulting polymers exhibited lower bulk densities and a porous structure formed by networked fibers.
Article
Biochemistry & Molecular Biology
Tomonori Saotome, Sawaros Onchaiya, Subbaian Brindha, Taichi Mezaki, Satoru Unzai, Keiichi Noguchi, Jose C. Martinez, Shun-ichi Kidokoro, Yutaka Kuroda
Summary: The third PDZ domain of PSD95 has a propensity to form amyloid fibrils at high temperatures. It exhibits reversible oligomerization at high temperatures, which is unusual for a small globular protein like PDZ3. By suppressing the high-temperature oligomerization, amyloid formation can be inhibited.
Article
Biochemistry & Molecular Biology
Nina Kurokawa, Rio Midorikawa, Manami Nakamura, Keiichi Noguchi, Ken Morishima, Rintaro Inoue, Masaaki Sugiyama, Masafumi Yohda
Summary: The study examined the oligomeric structural change of CgHspB1 using sedimentation velocity analytical ultracentrifugation. It was found that at low temperatures, CgHspB1 exists as an 18-mer and is relatively unstable, partially dissociating into smaller oligomers. At elevated temperatures, the 24-mer is more stable and in dynamic equilibrium with the dissociated oligomers in the hexameric unit. Additionally, the disulfide bond between conserved cysteine residues plays a role in stabilizing the hexamers.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Yosuke Fukutani, Yuko Nakamura, Nonoko Muto, Shunta Miyanaga, Reina Kanemaki, Kentaro Ikegami, Keiichi Noguchi, Ikuroh Ohsawa, Hiroaki Matsunami, Masafumi Yohda
Summary: Vertebrate animals detect odors through olfactory receptors, but the studies of their odor molecule recognition mechanisms have been hindered by the difficulty in their expression in heterologous cells. However, this study found that a single amino acid substitution in conserved amino acid residues of RTP-independent ORs can significantly improve their functional expression in heterologous cells.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Polymer Science
Naofumi Naga, Shingo Okado, Yui Ohara, Keiichi Noguchi
Summary: Poly(p-phenylene alkylene)s were successfully synthesized through Kumada coupling reaction, showing moderate yields and various properties depending on the choice of alpha,omega-dibromoalkane. X-ray diffraction and FT-IR analyses revealed differences in crystal structures among the polymers. Poly(p-phenylene co-alkylenes)s were newly prepared with lower melting temperatures compared to corresponding poly(p-phenylene alkylene)s. The WAXD profiles of the co-alkylene polymers demonstrated a mix of characteristics from the individual alkylene polymers, influenced by the feed ratios of the alpha,omega-dibromoalkanes.
JOURNAL OF POLYMER RESEARCH
(2022)
Article
Biochemistry & Molecular Biology
Keisuke Uematsu, Chikara Hayasaka, Ko Takase, Keiichi Noguchi, Koji Nakano
Summary: This study reported a method to synthesize [7]helicenes and [7]helicene-like compounds from thia[7]helicene as a common starting material, including silole- and phosphole-fused compounds, cyclopentadiene-fused compounds, and aza[7]helicenes. The synthesized compounds showed unique absorption and emission properties, with slightly red-shifted absorption for silole-fused compounds and strong violet emission for cyclopentadiene-fused compounds and aza[7]helicenes. Additionally, aza[7]helicenes displayed circularly-polarized luminescence with specific dissymmetry factors.
Article
Biochemistry & Molecular Biology
Koji Nakano, Ko Takase, Keiichi Noguchi
Summary: A new family of spiro-fused polycyclic aromatic compounds containing a furan unit was designed and successfully synthesized in enantiopure form. The properties of these furan-containing compounds, including absorption and emission, were found to be different from their thiophene analogs. Additionally, all of these compounds exhibited circularly polarized luminescence.
Article
Soil Science
Shoko Uchida, Yohey Hashimoto, Akira Takamoto, Keiichi Noguchi, Wantana Klysubun, Shan-Li Wang
Summary: This study investigates the adsorption behavior of allophane and ferrihydrite in volcanic ash soils with regards to phosphate. The results show that allophane has a higher affinity for phosphate compared to ferrihydrite, especially at low to intermediate concentrations. Additionally, the study finds that precipitation of Al-phosphate occurs in allophane and allophane-ferrihydrite mixtures.
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL
(2022)
Article
Chemistry, Organic
Daisuke Sato, Akira Tsubouchi, Yuichiro Watanabe, Keiichi Noguchi, Kazunori Miyamoto, Masanobu Uchiyama, Akio Saito
Summary: The activation of alkyne pi-bonds by transition metal complexes is well studied for the cycloisomerization of enynes into bicyclo[3.1.0]hexanes, enabling the introduction of carbon and oxygen functional groups. However, the cycloisomerization of enynones through the activation of carbonyl groups into bicyclo[3.1.0]hexanes has not yet been achieved. In this study, we report the aluminum halide-mediated cycloisomerization of 7-en-2-ynones into halogenated bicyclo[3.1.0]hexanes.
ORGANIC CHEMISTRY FRONTIERS
(2023)