Review
Chemistry, Multidisciplinary
Chenxi Duan, Chunming Cui
Summary: Low valent group 14 compounds with diazaborolyl substituents exhibit unique structures and reactivity due to the combination of sigma-electron donation and steric hindrance. The modulation of the HOMO-LUMO gap by the diazaborolyl substituents results in novel reaction patterns in the activation of small molecules and inert chemical bonds.
CHEMICAL SOCIETY REVIEWS
(2024)
Article
Chemistry, Inorganic & Nuclear
Shintaro Takahashi, Raphal Nougue, Thibault Troadec, Antoine Baceiredo, Nathalie Saffon-Merceron, Vicenc Branchadell, Tsuyoshi Kato
Summary: A base-stabilized C-phosphonio-Si-amino-silyne 3 was synthesized through a coupling reaction between a silyliumylidene ion 1 and a P,S-bis-ylide 2. This new cationic silyne 3 shows high stability at room temperature (t1/2 = 7 days in THF) and unique reactivity due to the phosphonio substituent.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Kristian L. Mears, Bronson Ruiz, Gia-Ann Nguyen, Wenxing Zou, James C. Fettinger, Philip P. Power
Summary: Half a century after the photolytic disproportionation of Lappert's dialkyl stannylene SnR2, R = CH(SiMe3)(2) (1) gave the persistent trivalent radical [SnR3], the characterization of the corresponding Sn(i) product, SnR is now described. It was isolated as the hexastannaprismane Sn6R6 (2), from the reduction of 1 by the Mg(i)-reagent, Mg(BDIDip)(2) (BDI = (DipNCMe)(2)CH, Dip = 2,6-diisopropylphenyl).
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Md Jabed Hossain, Brij Kumar Shah, Shabana Khan
Summary: In this study, a convenient method for the synthesis of amines using accessible Ce[N(SiMe3)(2)](3)(THF)(3) catalyst under mild conditions was developed. The reduction of 1 degrees and 2 degrees amides to amines was achieved with high yields. This methodology was also successfully applied for the synthesis of indole derivatives.
Article
Chemistry, Multidisciplinary
Miao Tian, Jianying Zhang, Lulu Guo, Chunming Cui
Summary: This study describes the isolation of a novel 1,2-dilithiodisilene and its potential as a synthetic reagent for novel silicon multiply bonded species. The results highlight the significant electronic effects of boryl substituents on silicon multiple bonding structures.
Article
Chemistry, Inorganic & Nuclear
Chong Yu, Chenjun Guo, Linhong Jiang, Mingliang Gong, Yunjie Luo
Summary: The deoxygenative reduction of amides using pinacolborane (HBpin) in the presence of a catalytic amount of Ca[N(SiMe3)(2)](2)(THF)(2) is an efficient method to access amines, with good tolerance to functional groups and heteroatoms. The proposed reaction mechanism provides insight into this transformation.
Review
Chemistry, Multidisciplinary
Kei Ota, Rei Kinjo
Summary: This review presents the recent developments of [4n+2]-electron systems of heavier heterocycles involving group 13-15 elements, including synthesis, spectroscopic data, structural parameters, computational data, and reactivity.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Chemistry, Physical
Adrianna Cyraniak, Sylwia Freza, Piotr Skurski
Summary: In this study, neutral and anionic BC2H4 systems were examined using ab initio methods. The most stable neutral isomer was found to have the H2CBCH2 structure, while the H3B-CCH system was identified as the highest energy isomer among other neutral isomers. The energetic order of anionic isomers was different, with (H2CBCH2)- and (H3B-CCH)- species being nearly isoenergetic and the most stable. Predictions and discussions on the vertical electron detachment energies (1.71-4.32 eV) characterizing (BC2H4)- anions were also made.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Giorgia A. Martino, Alessandro Piovano, Caterina Barzan, Yu-Kai Liao, Elena Morra, Kousou Hirokane, Mario Chiesa, Takashi Monoi, Elena Groppo
Summary: In this study, various spectroscopic techniques were used to investigate the local structure and function of chromium sites in Cr[CH(SiMe3)(2)](3)/SiO2 catalysts for ethene polymerization with different chromium loadings. Two different types of chromium sites were found working in tandem, with their relative abundances depending on the chromium loading. Carbon monoxide was shown to selectively poison the sites responsible for ethene oligomerization, providing a potential strategy for fine-tuning the properties of the produced polyethylene.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Ligia R. Gomes, John N. Low, James L. Wardell
Summary: X-ray crystallographic, Hirshfeld surface and PIXEL study were conducted on five benzyloxy substituted compounds, revealing intramolecular hydrogen bonding, E-configuration about the olefinic bond, and near planar chalcone cores. The phenyl groups in the benzyloxy substituents exhibited larger interplanar angles with the chalcone core rings. The linker units between the terminal phenyl rings in the chalcone cores showed electronic delocalization. The study also identified important motifs with antiparallel molecular arrangements and different slippage distances, highlighting the variety of interactions present. PIXEL calculations emphasized the significant contribution of dispersive forces to the overall energies of these molecules.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Inorganic & Nuclear
Alexander M. Fedoseev, Mikhail S. Grigoriev, Iraida A. Charushnikova, Nina A. Budantseva, Nadezhda M. Stanetskaya, Vladimir S. Tyurin
Summary: New complexes of neptunyl(V) isothiocyanate with 4'-aryl-substituted 2,2':6',2 ''-terpyridines and N,N-dimethylacetamide were obtained and their structures were determined by X-ray diffraction analysis. The neptunium coordination polyhedra were found to be pentagonal bipyramids. The substituted terpyridines were shown to be efficient for the extraction of various valence forms of neptunium from the isothiocyanate solutions.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Thien H. Nguyen, Christophe Pauly, Greggory T. Kent, Guang Wu, Trevor W. Hayton
Summary: In this study, the reaction of BAC with [U(NR2)(3)(CCPh)] was investigated, and a new compound, [cyclo-N(Pr-i)C(Me)(2)CH((NPr2)-Pr-i)C{ 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 CHC3((NPr2)-Pr-i)(2)}][U(NR2)(2)(N(SiMe3)SiMe2CH2)(CCPh)] (2), was discovered. The formation of compound 2 involves coupling and protonation of two BAC molecules, with compound 1 providing the required proton.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yusuke Ishizaka, Natsumi Arai, Kazuhiro Matsumoto, Hiroki Nagashima, Katsuhiko Takeuchi, Norihisa Fukaya, Hiroyuki Yasuda, Kazuhiko Sato, Jun-Chul Choi
Summary: Recent advancements in surface organometallic chemistry have allowed for detailed characterization of surface species in single-site heterogeneous catalysts. This study introduces a metal complex with bidentate disilicate ligands as a molecular precursor for selectively forming bis-grafted surface species on silica supports. Solid-state NMR analysis confirmed the maintenance of the bidentate coordination sphere following grafting.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Sachie Yamamoto, Zong Yang Zhou, Goki Hiruta, Katsuhiko Takeuchi, Jun-Chul Choi, Takeshi Yasuda, Takaki Kanbara, Junpei Kuwabara
Summary: The Povarov reaction is an efficient tool for the synthesis of aza-polycyclic aromatic hydrocarbons, with site selectivity depending on the HOMO distribution of the intermediate. Specific molecular structures can be synthesized through the Povarov reaction, with one derivative showing good performance as a hole-blocking material in organic light-emitting diodes.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Katsuhiko Takeuchi, Ming-Yu Chen, Hao-Yu Yuan, Hiroki Koizumi, Kazuhiro Matsumoto, Norihisa Fukaya, Yoong-Kee Choe, Shinji Shigeyasu, Seiji Matsumoto, Satoshi Hamura, Jun-Chul Choi
Summary: The study successfully isolated and characterized a zinc carbamate complex and proposed an improved catalytic system that can efficiently synthesize various carbamates, including industrially important polyurethane raw materials, using CO2 under atmospheric pressure.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Hee Kwon Park, Min Gyu Ham, Yong-Joo Kim, Katsuhiko Takeuchi, Jun-Chul Choi
Summary: This study investigates the oxidative addition reactions of [M-0(styrene)(PMe3)(2)] (M = Pd/Pt) with star-shaped molecules and thiophenyl halide derivatives to obtain trinuclear complexes. In addition, the study explores the oxidative addition of a Pd(0) complex and the coupling reactions of Pt(II) halides with alkynes, as well as the insertion reactions of organic isocyanides, resulting in the formation of trinuclear Pd(II) and Pt(II) complexes.
JOURNAL OF COORDINATION CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Hiroki Koizumi, Katsuhiko Takeuchi, Kazuhiro Matsumoto, Norihisa Fukaya, Kazuhiko Sato, Masahito Uchida, Seiji Matsumoto, Satoshi Hamura, Jun-Chul Choi
Summary: This article introduces a new method for synthesizing N-substituted carbamic acid esters (CAEs) using low purity and low concentration of CO2, which can reduce CO2 emissions and eliminate the energy-consuming processes of purifying and concentrating CO2.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Inorganic & Nuclear
Masaki Okada, Katsuhiko Takeuchi, Kazuhiro Matsumoto, Tomoharu Oku, Takayoshi Yoshimura, Miho Hatanaka, Jun-Chul Choi
Summary: An improved catalytic system for the hydroxycarbonylation of alkenes using formic acid was developed, showing high activity and selectivity with a variety of alkene substrates. The catalytic cycle was elucidated using density functional theory calculations.
Article
Chemistry, Organic
Katsuhiko Takeuchi, Kazuhiro Matsumoto, Norihisa Fukaya, Kazuhiko Sato, Jun-Chul Choi
Summary: This study successfully synthesized glycerol carbonate using calcium oxide as a regenerable dehydrating agent and Zn(OTf)(2)/1,10-phenanthroline as a catalyst. Mechanical stirring effectively resolves the issue of calcium components solidification and achieves a high yield.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Toshiki Nishitoba, Kazuhiro Matsumoto, Yusuke Ishizaka, Natsumi Arai, Katsuhiko Takeuchi, Norihisa Fukaya, Tadahiro Fujitani, Akira Endo, Hiroyuki Yasuda, Kazuhiko Sato, Jun-Chul Choi
Summary: This study reports the synthesis and characterization of amorphous silica-supported Pt nanoparticles that form bis-grafted surface Pt species regardless of surface heterogeneity. The synthesized Pt nanoparticles have higher dispersibility and hydrogenation activity compared to those prepared by the impregnation method.
Article
Chemistry, Medicinal
Keita Iio, Kao Hashimoto, Yasuyuki Nagumo, Mao Amezawa, Taisei Hasegawa, Naoshi Yamamoto, Noriki Kutsumura, Katsuhiko Takeuchi, Yukiko Ishikawa, Hikari Yamamoto, Akihisa Tokuda, Tetsu Sato, Yasuo Uchida, Asuka Inoue, Ryuji Tanimura, Masashi Yanagisawa, Hiroshi Nagase, Tsuyoshi Saitoh
Summary: Orexins are neuropeptides that regulate sleep, emotion, and feeding. We discovered a potent OX1R-selective agonist and demonstrated its antinociceptive and reinforcing effects in mice.
JOURNAL OF MEDICINAL CHEMISTRY
(2023)
Article
Chemistry, Organic
Hiroki Koizumi, Katsuhiko Takeuchi, Kazuhiro Matsumoto, Norihisa Fukaya, Kazuhiko Sato, Masahito Uchida, Seiji Matsumoto, Satoshi Hamura, Junya Hirota, Makoto Nakashige, Jun-Chul Choi
Summary: In this study, we developed a reaction system that directly converts low concentration CO2 into carbamic acid esters (CAEs), which are precursors for pharmaceuticals, agrochemicals, and isocyanates. The reaction system, using Si(OMe)4 and 1,8-diazabicyclo[5.4.0]undec-7-ene, does not require metal complex catalysts or additives, making it simpler than previous systems. Various N-aryl, N-alkyl, and bis CAEs were synthesized with moderate to high yields, and the method also worked successfully with impurities present in simulated exhaust gas. This method has the potential to eliminate the use of toxic phosgene and reduce CO2 emissions.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xiao-Tao Lin, Yusuke Ishizaka, Yoshifumi Maegawa, Katsuhiko Takeuchi, Shinji Inagaki, Kazuhiro Matsumoto, Jun-Chul Choi
Summary: This study presents the synthesis of a Phen-based periodic mesoporous organosilica (Phen-PMO) by directly incorporating Phen moieties into the organosilica framework. The immobilization of Co(OAc)(2) on Phen-PMO 3 showed excellent catalytic activity for the hydrosilylation reaction of phenylacetylene with phenylsilane.
Review
Chemistry, Inorganic & Nuclear
Katsuhiko Takeuchi, Kazuhiro Matsumoto, Norihisa Fukaya, Kohtaro Osakada, Kazuhiko Sato, Jun-Chul Choi
Summary: The utilization of carbon dioxide in chemical materials has gained attention for its potential contribution to the reduction of CO2 emissions and mitigating climate change. A practical and environmentally friendly method for the synthesis of various organic carbamates from CO2, including industrially important diisocyanate precursors, using alkoxysilanes is proposed.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Organic
Masaki Okada, Katsuhiko Takeuchi, Kazuhiro Matsumoto, Tomoharu Oku, Jun-Chul Choi
Summary: A new catalytic system for hydroxycarbonylation of alkenes using a Vaska-type Rh complex and a quaternary ammonium iodide salt as a promoter was developed in this study. The reaction system is safer and more environmentally friendly compared to similar systems using Rh catalysts, as it does not require high-pressure conditions, explosive gases, or environmentally unfriendly promoters. Additionally, it was experimentally confirmed that the catalytic reaction proceeds via a Rh(iii) complex without any promoters.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Xiao-Tao Lin, Kazuhiro Matsumoto, Yoshifumi Maegawa, Katsuhiko Takeuchi, Norihisa Fukaya, Kazuhiko Sato, Shinji Inagaki, Jun-Chul Choi
Summary: Zinc acetate was immobilized on a bipyridine-based periodic mesoporous organosilica, demonstrating good catalytic activity during N-formylations with lower Zn loading.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Polymer Science
Takahiro Kawatsu, Keita Fuchise, Katsuhiko Takeuchi, Jun-Chul Choi, Kazuhiko Sato, Kazuhiro Matsumoto
Summary: This study successfully synthesized macrocyclic polysiloxanes with unique structures, and then transformed them into novel organofunctional polysiloxanes, maintaining the macrocyclic and spiro structures.
