Article
Chemistry, Multidisciplinary
Paul Zaby, Jan Blasius, Anna K. Mueller, Steven P. Nolan, Oldamur Holloczki
Summary: The formation mechanism of metal-N-heterocyclic carbene (NHC) complexes from imidazolium salts in the presence of weak bases was investigated through theoretical methods. Quantum chemical calculations revealed that both sodium acetate and trimethylamine facilitate complex formation. Molecular dynamics simulations showed that the ionic nature of the [AuCl2](-) and imidazolium ions, as well as the sodium acetate base, keep these species associated in the reaction mixture through ion pairing. The neutral amine, however, remains mostly separated from the other reaction partners, making it a significantly less effective base.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Tingting Li, Chengli Mou, Puying Qi, Xiaolin Peng, Shichun Jiang, Gefei Hao, Wei Xue, Song Yang, Lin Hao, Yonggui Robin Chi, Zhichao Jin
Summary: A catalytic atroposelective cycloaddition reaction between thioureas and ynals has been developed, enabling the establishment of C-N axial chirality with excellent optical purities. The resulting axially chiral thiazine derivative products contain multiple functional groups and are suitable for further transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Simiao Zhang, Xiaoxue Wang, Li-Li Han, Jibin Li, Zheng Liang, Donghui Wei, Ding Du
Summary: Atropisomers bearing multiple stereogenic axes have become increasingly important in material science, pharmaceuticals, and catalysis. However, the construction of multi-axis atropisomers with high stereoselectivity remains rare and challenging. In this study, a new class of 1,2-diaxially chiral triaryl alpha-pyranones was successfully synthesized in a single-step reaction, demonstrating broad substrate scope and excellent stereo-control. The success of this reaction can be attributed to the rational design of structurally matched reaction partners and the careful selection of the asymmetric catalytic system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Alina Wessels, Martin Klussmann, Martin Breugst, Nils E. Schloerer, Albrecht Berkessel
Summary: In this study, the mechanism of the reaction between N-heterocyclic carbenes and aldehydes under aprotic conditions was investigated using kinetic studies and DFT calculations. Different mechanistic regimes were proposed depending on the NHC-to-aldehyde ratio, with the H-shift occurring either in the NHC-aldehyde adduct or in the equilibrium between the zwitterion and hemiacetal forms. Furthermore, an H-bonded complex of the reaction intermediate with excess NHC was detected.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Animesh Biswas, Jorg-M Neudoerfl, Nils E. Schlorer, Albrecht Berkessel
Summary: Azolium enolates and acyl azolium cations serve as crucial intermediates in N-heterocyclic carbene (NHC) catalyzed reactions, with acetyl azolium enolates showing selective reactivity towards alcohol nucleophiles. The formation of esters is proposed to originate from azolium enolate intermediates rather than acyl azolium cations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Hui Tan, Shen-An Wang, Zixi Yan, Jianzhong Liu, Jialiang Wei, Song Song, Ning Jiao
Summary: This study demonstrates a novel N-heterocyclic carbene (NHC) catalyzed oxidative transformation of organic halides into esters utilizing O-2 as the oxygen source. Mechanistic studies show the oxidation of deoxy Breslow intermediate to Breslow intermediate for further transformation. This method expands the field of NHC catalysis and promotes oxygenation reactions with O-2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Wioletta Kosnik, Dawid Lichosyt, Marcin Sniezek, Angelika Janaszkiewicz, Krzysztof Wozniak, Maura Malinska, Bartosz Trzaskowski, Anna Kajetanowicz, Karol Grela
Summary: The formation of sterically hindered C-C double bonds through catalytic olefin metathesis is a challenging task for Ru catalysts. To overcome this limitation, a new NHC ligand was designed, which reduced the susceptibility of small-size NHC catalysts to decomposition. The resulting isomeric complexes exhibited similar high thermodynamic stability but different application profiles in catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Arne Merschel, Dennis Rottschaefer, Beate Neumann, Hans-Georg Stammler, Mark Ringenberg, Maurice Van Gastel, T. Ilgin Demirer, Diego M. M. Andrada, Rajendra S. S. Ghadwal
Summary: In this study, we have successfully synthesized and isolated two stable anions K[SIPrBp] (4 a-K) and K[IPrBp] (4 b-K). These anions, derived from classical N-heterocyclic carbenes (NHCs), exist as violet crystalline solids.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Bastiaan Kooij, Zhaowen Dong, Paul Varava, Farzaneh Fadaei-Tirani, Rosario Scopelliti, Laura Piveteau, Kay Severin
Summary: This study reports the preparation and structural characterization of vanadium complexes with N-heterocyclic vinylidene ligands, enabled by utilizing diazoolefins as ligand precursors. Structural and theoretical analysis show that N-heterocyclic vinylidenes can act as strong 6e(-) donor ligands, forming strong metal-carbon interactions.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Runxia Nan, Yiwen Li, Zhouli Zhu, Fan Qi, Xu-Qiong Xiao
Summary: This study focused on the synthesis and transformation of functional groups in metallacarboranes, and investigated their impact on the structure and properties of the metallacarborane framework.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
[Anonymous]
Summary: Breslow intermediates are pivotal species in Umpolung catalysis. This study reveals that, under aprotic conditions, the Breslow intermediate itself promotes a critical hydrogen shift in an autocatalytic manner.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis has the potential to achieve oxidative and oxygenative transformations, generating various NHC-bound intermediates and enabling non-umpolung processes through the activation of carbon atoms and heteroatoms. This review aims to discuss the recent developments in the field of oxidative NHC catalysis since 2014, with a focus on pivotal intermediates and their mechanistic involvement. More details can be found in the review article by C. De Risi and co-workers.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis enables oxidative and oxygenative transformations, producing various NHC-bound intermediates and facilitating non-umpolung processes by activating carbon atoms and heteroatoms. This review discusses the developments in the literature on oxidative NHC catalysis since 2014, with a specific focus on pivotal intermediates and their mechanistic involvement.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Iris Berg, Einav Amit, Lillian Hale, F. Dean Toste, Elad Gross
Summary: In this study, a N-heterocyclic carbene (NHC) nanolayer was successfully anchored on the surface of a copper electrode using an electrochemical method, resulting in improved oxidation resistance of copper.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Physical
Sourav Sekhar Bera, Michal Szostak
Summary: This comprehensive review presents catalytic methods utilizing cobalt-NHC complexes, focusing on catalyst structure, the role of the NHC ligand, properties of the catalytic system, mechanism, and synthetic utility. The survey suggests that well-defined cobalt-NHC catalysts have great potential in the design and application of catalytic reactions using more abundant 3d transition metals.
Article
Chemistry, Multidisciplinary
Shohei Kumagai, Takeru Koguma, Tatsuro Annaka, Chizuru Sawabe, Yukio Tani, Hiroki Sugiura, Tetsuya Watanabe, Daisuke Hashizume, Jun Takeya, Toshihiro Okamoto
Summary: Functionalization of pi-conjugated compounds is an important strategy for developing high-performance organic optoelectronic materials. In this study, the regioselective dibromination of a nitrogen-embedded perylene diimide analogue was achieved through palladium(II)-catalyzed oxidation and dicyanation. The resulting compound exhibited a deep lowest-unoccupied molecular orbital and good redox stability, leading to high electron mobility in transistors.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2022)
Article
Chemistry, Multidisciplinary
Airi Kuroda, Naoko Fujita, Tomomi Horita, Kei Ota, Alfredo Rosas-Sanchez, Manabu Hoshino, Daisuke Hashizume, Tsukasa Matsuo
Summary: In this study, the reaction between the bulky EMind-based compound and pyridine N-oxide was investigated, resulting in the formation of different germanium compounds. The reaction mechanism was also explored.
Article
Chemistry, Multidisciplinary
Kentaro Tashiro, Toshiaki Takei, Alejandro M. Fracaroli, Hiroyoshi Ohtsu, Masaki Kawano, Daisuke Hashizume
Summary: The study found that an N-Fmoc and C-tBu-protected glutamate bearing a phenanthrene moiety could crystallize and form a gel, with different structures depending on its optical purity or solvent. Treatment of an enantiomeric mixture of the compound in acetonitrile resulted in a mixture of gel and supernatant, with enrichment of the major enantiomer in the gel. Additionally, a racemic mixture of the compound also provided a gel/supernatant mixture, with enrichment of either L or D form of the compound stochastically due to chiral symmetry breaking during gelation.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Physical
Retno Miranti, Ricky Dwi Septianto, Tomoka Kikitsu, Daisuke Hashizume, Nobuhiro Matsushita, Yoshihiro Iwasa, Satria Zulkarnaen Bisri
Summary: In this study, stable cubic SnS colloidal nanocrystals (NCs) were successfully synthesized using a one-pot synthesis method under inert conditions. The NCs exhibit quantum confinement effects and show significant variations in energy band gaps due to size changes. Furthermore, the photodetectors of the SnS NCs exhibit high responsivity comparable to other established QD systems, despite being made from only a single or few layer(s).
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Kazushi Enomoto, Kotaro Takeda, Naoto Iwata, Kiyohiro Adachi, Tomoka Kikitsu, Yasuhiro Ishida, Daisuke Hashizume, Manabu Tanaka, Hiroyoshi Kawakami, Yong-Jin Pu
Summary: This study achieved one-dimensional fibrous assembly of CdS QDs in viscoelastic wet gel and provided a new strategy for the creation of quantum nanowires.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Inorganic & Nuclear
Sushree Aradhana Patra, Gurunath Sahu, Pratikshya Das Pattanayak, Takahiro Sasamori, Rupam Dinda
Summary: In this study, five fluorescent organotin(IV) complexes based on ONO donors were successfully synthesized and their photophysical properties were characterized. The results showed that these compounds were easily absorbed by cells and mainly internalized in mitochondria with negligible cytotoxicity at imaging concentration. Additionally, these complexes exhibited high photostability and could be used for long-term real-time tracking of cell organelles. Therefore, this low-toxic organotin-based fluorescent probe has potential applications in imaging mitochondria and tracking changes in their morphology within living cells.
INORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Takayuki Motoyama, Toshihiko Nogawa, Takeshi Shimizu, Makoto Kawatani, Takeshi Kashiwa, Choong-Soo Yun, Daisuke Hashizume, Hiroyuki Osada
Summary: Proteasome inhibitors with gamma-lactam structure have potential as anticancer drugs. In this study, TAS1 homologues from two fungi were found to be capable of biosynthesizing gamma-lactam compounds similar to actinomycete proteasome inhibitors. One of these compounds, taslactam C, displayed strong proteasome inhibitory activity. This finding highlights the importance of TAS1 and its homologues in fungal gamma-lactam compound biosynthesis.
ACS CHEMICAL BIOLOGY
(2023)
Article
Chemistry, Applied
Yusuke Oyamada, Shintaro Yamasaki, Mika Tsuzuki, Takumi Kitagawa, Masaru Kondo, Takahiro Sasamori, Shuichi Nakamura
Summary: The catalytic enantioselective allenylation of ketimines derived from isatins is reported. High regio- and enantioselective products were obtained using a bis(imidazoline)-palladium catalyst. The obtained products were further converted into various chiral amines. The stereoselectivity origin was revealed by DFT calculations of the transition state.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Masahiro Hamura, Kohei Sugano, Ryo Matsukura, Kei Ota, Tsukasa Nakahodo, Daisuke Hashizume, Tsukasa Matsuo
Summary: The structures of arylthiolates were confirmed using X-ray diffraction analysis. Different substituents were found to have different solid-state structures, with bulky substituents forming monomeric structures. A salt metathesis reaction between one of the compounds and FeCl2 resulted in the formation of a three-coordinate anion.
Article
Chemistry, Multidisciplinary
Narumi Itoh, Koh Sugamata, Shogo Morisako, Shinobu Aoyagi, Hideki Yorimitstu, Takahiro Sasamori
Summary: A stable dibenzo-1,6,2,5-dioxadisilocine was synthesized and used as a difunctional electrophile for double-silylation reactions. Its molecular structure was characterized by spectroscopic means and single-crystal X-ray diffraction analysis. Unexpected silylated polycyclic compound was obtained through reductive coupling of phenanthrene via formal [3+3] dimerization reaction.
Article
Chemistry, Inorganic & Nuclear
Diego A. Resendiz-Lara, Alfredo Rosas-Sanchez, Daisuke Hashizume, Jose E. Barquera-Lozada, R. Alfredo Toscano, Jose G. Lopez-Cortes, M. Carmen Ortega-Alfaro
Summary: A series of stable eta(4)-[Fe(CO)(3)] complexes (3a-f) were successfully synthesized through the reaction of eta(2)-[Fe(CO)(4)] complexes under mild carbonylation conditions. The reaction of 3a-f under thermal conditions unexpectedly resulted in the formation of a novel family of complexes (5a-f) through a metathesis-haptotropic rearrangement between the starting eta(4)-vinylketene iron(0) complex 3 and a eta(4)-vinylcarbene iron(0) complex trapped in situ after a reversible carbonylation process favored by the thermal conditions. An analysis of the electron density distribution of 5e using high-resolution X-ray diffraction data and DFT framework was performed to understand the electronic communication between the two iron fragments.
DALTON TRANSACTIONS
(2023)
Article
Nanoscience & Nanotechnology
Baocai Du, Kenjiro Fukuda, Tomoyuki Yokota, Daishi Inoue, Daisuke Hashizume, Sixing Xiong, Shinyoung Lee, Masahito Takakuwa, Lulu Sun, Jiachen Wang, Takao Someya
Summary: Insufficient interfacial adhesion is a common problem in multilayered devices, causing reliability issues. In flexible organic photovoltaics (OPVs), poor adhesion between layers can lead to degradation and failure under mechanical deformations. By using argon plasma treatment, we were able to increase the interfacial adhesion between the active layer and the MoOX hole transport layer by 58%, improving mechanical reliability. The treated active layer had a higher surface energy, contributing to the improved adhesion. The mechanically stabilized interface prolonged the lifespan of the flexible OPV device under mechanical stress.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Aufandra C. Wardhana, Akira Yamaguchi, Kiyohiro Adachi, Daisuke Hashizume, Masahiro Miyauchi
Summary: The titanium dioxide photocatalyst is only active under UV irradiation, but a new excitation pathway called interfacial charge transfer (IFCT) has been found to activate copper(II) oxide nanoclusters-loaded TiO2 powder (Cu(II)/TiO2) for organic decomposition under visible-light irradiation. A photoelectrochemical study showed that the Cu(II)/TiO2 electrode exhibited a cathodic photoresponse under both visible-light and UV irradiation, generating H-2 evolution on the electrode. This study demonstrates a direct interfacial excitation-induced cathodic photoresponse for water splitting without the need for a sacrificial agent, which can contribute to the development of visible-light-active photocathode materials for fuel production.
Article
Chemistry, Inorganic & Nuclear
Mridhul R. K. Ramachandran, Philipp C. Brehm, Gregor Schnakenburg, Takahiro Sasamori, Rene T. Boere, Rainer Streubel
Summary: Tricyclic 1,4-dihydro-1,4-phosphasilines 3a,b were synthesized from Si(NR2)(2)-bridged imidazole-2-thione compounds 2a,b. Based on the calculated Frontier Molecular Orbitals (FMOs) of 3b, a possible P-selective P-N bond cleavage reduction could be predicted, and a redox cycle was established using solutions of P-centred anionic derivative K[4b]. The cycle started with the oxidation of K[4b] to form the P-P coupled product 5b, which could be chemically reduced by KC8 to regenerate K[4b].
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Ryoto Yura, Shohei Kumagai, Kiyohiro Adachi, Daisuke Hashizume, Toshihiro Okamoto, Yoshiyuki Nonoguchi
Summary: This study demonstrates that supramolecular salt-functionalized n-doped ladder-type conducting polymers exhibit excellent stability in the presence of dry air.
CHEMICAL COMMUNICATIONS
(2023)
