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Beaufils A, Melle P, Lentz N, Albrecht M. Air-Stable Coordinatively Unsaturated Ruthenium(II) Complex for Ligand Binding and Catalytic Transfer Hydrogenation of Ketones from Ethanol. Inorg Chem 2024; 63:2072-2081. [PMID: 38230574 DOI: 10.1021/acs.inorgchem.3c03859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Coordinatively unsaturated complexes are interesting from a fundamental level for their formally empty coordination site and, in particular, from a catalytic perspective as they provide opportunities for substrate binding and transformation. Here, we describe the synthesis of a novel underligated ruthenium complex [Ru(cym)(N,N')]+, 3, featuring an amide-functionalized pyridylidene amide (PYA) as the N,N'-bidentate coordinating ligand. In contrast to previously investigated underligated complexes, complex 3 offers potential for dynamic modifications, thanks to the flexible donor properties of the PYA ligand. Specifically, they allow both for stabilizing the formally underligated metal center in complex 3 through nitrogen π-donation and for facilitating through π-acidic bonding properties the coordination of a further ligand L to the ruthenium center to yield the formal 18 e- complexes [Ru(cym)(N,N')(L)]+ (4: L = P(OMe)3; 5: L = PPh3; 6: L = N-methylimidazole; 7: L = pyridine) and neutral complex [RuCl(cym)(N,N')] 8. Analysis by 1H NMR and UV-vis spectroscopies reveals an increasing Ru-L bond strength along the sequence pyridine <1-methylimidazole < PPh3 < P(OMe)3 with binding constants varying over 3 orders of magnitude with log(Keq) values between 2.8 and 5.7. The flexibility of the Ru(PYA) unit and the ensuing accessibility of saturated and unsaturated species with one and the same ligand are attractive from a fundamental point of view and also for catalytic applications, as catalytic transformations rely on the availability of transiently vacant coordination sites. Thus, while complex 3 does not form stable adducts with O-donors such as ketones or alcohols, it transiently binds these species, as evidenced by the considerable catalytic activity in the transfer hydrogenation of ketones. Notably, and as one of only a few catalysts, complex 3 is compatible with EtOH as a hydrogen source. Complex 3 shows excellent performance in the transfer hydrogenation of pyridyl-containing substrates, in agreement with the poor coordination strength of this functional group to the ruthenium center in 3.
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Affiliation(s)
- Alicia Beaufils
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
| | - Philipp Melle
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
| | - Nicolas Lentz
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
| | - Martin Albrecht
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
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2
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Kaur M, Adhikari M, Manar KK, Yogesh Y, Prakash D, Singh S. BICAAC-Derived Covalent and Cationic Ir(I) Complexes: Application of Ir(BICAAC)Cl(COD) Complexes as Catalysts for Transfer Hydrogenation and Hydrosilylation Reactions. Inorg Chem 2024; 63:1513-1523. [PMID: 38192194 DOI: 10.1021/acs.inorgchem.3c01914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The ambiphilic bicyclic (alkyl)(amino)carbenes (Me/iPrBICAAC) upon reaction with [IrCl(COD)]2 smoothly afford mononuclear Ir(I) complexes that have been spectroscopically and structurally characterized. These complexes exhibit good catalytic activity for transfer hydrogenation (TH) of 4-chlorobenzaldehyde using isopropyl alcohol (iPrOH), with turnover frequency values ranging between 6269 and 8093 h-1. Choosing the covalent complex Ir(MeBICAAC)Cl(COD) as a catalyst, a wide array of carbonyls and imines functionalized with electron-withdrawing and electron-donating substituents have been surveyed and afforded their reduced products in moderate-to-good yields. No detachment of the BICAAC unit from the Ir center was observed upon prolonged heating of Ir(MeBICAAC)Cl(COD) in toluene-d8 or isopropyl alcohol-d8, which evidenced good thermal stability of the catalyst. Complex Ir(MeBICAAC)Cl(COD) was also found to be catalytically active for the hydrosilylation of a variety of aldehydes using triethylsilane (Et3SiH).
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Affiliation(s)
- Mandeep Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
| | - Manu Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
| | - Krishna K Manar
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
| | - Yuvraj Yogesh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
| | - Darsana Prakash
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
| | - Sanjay Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India
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3
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Ohashi M, Ando K, Murakami S, Michigami K, Ogoshi S. N-Heterocyclic Carbenes with Polyfluorinated Groups at the 4- and 5-Positions from [3 + 2] Cycloadditions between Formamidinates and cis-1,2-Difluoroalkene Derivatives. J Am Chem Soc 2023; 145:23098-23108. [PMID: 37749910 DOI: 10.1021/jacs.3c06331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
We herein report the formation of fluorinated N-heterocyclic carbenes (NHCFs) that bear fluorine atoms at the 4- and 5-positions of the imidazol-2-ylidene ring. Treatment of sodium N,N'-bis(aryl)formamidinates with tetrafluoroethylene followed by the addition of LiBF4 induced a [3 + 2] cycloaddition to afford 4,5-difluorinated imidazolium salts, which served as the precursors for 4,5-difluorinated NHCs. A key feature of this procedure is its applicability to other perfluorinated compounds, which enabled us to incorporate polyfluorinated functional groups at 4- and 5-positions on the imidazol-2-ylidene skeleton. Thus, employing octafluorocyclopentene and hexafluorobenzene led to the formation of 4,4,5,5,6,6-hexafluoro-1,3-diaryl-3,4,5,6-tetrahydrocyclopenta[d]imidazolium (CypIPrF·HBF4) and 4,5,6,7-tetrafluoro-1,3-diarylbenzimidazolium (BIPrF·HBF4) salts, respectively. A thorough NMR analysis of these NHCFs, their selenium adducts, and their tricarbonyl nickel complexes, (NHCF)Ni(CO)3, demonstrated that the fluorine substituents, contrary to expectations, tend to act as electron donors owing to the considerable positive mesomeric effect, while the perfluorocyclopentene-fused and tetrafluorobenzo-fused rings are pure electron acceptors due to their strong negative inductive effect. The unique and increased π-accepting character of the perfluorocyclopentene-fused and tetrafluorobenzo-fused NHCFs in both stoichiometric and catalytic reactions is further demonstrated by employing (NHCF)Ni(CO)3 and (NHCF)AuCl species, respectively. Moreover, an analysis of the % buried volume (%Vbur) values clearly suggests that the modification of the NHC backbone with polyfluorinated groups can drastically alter the electronic properties of the NHC ligand without substantially changing its steric properties. Our experimental results were further corroborated by a series of computational calculations.
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Affiliation(s)
- Masato Ohashi
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, Sakai 599-8531 Osaka, Japan
| | - Kota Ando
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita 565-0871 Osaka, Japan
| | - Shoichi Murakami
- Department of Chemistry, Faculty of Science, Osaka Prefecture University, Sakai 599-8531 Osaka, Japan
| | - Kenichi Michigami
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, Sakai 599-8531 Osaka, Japan
| | - Sensuke Ogoshi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita 565-0871 Osaka, Japan
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4
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Sonoda T, Kanamori M, Endo K, Miwa K, Kurumada S, Suzuki K, Yamashita M, Shibahara F. 5‐Sulfurated Imidazo[1,5‐
a
]Pyridin‐3‐ylidenes: Ligands for π‐Acidic Catalysts. Isr J Chem 2022. [DOI: 10.1002/ijch.202200038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Takuya Sonoda
- Takuya Sonoda Masaya Kanamori Koki Endo Fumitoshi Shibahara Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Yanagido Gifu 501-1193 Japan
| | - Masaya Kanamori
- Takuya Sonoda Masaya Kanamori Koki Endo Fumitoshi Shibahara Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Yanagido Gifu 501-1193 Japan
| | - Koki Endo
- Takuya Sonoda Masaya Kanamori Koki Endo Fumitoshi Shibahara Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Yanagido Gifu 501-1193 Japan
| | - Kazuki Miwa
- Takuya Sonoda Masaya Kanamori Koki Endo Fumitoshi Shibahara Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Yanagido Gifu 501-1193 Japan
| | - Satoshi Kurumada
- Satoshi Kurumada Katsunori Suzuki Makoto Yamashita Department of Molecular and Macromolecular Chemistry Graduate School of Engineering Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
| | - Katsunori Suzuki
- Satoshi Kurumada Katsunori Suzuki Makoto Yamashita Department of Molecular and Macromolecular Chemistry Graduate School of Engineering Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
| | - Makoto Yamashita
- Satoshi Kurumada Katsunori Suzuki Makoto Yamashita Department of Molecular and Macromolecular Chemistry Graduate School of Engineering Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
| | - Fumitoshi Shibahara
- Takuya Sonoda Masaya Kanamori Koki Endo Fumitoshi Shibahara Department of Chemistry and Biomolecular Science Faculty of Engineering Gifu University Yanagido Gifu 501-1193 Japan
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5
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Shibahara F, Shibata Y, Murai T. Imidazo[1,5- a]pyridinylidenes as π-Accepting NHC Ligands in Catalysis. CHEM LETT 2021. [DOI: 10.1246/cl.210461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Fumitoshi Shibahara
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Yoshifuru Shibata
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Toshiaki Murai
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
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6
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Kuriyama S, Zhao W, Nishibayashi Y. Synthesis and Characterization of Rhodium Complex Bearing Anionic CNC‐Type Pincer Ligand with Pyrrolide and Imidazo[1,5‐
a
]pyridin‐3‐ylidene Moieties. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202100065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Shogo Kuriyama
- Department of Applied Chemistry School of Engineering The University of Tokyo, Hongo Bunkyo-ku Tokyo 113-8656 Japan
| | - Wenhao Zhao
- Department of Applied Chemistry School of Engineering The University of Tokyo, Hongo Bunkyo-ku Tokyo 113-8656 Japan
| | - Yoshiaki Nishibayashi
- Department of Applied Chemistry School of Engineering The University of Tokyo, Hongo Bunkyo-ku Tokyo 113-8656 Japan
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7
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Shibahara F, Mizuno T, Shibata Y, Murai T. Transfer Semihydrogenation of Alkynes Catalyzed by Imidazo[1,5- a]pyrid-3-ylidene–Pd Complexes: Positive Effects of Electronic and Steric Features on N-Heterocyclic Carbene Ligands. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20190333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Fumitoshi Shibahara
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Takahiro Mizuno
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Yoshifuru Shibata
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
| | - Toshiaki Murai
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
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8
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Ruthenium(II) complexes bearing N-heterocyclic carbene ligands with wingtip groups and their catalytic activity in the transfer hydrogenation of ketones. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2019.119199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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9
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Kashihara M, Zhong RL, Semba K, Sakaki S, Nakao Y. Pd/NHC-catalyzed cross-coupling reactions of nitroarenes. Chem Commun (Camb) 2019; 55:9291-9294. [DOI: 10.1039/c9cc05055h] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
N-Heterocyclic carbene (NHC) ligands effective for the cross-coupling of nitroarenes were identified.
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Affiliation(s)
- Myuto Kashihara
- Department of Material Chemistry
- Graduate School of Engineering
- Kyoto University
- Kyoto 615-8510
- Japan
| | - Rong-Lin Zhong
- Fukui Institute for Fundamental Chemistry
- Kyoto University
- Japan
| | - Kazuhiko Semba
- Department of Material Chemistry
- Graduate School of Engineering
- Kyoto University
- Kyoto 615-8510
- Japan
| | | | - Yoshiaki Nakao
- Department of Material Chemistry
- Graduate School of Engineering
- Kyoto University
- Kyoto 615-8510
- Japan
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10
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Yagishita F, Kinouchi T, Hoshi K, Tezuka Y, Jibu Y, Karatsu T, Uemura N, Yoshida Y, Mino T, Sakamoto M, Kawamura Y. Highly efficient blue emission from boron complexes of 1-(o-hydroxyphenyl)imidazo[1,5-a]pyridine. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.05.048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Yagishita F, Kozai N, Nii C, Tezuka Y, Uemura N, Yoshida Y, Mino T, Sakamoto M, Kawamura Y. Synthesis of Dimeric Imidazo[1, 5-a
]pyridines and Their Photophysical Properties. ChemistrySelect 2017. [DOI: 10.1002/slct.201702277] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Fumitoshi Yagishita
- Department of Applied Chemistry; Graduate School of Science and Technology; Tokushima University; Tokushima 770-8506 Japan
| | - Natsumi Kozai
- Department of Applied Chemistry; Graduate School of Science and Technology; Tokushima University; Tokushima 770-8506 Japan
| | - Chiho Nii
- Department of Applied Chemistry; Graduate School of Science and Technology; Tokushima University; Tokushima 770-8506 Japan
| | - Yoshihiko Tezuka
- Department of Optical Science and Technology; Graduate School of Science and Technology; Tokushima University; Tokushima 770-8506 Japan
| | - Naohiro Uemura
- Graduate School of Engineering; Chiba University; Chiba 263-8522 Japan
| | - Yasushi Yoshida
- Graduate School of Engineering; Chiba University; Chiba 263-8522 Japan
| | - Takashi Mino
- Graduate School of Engineering; Chiba University; Chiba 263-8522 Japan
| | - Masami Sakamoto
- Graduate School of Engineering; Chiba University; Chiba 263-8522 Japan
| | - Yasuhiko Kawamura
- Department of Applied Chemistry; Graduate School of Science and Technology; Tokushima University; Tokushima 770-8506 Japan
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12
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Koto Y, Shibahara F, Murai T. Imidazo[1,5-a]pyridin-3-ylidenes as π-accepting carbene ligands: substituent effects on properties of N-heterocyclic carbenes. Org Biomol Chem 2017; 15:1810-1820. [DOI: 10.1039/c6ob02827f] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Imidazo[1,5-a]pyridine-derived NHCs gained strong π-accepting character due to their structural features.
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Affiliation(s)
- Yuma Koto
- Department of Chemistry and Molecular Science
- Faculty of Engineering
- Gifu University
- Gifu 501-1193
- Japan
| | - Fumitoshi Shibahara
- Department of Chemistry and Molecular Science
- Faculty of Engineering
- Gifu University
- Gifu 501-1193
- Japan
| | - Toshiaki Murai
- Department of Chemistry and Molecular Science
- Faculty of Engineering
- Gifu University
- Gifu 501-1193
- Japan
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