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Neshat A, Mousavizadeh Mobarakeh A, Yousefshahi MR, Varmaghani F, Dusek M, Eigner V, Kucerakova M. Introducing Novel Redox-Active Bis(phenolate) N-Heterocyclic Carbene Proligands: Investigation of Their Coordination to Fe(II)/Fe(III) and Their Catalytic Activity in Transfer Hydrogenation of Carbonyl Compounds. ACS OMEGA 2024; 9:25135-25145. [PMID: 38882110 PMCID: PMC11170717 DOI: 10.1021/acsomega.4c02602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/19/2024] [Accepted: 05/23/2024] [Indexed: 06/18/2024]
Abstract
A simple and efficient procedure for synthesizing novel pincer-type tridentate N-heterocyclic carbene bisphenolate ligands is reported. The synthesis of pincer proligands with N,N'-disubstituted imidazoline core, 5 and 6, was carried out via triethylorthoformate-promoted cyclization of either N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)cyclohexanediamine, 3, or N,N'-bis(2-hydroxyphenyl)cyclohexanediamine, 4, in the presence of concentrated hydrochloric acid. Cyclic voltammograms of the ligands revealed ligand-centered redox activity, indicating the noninnocent nature of the ligands. The voltammograms of the ligands exhibit two successive one-electron oxidations and two consecutive one-electron reductions. In contrast to previous reports, the redox-active ligands in this study exhibit one-electron oxidation and reduction processes. All products were thoroughly characterized by using 1H and 13C NMR spectroscopy. The base-promoted deprotonation of the proligands and subsequent reaction with iron(II) and iron(III) chlorides yielded compounds 7 and 8. These compounds are binuclear and tetranuclear iron(III) complexes that do not contain carbene functional groups. Complexes 7 and 8 were characterized by using elemental analysis and single-crystal X-ray crystallography. At low catalyst loadings, both 7 and 8 exhibited high catalytic activity in the transfer hydrogenation of selected aldehydes and ketones.
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Affiliation(s)
- Abdollah Neshat
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), 444 Prof. Sobouti Blvd., Gava Zang, Zanjan 45137-66731, Iran
| | - Ali Mousavizadeh Mobarakeh
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), 444 Prof. Sobouti Blvd., Gava Zang, Zanjan 45137-66731, Iran
| | - Mohammad Reza Yousefshahi
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), 444 Prof. Sobouti Blvd., Gava Zang, Zanjan 45137-66731, Iran
| | - Fahimeh Varmaghani
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), 444 Prof. Sobouti Blvd., Gava Zang, Zanjan 45137-66731, Iran
| | - Michal Dusek
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 18221 Prague 8, The Czech Republic
| | - Vaclav Eigner
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 18221 Prague 8, The Czech Republic
| | - Monika Kucerakova
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 18221 Prague 8, The Czech Republic
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2
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Sarkar A, Das S, Mondal P, Maiti B, Sen Gupta S. Synthesis, Characterization, and Reactivity of High-Valent Carbene Dicarboxamide-Based Nickel Pincer Complexes. Inorg Chem 2023. [PMID: 38001041 DOI: 10.1021/acs.inorgchem.3c03465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
High-valent metal-fluoride complexes are currently being explored for concerted proton-electron transfer (CPET) reactions, the driving force being the high bond dissociation energy of H-F (BDEH-F = 135 kcal/mol) that is formed after the reaction. Ni(III)-fluoride-based complexes on the pyridine dicarboxamide pincer ligand framework have been utilized for CPET reactions toward phenols and hydrocarbons. We have replaced the central pyridine ligand with an N-heterocyclic carbene carbene to probe its effect in both stabilizing the high-valent Ni(III) state and its ability to initiate CPET reactions. We report a monomeric carbene-diamide-based Ni(II)-fluoride pincer complex that was characterized through 1H/19F NMR, mass spectrometry, UV-vis, and X-ray crystallography analysis. Although carbenes and deprotonated carboxamides in the Ni(II)-fluoride complex are expected to stabilize the Ni(III) state upon oxidation, the Ni(III)/Ni(II) redox process occurred at very high potential (0.87 V vs Fc+/Fc, dichloromethane) and was irreversible. Structural studies indicate significant distortion in the imidazolium "NCN" carbene plane of Ni(II)-fluoride caused by the formation of six-membered metallacycles. The high-valent NiIII-fluoride analogue was synthesized by the addition of 1.0 equiv CTAN (ceric tetrabutylammonium nitrate) in dichloromethane at -20 °C which was characterized by UV-vis, mass spectrometry, and EPR spectroscopy. Density functional theory studies indicate that the Ni-carbene bond elongated, while the Ni-F bond shortened upon oxidation to the Ni(III) species. The high-valent Ni(III)-fluoride was found to react with the substituted phenols. Analysis of the KIE and linear free energy relationship correlates well with the CPET nature of the reaction. Preliminary analysis indicates that the CPET is asynchronous and is primarily driven by the E0' of the Ni(III)-fluoride complex.
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Affiliation(s)
- Aniruddha Sarkar
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India
| | - Soumadip Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India
| | - Prasenjit Mondal
- Department of Chemistry, Indian Institute of Technology Tirupati (IIT Tirupati), Tirupati, AP 517619, India
| | - Biswajit Maiti
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Sayam Sen Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India
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3
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Ameskal M, Taakili R, Gulyaeva ES, Duhayon C, Willot J, Lugan N, Lepetit C, Valyaev DA, Canac Y. Phosphine-NHC-Phosphonium Ylide Pincer Ligand: Complexation with Pd(II) and Unconventional P-Coordination of the Ylide Moiety. Inorg Chem 2023. [PMID: 37996076 DOI: 10.1021/acs.inorgchem.3c03025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
An efficient synthesis of two pincer preligands [Ph2PCH(R)ImCH2CH2CH2PPh3]X2 (R = H, X = OTf; R = Ph, X = BF4) was developed. Subsequent reactions with PdCl2 and an excess of Cs2CO3 led to the formation of highly stable cationic ortho-metalated Pd(II) complexes [(P,C,C,C)Pd]X exhibiting phosphine, NHC, phosphonium ylide, and σ-aryl donor extremities. The protonation of one of the latter complexes with R = H affords the Pd(II) complex [(P,C,C)Pd(MeCN)](OTf)2 bearing an unprecedented nonsymmetrical NHC core pincer scaffold with a 5,6-chelating framework. The overall donor properties of this phosphine-NHC-phosphonium ylide ligand were estimated using the experimental νCN stretching frequency in the corresponding [(P,C,C)Pd(CNtBu](OTf)2 derivative and were shown to be competitive with the related bis(NHC)-phosphonium ylide and phenoxy-NHC-phosphonium ylide pincers. The presence of a phenyl substituent in the bridge between phosphine and NHC moieties in the ortho-metalated complex [(P,C,C,C)Pd](BF4) makes possible the deprotonation of this position using LDA to provide a persistent zwitterionic complex [(P,C,C,C)Pd] featuring a rare P-coordinated phosphonium ylide moiety in addition to a conventional C-coordinated one. The comparison of the 31P and 13C NMR data for these C- and P-bound phosphonium ylide fragments within the same molecule was performed for the first time, and the bonding situation in both cases was studied in detail by QTAIM and ELF topological analyses.
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Affiliation(s)
- Mohammad Ameskal
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Rachid Taakili
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Ekaterina S Gulyaeva
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences, 28/1 Vavilov str., GSP-1, B-334, Moscow 119334, Russia
| | - Carine Duhayon
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Jérémy Willot
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Noël Lugan
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Christine Lepetit
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Dmitry A Valyaev
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
| | - Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse cedex 4, France
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4
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Canac Y. Carbon-Phosphorus Ligands with Extreme Donating Character. CHEM REC 2023; 23:e202300187. [PMID: 37435947 DOI: 10.1002/tcr.202300187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/22/2023] [Indexed: 07/13/2023]
Abstract
Carbeniophosphines [R2 C+ -PR2 ] and phosphonium ylides [R3 P+ -CR2 - ] are two complementary classes of carbon-phosphorus based ligands defined by their unique donor properties. Indeed, while carbeniophosphines are electron-poor P-ligands due to the positioning of a positive charge near the coordinating P-atom, phosphonium ylides are electron-rich C-ligands due to the presence of a negatively charged coordinating C-atom. Based on this knowledge, this account summarizes our recent contribution on these two classes of carbon-phosphorus ligands, and in particular the strategies developed to lower the donor character of carbeniophosphines and enhance that of phosphonium ylides. This led us to design, at both extremities of the donating scale, extremely electron-poor P-ligands exemplified by imidazoliophosphonites [R2 C+ -P(OR)2 ] and dicarbeniophosphines [(R2 C+ )2 -PR], and extremely electron-rich C-ligands illustrated by pincer architectures exhibiting several phosphonium ylide donor extremities. In the context of carbon-phosphorus analogy, the closely related cases of ligands where the C-atom of a NHC ligand is in close proximity of two positive charges, and that of a phosphonium ylide coordinated through its P-atom are also discussed. An overview of the synthetic methods, coordinating properties, general reactivity and electronic structure of all these C,P-based species is presented here.
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Affiliation(s)
- Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077, Toulouse Cedex 4, France
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5
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Singh S, Shinde VN, Kumar S, Meena N, Bhuvanesh N, Rangan K, Kumar A, Joshi H. Mono and Dinuclear Palladium Pincer Complexes of NNSe Ligand as a Catalyst for Decarboxylative Direct C-H Heteroarylation of (Hetero)arenes. Chem Asian J 2023; 18:e202300628. [PMID: 37602812 DOI: 10.1002/asia.202300628] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 08/22/2023]
Abstract
This report describes the synthesis of a new NNSe pincer ligand and its mono- and dinuclear palladium(II) pincer complexes. In the absence of a base, a dinuclear palladium pincer complex (C1) was isolated, while in the presence of Et3 N base a mononuclear palladium pincer complex (C2) was obtained. The new ligand and complexes were characterized using techniques like 1 H, 13 C{1 H} nuclear magnetic resonance (NMR), fourier transform infrared (FTIR), high-resolution mass spectrometry (HRMS), ultraviolet-visible (UV-Visible), and cyclic voltammetry. Both the complexes showed pincer coordination mode with a distorted square planar geometry. The complex C1 has two pincer ligands attached through a Pd-Pd bond in a dinuclear pincer fashion. The air and moisture-insensitive, thermally robust palladium pincer complexes were used as the catalyst for decarboxylative direct C-H heteroarylation of (hetero)arenes. Among the complexes, dinuclear pincer complex C1 showed better catalytic activity. A variety of (hetero)arenes were successfully activated (43-87 % yield) using only 2.5 mol % of catalyst loading under mild reaction conditions. The PPh3 and Hg poisoning experiments suggested a homogeneous nature of catalysis. A plausible reaction pathway was proposed for the dinuclear palladium pincer complex catalyzed decarboxylative C-H bond activation reaction of (hetero)arenes.
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Affiliation(s)
- Sohan Singh
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Vikki N Shinde
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, Pilani Campus, Pilani, 333031, India
| | - Sunil Kumar
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Neha Meena
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, Pilani Campus, Pilani, 333031, India
| | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A&M University, PO Box 30012, College Station, Texas, 77842-3012, USA
| | - Krishnan Rangan
- Department of Chemistry, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Telangana, 500078, India
| | - Anil Kumar
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, Pilani Campus, Pilani, 333031, India
| | - Hemant Joshi
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
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6
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Watson LJ, Hill AF. C-H activation in bimetallic rhodium complexes to afford N-heterocyclic carbene pincer complexes. Dalton Trans 2023; 52:2164-2174. [PMID: 36723105 DOI: 10.1039/d2dt03984b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The pro-ligands 1,8-bis(di-R-phosphinomethyl)-2,3-dihydroperimidine (RH2Pm, R = phenyl, cyclohexyl) react with [RhCl(CE)(PPh3)2] (E = O, S) to afford the bimetallic complexes [RhCl(CE)(μ-RH2Pm)]2 (E = O, S). Upon heating, these species undergo double C-H activation to afford the N-heterocyclic carbene (NHC) pincer complexes [RhCl(RPm)]. Reduction of [RhCl(CO)(μ-PhH2Pm)]2 with KC8 results in the bimetallic rhodium(0) complex, [Rh(μ-CO)(PhH2Pm)]2, with a formal Rh-Rh bond and a hydrogen-bonding interaction between rhodium and the central methylene group (C-H⋯Rh = 2.802 Å). Upon treatment with tritylium, ferrocenium or triphenylcyclopropenium tetrafluoroborates this species undergoes double C-H activation to afford a mononuclear NHC pincer complex salt, [Rh(CO)(PhPm)]BF4. Treatment of [RhCl(CO)(PhH2Pm)]2 with lithium (trimethylsilyl)acetylide provides another bimetallic species, [Rh(CCSiMe3)(CO)(PhH2Pm)]2, however heating this species does not proceed cleanly to the monomeric NHC complex, [Rh(CCSiMe3)(CO)(PhPm)] which may however be obtained from [RhCl(RPm)] and LiCCSiMe3.
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Affiliation(s)
- Lachlan J Watson
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
| | - Anthony F Hill
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
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7
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He F, Gourlaouen C, Pang H, Braunstein P. Experimental and Theoretical Study of Ni
II
‐ and Pd
II
‐Promoted Double Geminal C(sp
3
)−H Bond Activation Providing Facile Access to NHC Pincer Complexes: Isolated Intermediates and Mechanism. Chemistry 2022; 28:e202200507. [PMID: 35543286 PMCID: PMC9401054 DOI: 10.1002/chem.202200507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Indexed: 11/11/2022]
Abstract
We report the first examples of metal‐promoted double geminal activation of C(sp3)−H bonds of the N−CH2−N moiety in an imidazole‐type heterocycle, leading to nickel and palladium N‐heterocyclic carbene complexes under mild conditions. Reaction of the new electron‐rich diphosphine 1,3‐bis((di‐tert‐butylphosphaneyl)methyl)‐2,3‐dihydro‐1H‐benzo[d]imidazole (1) with [PdCl2(cod)] occurred in a stepwise fashion, first by single C−H bond activation yielding the alkyl pincer complex [PdCl(PCsp3HP)] (3) with two trans phosphane donors and a covalent Pd−Csp3
bond. Activation of the C−H bond of the resulting α‐methine Csp3
H−M group occurred subsequently when 3 was treated with HCl to yield the NHC pincer complex [PdCl(PCNHCP)]Cl (2). Treatment of 1 with [NiBr2(dme)] also afforded a NHC pincer complex, [NiBr(PCNHCP)]Br (6), but the reactions leading to the double geminal C−H bond activation of the N−CH2−N group were too fast to allow identification or isolation of an intermediate analogous to 3. The determination of six crystal structures, the isolation of reaction intermediates and DFT calculations provided the basis for suggesting the mechanism of the stepwise transformation of a N−CH2−N moiety in the N−CNHC−N unit of NHC pincer complexes and explain the key differences observed between the Pd and Ni chemistries.
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Affiliation(s)
- Fengkai He
- School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225009 Jiangsu P. R. China) E-mail: s
- Laboratoire de Chimie de Coordination Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
| | - Christophe Gourlaouen
- Laboratoire de Chimie Quantique Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
| | - Huan Pang
- School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225009 Jiangsu P. R. China) E-mail: s
| | - Pierre Braunstein
- Laboratoire de Chimie de Coordination Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
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8
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Synthesis, structure, and properties of the Sc chloride complex coordinated by the tridentate bis(phenolate)-tethered NHC ligand. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3412-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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He F, Gourlaouen C, Pang H, Braunstein P. Influence of the Flexibility of Nickel PCP‐Pincer Complexes on C−H and P−C Bond Activation and Ethylene Reactivity: A Combined Experimental and Theoretical Investigation. Chemistry 2022; 28:e202104234. [DOI: 10.1002/chem.202104234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Indexed: 11/10/2022]
Affiliation(s)
- Fengkai He
- School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225009 Jiangsu P. R. China
- Laboratoire de Chimie de Coordination Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
| | - Christophe Gourlaouen
- Laboratoire de Chimie Quantique Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
| | - Huan Pang
- School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225009 Jiangsu P. R. China
| | - Pierre Braunstein
- Laboratoire de Chimie de Coordination Institut de Chimie (UMR 7177 CNRS) Université de Strasbourg 4 rue Blaise Pascal 67081 Strasbourg France
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10
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El Kadiri M, Chihab A, Taakili R, Duhayon C, Valyaev DA, Canac Y. Diverse C-Coordination Modes of NHC-Tricyclohexylphosphonium Ylide Ligands in Palladium(II) Complexes. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Mustapha El Kadiri
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
| | - Abdelali Chihab
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
| | - Rachid Taakili
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
| | - Carine Duhayon
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
| | - Dmitry A. Valyaev
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
| | - Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France
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11
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Bisamidate-functionalized NHC ligands: Electronic and steric influences of N-substituents on the bisamidate moieties. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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12
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Bawari D, Volodarsky S, Ginzburg Y, Jaiswal K, Joshi P, Dobrovetsky R. Phosphorus mediated imidazolinium to oxazolium ring rearrangement. Dalton Trans 2021; 50:16478-16482. [PMID: 34730572 DOI: 10.1039/d1dt03363h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
An unexpected rearrangement occurred when an imidazolinium based OCO pincer-type ligand (1) reacted with PCl3 producing a chlorophosphine with a pendant oxazolium "arm" (3). The mechanism of this rearrangement was studied both experimentally and by density functional theory (DFT) computations. The deprotonation of 3 led to further unexpected results.
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Affiliation(s)
- Deependra Bawari
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Solomon Volodarsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Yael Ginzburg
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Kuldeep Jaiswal
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Pooja Joshi
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Roman Dobrovetsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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13
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Valyaev DA, Canac Y. Carbenes and phosphonium ylides: a fruitful association in coordination chemistry. Dalton Trans 2021; 50:16434-16442. [PMID: 34664574 DOI: 10.1039/d1dt03155d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Among a plethora of σ-donor ligands available, carbon-centered ones have become essential, in particular with the emergence of N-heterocyclic carbenes (NHCs), positioning themselves as credible alternatives to traditional nitrogen- and phosphorus-based systems. Phosphonium ylides representing another class of neutral η1-bonded carbon ligands have also been shown to act as effective Lewis bases. Considering the intrinsic features of the carbene and phosphonium ylide ligands, similar in terms of electronic properties, but different in terms of bonding mode, the design of hybrid systems combining these two types of carbon functionalities appeared to be a natural and exciting challenge. This Perspective comprehensively covers the chemistry of such ligand architectures from synthesis and fundamental aspects to catalytic applications.
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Affiliation(s)
- Dmitry A Valyaev
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse Cedex 4 31077, France.
| | - Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse Cedex 4 31077, France.
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14
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Neururer F, Liu S, Leitner D, Baltrun M, Fisher KR, Kopacka H, Wurst K, Daumann LJ, Munz D, Hohloch S. Mesoionic Carbenes in Low- to High-Valent Vanadium Chemistry. Inorg Chem 2021; 60:15421-15434. [PMID: 34590834 PMCID: PMC8527456 DOI: 10.1021/acs.inorgchem.1c02087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Indexed: 12/12/2022]
Abstract
We report the synthesis of vanadium(V) oxo complex 1 with a pincer-type dianionic mesoionic carbene (MIC) ligand L1 and the general formula [VOCl(L1)]. A comparison of the structural (SC-XRD), electronic (UV-vis), and electrochemical (cyclic voltammetry) properties of 1 with the benzimidazolinylidene congener 2 (general formula [VOCl(L2)]) shows that the MIC is a stronger donor also for early transition metals with low d-electron population. Since electrochemical studies revealed both complexes to be reversibly reduced, the stronger donor character of MICs was not only demonstrated for the vanadium(V) but also for the vanadium(IV) oxidation state by isolating the reduced vanadium(IV) complexes [Co(Cp*)2][1] and [Co(Cp*)2][2] ([Co(Cp*)2] = decamethylcobaltocenium). The electronic structures of the compounds were investigated by computational methods. Complex 1 was found to be a moderate precursor for salt metathesis reactions, showing selective reactivity toward phenolates or secondary amides, but not toward primary amides and phosphides, thiophenols, or aryls/alkyls donors. Deoxygenation with electron-rich phosphines failed to give the desired vanadium(III) complex. However, treatment of the deprotonated ligand precursor with vanadium(III) trichloride resulted in the clean formation of the corresponding MIC vanadium(III) complex 6, which undergoes a clean two-electron oxidation with organic azides yielding the corresponding imido complexes. The reaction with TMS-N3 did not afford a nitrido complex, but instead the imido complex 10. This study reveals that, contrary to popular belief, MICs are capable of supporting early transition-metal complexes in a variety of oxidation states, thus making them promising candidates for the activation of small molecules and redox catalysis.
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Affiliation(s)
- Florian
R. Neururer
- Institute
of Inorganic, General and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Shenyu Liu
- Faculty
of Science, Department of Chemistry, University
of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Daniel Leitner
- Institute
of Inorganic, General and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Marc Baltrun
- Faculty
of Science, Department of Chemistry, University
of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Katherine R. Fisher
- Department
Chemie, Ludwigs-Maximilians-University Munich, Butenandtstraße 5-13 Haus D, 81377 Munich, Germany
| | - Holger Kopacka
- Institute
of Inorganic, General and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Klaus Wurst
- Institute
of Inorganic, General and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Lena J. Daumann
- Department
Chemie, Ludwigs-Maximilians-University Munich, Butenandtstraße 5-13 Haus D, 81377 Munich, Germany
| | - Dominik Munz
- Fakultät
NT, Inorganic Chemistry: Coordination Chemistry, Saarland University, Campus C4.1, 66123 Saarbrücken, Germany
| | - Stephan Hohloch
- Institute
of Inorganic, General and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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15
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Cooper EN, Averkiev B, Day VW, Sues PE. Ring-Opening Polymerization of ε-Caprolactone Utilizing Aluminum Alkyl Complexes Bearing Dianionic Scorpionate Ligands. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Elizabeth N. Cooper
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66503, United States
| | - Boris Averkiev
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66503, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Peter E. Sues
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66503, United States
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16
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Zapf L, Radius U, Finze M. 1,3-Bis(tricyanoborane)imidazoline-2-ylidenate Anion-A Ditopic Dianionic N-Heterocyclic Carbene Ligand. Angew Chem Int Ed Engl 2021; 60:17974-17980. [PMID: 33961330 PMCID: PMC8453866 DOI: 10.1002/anie.202105529] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Indexed: 01/14/2023]
Abstract
The 1,3-bis(tricyanoborane)imidazolate anion 1 was obtained in high yield from lithium imidazolate and B(CN)3 -pyridine adduct. Anion 1 is chemically very robust and thus allowed the isolation of the corresponding H5 O2 + salt. Furthermore, monoanion 1 served as starting species for the novel dianionic N-heterocyclic carbene (NHC), 1,3-bis(tricyanoborane)imidazoline-2-ylidenate anion 3 that acts as ditopic ligand via the carbene center and the cyano groups at boron. First reactions of this new NHC 3 with methyl iodide, elemental selenium, and [Ni(CO)4 ] led to the methylated imidazolate ion 4, the dianionic selenium adduct 5, and the dianionic nickel tricarbonyl complex 6. These NHC derivatives provide a first insight into the electronic and steric properties of the dianionic NHC 3. Especially the combination of properties, such as double negative charge, different coordination sites, large buried volume and good σ-donor and π-acceptor ability, make NHC 3 a unique and promising ligand and building block.
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Affiliation(s)
- Ludwig Zapf
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB)Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Udo Radius
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB)Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Maik Finze
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB)Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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17
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Zapf L, Radius U, Finze M. Das 1,3‐Bis(tricyanoboran)imidazolin‐2‐ylidenat‐Anion – Ein ditopischer dianionischer N‐heterocyclischer Carben‐Ligand. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202105529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ludwig Zapf
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB) Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Udo Radius
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB) Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Maik Finze
- Institut für nachhaltige Chemie & Katalyse mit Bor (ICB) Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
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18
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Taakili R, Barthes C, Lepetit C, Duhayon C, Valyaev DA, Canac Y. Direct Access to Palladium(II) Complexes Based on Anionic C, C, C-Phosphonium Ylide Core Pincer Ligand. Inorg Chem 2021; 60:12116-12128. [PMID: 34333976 DOI: 10.1021/acs.inorgchem.1c01316] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of readily available imidazolium-phosphonium salt [MesIm(CH2)3PPh3](OTf)2 with PdCl2 in the presence of an excess of Cs2CO3 afforded selectively in one step the cationic Pd(II) complex [(C,C,C)Pd(NCMe)](OTf) exhibiting an LX2-type NHC-ylide-aryl C,C,C-pincer ligand via formal triple C-H bond activation. The replacement of labile MeCN in the latter by CNtBu and CO fragments allowed to estimate the overall electronic properties of this phosphonium ylide core pincer scaffold incorporating three different carbon-based donor ends by IR spectroscopy, cyclic voltammetry, and molecular orbital analysis, revealing its significantly higher electron-rich character compared to the structurally close NHC core pincer system with two phosphonium ylide extremities. The pincer complex [(C,C,C)Pd(CO)](OTf) represents a rare example of Pd(II) carbonyl species stable at room temperature and characterized by X-ray diffraction analysis. The treatment of isostructural cationic complexes [(C,C,C)Pd(NCMe)](OTf) and [(C,C,C)Pd(CO)](OTf) with (allyl)MgBr and nBuLi led to the formation of zwitterionic phosphonium organopalladates [(C,C,C)PdBr] and [(C,C,C)Pd(COnBu)], respectively.
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Affiliation(s)
- Rachid Taakili
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
| | - Cécile Barthes
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
| | - Christine Lepetit
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
| | - Carine Duhayon
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
| | - Dmitry A Valyaev
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
| | - Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, 31077 Cedex 4 Toulouse, France
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19
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Toda T, Kuwata S. Synthesis, Structures, and Reactivities of Iron Complexes Bearing an Isoindoline‐Based, Polyprotic Pincer‐Type Pyrazole Ligand. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202100103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Tatsuro Toda
- Department of Chemical Science and Engineering School of Materials and Chemical Technology Tokyo Institute of Technology 2-12-1 E4-1 O-okayama Meguro-ku Tokyo 152-8552 Japan
| | - Shigeki Kuwata
- Department of Chemical Science and Engineering School of Materials and Chemical Technology Tokyo Institute of Technology 2-12-1 E4-1 O-okayama Meguro-ku Tokyo 152-8552 Japan
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20
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Nakanishi K, Jimenez-Halla JOC, Yamazoe S, Nakamoto M, Shang R, Yamamoto Y. Synthesis and Isolation of an Anionic Bis(dipyrido-annulated) N-Heterocyclic Carbene CCC-Pincer Iridium(III) Complex by Facile C-H Bond Activation. Inorg Chem 2021; 60:9970-9976. [PMID: 34156239 DOI: 10.1021/acs.inorgchem.1c01236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Meridional tridentate N-heterocyclic carbene (NHC)-based pincer ligands contribute to a substantial growth in modern organometallic chemistry in both homogeneous catalysis and luminescence materials. Among all NHC-based pincer ligands, the dianionic LX2-type CCC-pincer ones constitute the smallest subcategory owing to their limited ligand frameworks suitable for complexation. This work reports a one-pot, high-yield synthesis of a homoleptic anionic all-carbon bis-pincer iridium(III) complex (4) directly from a bis(aryl)-substituted dipyrido-annulated (dpaAr2) imidazolium salt and [Ir(COD)Cl]2 via a cascade of deprotonation/C-H activation processes. Both experimental complexation chemistry and computational mechanistic investigation suggest that the large bite angle and π-rich character of the dpaAr2 NHC are responsible for its facile complexation as a dianionic LX2-type CCC-pincer ligand precursor. The all-carbon ligated iridium(III) complex (4) bearing a π-conjugated ligand scaffold showed remarkably low oxidation potentials, which allows future investigations in its redox chemistry and photophysical properties.
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Affiliation(s)
- Kazuki Nakanishi
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - J Oscar C Jimenez-Halla
- Department of Chemistry, Division of Natural and Exact Sciences, University of Guanajuato, Campus Gto, Noria Alta s/n, 36050 Guanajuato, Mexico
| | - Seiji Yamazoe
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Masaaki Nakamoto
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Rong Shang
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Yohsuke Yamamoto
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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21
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Canac Y. Carbon Ligands: From Fundamental Aspects to Applications. Molecules 2021; 26:2132. [PMID: 33917652 PMCID: PMC8068049 DOI: 10.3390/molecules26082132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022] Open
Abstract
Ligand design is at the forefront of many advances in various areas of chemistry such as organometallic chemistry, functional materials, and homogeneous catalysis [...].
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Affiliation(s)
- Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, UPS, CEDEX 4, 31077 Toulouse, France
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22
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Liu S, Amaro-Estrada JI, Baltrun M, Douair I, Schoch R, Maron L, Hohloch S. Catalytic Deoxygenation of Nitroarenes Mediated by High-Valent Molybdenum(VI)–NHC Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00352] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shenyu Liu
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | | | - Marc Baltrun
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Iskander Douair
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Roland Schoch
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Stephan Hohloch
- University of Innsbruck, Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Innrain 80-82, 6020 Innsbruck, Austria
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23
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Buhaibeh R, Duhayon C, Valyaev DA, Sortais JB, Canac Y. Cationic PCP and PCN NHC Core Pincer-Type Mn(I) Complexes: From Synthesis to Catalysis. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00717] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Ruqaya Buhaibeh
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, Toulouse CEDEX 4 31077, France
| | - Carine Duhayon
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, Toulouse CEDEX 4 31077, France
| | - Dmitry A. Valyaev
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, Toulouse CEDEX 4 31077, France
| | - Jean-Baptiste Sortais
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, Toulouse CEDEX 4 31077, France
- Institut Universitaire de France, 1 rue Descartes, Paris CEDEX 5 75231, France
| | - Yves Canac
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, Toulouse CEDEX 4 31077, France
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