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Rudolf R, Batman D, Mehner N, Walter RRM, Sarkar B. Redox-Active Triazole-Derived Mesoionic Imines with Ferrocenyl Substituents and their Metal Complexes: Directed Hydrogen-Bonding, Unusual C-H Activation and Ion-Pair Formation. Chemistry 2024:e202400730. [PMID: 38634285 DOI: 10.1002/chem.202400730] [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: 02/22/2024] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 04/19/2024]
Abstract
We present herein the synthesis, characterization and complexation of ferrocenyl-substituted MIIs (mesoionic imines) and their metal complexes. In the free MIIs, strong hydrogen bonding interactions are observed between the imine-N and the C-H bonds of the ferrocenyl substituents both in the solid state and in solution. The influence of this hydrogen bonding is so strong that complexation of the MIIs with [IrCp*Cl2]2 yields unique six-membered iridacycles via C-H-activation of the corresponding C-H-site at the Fc-substituent and not the Ph-substituent. This result is in contrast to previous reports in which always a preferential C-H activation at the phenyl substituent is observed in competitive reactions in the presence of ferrocenyl substituents. The corresponding Ir complexes formed after in-situ halide exchange reaction exist in either [Ir-I] contact or as [Ir]+I- solvent separated ion-pairs depending on the solvent polarity. The iodide coordinated and solvent separated ion-pairs display drastically different physical properties. The TEP (Tolman-electronic-parameter) of these ligands was determined and lines up with previously reported MII-ligands. The redox properties were investigated by a combination of electrochemical and spectroelectrochemical methods. We show here how non-covalent interactions can have a drastic influence on the physical and chemical properties of these new class of compounds.
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Affiliation(s)
- Richard Rudolf
- Universität Stuttgart, Institut für Anorganische Chemie, Pfaffenwaldring 55, 70569, Stuttgart
| | - Derman Batman
- Universität Stuttgart, Institut für Anorganische Chemie, Pfaffenwaldring 55, 70569, Stuttgart
| | - Niklas Mehner
- Universität Stuttgart, Institut für Anorganische Chemie, Pfaffenwaldring 55, 70569, Stuttgart
| | - Robert R M Walter
- Universität Stuttgart, Institut für Anorganische Chemie, Pfaffenwaldring 55, 70569, Stuttgart
| | - Biprajit Sarkar
- Universität Stuttgart, Institut für Anorganische Chemie, Pfaffenwaldring 55, 70569, Stuttgart
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Menia D, Pittracher M, Kopacka H, Wurst K, Neururer FR, Leitner D, Hohloch S, Podewitz M, Bildstein B. Curious Case of Cobaltocenium Carbaldehyde. Organometallics 2023; 42:377-383. [PMID: 36937785 PMCID: PMC10015550 DOI: 10.1021/acs.organomet.2c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Indexed: 02/23/2023]
Abstract
Cobaltocenium carbaldehyde (formylcobaltocenium) hexafluoridophosphate, a long sought-after functionalized cobaltocenium salt, is accessible from cobaltocenium carboxylic acid by a three-step synthetic sequence involving (i) chlorination to the acid chloride, (ii) copper-borohydride reduction to the hydroxymethyl derivative, and (iii) Dess-Martin oxidation to the title compound. Due to the strongly electron-withdrawing cationic cobaltocenium moiety, no standard aldehyde reactivity is observed. Instead, nucleophilic addition followed by haloform-type cleavage prevails, thereby ruling out common useful aldehyde derivatization. One-electron reduction of cobaltocenium carbaldehyde hexafluoridophosphate affords the deep-blue, isolable cobaltocene carbaldehyde 19-valence-electron radical whose spin density is located fully at cobalt and not at the formyl carbon atom. 1H/13C NMR, IR, EPR spectroscopy, high-resolution mass spectrometry, cyclic voltammetry, single crystal structure analysis (XRD), and density functional theory are applied to characterize these unusual formyl-cobaltocenium/cobaltocene compounds.
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Affiliation(s)
- Daniel Menia
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Michael Pittracher
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Holger Kopacka
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Klaus Wurst
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Florian R. Neururer
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Daniel Leitner
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Stephan Hohloch
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Maren Podewitz
- Institute
of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Benno Bildstein
- Institut
für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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Chen Z, Kacmaz A, Xiao J. Recent Development in the Synthesis and Catalytic Application of Iridacycles. CHEM REC 2021; 21:1506-1534. [PMID: 33939250 DOI: 10.1002/tcr.202100051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022]
Abstract
Cyclometallated complexes are well-known and have found many applications. This article provides a short review on the progress made in the synthesis and application to catalysis of cyclometallated half-sandwich Cp*Ir(III) complexes (Cp*: pentamethylcyclopentadienyl) since 2017. Covered in the review are iridacycles featuring conventional C,N chelates and less common metallocene and carbene-derived C,N and C,C ligands. This is followed by an overview of the studies of their applications in catalysis ranging from asymmetric hydrogenation, transfer hydrogenation, hydrosilylation to dehydrogenation.
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Affiliation(s)
- Zhenyu Chen
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Aysecik Kacmaz
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.,Department of Chemistry, Faculty of Engineering, Istanbul University - Cerrahpasa, Avcilar, Istanbul, 34320, Turkey
| | - Jianliang Xiao
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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Staples O, Gau MR, Mindiola DJ. Reversible Chelation and η 5-Pyrrolyl Coordination in a [Cp*Ir] 2+ Fragment. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Orion Staples
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania United States
| | - Michael R. Gau
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania United States
| | - Daniel J. Mindiola
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania United States
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Avello MG, Torre MC, Sierra MA, Gornitzka H, Hemmert C. Central (S) to Central (M=Ir, Rh) to Planar (Metallocene, M=Fe, Ru) Chirality Transfer Using Sulfoxide‐Substituted Mesoionic Carbene Ligands: Synthesis of Bimetallic Planar Chiral Metallocenes. Chemistry 2019; 25:13344-13353. [DOI: 10.1002/chem.201902102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/24/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Marta G. Avello
- Instituto de Química Orgánica General Consejo Superior de Investigaciones Científicas (IQOG-CSIC) Juan de la Cierva 3 28006 Madrid Spain
- Centro de Investigación en Química Avanzada (ORFEO-CINQA) Universidad Complutense 28040 Madrid Spain
| | - María C. Torre
- Instituto de Química Orgánica General Consejo Superior de Investigaciones Científicas (IQOG-CSIC) Juan de la Cierva 3 28006 Madrid Spain
- Centro de Investigación en Química Avanzada (ORFEO-CINQA) Universidad Complutense 28040 Madrid Spain
| | - Miguel A. Sierra
- Centro de Investigación en Química Avanzada (ORFEO-CINQA) Universidad Complutense 28040 Madrid Spain
- Departamento de Química Orgánica I Facultad de Química Universidad Complutense 28040 Madrid Spain
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Arthurs RA, Hughes DL, Horton PN, Coles SJ, Richards CJ. Application of Transmetalation to the Synthesis of Planar Chiral and Chiral-at-Metal Iridacycles. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ross A. Arthurs
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - David L. Hughes
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - Peter N. Horton
- EPSRC National Crystallography Service, School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, U.K
| | - Simon J. Coles
- EPSRC National Crystallography Service, School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, U.K
| | - Christopher J. Richards
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
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Arthurs RA, Prior CC, Hughes DL, Oganesyan VS, Richards CJ. Enantiopure Planar Chiral and Chiral-at-Metal Iridacycles Derived from Bulky Cobalt Sandwich Complexes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00495] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ross A. Arthurs
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - Christopher C. Prior
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - David L. Hughes
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - Vasily S. Oganesyan
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
| | - Christopher J. Richards
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K
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Bissember AC, Gardiner MG, Wierenga TS. α-Cyanocarbanion complexes and their application in synthesis. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Holz J, Ayerbe García M, Frey W, Krupp F, Peters R. Diastereoselective synthesis, structure and reactivity studies of ferrocenyloxazoline gold(i) and gold(ii) complexes. Dalton Trans 2018; 47:3880-3905. [PMID: 29451574 DOI: 10.1039/c8dt00109j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In the last few decades, gold complexes have demonstrated huge potential for soft Lewis acid catalysis. Despite the intensive research on Au complexes and planar chiral metallacycles, enantiopure ferrocenylgold complexes have - surprisingly - not been reported until the studies presented in this article. Herein, we report the asymmetric synthesis of planar chiral ferrocenyl Au(i) complexes. These dinuclear species form helically chiral ten-membered (NCCCAu)2 rings stabilized by aurophilic interactions. In supramolecular solid state structures, linear, zigzag or helical Au(i) wires with regular AuAu separations were observed. The dissolved dinuclear entities could be oxidized by Au(i) to unique ferrocenyl Au(ii) complexes featuring short Au(ii)-Au(ii) bonds, while the ferrocene core remained intact. However, our initial studies revealed the issue of configurational lability of the ferrocenyl Au(ii) complexes in terms of the element of planar chirality in the presence of the gold source, (Me2S)AuCl. This was successfully addressed by a systematic study implementing permanent σ-donor ortho-protecting groups such as methyl and trimethylsilyl, which impede an epimerization event. Oxidation of the dinuclear Au(i) complexes was also accomplished by oxidative addition reactions with halogenated solvents, preferably CHCl3. Additional reactivity studies revealed that dinuclear Au(ii) dihalide complexes are also formed with reactive alkylhalides such as iodomethane, benzylbromide and benzyliodide. Interestingly, the whole spectral range of colors (violet, blue, green, yellow, and red) is covered by the title complexes depending on the Au oxidation state and the anionic ligands in the Au(ii) complexes. This appears to be quite unusual for ferrocenes, which typically adopt orange to red colors in a non-oxidized state.
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Affiliation(s)
- Julia Holz
- Universität Stuttgart, Institut für Organische Chemie, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
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