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Borys AM, Vedani L, Hevia E. The coordination of alkali-metal nickelates to organic π-systems: synthetic, structural and spectroscopic insights. Dalton Trans 2024; 53:8382-8390. [PMID: 38680126 DOI: 10.1039/d4dt00889h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
Low-valent nickelates have recently been shown to be key intermediates in challenging cross-coupling reactions using aryl ethers as electrophiles. Key for the success of these transformations is the activation of the substrate through π-coordination to the nickelate intermediate, however there is still limited knowledge about the fundamental structure and coordination chemistry of these heterobimetallic complexes. Herein, we report the synthesis, structures, and spectroscopic analysis of a diverse family of alkali-metal nickelates derived from phenyl-alkali-metal reagents and Ni(ttt-CDT), where ttt-CDT = trans,trans,trans-1,5,9-cyclododecatriene. The co-complexation of PhLi with Ni(ttt-CDT) was found to yield 1 : 1, 2 : 1 or 4 : 2 lithium nickelates depending on the stoichiometry and reaction conditions employed. The high lability of the ttt-CDT ligand enables facile ligand exchange with an assorted series of organic π-acceptors, ranging from polyaromatic hydrocarbons to ketones, imines and nitriles. For anthracene and phenanthrene, a homologous series of Li, Na and K nickelates could be obtained, which lead to different structural motifs or degrees of aggregation in the solid-state spanning solvated monomers to complex polymeric arrangements. For π-extended systems such as perylene or coronene, competing single-electron-transfer to give the corresponding radical anions was observed, illustrating the highly reducing nature of the alkali-metal nickelates. X-ray crystallographic analysis and NMR spectroscopy of the phenyl-alkali-metal nickelates reveal extreme back-bonding from Ni(0) to the organic π-acceptors due to strong σ-donation from the carbanionic ligands.
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Affiliation(s)
- Andryj M Borys
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland.
| | - Luca Vedani
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland.
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland.
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2
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Borys AM, Vedani L, Hevia E. Stoichiometric and Catalytic Lithium Nickelate-Mediated C-F Bond Alkynylation of Fluoroarenes. J Am Chem Soc 2024; 146:10199-10205. [PMID: 38545862 DOI: 10.1021/jacs.4c02606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Low-valent nickelates have recently been shown to be key intermediates that facilitate challenging cross-coupling reactions under mild conditions. Expanding the synthetic potential of these heterobimetallic complexes, herein we report the success of trilithium nickelate Li3(TMEDA)3Ni(C≡C-Ph)3 in promoting stoichiometric C-F activation of assorted aryl fluorides furnishing novel mixed Li/Ni(0) or Li/Ni(II) species depending on the substrate and conditions employed. These stoichiometric successes can be upgraded to catalytic regimes to enable the atom-efficient alkynylation of aryl fluorides and polyfluoroarenes with lithium acetylides and precatalyst Ni(COD)2, which operates without the intervention of external ligands, Cu cocatalysts, or additives.
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Affiliation(s)
- Andryj M Borys
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland
| | - Luca Vedani
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmacie, Universität Bern, 3012 Bern, Switzerland
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3
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Landaeta VR, Horsley Downie TM, Wolf R. Low-Valent Transition Metalate Anions in Synthesis, Small Molecule Activation, and Catalysis. Chem Rev 2024; 124:1323-1463. [PMID: 38354371 PMCID: PMC10906008 DOI: 10.1021/acs.chemrev.3c00121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 02/16/2024]
Abstract
This review surveys the synthesis and reactivity of low-oxidation state metalate anions of the d-block elements, with an emphasis on contributions reported between 2006 and 2022. Although the field has a long and rich history, the chemistry of transition metalate anions has been greatly enhanced in the last 15 years by the application of advanced concepts in complex synthesis and ligand design. In recent years, the potential of highly reactive metalate complexes in the fields of small molecule activation and homogeneous catalysis has become increasingly evident. Consequently, exciting applications in small molecule activation have been developed, including in catalytic transformations. This article intends to guide the reader through the fascinating world of low-valent transition metalates. The first part of the review describes the synthesis and reactivity of d-block metalates stabilized by an assortment of ligand frameworks, including carbonyls, isocyanides, alkenes and polyarenes, phosphines and phosphorus heterocycles, amides, and redox-active nitrogen-based ligands. Thereby, the reader will be familiarized with the impact of different ligand types on the physical and chemical properties of metalates. In addition, ion-pairing interactions and metal-metal bonding may have a dramatic influence on metalate structures and reactivities. The complex ramifications of these effects are examined in a separate section. The second part of the review is devoted to the reactivity of the metalates toward small inorganic molecules such as H2, N2, CO, CO2, P4 and related species. It is shown that the use of highly electron-rich and reactive metalates in small molecule activation translates into impressive catalytic properties in the hydrogenation of organic molecules and the reduction of N2, CO, and CO2. The results discussed in this review illustrate that the potential of transition metalate anions is increasingly being tapped for challenging catalytic processes with relevance to organic synthesis and energy conversion. Therefore, it is hoped that this review will serve as a useful resource to inspire further developments in this dynamic research field.
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Affiliation(s)
| | | | - Robert Wolf
- University of Regensburg, Institute
of Inorganic Chemistry, 93040 Regensburg, Germany
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4
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Liang H, Borys AM, Hevia E, Perrin MEL, Payard PA. Shedding Light on the Hidden Roles of Lithium in the Nickel-Catalyzed Cross-Coupling of Aryl Ethers. J Am Chem Soc 2023; 145:19989-19999. [PMID: 37646479 DOI: 10.1021/jacs.3c06647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The Ni-catalyzed cross-coupling of aryl ethers is a powerful synthetic tool to transform widely available phenol derivatives into functionalized aromatic molecules. Recent theoretical and experimental mechanistic studies have identified the involvement of heterobimetallic nickelates as key intermediates that facilitate the challenging transformation under mild conditions and often without the need for external ligands or additives. In this work, based on calculations performed at the density functional theory (DFT) level and by comparison with spectroscopic and kinetic data, we investigate the mechanism of the Ni(COD)2-catalyzed cross-coupling of 2-methoxynaphthalene with PhLi and assess the speciation of lithium nickelate intermediates. The crucial role of solvent on the reaction is explained, and the multiple roles played by lithium are unveiled. Experimental studies have identified key lithium nickelate species which support and help to evolve the calculated reaction mechanism and ultimately complete the catalytic cycle. Based on this new mechanistic knowledge, a well-known experimental challenge of these transformations, the so-called "naphthalene problem" which restricts the use of electrophilic coupling partners to π-extended systems, can be addressed to enable the cross-coupling of unbiased aryl ethers under mild conditions.
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Affiliation(s)
- Haosheng Liang
- Université de Lyon, Université Claude Bernard Lyon I, CNRS, INSA, CPE, UMR 5246, ICBMS, Rue Victor Grignard, Villeurbanne Cedex F-69622, France
| | - Andryj M Borys
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Bern 3012, Switzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Bern 3012, Switzerland
| | - Marie-Eve L Perrin
- Université de Lyon, Université Claude Bernard Lyon I, CNRS, INSA, CPE, UMR 5246, ICBMS, Rue Victor Grignard, Villeurbanne Cedex F-69622, France
| | - Pierre-Adrien Payard
- Université de Lyon, Université Claude Bernard Lyon I, CNRS, INSA, CPE, UMR 5246, ICBMS, Rue Victor Grignard, Villeurbanne Cedex F-69622, France
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Borys AM, Hevia E. Organolithium aggregation as a blueprint to construct polynuclear lithium nickelate clusters. Chem Commun (Camb) 2023. [PMID: 37191064 DOI: 10.1039/d3cc01729j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
By exploiting the high aggregation of aliphatic lithium acetylides, here we report the synthesis and structural analysis of polynuclear lithium nickelate clusters in which up to 10 equivalents of organolithium can co-complex per Ni(0) centre. Exposure of the Ni(0)-ate clusters to dry air provides an alternative route to homoleptic Ni(II)-ates.
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Affiliation(s)
- Andryj M Borys
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Bern 3012, Switzerland.
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Bern 3012, Switzerland.
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Borys AM, Hevia E. Diphenylacetylene stabilised alkali-metal nickelates: synthesis, structure and catalytic applications. Dalton Trans 2023; 52:2098-2105. [PMID: 36722457 PMCID: PMC9926332 DOI: 10.1039/d3dt00069a] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Whilst low-valent nickelates have recently been proposed as intermediates in Ni-catalysed reactions involving polar organometallics, their isolation and characterisation is often challenging due to their high sensitivity and reactivity. Advancing the synthetic, spectroscopic and structural insights of these heterobimetallic systems, here we report a new family of alkyne supported alkali-metal nickelates of the formula Li4(solv)n(Ar)4Ni2{μ2:η2,η2-Ph-CC-Ph} (where solv = Et2O, THF; Ar = Ph, o-Tol, naphthyl, 4-tBu-C6H4) which can be accessed through the combination of Ni(COD)2, Ph-CC-Ph and the relevant lithium aryl in a 2 : 1 : 4 ratio. Demonstrating the versatility of this approach, the sodium and potassium nickelates can also be accessed when using PhNa or via alkali-metal exchange with AMOtBu (AM = Na, K). When employing bulky or structurally constrained aryl-lithiums, mononickel complexes of the formula Li2(solv)n(Ar)2Ni{η2-Ph-CC-Ph} are instead obtained, highlighting the structural diversity of alkali-metal nickelates bearing alkyne ligands. Expanding the catalytic potential of these systems, their ability to promote the catalytic cyclotrimerisation of diphenylacetylene to hexaphenylbenzene was explored, with mononickel compounds bearing electron rich aryl-substituents displaying the best performance.
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Affiliation(s)
- Andryj M. Borys
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern3012 BernSwitzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern, 3012 Bern, Switzerland.
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Navarro M, Moreno JJ, Pérez-Jiménez M, Campos J. Small molecule activation with bimetallic systems: a landscape of cooperative reactivity. Chem Commun (Camb) 2022; 58:11220-11235. [PMID: 36128973 PMCID: PMC9536487 DOI: 10.1039/d2cc04296g] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/06/2022] [Indexed: 11/22/2022]
Abstract
There is growing interest in the design of bimetallic cooperative complexes, which have emerged due to their potential for bond activation and catalysis, a feature widely exploited by nature in metalloenzymes, and also in the field of heterogeneous catalysis. Herein, we discuss the widespread opportunities derived from combining two metals in close proximity, ranging from systems containing multiple M-M bonds to others in which bimetallic cooperation occurs even in the absence of M⋯M interactions. The choice of metal pairs is crucial for the reactivity of the resulting complexes. In this context, we describe the prospects of combining not only transition metals but also those of the main group series, which offer additional avenues for cooperative pathways and reaction discovery. Emphasis is given to mechanisms by which bond activation occurs across bimetallic structures, which is ascribed to the precise synergy between the two metal atoms. The results discussed herein indicate a future landscape full of possibilities within our reach, where we anticipate that bimetallic synergism will have an important impact in the design of more efficient catalytic processes and the discovery of new catalytic transformations.
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Affiliation(s)
- Miquel Navarro
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain.
| | - Juan José Moreno
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain.
| | - Marina Pérez-Jiménez
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain.
| | - Jesús Campos
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain.
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Borys AM, Malaspina LA, Grabowsky S, Hevia E. Towards Hexagonal Planar Nickel: A Dispersion-Stabilised Tri-Lithium Nickelate. Angew Chem Int Ed Engl 2022; 61:e202209797. [PMID: 35921213 PMCID: PMC9804205 DOI: 10.1002/anie.202209797] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Indexed: 01/05/2023]
Abstract
Advancing the understanding of lithum nickelate complexes, here we report a family of homoleptic organonickelate complexes obtained by reacting Ni(COD)2 and lithium aryl-acetylides in the presence of the bidentate donor TMEDA. These compounds represent rare examples of low-valent transition-metals supported solely by organolithium ligands. Whilst the solid-state structures indicate a hexagonal planar geometry around Ni0 with Ni-Li bonds, bonding analysis via QTAIM, NCI, NBO and ELI methods reveals that the Ni-Li interactions are repulsive in nature, characterising these complexes as tri-coordinated. London dispersion forces between TMEDA and the organic substituents on nickel are found to play a crucial role in the stabilisation and thus isolation of these complexes. Preliminary reactivity studies demonstrate that the homoleptic lithium nickelates undergo stoichiometric cross-coupling with PhI to give dinickel clusters containing both anionic acetylide and neutral alkyne ligands.
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Affiliation(s)
- Andryj M. Borys
- Departement für Chemie, Biochemie und PharmazieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Lorraine A. Malaspina
- Departement für Chemie, Biochemie und PharmazieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Simon Grabowsky
- Departement für Chemie, Biochemie und PharmazieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und PharmazieUniversität BernFreiestrasse 33012BernSwitzerland
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9
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Borys AM, Malaspina LA, Grabowsky S, Hevia E. Towards Hexagonal Planar Nickel: A Dispersion‐Stabilised Tri‐Lithium Nickelate. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Andryj M. Borys
- University of Bern: Universitat Bern Departement für Chemie, Biochemie und Pharmazie SWITZERLAND
| | - Lorraine A. Malaspina
- University of Bern: Universitat Bern Departement für Chemie, Biochemie und Pharmazie SWITZERLAND
| | - Simon Grabowsky
- University of Bern: Universitat Bern DDepartement für Chemie, Biochemie und Pharmazie SWITZERLAND
| | - Eva Hevia
- Universitat Bern Department of Chemistry and Biochemistry Freiestrasse 3 3012 Bern SWITZERLAND
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