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Sengupta S, Schüler P, Görls H, Liebing P, Krieck S, Westerhausen M. In Situ Grignard Metalation Method for the Synthesis of Hauser Bases. Chemistry 2022; 28:e202201359. [PMID: 35686618 PMCID: PMC9546396 DOI: 10.1002/chem.202201359] [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: 05/03/2022] [Indexed: 12/03/2022]
Abstract
The in situ Grignard Metalation Method (iGMM) is a straightforward one‐pot procedure to quickly produce multigram amounts of Hauser bases R2N‐MgBr which are valuable and vastly used metalation reagents and novel electrolytes for magnesium batteries. During addition of bromoethane to a suspension of Mg metal and secondary amine at room temperature in an ethereal solvent, a smooth reaction yields R2N‐MgBr under evolution of ethane within a few hours. A Schlenk equilibrium is operative, interconverting the Hauser bases into their solvated homoleptic congeners Mg(NR2)2 and MgBr2 depending on the solvent. Scope and preconditions are studied, and side reactions limiting the yield have been investigated. DOSY NMR experiments and X‐ray crystal structures of characteristic examples clarify aggregation in solution and the solid state.
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Affiliation(s)
- Simon Sengupta
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
| | - Philipp Schüler
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
| | - Phil Liebing
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
| | - Sven Krieck
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry Friedrich Schiller University Jena Humboldtstraße 8 07743 Jena Germany
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2
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Jędrzkiewicz D, Langer J, Harder S. Low‐valent Mg(I) complexes by ball‐milling. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200138] [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)
- Dawid Jędrzkiewicz
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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3
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Liu Y, Liu FZ, Yan K. Mechanochemical Access to a Short-Lived Cyclic Dimer Pd 2 L 2 : An Elusive Kinetic Species En Route to Molecular Triangle Pd 3 L 3 and Molecular Square Pd 4 L 4. Angew Chem Int Ed Engl 2022; 61:e202116980. [PMID: 35191567 DOI: 10.1002/anie.202116980] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Indexed: 11/08/2022]
Abstract
Pd-based molecular square Pd4 L4 and triangle Pd3 L3 represent the molecular ancestors of metal-coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution-based reactions between cis-protected Pd ions and 2,2'-bipyridine exclusively give Pd4 L4 and/or Pd3 L3 as the sole products. We herein show that, under solvent-free mechanochemical conditions, the self-assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2 L2 for the first time. In the absence of solvent, Pd2 L2 is indefinitely stable in the solid-state, but converts rapidly to its thermodynamic products Pd3 L3 and Pd4 L4 in solution, confirming Pd2 L2 as a short-lived kinetic species in the solution-based self-assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self-assembly processes that are too reactive to both "see" and "capture".
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Affiliation(s)
- Yan Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Fang-Zi Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - KaKing Yan
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
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4
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Jędrzkiewicz D, Mai J, Langer J, Mathe Z, Patel N, DeBeer S, Harder S. Access to a Labile Monomeric Magnesium Radical by Ball-Milling. Angew Chem Int Ed Engl 2022; 61:e202200511. [PMID: 35108440 PMCID: PMC9306460 DOI: 10.1002/anie.202200511] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Indexed: 12/13/2022]
Abstract
In order to isolate a monometallic Mg radical, the precursor (Am)MgI⋅(CAAC) (1) was prepared (Am=tBuC(N‐DIPP)2, DIPP=2,6‐diisopropylphenyl, CAAC=cyclic (alkyl)(amino)carbene). Reduction of a solution of 1 in toluene with the reducing agent K/KI led to formation of a deep purple complex that rapidly decomposed. Ball‐milling of 1 with K/KI gave the low‐valent MgI complex (Am)Mg⋅(CAAC) (2) which after rapid extraction with pentane and crystallization was isolated in 15 % yield. Although a benzene solution of 2 decomposes rapidly to give Mg(Am)2 (3) and unidentified products, the radical is stable in the solid state. Its crystal structure shows planar trigonal coordination at Mg. The extremely short Mg−C distance of 2.056(2) Å indicates strong Mg−CAAC bonding. Calculations and EPR measurements show that most of the spin density is in a π* orbital located at the C−N bond in CAAC, leading to significant C−N bond elongation. This is supported by calculated NPA charges in 2: Mg +1.73, CAAC −0.82. Similar metal‐to‐CAAC charge transfer was calculated for M0(CAAC)2 and [MI(CAAC)2+] (M=Be, Mg, Ca) complexes in which the metal charges range from +1.50 to +1.70. Although the spin density of the radical is mainly located at the CAAC ligand, complex 2 reacts as a low‐valent MgI complex: reaction with a I2 solution in toluene gave (Am)MgI⋅(CAAC) (1) as the major product.
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Affiliation(s)
- Dawid Jędrzkiewicz
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Jonathan Mai
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Zachary Mathe
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45472, Mülheim an der Ruhr, Germany
| | - Neha Patel
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45472, Mülheim an der Ruhr, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
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5
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Liu Y, Liu F, Yan K. Mechanochemical Access to a Short‐Lived Cyclic Dimer Pd
2
L
2
: An Elusive Kinetic Species En Route to Molecular Triangle Pd
3
L
3
and Molecular Square Pd
4
L
4. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202116980] [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)
- Yan Liu
- School of Physical Science and Technology ShanghaiTech University 201210 Shanghai China
| | - Fang‐Zi Liu
- School of Physical Science and Technology ShanghaiTech University 201210 Shanghai China
| | - KaKing Yan
- School of Physical Science and Technology ShanghaiTech University 201210 Shanghai China
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6
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Jędrzkiewicz D, Mai J, Langer J, Mathe Z, Patel N, DeBeer S, Harder S. Access to a Labile Monomeric Magnesium Radical by Ball‐Milling. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dawid Jędrzkiewicz
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jonathan Mai
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Zachary Mathe
- Max Planck Institute for Chemical Energy Conversion Stiftstr. 34–36 45472 Mülheim an der Ruhr Germany
| | - Neha Patel
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion Stiftstr. 34–36 45472 Mülheim an der Ruhr Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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7
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Affiliation(s)
- Ross F. Koby
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
| | - Nathan D. Schley
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
| | - Timothy P. Hanusa
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
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8
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Koby RF, Schley ND, Hanusa TP. Di(indenyl)beryllium. Angew Chem Int Ed Engl 2021; 60:21174-21178. [PMID: 34227203 DOI: 10.1002/anie.202107980] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Indexed: 12/16/2022]
Abstract
The bonding in beryllocene, [BeCp2 ], took decades to establish, owing to its unexpected mixed hapticity structure (i.e., [Be(η5 -Cp)(η1 -Cp)]). Beryllium complexes containing the indenyl ligand, which is a close relative of the cyclopentadienyl anion, but which is also known to exhibit its own bonding peculiarities (e.g., facile η5 ⇄ η3 shifts), have remained unknown. Standard metathetical approaches to their synthesis (e.g., with K[Ind'] + BeX2 in an ether solvent) give rise to intractable oils from which nothing identifiable can be isolated. In contrast, mechanochemical preparation, involving the solvent-free grinding of BeBr2 and potassium indenides, leads to the production of discrete (indenyl)beryllium complexes, including [Be(C9 H7 )2 ] (1) and [Be{1,3-(SiMe3 )2 C9 H5 }Br] (2). The former displays η5 /η1 -coordinated ligands in the solid state, but DFT calculations indicate that an η5 /η5 -conformation is less than 5 kcal mol-1 higher in energy.
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Affiliation(s)
- Ross F Koby
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Nathan D Schley
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Timothy P Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
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Virieux D, Delogu F, Porcheddu A, García F, Colacino E. Mechanochemical Rearrangements. J Org Chem 2021; 86:13885-13894. [PMID: 34259516 DOI: 10.1021/acs.joc.1c01323] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Molecular rearrangements are a powerful tool for constructing complex structures in an atom- and step-economic manner, translating multistep transformations into an intrinsically more sustainable process. Mechanochemical molecular rearrangements become an even more appealing eco-friendly synthetic approach, especially for preparing active pharmaceutical ingredients (APIs) and natural products. Still in their infancy, rearrangements promoted by mechanochemistry represent a promising approach for chemists to merge molecular diversity and green chemistry perspectives toward more selective and efficient syntheses with a reduced environmental footprint.
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Affiliation(s)
- David Virieux
- ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier 34296, France
| | - Francesco Delogu
- Dipartimento di Ingegneria Meccanica, Chimica e dei Materiali, Universita degli Studi di Cagliari, Via Marengo 2, 09123 Cagliari, Italy
| | - Andrea Porcheddu
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria, 09042 Monserrato, 09028 Cagliari, Italy
| | - Felipe García
- School of Physical and Mathematical Sciences, Division of Chemistry and Biological Chemistry, 21 Nanyang Link, 63737 Singapore
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Koby RF, Doerr AM, Rightmire NR, Schley ND, Brennessel WW, Long BK, Hanusa TP. Mechanochemical Formation, Solution Rearrangements, and Catalytic Behavior of a Polymorphic Ca/K Allyl Complex. Chemistry 2021; 27:8195-8202. [DOI: 10.1002/chem.202100589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Indexed: 12/24/2022]
Affiliation(s)
- Ross F. Koby
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
| | - Alicia M. Doerr
- Department of Chemistry University of Tennessee Knoxville TN 37996–1600 USA
| | | | - Nathan D. Schley
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
| | - William W. Brennessel
- X-ray Crystallographic Facility, Department of Chemistry University of Rochester Rochester NY 14627 USA
| | - Brian K. Long
- Department of Chemistry University of Tennessee Knoxville TN 37996–1600 USA
| | - Timothy P. Hanusa
- Department of Chemistry Vanderbilt University Nashville TN 37235 USA
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