1
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Brouillet EV, Brown SA, Kennedy AR, Rae A, Walton HP, Robertson SD. Atom-economic access to cationic magnesium complexes. Dalton Trans 2023; 52:13332-13338. [PMID: 37671570 DOI: 10.1039/d3dt02669h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Cationic alkaline-earth complexes attract interest for their enhanced Lewis acidity and reactivity compared with their neutral counterparts. Synthetic protocols to these complexes generally utilize expensive specialized reagents in reactions generating multiple by-products. We have studied a simple ligand transfer approach to these complexes using (NacNac)MgR and ER3 (NacNac = β-diketiminate anion; E = group 13 element; R = aryl/amido anion) which demonstrates high atom economy, opening up the ability to target these species in a more sustainable manner. The success of this methodology is dependent on the identity of the group 13 element with the heavier elements facilitating faster ligand exchange. Furthermore, while this reaction is successful with aromatic ligands such as phenyl and pyrrolyl, the secondary amide piperidide (pip) fails to transfer, which we attribute to the stronger 3-centre-4-electron dimerization interaction of Al2(pip)6.
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Affiliation(s)
- Etienne V Brouillet
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Scott A Brown
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Alan R Kennedy
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Annabel Rae
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Heather P Walton
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Stuart D Robertson
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
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2
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Mai J, Rösch B, Patel N, Langer J, Harder S. On the existence of low-valent magnesium-calcium complexes. Chem Sci 2023; 14:4724-4734. [PMID: 37181774 PMCID: PMC10171184 DOI: 10.1039/d3sc00909b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023] Open
Abstract
DFT-Calculations predict that a low-valent complex (BDI)Mg-Ca(BDI) with bulky β-diketiminate (BDI) ligands is thermodynamically stable. It was attempted to isolate such a complex by salt-metathesis between [(DIPePBDI*)Mg-Na+]2 and [(DIPePBDI)CaI]2 (DIPePBDI = HC[C(Me)N-DIPeP]2; DIPePBDI* = HC[C(tBu)N-DIPeP]2; DIPeP = 2,6-CH(Et)2-phenyl). Whereas in alkane solvents no reaction was observed, salt-metathesis in C6H6 led to immediate C-H activation of benzene to give (DIPePBDI*)MgPh and (DIPePBDI)CaH, the latter crystallizing as a THF-solvated dimer [(DIPePBDI)CaH·THF]2. Calculations suggest reduction and insertion of benzene in the Mg-Ca bond. The activation enthalpy for the subsequent decomposition of C6H62- into Ph- and H- is only 14.4 kcal mol-1. Repeating this reaction in the presence of naphthalene or anthracene led to heterobimetallic complexes in which naphthalene2- or anthracene2- anions are sandwiched between (DIPePBDI*)Mg+ and (DIPePBDI)Ca+ cations. These complexes slowly decompose to their homometallic counterparts and further decomposition products. Complexes in which naphthalene2- or anthracene2- anions are sandwiched between two (DIPePBDI)Ca+ cations were isolated. The low-valent complex (DIPePBDI*)Mg-Ca(DIPePBDI) could not be isolated due to its high reactivity. There is, however, strong evidence that this heterobimetallic compound is a fleeting intermediate.
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Affiliation(s)
- Jonathan Mai
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Bastian Rösch
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Neha Patel
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
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3
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Zhang L, Kaukver S, McMullen J, White AJP, Crimmin MR. Catalytic C–H Alumination of Thiophenes: DFT Predictions and Experimental Verification. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Affiliation(s)
- Linxing Zhang
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherds Bush, London W12 0BZ, U.K
- Shenzhen Bay Laboratory, Shenzhen 518055, People’s Republic of China
- School of Chemistry and Materials Science, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Siim Kaukver
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherds Bush, London W12 0BZ, U.K
| | - Jacob McMullen
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherds Bush, London W12 0BZ, U.K
| | - Andrew J. P. White
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherds Bush, London W12 0BZ, U.K
| | - Mark R. Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherds Bush, London W12 0BZ, U.K
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4
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Garçon M, Phanopoulos A, White AJP, Crimmin MR. Reversible Dihydrogen Activation and Catalytic H/D Exchange with Group 10 Heterometallic Complexes. Angew Chem Int Ed Engl 2023; 62:e202213001. [PMID: 36350647 PMCID: PMC10107683 DOI: 10.1002/anie.202213001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Indexed: 11/10/2022]
Abstract
Reaction of a hexagonal planar palladium complex featuring a [PdMg3 H3 ] core with H2 is reversible and leads to the formation of a new [PdMg2 H4 ] tetrahydride species alongside an equivalent of a magnesium hydride co-product [MgH]. While the reversibility of this process prevented isolation of [PdMg2 H4 ], analogous [PtMg2 H4 ] and [PtZn2 H4 ] complexes could be isolated and characterised through independent syntheses. Computational analysis (DFT, AIM, NCIPlot) of the bonding in a series of heterometallic tetrahydride compounds (Ni-Pt; Mg and Zn) suggests that these complexes are best described as square planar with marginal metal-metal interactions; the strength of which increases slightly as group 10 is descended and increases from Mg to Zn. DFT calculations support a mechanism for H2 activation involving a ligand-assisted oxidative addition to Pd. These findings were exploited to develop a catalytic protocol for H/D exchange into magnesium hydride and zinc hydride bonds.
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Affiliation(s)
- Martí Garçon
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Andreas Phanopoulos
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Andrew J P White
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Mark R Crimmin
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
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5
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Mullins JC, Yuvaraj K, Jiang Y, Van Trieste GP, Maity A, Powers DC, Jones C. C-H Activation of Inert Arenes using a Photochemically Activated Guanidinato-Magnesium(I) Compound. Chemistry 2022; 28:e202202103. [PMID: 36017712 PMCID: PMC9828268 DOI: 10.1002/chem.202202103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Indexed: 01/12/2023]
Abstract
UV irradiation of solutions of a guanidinate coordinated dimagnesium(I) compound, [{(Priso)Mg}2 ] 3 (Priso=[(DipN)2 CNPri 2 ]- , Dip=2,6-diisopropylphenyl), in either benzene, toluene, the three isomers of xylene, or mesitylene, leads to facile activation of an aromatic C-H bond of the solvent in all cases, and formation of aryl/hydride bridged magnesium(II) products, [{(Priso)Mg}2 (μ-H)(μ-Ar)] 4-9. In contrast to similar reactions reported for β-diketiminate coordinated counterparts of 3, these C-H activations proceed with little regioselectivity, though they are considerably faster. Reaction of 3 with an excess of the pyridine, p-NC5 H4 But (pyBut ), gave [(Priso)Mg(pyBut H)(pyBut )2 ] 10, presumably via reduction of the pyridine to yield a radical intermediate, [(Priso)Mg(pyBut ⋅)(pyBut )2 ] 11, which then abstracts a proton from the reaction solvent or a reactant. DFT calculations suggest two possible pathways to the observed arene C-H activations. One of these involves photochemical cleavage of the Mg-Mg bond of 3, generating magnesium(I) doublet radicals, (Priso)Mg⋅. These then doubly reduce the arene substrate to give "Birch-like" products, which subsequently rearrange via C-H activation of the arene. Circumstantial evidence for the photochemical generation of transient magnesium radical species includes the fact that irradiation of a cyclohexane solution of 3 leads to an intramolecular aliphatic C-H activation process and formation of an alkyl-bridged magnesium(II) species, [{Mg(μ-Priso-H )}2 ] 12. Furthermore, irradiation of a 1 : 1 mixture of 3 and the β-diketiminato dimagnesium(I) compound, [{(Dip Nacnac)Mg}2 ] (Dip Nacnac=[HC(MeCNDip)2 ]- ), effects a "scrambling" reaction, and the near quantitative formation of an unsymmetrical dimagnesium(I) compound, [(Priso)Mg-Mg(Dip Nacnac)] 13. Finally, the EPR spectrum (77 K) of a glassed solution of UV irradiated 3 is dominated by a broad featureless signal, indicating the presence of a doublet radical species.
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Affiliation(s)
- Jeremy C. Mullins
- School of ChemistryPO Box 23Monash UniversityMelbourne, <countryPartVIC3800Australia
| | - K. Yuvaraj
- School of ChemistryPO Box 23Monash UniversityMelbourne, <countryPartVIC3800Australia
| | - Yixiao Jiang
- School of ChemistryPO Box 23Monash UniversityMelbourne, <countryPartVIC3800Australia
| | | | - Asim Maity
- Department of ChemistryTexas A&M University College Station, TX 77843USA
| | - David C. Powers
- Department of ChemistryTexas A&M University College Station, TX 77843USA
| | - Cameron Jones
- School of ChemistryPO Box 23Monash UniversityMelbourne, <countryPartVIC3800Australia
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6
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Morris LJ, Rajeshkumar T, Maron L, Okuda J. Reversible Oxidative Addition of Zinc Hydride at a Gallium(I)-Centre: Labile Mono- and Bis(hydridogallyl)zinc Complexes. Chemistry 2022; 28:e202201480. [PMID: 35819049 PMCID: PMC9804236 DOI: 10.1002/chem.202201480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Indexed: 01/05/2023]
Abstract
In the presence of TMEDA (N,N,N',N'-tetramethylethylenediamine), partially deaggregated zinc dihydride as hydrocarbon suspensions react with the gallium(I) compound [(BDI)Ga] (I, BDI={HC(C(CH3 )N(2,6-iPr2 -C6 H3 ))2 }- ) by formal oxidative addition of a Zn-H bond to the gallium(I) centre. Dissociation of the labile TMEDA ligand in the resulting complex [(BDI)Ga(H)-(H)Zn(tmeda)] (1) facilitates insertion of a second equiv. of I into the remaining Zn-H to form a thermally sensitive trinuclear species [{(BDI)Ga(H)}2 Zn] (2). Compound 1 exchanges with polymeric zinc dideuteride [ZnD2 ]n in the presence of TMEDA, and with compounds I and 2 via sequential and reversible ligand dissociation and gallium(I) insertion. Spectroscopic and computational studies demonstrate the reversibility of oxidative addition of each Zn-H bond to the gallium(I) centres.
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Affiliation(s)
- Louis J. Morris
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany,Chemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUnited Kingdom
| | | | - Laurent Maron
- CNRSINSAUPSUMR 5215LPCNOUniversité de Toulouse31077ToulouseFrance
| | - Jun Okuda
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
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7
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Burnett S, de Vere-Tucker M, Davitt M, Cordes DB, Slawin AMZ, Ferns R, van Mourik T, Stasch A. Magnesium Complexes with Isomeric Pyrazol‐4‐ylidene and Imidazol‐2‐ylidene Ligands. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Andreas Stasch
- University of St Andrews School of Chemistry North Haugh KY169ST St Andrews UNITED KINGDOM
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8
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Cai Y, Jiang S, Dong L, Xu X. Synthesis and reactivity of heterometallic complexes containing Mg- or Zn-metalloligands. Dalton Trans 2022; 51:3817-3827. [PMID: 35107467 DOI: 10.1039/d1dt04117g] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Heteronuclear metal complexes comprising main group metals and transition metals have attracted widespread attention from researchers due to their applications in stoichiometric and catalytic activation of small molecules with possible cooperative effects. Herein, the advances of heterometallic complexes containing Mg- or Zn-metalloligands over the past ten years are reviewed. They consist of two parts: (i) synthetic approaches to heterometallic complexes. Only a brief discussion is made on the different Mg/Zn precursors since they have been summarized before. (ii) Stoichiometric and catalytic reactivities of heterometallic complexes containing Mg/Zn metalloligands. The exploration of the cooperative catalytic reaction of heterometallic complexes is still in its infancy, promising but challenging; thus, further investigations are required in the future.
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Affiliation(s)
- Yanping Cai
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.
| | - Shengjie Jiang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.
| | - Liqiu Dong
- Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Xin Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.
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9
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Li Y, Pan H, Lu Y, Luo Y, Dang Y, Wang Y, Xia S, Li Y, Xia Y. Lithium and magnesium complexes from the employment of pyridyl-pendanted unsymmetrical β-diketiminates: syntheses and utilization as catalysts for the hydroboration of carbonyl compounds. Dalton Trans 2022; 51:3616-3624. [DOI: 10.1039/d1dt03235f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The push for environmentally benign and sustainable chemical processes has reinforced the demand to displace transition metals with cheap, nontoxic and naturally abundant metals. To fulfil this requirement, we endeavored...
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10
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Shi Y, Bai W, Mu W, Li J, Yu J, Lian B. Research Progress on Density Functional Theory Study of Palladium-Catalyzed C—H Functionalization to Form C—X (X=O, N, F, I, …) Bonds. CHINESE J ORG CHEM 2022. [DOI: 10.6023/cjoc202110027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Roy MMD, Omaña AA, Wilson ASS, Hill MS, Aldridge S, Rivard E. Molecular Main Group Metal Hydrides. Chem Rev 2021; 121:12784-12965. [PMID: 34450005 DOI: 10.1021/acs.chemrev.1c00278] [Citation(s) in RCA: 102] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, and 12-16. Particular attention will be given to the emerging use of said hydrides in the rapidly expanding field of Main Group element-mediated catalysis. While this review is comprehensive in nature, focus will be given to research appearing in the open literature since 2001.
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Affiliation(s)
- Matthew M D Roy
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Alvaro A Omaña
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Andrew S S Wilson
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Michael S Hill
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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12
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Rösch B, Harder S. New horizons in low oxidation state group 2 metal chemistry. Chem Commun (Camb) 2021; 57:9354-9365. [PMID: 34528959 DOI: 10.1039/d1cc04147a] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Since the seminal report on Mg in the +I oxidation state in 2007, low-valent complexes featuring a MgI-MgI bond developed from trophy molecules to state-of-the-art reducing agents. Despite increasing interest in low-valency of the other group 2 metals, this area was restricted for a long time to a rare example of a CaI(arene)CaI inverse sandwich. This feature article focuses on the most recent developments in the field, highlighting recent breakthroughs for Be, Mg and Ca. The more exotic metal Be was the first to be isolated as a zero-valent complex which could be oxidized to a BeI species. There also has been interest in breaking the MgI-MgI bond with superbulky β-diketiminate ligands (BDI) that suppress (BDI)Mg-Mg(BDI) bond formation. This led to Mg-Mg bond elongation or Mg-N bond cleavage. Several reports on attempts to isolate (BDI)Mg˙ radicals by combinations of ligand bulk, addition of neutral ligands or UV(vis) irradiation led to reduction of the aromatic solvents, underscoring the high reactivity of these open shell species. Only recently, zero-valent complexes of Mg were introduced. Double reduction of a (BDI)MgI complex with Na gave [(BDI)Mg-]Na+. This Mg0 complex crystallized as a dimer in which the Na+ cations bridge the two (BDI)Mg- anions which react as Mg nucleophiles. Thermal decomposition led to spontaneous formation of Na0 and a trinuclear (BDI)MgMgMg(BDI) complex. This mixed-valence Mg3-complex is a prime example of the fleeting multinuclear Mgn intermediates discussed on the way from Mg metal to Grignard reagent. Attempts to prepare low-valent CaI compounds by reduction of (BDI)CaI led to dearomatization of the arene solvents: (BDI)Ca(arene)Ca(BDI). Reduction in alkanes prevented this decomposition pathway but led to N2 reduction and isolation of (BDI)Ca(N2)Ca(BDI), representing the first example of molecular nitrogen fixation with an early main group metal. As the N22- anion reacts in most cases as a very strong two-electron reductant, LCa(N2)CaL could be seen as a synthon for hitherto elusive CaI-CaI complexes. Theoretical calculations suggest that participation of Ca d-orbitals is relevant for N2 activation. These most recent developments in low-valent group 2 metal chemistry will revive this area and undoubtly lead to new reactivities and applications.
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Affiliation(s)
- Bastian Rösch
- 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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13
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Wiesinger M, Knüpfer C, Elsen H, Mai J, Langer J, Harder S. Heterometallic Mg−Ba Hydride Clusters in Hydrogenation Catalysis. ChemCatChem 2021. [DOI: 10.1002/cctc.202101071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michael Wiesinger
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Christian Knüpfer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Holger Elsen
- 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
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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14
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Garçon M, Mun NW, White AJP, Crimmin MR. Palladium-Catalysed C-H Bond Zincation of Arenes: Scope, Mechanism, and the Role of Heterometallic Intermediates. Angew Chem Int Ed Engl 2021; 60:6145-6153. [PMID: 33275830 DOI: 10.1002/anie.202014960] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Indexed: 11/06/2022]
Abstract
Catalytic methods that transform C-H bonds into C-X bonds are of paramount importance in synthesis. A particular focus has been the generation of organoboranes, organosilanes and organostannanes from simple hydrocarbons (X=B, Si, Sn). Despite the importance of organozinc compounds (X=Zn), their synthesis by the catalytic functionalisation of C-H bonds remains unknown. Herein, we show that a palladium catalyst and zinc hydride reagent can be used to transform C-H bonds into C-Zn bonds. The new catalytic C-H zincation protocol has been applied to a variety of arenes-including fluoroarenes, heteroarenes, and benzene-with high chemo- and regioselectivity. A mechanistic study shows that heterometallic Pd-Zn complexes play a key role in catalysis. The conclusions of this work are twofold; the first is that valuable organozinc compounds are finally accessible by catalytic C-H functionalisation, the second is that heterometallic complexes are intimately involved in bond-making and bond-breaking steps of C-H functionalisation.
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Affiliation(s)
- Martí Garçon
- Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Nicolette Wee Mun
- Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Andrew J P White
- Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Mark R Crimmin
- Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
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15
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Jones DDL, Douair I, Maron L, Jones C. Photochemically Activated Dimagnesium(I) Compounds: Reagents for the Reduction and Selective C−H Bond Activation of Inert Arenes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202017126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Dafydd D. L. Jones
- School of Chemistry Monash University PO Box 23 Clayton VIC 3800 Australia
| | - Iskander Douair
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Laurent Maron
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Cameron Jones
- School of Chemistry Monash University PO Box 23 Clayton VIC 3800 Australia
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16
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Jones DDL, Douair I, Maron L, Jones C. Photochemically Activated Dimagnesium(I) Compounds: Reagents for the Reduction and Selective C−H Bond Activation of Inert Arenes. Angew Chem Int Ed Engl 2021; 60:7087-7092. [DOI: 10.1002/anie.202017126] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Dafydd D. L. Jones
- School of Chemistry Monash University PO Box 23 Clayton VIC 3800 Australia
| | - Iskander Douair
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Laurent Maron
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Cameron Jones
- School of Chemistry Monash University PO Box 23 Clayton VIC 3800 Australia
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17
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Garçon M, Mun NW, White AJP, Crimmin MR. Palladium‐Catalysed C−H Bond Zincation of Arenes: Scope, Mechanism, and the Role of Heterometallic Intermediates. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014960] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Martí Garçon
- Molecular Sciences Research Hub Imperial College London White City Campus, 82 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Nicolette Wee Mun
- Molecular Sciences Research Hub Imperial College London White City Campus, 82 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Andrew J. P. White
- Molecular Sciences Research Hub Imperial College London White City Campus, 82 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Mark R. Crimmin
- Molecular Sciences Research Hub Imperial College London White City Campus, 82 Wood Lane, Shepherds Bush London W12 0BZ UK
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Batuecas M, Gorgas N, Crimmin MR. Catalytic C-H to C-M (M = Al, Mg) bond transformations with heterometallic complexes. Chem Sci 2020; 12:1993-2000. [PMID: 34163961 PMCID: PMC8179254 DOI: 10.1039/d0sc03695a] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/16/2020] [Indexed: 12/20/2022] Open
Abstract
C-H functionalisation is one of the cornerstones of modern catalysis and remains a topic of contemporary interest due its high efficiency and atom-economy. Among these reactions, C-H borylation, that is the transformation of C-H to C-B bonds, has experienced a fast development because of the wide utility of organoboron reagents as synthetic intermediates. The mechanistic background is now well-understood and the role of transition metal boryl or σ-borane intermediates in this transformation is well documented. This mini-review focuses on efforts made by our group, and others, to establish palladium- and calcium-catalysed methods for C-H metalation employing heavier main group elements (M = Al, Mg). These are new catalytic reactions first accomplished in our group that we have termed C-H alumination and magnesiation respectively. Unusual heterometallic complexes have been identified as key on-cycle intermediates and their unique reactivity is discussed in the context of new catalytic pathways for C-H functionalisation. Hence, this mini-review summarises the recent progress in the area of C-H metalation reactions as well as the new opportunities that may arise from this concept.
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Affiliation(s)
- Maria Batuecas
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Nikolaus Gorgas
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
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Gentner TX, Rösch B, Ballmann G, Langer J, Elsen H, Harder S. Low Valent Magnesium Chemistry with a Super Bulky β-Diketiminate Ligand. Angew Chem Int Ed Engl 2018; 58:607-611. [PMID: 30422354 DOI: 10.1002/anie.201812051] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Indexed: 11/07/2022]
Abstract
The steric bulk of the well-known DIPP BDI ligand (CH[C(CH3 )N-DIPP]2 , DIPP=2,6-diisopropylphenyl) was increased by replacing isopropyl for isopentyl groups. This very bulky DIPeP BDI ligand could not stabilize the radical species (DIPeP BDI)Mg. : reduction of (DIPeP BDI)MgI with Na gave (DIPeP BDI)2 Mg2 with a rather long Mg-Mg bond of 3.0513(8) Å. Addition of TMEDA prior to reduction gave complex (DIPeP BDI)2 Mg2 (C6 H6 ), which could also be obtained as its THF adduct. It is speculated that combination of a bulky spectator ligand and TMEDA prevents dimerization of the intermediate MgI radical, which then reacts with the benzene solvent. Complex (DIPeP BDI)2 Mg2 (C6 H6 ), which formally contains the anti-aromatic anion C6 H6 2- , reacted with tBuOH as a Brønsted base to 1,3- and 1,4-cyclohexadiene and with H2 as a two electron donor to (DIPeP BDI)2 Mg2 H2 and C6 H6 . It also reductively cleaved the C-F bond in fluorobenzene and gave (DIPeP BDI)MgPh, (DIPeP BDI)MgF, and C6 H6 .
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Affiliation(s)
- Thomas Xaver Gentner
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Bastian Rösch
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Gerd Ballmann
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Jens Langer
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Holger Elsen
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
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Gentner TX, Rösch B, Ballmann G, Langer J, Elsen H, Harder S. Low Valent Magnesium Chemistry with a Super Bulky β-Diketiminate Ligand. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201812051] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Thomas Xaver Gentner
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Bastian Rösch
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Gerd Ballmann
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Holger Elsen
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic Chemistry; Universität Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
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