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Krischer F, Gessner VH. Ligand Exchange at Carbon: Synthetic Entry to Elusive Species and Versatile Reagents. JACS AU 2024; 4:1709-1722. [PMID: 38818072 PMCID: PMC11134600 DOI: 10.1021/jacsau.4c00112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 06/01/2024]
Abstract
How different is carbon compared to other elements in the periodic table? Can carbon compounds be regarded as coordination complexes with carbon as the central element undergoing a facile exchange of its ligands? Although carbon clearly plays a special role among the elements of the periodic table, recent studies have drawn parallels between the bonding situation and the reactivity of carbon compounds to transition metal complexes. This Perspective summarizes recent reports about ylidic and zwitterionic compounds that were shown to exhibit ambiguous bonding situations that can be interpreted as donor-acceptor interactions similar to the bond between a metal and a neutral ligand. Based on this conception, ligand exchange reactions prototypical of transition metal complexes were realized at carbon atoms, enabling new synthetic strategies for the synthesis of reactive species and building blocks. In particular, the exchange of N2, CO, and phosphine ligands led to the development of a mild method for accessing new compounds and reagents with unusual properties, such as vinylidene ketenes or stable ketenyl anions, that open up a diverse but still poorly explored follow-up chemistry.
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Affiliation(s)
- Felix Krischer
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany
| | - Viktoria H. Gessner
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany
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2
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Qiao Z, Li X, Chen M, Cao F, Mo Z. Double 1,2-Carbon Migration at Mixed Heavier Sn=Ge Vinylidenes. Angew Chem Int Ed Engl 2024; 63:e202401570. [PMID: 38380578 DOI: 10.1002/anie.202401570] [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: 01/22/2024] [Revised: 02/17/2024] [Accepted: 02/20/2024] [Indexed: 02/22/2024]
Abstract
1,2-migration is one recurring isomerization reaction in organic chemistry. In contrast, double 1,2-migration remains rare and limited to transition-metal complexes. Herein, we describe the synthesis, characterization and reactivity of mixed heavier Sn=Ge vinylidenes. Double 1,2-carbon migration enables the isomerization of the stannagermenylidene (3) to the germastannenylidene (4). X-ray diffraction analysis and DFT calculations revealed that 3 and 4 feature a Sn=Ge double bond. The reaction of 3 with IMe4 (1,3,4,5-tetramethylimidazoline-2-ylidene) results in the electron redistribution in the Sn=Ge core to give the germylone-stannylene adduct (5). Moreover, treatment of 3 with 0.25 equiv. of (AlCp*)4 produces the heteronuclear aluminyl stannagermyne (6).
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Affiliation(s)
- Zihao Qiao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xueyan Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Ming Chen
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Fanshu Cao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Zhenbo Mo
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
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3
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Roth AD, Thamattoor DM. Carbenes from cyclopropanated aromatics. Org Biomol Chem 2023. [PMID: 37994575 DOI: 10.1039/d3ob01525d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Although a ripe old discipline by now, carbene chemistry continues to flourish as both theorists and experimentalists have shown sustained interest in this area of research. While there are numerous ways of generating carbenes, the thermal and/or photochemical decomposition of diazo compounds and diazirines remains, by far, the most commonly used method of producing these intermediates. There is no disputing the fact that these nitrogenous precursors have served carbene researchers well, but their use is not without problems. They are often sensitive and hazardous to handle and, sometimes, the desired nitrogenous precursor simply may not be available, e.g., for synthetic reasons, to study the particular carbene of interest. Furthermore, there is a legitimate concern that the photochemical generation of carbenes in solution from diazo compounds and diazirines may be contaminated by reactions in the excited states (RIES) of the precursors themselves. As an alternative, several laboratories, including ours, have used cyclopropanated aromatic systems to generate a wide range of carbenes. In each case, the cheleotropic extrusion of carbenes is accompanied by the formation of stable aromatic by-products such as phenanthrene, indane, naphthalene, and 1,4-dihydronaphthalene. The emergence of these "non-traditional" carbene sources, their versatility, and promise are reviewed in this work.
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Affiliation(s)
- Alexander D Roth
- Department of Chemistry, Colby College, Waterville, ME 04901, USA.
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4
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Roth A, Wamsley CE, Haynes SM, Thamattoor DM. Adamantylidenecarbene: Photochemical Generation, Trapping, and Theoretical Studies. J Org Chem 2023; 88:14413-14422. [PMID: 37768172 PMCID: PMC10594661 DOI: 10.1021/acs.joc.3c01399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Indexed: 09/29/2023]
Abstract
Photolysis of 1-(2-adamantylidene)-1a,9b-dihydro-1H-cyclopropa[l]phenanthrene in benzene (or benzene-d6) at ambient temperature produces adamantylidenecarbene. The carbene undergoes dimerization to a cumulene and may also be trapped in a stereospecific fashion by cis- and trans-4-methyl-2-pentene. No products attributable to 4-homoadamantyne, resulting from ring expansion of the carbene, could be detected. Coupled cluster/density functional theory calculations place the singlet carbene ∼49 kcal/mol below the triplet and show that the former must overcome a barrier of ∼13.5 kcal/mol to rearrange into 4-homoadamantyne.
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Affiliation(s)
- Alexander
D. Roth
- Department of Chemistry, Colby College, Waterville, Maine 04901, United States
| | | | - Sarah M. Haynes
- Department of Chemistry, Colby College, Waterville, Maine 04901, United States
| | - Dasan M. Thamattoor
- Department of Chemistry, Colby College, Waterville, Maine 04901, United States
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5
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Hansmann MM. Diazoalkenes: From an Elusive Intermediate to a Stable Substance Class in Organic Chemistry. Angew Chem Int Ed Engl 2023; 62:e202304574. [PMID: 37095063 DOI: 10.1002/anie.202304574] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 04/26/2023]
Abstract
Over decades diazoalkenes (R2 C=C=N2 ) were postulated as reactive intermediates in organic chemistry even though their direct spectroscopic detection proved very challenging. In the 1970/80ies several groups probed their existence mainly indirectly by trapping experiments or directly by matrix-isolation studies. In 2021, our group and the Severin group reported independently the synthesis and characterization of the first room-temperature stable diazoalkenes, which initiated a rapidly expanding research field. Up to now four different classes of N-heterocyclic substituted room-temperature stable diazoalkenes have been reported. Their properties and unique reactivity, such as N2 /CO exchange or utilization as vinylidene precursors in organic and transition metal chemistry are presented. This review summarizes the early discoveries of diazoalkenes from their initial postulation as transient, elusive species up to the recent findings of the room-temperature stable derivatives.
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Affiliation(s)
- Max M Hansmann
- Technische Universität Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn-Str. 6, Dortmund, Germany
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6
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Abstract
This Perspective article highlights the recent development of mesoionic N-heterocyclic olefins (mNHOs), where the exo-cyclic olefinic carbon is not bonded to strongly electron-withdrawing groups. The unquenched basicity and nucleophilicity of the exo-cyclic olefinic carbon make mNHOs strong σ-donors and enable unique reactivity patterns.
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Affiliation(s)
- Qiuming Liang
- Davenport Chemical Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6.
| | - Datong Song
- Davenport Chemical Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6.
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7
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Kooij B, Dong Z, Varava P, Fadaei-Tirani F, Scopelliti R, Piveteau L, Severin K. Vanadium complexes with N-heterocyclic vinylidene ligands. Chem Commun (Camb) 2022; 58:4204-4207. [PMID: 35274647 DOI: 10.1039/d2cc00768a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The preparation and the structural characterization of vanadium complexes with terminal and bridging N-heterocyclic vinylidene ligands is reported. The synthesis of the complexes was enabled by utilization of diazoolefins as ligand precursors. Structural data and theoretical results show that N-heterocyclic vinylidenes can act as 6e- donor ligands, leading to strong metal-carbon interactions.
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Affiliation(s)
- Bastiaan Kooij
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Zhaowen Dong
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Paul Varava
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Farzaneh Fadaei-Tirani
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Rosario Scopelliti
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Laura Piveteau
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
| | - Kay Severin
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
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