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Bhunia M, Sandoval-Pauker C, Fehn D, Grant LN, Senthil S, Gau MR, Ozarowski A, Krzystek J, Telser J, Pinter B, Meyer K, Mindiola DJ. Divalent Titanium via Reductive N-C Coupling of a Ti IV Nitrido with π-Acids. Angew Chem Int Ed Engl 2024; 63:e202404601. [PMID: 38619509 DOI: 10.1002/anie.202404601] [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: 03/06/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
The nitrido-ate complex [(PN)2Ti(N){μ2-K(OEt2)}]2 (1) (PN-=(N-(2-PiPr2-4-methylphenyl)-2,4,6-Me3C6H2) reductively couples CO and isocyanides in the presence of DME or cryptand (Kryptofix222), to form rare, five-coordinate TiII complexes having a linear cumulene motif, [K(L)][(PN)2Ti(NCE)] (E=O, L=Kryptofix222, (2); E=NAd, L=3 DME, (3); E=NtBu, L=3 DME, (4); E=NAd, L=Kryptofix222, (5)). Oxidation of 2-5 with [Fc][OTf] afforded an isostructural TiIII center containing a neutral cumulene, [(PN)2Ti(NCE)] (E=O, (6); E=NAd (7), NtBu (8)) and characterization by CW X-band EPR spectroscopy, revealed unpaired electron to be metal centric. Moreover, 1e- reduction of 6 and 7 in the presence of Kryptofix222cleanly reformed corresponding discrete TiII complexes 2 and 5, which were further characterized by solution magnetization measurements and high-frequency and -field EPR (HFEPR) spectroscopy. Furthermore, oxidation of 7 with [Fc*][B(C6F5)4] resulted in a ligand disproportionated TiIV complex having transoid carbodiimides, [(PN)2Ti(NCNAd)2] (9). Comparison of spectroscopic, structural, and computational data for the divalent, trivalent, and tetravalent systems, including their 15N enriched isotopomers demonstrate these cumulenes to decrease in order of backbonding as TiII→TiIII→TiIV and increasing order of π-donation as TiII→TiIII→TiIV, thus displaying more covalency in TiIII species. Lastly, we show a synthetic cycle whereby complex 1 can deliver an N-atom to CO and CNAd.
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Affiliation(s)
- Mrinal Bhunia
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Dominik Fehn
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander- Universität Erlangen-Nürnberg (FAU), 91058, Erlangen, Germany
| | - Lauren N Grant
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shuruthi Senthil
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael R Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, 32310, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, 32310, USA
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois, 60605, USA
| | - Balazs Pinter
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander- Universität Erlangen-Nürnberg (FAU), 91058, Erlangen, Germany
| | - Daniel J Mindiola
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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Spivey JA, Collum DB. Potassium Hexamethyldisilazide (KHMDS): Solvent-Dependent Solution Structures. J Am Chem Soc 2024; 146:17827-17837. [PMID: 38901126 DOI: 10.1021/jacs.4c03418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Solution structures of potassium hexamethyldisilazide [KHMDS] and labeled [15N]KHMDS were examined using a number of analytical methods including 29Si NMR spectroscopy and density functional theory computations. A combination of 15N-29Si couplings, 29Si chemical shifts, and the method of continuous variations reveals dimers, monomers, and ion pairs. Weakly coordinating monofunctional ligands such as toluene, N,N-dimethylethylamine, and Et3N afford exclusively dimers. 1,3-Dioxolane, THF, dimethoxyethane, hexamethylphosphoramide, and diglyme provide dimers at low ligand concentrations and monomers at high ligand concentrations. N,N,N',N'-Tetramethylethylenediamine and N,N,N',N'-tetramethylcyclohexanediamine provide exclusively dimers at all ligand concentrations at ambient temperatures and significant monomer at -80 °C. Studies of 12-crown-4 ran into technical problems. Equimolar 15-crown-5 forms a dimer, whereas excess 15-crown-5 affords a putative ion pair. Whereas equimolar 18-crown-6 also affords a dimer, an excess provides a monomer rather than a solvent-separated ion pair. [2.2.2]cryptand affords what is believed to be a contact-ion-paired cryptate. Solvation was probed using largely density functional theory (DFT) computations. Thermally corrected energies are consistent with lower aggregates and higher solvates at low temperatures, but the magnitudes of the computed temperature dependencies were substantially larger than the experimentally derived data.
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Affiliation(s)
- Jesse A Spivey
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
| | - David B Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
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3
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Wang T, Guo Z, English LE, Stephan DW, Jupp AR, Xu M. Synthesis and Reactivity of the [NCCCO] - Cyanoketenate Anion. Angew Chem Int Ed Engl 2024; 63:e202402728. [PMID: 38483891 DOI: 10.1002/anie.202402728] [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: 02/06/2024] [Indexed: 04/11/2024]
Abstract
Cyanoketene is a fundamental molecule that is actively being searched for in the interstellar medium. Its deprotonated form (cyanoketenate) is a heterocumulene that is isoelectronic to carbon suboxide whose structure has been the subject of debate. However, the investigation of cyanoketene and its derivatives is hampered by the lack of practical synthetic routes to these compounds. We report the first synthesis of the cyanoketenate anion in [K(18-crown-6)][NCCCO] (1) as a stable molecule on a multigram scale in excellent yields (>90 %). The structure of this molecule is probed crystallographically and computationally. We also explore the protonation of 1, and its reaction with triphenylsilylchloride and carbon dioxide. In all cases, anionic dimers are formed. The cyanoketene could be synthesized and crystallographically characterized when stabilized by a N-heterocyclic carbene. The cyanoketenate is a very useful unsaturated building block containing N, C and O atoms that can now be explored with relative ease and will undoubtedly unlock more interesting reactivity.
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Affiliation(s)
- Tongtong Wang
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Rd, Shanghai, China, 200092
| | - Zhuangzhuang Guo
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Rd, Shanghai, China, 200092
| | - Laura E English
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, West Midlands, UK, B15 2TT
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, Canada, M5S3H6
| | - Andrew R Jupp
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, West Midlands, UK, B15 2TT
| | - Maotong Xu
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Rd, Shanghai, China, 200092
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4
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Knüpfer C, Klerner L, Mai J, Langer J, Harder S. s-Block metal complexes of superbulky ( tBu 3Si) 2N -: a new weakly coordinating anion? Chem Sci 2024; 15:4386-4395. [PMID: 38516089 PMCID: PMC10952107 DOI: 10.1039/d3sc06896j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/19/2024] [Indexed: 03/23/2024] Open
Abstract
Sterically hindered amide anions have found widespread application as deprotonation agents or as ligands to stabilize metals in unusual coordination geometries or oxidation states. The use of bulky amides has also been advantageous in catalyst design. Herein we present s-block metal chemistry with one of the bulkiest known amide ligands: (tBu3Si)2N- (abbreviated: tBuN-). The parent amine (tBuNH), introduced earlier by Wiberg, is extremely resistant to deprotonation (even with nBuLi/KOtBu superbases) but can be deprotonated slowly with a blue Cs+/e- electride formed by addition of Cs0 to THF. (tBuN)Cs crystallized as a separated ion-pair, even without cocrystallized solvent. As salt-metathesis reactions with (tBuN)Cs are sluggish and incomplete, it has only limited use as an amide transfer reagent. However, ball-milling with LiI led to quantitative formation of (tBuN)Li and CsI. Structural characterization shows that (tBuN)Li is a monomeric contact ion-pair with a relatively short N-Li bond, an unusual T-shaped coordination geometry around N and extremely short Li⋯Me anagostic interactions. Crystal structures are compared with Li and Cs complexes of less bulky amide ligands (iPr3Si)2N- (iPrN-) and (Me3Si)2N- (MeN-). DFT calculations show trends in the geometries and electron distributions of amide ligands of increasing steric bulk (MeN- < iPrN- < tBuN-) and confirm that tBuN- is a rare example of a halogen-free weakly coordinating anion.
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Affiliation(s)
- Christian Knüpfer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Lukas Klerner
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jonathan Mai
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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5
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Yeganeh-Salman A, Yeung J, Miao L, Stephan DW. Coordination chemistry and FLP reactivity of 1,1- and 1,2-bis-boranes. Dalton Trans 2024; 53:1178-1189. [PMID: 38108120 DOI: 10.1039/d3dt03660j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Coordination chemistry and frustrated Lewis pair (FLP) chemistry have been most commonly studied using monodentate Lewis acids. In this paper, we examine the corresponding reactions employing the 1,1- and 1,2-bis-boranes, PhCH2CH(B(C6F5)2)21 and Me3SiCH(B(C6F5)2)CH2B(C6F5)22, respectively. Coordination of isocyanide to these species results in the formation of the products RCH(B(C6F5)2CNtBu)CH2(B(C6F5)2CNtBu) (R = Ph 3, Me3Si 4). The rearrangement of 1 to give the 1,2-bis-borane adduct 3 was probed and attributed to a donor-induced retrohydroboration and subsequent hydroboration. The analogous reaction of 1 is evident in efforts to use the Gutman-Beckett method to assess its Lewis acidity. However, in combination with tBu3P, bis-boranes 1 and 2 form FLPs and react with H2 to give [tBu3PH][PhCH2CH(B(C6F5)2)2(μ-H)] 5a and [tBu3PH][Me3SiCH(B(C6F5)2)CH2(B(C6F5)2)(μ-H)] 6, respectively. Reactions of 1 and 2 with various donors and PhCCH were shown to give deprotonation and addition products, depending on the nature of the base. However, in the case of 1, products resulting from retrohydroboration, and subsequent hydroboration are evident. Several of these alkyne products are crystallographically characterized.
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Affiliation(s)
- Amir Yeganeh-Salman
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Jason Yeung
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Linkun Miao
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
- Institute of Drug Discovery Technology, Ningbo University, Zhejiang, P. R. China
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6
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Reuter MB, Javier-Jiménez DR, Bushey CE, Waterman R. Group I Alkoxides and Amylates as Highly Efficient Silicon-Nitrogen Heterodehydrocoupling Precatalysts for the Synthesis of Aminosilanes. Chemistry 2023; 29:e202302618. [PMID: 37728424 DOI: 10.1002/chem.202302618] [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: 08/10/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/21/2023]
Abstract
Group I alkoxides are highly active precatalysts in the heterodehydrocoupling of silanes and amines to afford aminosilane products. The broadly soluble and commercially available KOt Amyl was utilized as the benchmark precatalyst for this transformation. Challenging substrates such as anilines were found to readily couple primary, secondary, and tertiary silanes in high conversions (>90 %) after only 2 h at 40 °C. Traditionally challenging silanes such as Ph3 SiH were also easily coupled to simple primary and secondary amines under mild conditions, with reactivity that rivals many rare earth and transition-metal catalysts for this transformation. Preliminary evidence suggests the formation of hypercoordinated intermediates, but radicals were detected under catalytic conditions, indicating a mechanism that is rare for Si-N bond formation.
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Affiliation(s)
- Matthew B Reuter
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Diego R Javier-Jiménez
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Claire E Bushey
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Rory Waterman
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
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7
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Heilmann A, Saddington AM, Goicoechea JM, Aldridge S. Aluminium and Gallium Silylimides as Nitride Sources. Chemistry 2023; 29:e202302512. [PMID: 37604785 DOI: 10.1002/chem.202302512] [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: 08/02/2023] [Revised: 08/19/2023] [Accepted: 08/21/2023] [Indexed: 08/23/2023]
Abstract
Terminal aluminium and gallium imides of the type K[(NON)M(NR)], bearing heteroatom substituents at R, have been synthesised via reactions of anionic aluminium(I) and gallium(I) reagents with silyl and boryl azides (NON=4,5-bis(2,6-diisopropyl-anilido)-2,7-di-tert-butyl-9,9-dimethyl-xanthene). These systems vary significantly in their lability in solution: the N(Sii Pr3 ) and N(Boryl) complexes are very labile, on account of the high basicity at nitrogen. Phenylsilylimido derivatives provide greater stabilization through the π-acceptor capabilities of the SiR3 group. K[(NON)AlN(Sit BuPh2 )] offers a workable compromise between stability and solubility, and has been completely characterized by spectroscopic, analytical and crystallographic methods. The silylimide species examined feature minimal π-bonding between the imide ligand and aluminium/gallium, with the HOMO and HOMO-1 orbitals effectively comprising orthogonal lone pairs centred at N. Reactivity-wise, both aluminium and gallium silylimides can act as viable sources of nitride, [N]3- , with systems derived from either metal reacting with CO to afford cyanide complexes. By contrast, only the gallium system K[(NON)Ga{N(SiPh3 )}] is capable of effecting a similar transformation with N2 O to yield azide, N3 - , via formal oxide/nitride metathesis. The aluminium systems instead generate RN3 via transfer of the imide fragment [RN]2- .
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Affiliation(s)
- Andreas Heilmann
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Artemis M Saddington
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Jose M Goicoechea
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
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8
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Reuter MB, Bushey CE, Javier-Jiménez DR, Waterman R. Commercially available organolithium compounds as effective, simple precatalysts for silicon-nitrogen heterodehydrocoupling. Dalton Trans 2023; 52:13497-13506. [PMID: 37605890 DOI: 10.1039/d3dt02564k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
A family of commercially available organolithium compounds were found to effectively catalyze the heterodehydrocoupling of silanes and amines under ambient conditions. Ubiquitous nBuLi (1) was utilized as the benchmark catalyst, where an array of primary, secondary, and tertiary arylsilanes were coupled to electron-donating amines, affording aminosilanes in high conversions with short reaction times. Preliminary mechanistic analysis is consistent with a nucleophilic-type system that involves the formation of a hypervalent silicon intermediate. This work underscores the accessibility of Si-N heterodehydrocoupling, with organolithium reagents emerging as some of the most straightforward and cost-effective precatalysts for this transformation.
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Affiliation(s)
- Matthew B Reuter
- University of Vermont, Department of Chemistry, Discovery Hall, Burlington, VT 05405, USA.
| | - Claire E Bushey
- University of Vermont, Department of Chemistry, Discovery Hall, Burlington, VT 05405, USA.
| | - Diego R Javier-Jiménez
- University of Vermont, Department of Chemistry, Discovery Hall, Burlington, VT 05405, USA.
| | - Rory Waterman
- University of Vermont, Department of Chemistry, Discovery Hall, Burlington, VT 05405, USA.
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9
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Jörges M, Krischer F, Gessner VH. Transition metal-free ketene formation from carbon monoxide through isolable ketenyl anions. Science 2022; 378:1331-1336. [PMID: 36548404 DOI: 10.1126/science.ade4563] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The capacity of transition metals to bind and transform carbon monoxide (CO) is critical to its use in many chemical processes as a sustainable, inexpensive C1 building block. By contrast, only few s- and p-block element compounds bind and activate CO, and conversion of CO into useful carbonyl-containing organic compounds in such cases remains elusive. We report that metalated phosphorus ylides provide facile access to ketenyl anions ([RC=C=O]-) by phosphine displacement with CO. These anions are very stable and storable reagents with a distinctive electronic structure between that of the prototypical ketene (H2C=C=O) and that of ethynol (HC≡C-OH). Nonetheless, the ketenyl anions selectively react with a range of electrophiles at the carbon atom, thus offering high-yielding and versatile access to ketenes and related compounds.
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Affiliation(s)
- Mike Jörges
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Felix Krischer
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Viktoria H Gessner
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
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10
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Ding Y, Zhang J, Li Y, Cui C. Disilicon Dicarbonyl Complex: Synthesis and Protonation of CO with O–H Bond. J Am Chem Soc 2022; 144:20566-20570. [DOI: 10.1021/jacs.2c10599] [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)
- Yazhou Ding
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, People’s Republic of China
| | - Jianying Zhang
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, People’s Republic of China
| | - Yang Li
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, People’s Republic of China
| | - Chunming Cui
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, People’s Republic of China
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11
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Kurumada S, Yamashita M. A Tetraorganyl-Alumaborane with An Al-B σ-Bond and Two Adjacent Lewis-Acidic Centers. J Am Chem Soc 2022; 144:4327-4332. [PMID: 35245043 DOI: 10.1021/jacs.2c01580] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A tetraorganyl-alumaborane (3) that contains an Al-B bond and twisted Al and B planes was synthesized and structurally characterized. UV-vis absorption spectroscopy, electrochemical measurement, and DFT calculations were employed to reveal the electronic properties of 3. The reactivity of 3 toward DMSO and CO was studied to demonstrate its deoxygenating abilities. On the basis of the results of the DFT calculations, a detailed reaction mechanism was developed, which highlighted the important role of the distinct Lewis acidity of the group-13 elements Al and B in 3.
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Affiliation(s)
- Satoshi Kurumada
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
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12
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Yao C, Zhang T, Gonçalves TP, Huang KW. Selective benzylic C sp3-H bond activations mediated by a phosphorus-nitrogen PN 3P-nickel complex. Chem Commun (Camb) 2022; 58:1593-1596. [PMID: 35018914 DOI: 10.1039/d1cc06507f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In contrast to the typical Csp2-H activation, a PN3P-Nickel complex chemoselectively cleaved the benzylic Csp3-H bond of toluene in the presence of KHMDS, presumably via an in situ generated potassium benzyl intermediate. Under similar conditions, CO underwent deoxygenation to afford the corresponding nickel cyano complex, and ethylbenzene was dehydrogenated to give styrene and a nickel hydride compound. 2,6-Xylyl isocyanide was transformed into an unprecedented indolyl complex, likely by trapping the activated benzyl species with an isocyanide moiety.
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Affiliation(s)
- Changguang Yao
- School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China.,KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
| | - Tonghuan Zhang
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia. .,Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University, Shenzhen Graduate School, Shenzhen 518055, China
| | - Théo P Gonçalves
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
| | - Kuo-Wei Huang
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
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13
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Affiliation(s)
- Shiori Fujimori
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
| | - Shigeyoshi Inoue
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
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14
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Schneider C, Guggolz L, Werncke CG. High-spin carbonyl complexes of iron(I) and cobalt(I). Dalton Trans 2021; 51:179-184. [PMID: 34874371 DOI: 10.1039/d1dt03924e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Metal carbonyl complexes are almost exclusively found in a low-spin state due to the strong-field nature of the CO ligand. Here the characterisation of highly labile three-coordinate metal(I) monocarbonyl complexes of iron and cobalt is presented. Experimental and quantum chemical examinations reveal their high-spin configuration.
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Affiliation(s)
- Christian Schneider
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - Lukas Guggolz
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - C Gunnar Werncke
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
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15
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Marchenko A, Koidan G, Hurieva A, Shvydenko K, Rozhenko AB, Rusanov EB, Kyrylchuk AA, Kostyuk A. Latent Nucleophilic Carbenes. J Org Chem 2021; 87:373-385. [PMID: 34898214 DOI: 10.1021/acs.joc.1c02397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using DFT and ab initio calculations, we demonstrate that noncyclic formamidines can undergo thermal rearrangement into their isomeric aminocarbenes under rather mild conditions. We synthesized the silylformamidine, for which the lowest activation energy in this process was predicted. Experimental studies proved it to serve as a very reactive nucleophilic carbene. The reactions with acetylenes, benzenes, and trifluoromethane proceeded via insertion into sp, sp2, and sp3 CH bonds. The carbene also reacted with the functional groups, such as CHO, COR, and CN at double or triple bonds, displaying high mobility of the trimethylsilyl group. The obtained silylformamidine can be considered as a latent nucleophilic carbene. It can be prepared in bulk quantities, stored, and used when the need arises. Calculation results predict similar behavior for some other silylated formamidines and related compounds.
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Affiliation(s)
- Anatoliy Marchenko
- Department of Organophosphorus Chemistry, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Georgyi Koidan
- Department of Organophosphorus Chemistry, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Anastasiya Hurieva
- Department of Organophosphorus Chemistry, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Kostiantyn Shvydenko
- Department of Organophosphorus Chemistry, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Alexander B Rozhenko
- Igor Sikorsky Kyiv Polytechnic Institute, National Technical University of Ukraine, Prosp. Peremohy 37, Kyiv 03056, Ukraine.,Department of Physicochemical Investigations, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Eduard B Rusanov
- Department of Physicochemical Investigations, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Andrii A Kyrylchuk
- Department of Physicochemical Investigations, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
| | - Aleksandr Kostyuk
- Department of Organophosphorus Chemistry, Institute of Organic Chemistry, Murmanska 5, Kyiv 02660, Ukraine
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16
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Reactions of a Dilithiomethane with CO and N
2
O: An Avenue to an Anionic Ketene and a Hexafunctionalized Benzene. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111486] [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]
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17
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Xu M, Wang T, Qu ZW, Grimme S, Stephan DW. Reactions of a Dilithiomethane with CO and N 2 O: An Avenue to an Anionic Ketene and a Hexafunctionalized Benzene. Angew Chem Int Ed Engl 2021; 60:25281-25285. [PMID: 34559447 DOI: 10.1002/anie.202111486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/22/2021] [Indexed: 01/07/2023]
Abstract
Synthesis of value-added products from simple C1 feedstocks is an attractive alternative avenue to traditional fossil fuels. Hexa-substituted benzene derivatives are highly useful molecules but are often challenging to prepare. Herein, we report that the lithium complex [(Ph2 P(S))2 CLi2 (THF)]2 1 reacts with CO lead to C-C bond formation and migration of a Ph2 P(S)-fragment affording 2. Subsequent reaction with N2 O results in oxidative cleavage of a P-C bond affording [Ph2 P(S)OLi(THF)2 ]2 4 and the anionic ketene-derivative Ph2 P(S)CCOLi(THF)2 5. Heating 5 prompts cyclotrimerization giving the hexa-substituted benzene derivative [Ph2 P(S)CCOLi(THF)2 ]3 6 regioselectively. This transition metal-free protocol to a hexa-substituted benzene is viable on a gram scale and permits the incorporation of 13 C labels. The mechanisms of these reactions are detailed via extensive DFT computations.
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Affiliation(s)
- Maotong Xu
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada
| | - Tongtong Wang
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada.,School of Chemistry, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116023, China
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada
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18
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Wang T, Xu M, Jupp AR, Qu ZW, Grimme S, Stephan DW. Steric Influence on Reactions of Benzyl Potassium Species with CO. Chem Asian J 2021; 16:3640-3644. [PMID: 34592053 PMCID: PMC9292647 DOI: 10.1002/asia.202101127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Indexed: 11/20/2022]
Abstract
Reactions of benzyl potassium species with CO are shown to proceed via transient carbene‐like intermediates that can undergo either dimerization or further CO propagation. In a sterically unhindered case, formal dimerization of the carbene is the dominant reaction pathway, as evidenced by the isolation of ((Ph3SiO)(PhCH2)C)22 and PhCH2C(O)CH(OH)CH2Ph 3. Reactions with increasingly sterically encumbered reagents show competitive reaction pathways involving intermolecular dimerization leading to species analogous to 2 and 3 and those containing newly‐formed five‐membered rings tBu2C6H2(C(OSiR3)C(OSiR3)CH2) (R=Me 6, Ph 7). Even further encumbered reagents proceed to either dimerize or react with additional CO to give a ketene‐like intermediates, thus affording a 7‐membered tropolone derivative 14 or the dione (3,5‐tBu2C6H3)3C6H2CH2C(O))215.
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Affiliation(s)
- Tongtong Wang
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada.,School of Chemistry, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology (P. R. China)
| | - Maotong Xu
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada
| | - Andrew R Jupp
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario, M5S3H6, Canada
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