1
|
Campagnolo F, Aneggi E, Baratta W, Munir T, Zuccaccia D. Diffusion Nuclear Magnetic Resonance Measurements on Cationic Gold (I) Complexes in Catalytic Conditions: Counterion and Solvent Effects. Molecules 2024; 29:3018. [PMID: 38998970 DOI: 10.3390/molecules29133018] [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: 05/10/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
The amount of free ions, ion pairs, and higher aggregate of the possible species present in a solution during the gold(I)-catalyzed alkoxylation of unsaturated hydrocarbon, i.e., ISIP (inner sphere ion pair) [(NHC)AuX] and OSIP (outer sphere ion pairs) [(NHC)Au(TME)X] [NHC 1,3-bis(2,6-di-isopropylphenyl)-imidazol-2-ylidene; TME = tetramethylethylene (2,3-bis methyl-butene); X- = Cl-, BF4-, OTf-; and OTs- BArF4- (ArF = 3,5-(CF3)2C6H3)], has been determined. The 1H and 19F DOSY NMR measurements conducted in catalytic conditions indicate that the dissociation degree (α) of the equilibrium ion pair/free ions {[(NHC)Au(TME)X] [(NHC)Au(TME)]+ + X-} depends on the nature of the counterion (X-) when chloroform is the catalytic solvent: while the compounds containing OTs- and OTf- as the counterion gave a low α (which means a high number of ion pairs) of 0.13 and 0.24, respectively, the compounds containing BF4- and BArF4- showed higher α values of 0.36 and 0.32, respectively. These results experimentally confirm previous deductions based on catalytic and theoretical data: the lower the α value, the greater the catalytic activity because the anion that can activate methanol during a nucleophilic attack, although the lower propensity to activate methanol of BF4- and BArF4-, as suggested by the DFT calculations, cannot be completely overlooked. As for the effect of the solvent, α increases as the dielectric constant increases, as expected, and in particular, green solvents with high dielectric constants show a very high α (0.90, 0.84, 0.80, and 0.70 for propylene carbonate, γ-valerolactone, acetone, and methanol, respectively), thus confirming that the moderately high activity of NHC-Au-OTf in these solvents is due to the specific effect of polar functionalities (O-H, C=O, O-R) in activating methanol. Finally, the DOSY measurements conducted in p-Cymene show the formation of quadrupole species: under these conditions, the anion can better exercise its 'template' and 'activating' roles, giving the highest TOF.
Collapse
Affiliation(s)
- Filippo Campagnolo
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Sezione di Chimica, Università di Udine, Via Cotonificio 108, I-33100 Udine, Italy
| | - Eleonora Aneggi
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Sezione di Chimica, Università di Udine, Via Cotonificio 108, I-33100 Udine, Italy
| | - Walter Baratta
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Sezione di Chimica, Università di Udine, Via Cotonificio 108, I-33100 Udine, Italy
| | - Talha Munir
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Sezione di Chimica, Università di Udine, Via Cotonificio 108, I-33100 Udine, Italy
| | - Daniele Zuccaccia
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Sezione di Chimica, Università di Udine, Via Cotonificio 108, I-33100 Udine, Italy
| |
Collapse
|
2
|
Nguyen DT, Helling C, Evans MJ, Jones C. Enforcing Metal-Arene Interactions in Bulky p-Terphenyl Bis(anilide) Complexes of Group 2 Metals (Be-Ba): Potential Precursors for Low-Oxidation-State Alkaline Earth Metal Systems. Inorg Chem 2024; 63:5718-5726. [PMID: 38471088 DOI: 10.1021/acs.inorgchem.4c00207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
An extremely bulky p-terphenyl bis(aniline), p-C6H4{C6H4[N(H)TCHP]-2}2 (TCHP = 2,4,6-tricyclohexylphenyl) TCHPTerphH2, has been developed. Deprotonation of a less bulky analogue, DipTerphH2 (Dip = 2,6-diisopropylphenyl), with BePh2 affords the bimetallic system, [(BePh)2(μ-DipTerph)] 1. Treating either TCHPTerphH2 or DipTerphH2 with Mg{CH2(SiMe3)}2 gives the monomeric bis(anilide) complexes [Mg(ArTerph)] (Ar = Dip 2, TCHP 3) which display rare examples of η6-arene coordination to the metal center. Treating 2 with THF leads to partial dissociation of the Mg···arene interaction and formation of [Mg(DipTerph)(THF)] 4. Reactions of the bis(aniline)s with the group 2 metal amides [M{N(SiMe3)2}2] afford dimeric, structurally analogous compounds [{M(ArTerph)}2] (Ar = Dip, M = Ca 5, Sr 6, Ba 7; Ar = TCHP, M = Ca 8, Sr 9, Ba 10) which display intermolecular M···arene interactions in the solid state. Computational studies have shown that the intramolecular M···η6-arene interactions in models of the ether-free metal bis(anilide) compounds are largely electrostatic in nature. Reductions of these compounds with alkali metals led to mixtures of unidentified products.
Collapse
Affiliation(s)
- Dat T Nguyen
- School of Chemistry, Monash University, P.O. Box 23, Melbourne 3800, Victoria, Australia
| | - Christoph Helling
- School of Chemistry, Monash University, P.O. Box 23, Melbourne 3800, Victoria, Australia
| | - Matthew J Evans
- School of Chemistry, Monash University, P.O. Box 23, Melbourne 3800, Victoria, Australia
| | - Cameron Jones
- School of Chemistry, Monash University, P.O. Box 23, Melbourne 3800, Victoria, Australia
| |
Collapse
|
3
|
Demidov N, Grebogi M, Bourne C, McKay AP, Cordes DB, Stasch A. A Convenient One-Pot Synthesis of a Sterically Demanding Aniline from Aryllithium Using Trimethylsilyl Azide, Conversion to β-Diketimines and Synthesis of a β-Diketiminate Magnesium Hydride Complex. Molecules 2023; 28:7569. [PMID: 38005290 PMCID: PMC10673297 DOI: 10.3390/molecules28227569] [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: 10/19/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
This work reports the one-pot synthesis of sterically demanding aniline derivatives from aryllithium species utilising trimethylsilyl azide to introduce amine functionalities and conversions to new examples of a common N,N'-chelating ligand system. The reaction of TripLi (Trip = 2,4,6-iPr3-C6H2) with trimethylsilyl azide afforded the silyltriazene TripN2N(SiMe3)2 in situ, which readily reacts with methanol under dinitrogen elimination to the aniline TripNH2 in good yield. The reaction pathways and by-products of the system have been studied. The extension of this reaction to a much more sterically demanding terphenyl system suggested that TerLi (Ter = 2,6-Trip2-C6H3) slowly reacted with trimethylsilyl azide to form a silyl(terphenyl)triazenide lithium complex in situ, predominantly underwent nitrogen loss to TerN(SiMe3)Li in parallel, which afforded TerN(SiMe3)H after workup, and can be deprotected under acidic conditions to form the aniline TerNH2. TripNH2 was furthermore converted to the sterically demanding β-diketimines RTripnacnacH (=HC{RCN(Trip)}2H), with R = Me, Et and iPr, in one-pot procedures from the corresponding 1,3-diketones. The bulkiest proligand was employed to synthesise the magnesium hydride complex [{(iPrTripnacnac)MgH}2], which shows a distorted dimeric structure caused by the substituents of the sterically demanding ligand moieties.
Collapse
Affiliation(s)
| | | | | | | | | | - Andreas Stasch
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK; (N.D.); (M.G.); (C.B.); (A.P.M.); (D.B.C.)
| |
Collapse
|
4
|
Sato M, Rawat VK, Higashida K, Sawamura M. Gold-Zinc Cooperative Catalysis for Seven-exo-dig Hydrocarboxylation of Internal Alkynes. Chemistry 2023; 29:e202301917. [PMID: 37474450 DOI: 10.1002/chem.202301917] [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: 06/16/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/22/2023]
Abstract
Seven-exo-dig hydrocarboxylation of nonactivated internal alkynes with conformationally flexible linker chains was achieved with cooperative gold-zinc catalysts composed of an imidazo[1,5-a]pyridinylidene ligand including a bipyridine coordination site at the C5 position. A proximity effect of the gold and zinc sites was essential for their high catalytic activity, in which the internal alkyne activated by the cationic gold species was attacked by the carboxylic acid deprotonated by the basic zinc site. Using a gold(I)-complex with a bulky aromatic N-substituent, 2,6-dibenzhydryl-4-methylphenyl group, for the NHC ligand facilitated seven-membered ring formation while minimizing intermolecular hydrocarboxylation as an undesired side reaction. The reaction mechanism was investigated by quantum chemical calculations.
Collapse
Affiliation(s)
- Miyu Sato
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, 060-0810, Japan
| | - Vishal Kumar Rawat
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, 060-0810, Japan
| | - Kosuke Higashida
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
| | - Masaya Sawamura
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, 060-0810, Japan
| |
Collapse
|
5
|
Kagilev AA, Gafurov ZN, Sakhapov IF, Islamov DR, Kantyukov AO, Mikhailov IK, Yakhvarov DG. Crystal Structure of the Organonickel Sigma Complex [NiBr(Tcpp)(bpy)]. RUSS J GEN CHEM+ 2022. [DOI: 10.1134/s1070363222120155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
6
|
Wang L, Lu Y, Zhang L, Fang H, Zhang X, Li Y. Synthesis, structures, and catalytic activity toward the ring-opening polymerization of ε-caprolactone of zinc complexes supported by β-diketiminate ligands with a large aryl group. J Organomet Chem 2022. [DOI: 10.1016/j.jorganchem.2022.122434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Bysewski O, Winter A, Liebing P, Schubert US. Noble Metal Complexes of a Bis-Caffeine Containing NHC Ligand. Molecules 2022; 27:molecules27134316. [PMID: 35807559 PMCID: PMC9268361 DOI: 10.3390/molecules27134316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/26/2022] [Accepted: 06/28/2022] [Indexed: 12/04/2022] Open
Abstract
N-Heterocyclic carbenes (NHCs) have seen more and more use over the years. The go-to systems that are usually considered are derivatives of benzimidazole or imidazole. Caffeine possesses an imidazole unit and was already utilized as a carbene-type ligand; however, its use within a tridentate bis-NHC system has—to the best of our knowledge—not been reported so far. The synthesis of the ligand is straightforward and metal complexes are readily available via silver-salt metathesis. A platinum(II) and a palladium(II) complex were isolated and a crystal structure of the former was examined. For the Pt(II) complex, luminescence is observed in solid state as well as in solution.
Collapse
Affiliation(s)
- Oliver Bysewski
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; (O.B.); (A.W.)
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; (O.B.); (A.W.)
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
| | - Phil Liebing
- Institute for Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstr. 8, 07743 Jena, Germany;
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; (O.B.); (A.W.)
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
- Correspondence:
| |
Collapse
|
8
|
Shekhar S, Ahmed TS, Ickes AR, Haibach MC. Recent Advances in Nonprecious Metal Catalysis. Org Process Res Dev 2021. [DOI: 10.1021/acs.oprd.1c00410] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Shashank Shekhar
- Process Research and Development, AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Tonia S. Ahmed
- Process Research and Development, AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Andrew R. Ickes
- Process Research and Development, AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Michael C. Haibach
- Process Research and Development, AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| |
Collapse
|
9
|
Abstract
Sterically bulky β-diketiminate (or Nacnac) ligand systems have recently shown the ability to kinetically stabilize highly reactive low-oxidation state main group complexes. Metal halide precursors to such systems can be formed via salt metathesis reactions involving alkali metal complexes of these large ligand frameworks. Herein, we report the synthesis and characterization of lithium and potassium complexes of the super bulky anionic β-diketiminate ligands, known [TCHPNacnac]− and new [TCHP/DipNacnac]− (ArNacnac = [(ArNCMe)2CH]−) (Ar = 2,4,6-tricyclohexylphenyl (TCHP) or 2,6-diisopropylphenyl (Dip)). The reaction of the proteo-ligands, ArNacnacH, with nBuLi give the lithium etherate compounds, [(TCHPNacnac)Li(OEt2)] and [(TCHP/DipNacnac)Li(OEt2)], which were isolated and characterized by multinuclear NMR spectroscopy and X-ray crystallography. The unsolvated potassium salts, [{K(TCHPNacnac)}2] and [{K(TCHP/DipNacnac)}∞], were also synthesized and characterized in solution by NMR spectroscopy. In the solid state, these highly reactive potassium complexes exhibit differing alkali metal coordination modes, depending on the ligand involved. These group 1 complexes have potential as reagents for the transfer of the bulky ligand fragments to metal halides, and for the subsequent stabilization of low-oxidation state metal complexes.
Collapse
|
10
|
Acenaphthene-Based N-Heterocyclic Carbene Metal Complexes: Synthesis and Application in Catalysis. Catalysts 2021. [DOI: 10.3390/catal11080972] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
N-Heterocyclic carbene (NHC) ligands have become a privileged structural motif in modern homogenous and heterogeneous catalysis. The last two decades have brought a plethora of structurally and electronically diversified carbene ligands, enabling the development of cutting-edge transformations, especially in the area of carbon-carbon bond formation. Although most of these were accomplished with common imidazolylidene and imidazolinylidene ligands, the most challenging ones were only accessible with the acenaphthylene-derived N-heterocyclic carbene ligands bearing a π-extended system. Their superior σ-donor capabilities with simultaneous ease of modification of the rigid backbone enhance the catalytic activity and stability of their transition metal complexes, which makes BIAN-NHC (BIAN—bis(imino)acenaphthene) ligands an attractive tool for the development of challenging reactions. The present review summarizes synthetic efforts towards BIAN-NHC metal complexes bearing acenaphthylene subunits and their applications in modern catalysis, with special emphasis put on recently developed enantioselective processes.
Collapse
|
11
|
Twycross D, Davey CJ, Cole ML, McKay AI. Stereoelectronic Characterization and Catalytic Potential of a 1,3‐Bis(2,6‐terphenyl)‐Substituted N‐Heterocyclic Carbene. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100148] [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)
- Daniel Twycross
- School of Chemistry University of New South Wales Kensington NSW, 2052 Australia
| | - Christopher J. Davey
- School of Chemistry University of New South Wales Kensington NSW, 2052 Australia
| | - Marcus L. Cole
- School of Chemistry University of New South Wales Kensington NSW, 2052 Australia
| | - Alasdair I. McKay
- School of Chemistry University of New South Wales Kensington NSW, 2052 Australia
- School of Chemistry Monash University Clayton VIC 3080 Australia
| |
Collapse
|
12
|
Zheng YL, Xie PP, Daneshfar O, Houk KN, Hong X, Newman SG. Direct Synthesis of Ketones from Methyl Esters by Nickel-Catalyzed Suzuki-Miyaura Coupling. Angew Chem Int Ed Engl 2021; 60:13476-13483. [PMID: 33792138 DOI: 10.1002/anie.202103327] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Indexed: 12/14/2022]
Abstract
The direct conversion of alkyl esters to ketones has been hindered by the sluggish reactivity of the starting materials and the susceptibility of the product towards subsequent nucleophilic attack. We have now achieved a cross-coupling approach to this transformation using nickel, a bulky N-heterocyclic carbene ligand, and alkyl organoboron coupling partners. 65 alkyl ketones bearing diverse functional groups and heterocyclic scaffolds have been synthesized with this method. Catalyst-controlled chemoselectivity is observed for C(acyl)-O bond activation of multi-functional substrates bearing other bonds prone to cleavage by Ni, including aryl ether, aryl fluoride, and N-Ph amide functional groups. Density functional theory calculations provide mechanistic support for a Ni0 /NiII catalytic cycle and demonstrate how stabilizing non-covalent interactions between the bulky catalyst and substrate are critical for the reaction's success.
Collapse
Affiliation(s)
- Yan-Long Zheng
- Centre for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Pei-Pei Xie
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Omid Daneshfar
- Centre for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Xin Hong
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Stephen G Newman
- Centre for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, K1N 6N5, Canada
| |
Collapse
|
13
|
Zheng Y, Xie P, Daneshfar O, Houk KN, Hong X, Newman SG. Direct Synthesis of Ketones from Methyl Esters by Nickel‐Catalyzed Suzuki–Miyaura Coupling. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Yan‐Long Zheng
- Centre for Catalysis Research and Innovation Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie-Curie Ottawa Ontario K1N 6N5 Canada
| | - Pei‐Pei Xie
- Department of Chemistry Zhejiang University Hangzhou 310027 China
| | - Omid Daneshfar
- Centre for Catalysis Research and Innovation Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie-Curie Ottawa Ontario K1N 6N5 Canada
| | - Kendall N. Houk
- Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA
| | - Xin Hong
- Department of Chemistry Zhejiang University Hangzhou 310027 China
| | - Stephen G. Newman
- Centre for Catalysis Research and Innovation Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie-Curie Ottawa Ontario K1N 6N5 Canada
| |
Collapse
|
14
|
Chen C, Liu FS, Szostak M. BIAN-NHC Ligands in Transition-Metal-Catalysis: A Perfect Union of Sterically Encumbered, Electronically Tunable N-Heterocyclic Carbenes? Chemistry 2021; 27:4478-4499. [PMID: 32989914 PMCID: PMC7940599 DOI: 10.1002/chem.202003923] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/24/2020] [Indexed: 12/12/2022]
Abstract
The discovery of NHCs (NHC = N-heterocyclic carbenes) as ancillary ligands in transition-metal-catalysis ranks as one of the most important developments in synthesis and catalysis. It is now well-recognized that the strong σ-donating properties of NHCs along with the ease of scaffold modification and a steric shielding of the N-wingtip substituents around the metal center enable dramatic improvements in catalytic processes, including the discovery of reactions that are not possible using other ancillary ligands. In this context, although the classical NHCs based on imidazolylidene and imidazolinylidene ring systems are now well-established, recently tremendous progress has been made in the development and catalytic applications of BIAN-NHC (BIAN = bis(imino)acenaphthene) class of ligands. The enhanced reactivity of BIAN-NHCs is a direct result of the combination of electronic and steric properties that collectively allow for a major expansion of the scope of catalytic processes that can be accomplished using NHCs. BIAN-NHC ligands take advantage of (1) the stronger σ-donation, (2) lower lying LUMO orbitals, (3) the presence of an extended π-system, (4) the rigid backbone that pushes the N-wingtip substituents closer to the metal center by buttressing effect, thus resulting in a significantly improved control of the catalytic center and enhanced air-stability of BIAN-NHC-metal complexes at low oxidation state. Acenaphthoquinone as a precursor enables facile scaffold modification, including for the first time the high yielding synthesis of unsymmetrical NHCs with unique catalytic properties. Overall, this results in a highly attractive, easily accessible class of ligands that bring major advances and emerge as a leading practical alternative to classical NHCs in various aspects of catalysis, cross-coupling and C-H activation endeavors.
Collapse
Affiliation(s)
- Changpeng Chen
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ, 07102, USA
| | - Feng-Shou Liu
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ, 07102, USA
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan, Guangdong, 528458, China
| | - Michal Szostak
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ, 07102, USA
| |
Collapse
|
15
|
|
16
|
Appel S, Brüggemann P, Ganter C. A tropylium annulated N-heterocyclic carbene. Chem Commun (Camb) 2020; 56:9020-9023. [PMID: 32639486 DOI: 10.1039/d0cc04482b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Derivatives of the cationic tropylium annulated imidazolylidene ITrop+ are obtained by hydride abstraction from related cycloheptatriene compounds. Spectroscopic, structural and theoretical data indicate that, as a cationic relative of benzimidazolylidenes, ITrop+ has highly reduced σ-donor and strong π-acceptor character.
Collapse
Affiliation(s)
- Sebastian Appel
- Institut für Anorganische Chemie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
| | | | | |
Collapse
|
17
|
Dai S, Li S, Xu G, Wu C, Liao Y, Guo L. Flexible cycloalkyl substituents in insertion polymerization with α-diimine nickel and palladium species. Polym Chem 2020. [DOI: 10.1039/c9py01901d] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The investigation of the relationship between the structure of the catalyst and the microstructure of the obtained polymer has attracted much attention and broad interest in the field of transition metal-catalyzed olefin polymerization.
Collapse
Affiliation(s)
- Shengyu Dai
- Institutes of Physical Science and Information Technology
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education
- Anhui University
- Hefei
- China
| | - Shuaikang Li
- Institutes of Physical Science and Information Technology
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education
- Anhui University
- Hefei
- China
| | - Guoyong Xu
- Institutes of Physical Science and Information Technology
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education
- Anhui University
- Hefei
- China
| | - Cheng Wu
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022
- China
| | - Yudan Liao
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022
- China
| | - Lihua Guo
- Institute of Anticancer Agents Development and Theranostic Application
- The Key Laboratory of Life-Organic Analysis and Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine
- Department of Chemistry and Chemical Engineering
- Qufu Normal University
- Qufu 273165
| |
Collapse
|
18
|
Zheng YL, Newman SG. Methyl Esters as Cross-Coupling Electrophiles: Direct Synthesis of Amide Bonds. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00884] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Yan-Long Zheng
- Centre for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Stephen G. Newman
- Centre for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario K1N 6N5, Canada
| |
Collapse
|
19
|
Shen A, Wu Z, Fang Y, Yang J, Zhu H, Tu T. A Concerted Catalytic System for Sonogashira Coupling Reactions: Combination of N-Heterocyclic Carbene Palladium and Copper Complexes. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201800181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ancheng Shen
- School of Pharmacy; Yancheng Teachers University; Yancheng Jiangsu 224051 China
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials; Department of Chemistry; Fudan University; 2205 Songhu Road Shanghai 200438 China
| | - Zhen Wu
- School of Pharmacy; Yancheng Teachers University; Yancheng Jiangsu 224051 China
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials; Department of Chemistry; Fudan University; 2205 Songhu Road Shanghai 200438 China
| | - Yue Fang
- School of Pharmacy; Yancheng Teachers University; Yancheng Jiangsu 224051 China
| | - Jinming Yang
- School of Pharmacy; Yancheng Teachers University; Yancheng Jiangsu 224051 China
| | - Haibo Zhu
- School of Chemistry, Biological and Materials Sciences; East China University of Technology; Nanchang Jiangxi Province 330013 China
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials; Department of Chemistry; Fudan University; 2205 Songhu Road Shanghai 200438 China
| | - Tao Tu
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials; Department of Chemistry; Fudan University; 2205 Songhu Road Shanghai 200438 China
| |
Collapse
|
20
|
Sakaine G, Smits G. Modified Julia–Kocienski Reagents for a Stereoselective Introduction of Trisubstituted Double Bonds: A Formal Total Synthesis of Limazepine E and Barmumycin. J Org Chem 2018; 83:5323-5330. [DOI: 10.1021/acs.joc.8b00643] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guna Sakaine
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga LV-1006, Latvia
| | - Gints Smits
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga LV-1006, Latvia
| |
Collapse
|
21
|
Huynh HV. Electronic Properties of N-Heterocyclic Carbenes and Their Experimental Determination. Chem Rev 2018; 118:9457-9492. [DOI: 10.1021/acs.chemrev.8b00067] [Citation(s) in RCA: 446] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Han Vinh Huynh
- Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, Singapore 117543, Republic of Singapore
| |
Collapse
|
22
|
Abstract
The reaction of 1-amino,4-hydroxy-pentiptycene with diacetyl or acenaphthene-1,2-dione gave the respective diimines, followed by alkylation of the hydroxyl groups, and cyclization of the alkylated diimines to the respective bispentiptycene-imidazolium salts NHC·HCl. The azolium salts, being precursors to N-heterocyclic carbenes, were converted into metal complexes [(NHC)MX] (MX = CuI, AgCl, AuCl) and [(NHC)IrCl(cod)] and [(NHC)IrCl(CO)2] in good yields. In the solid state [(NHC)AgCl] displays a bowl-shaped structure of the ligand with the metal center buried within the concave unit.
Collapse
Affiliation(s)
- Roman Savka
- Organometallic Chemistry, Alarich-Weiss-Str. 12, TU Darmstadt, 64287 Darmstadt, Germany.
| | - Sabine Foro
- Organometallic Chemistry, Alarich-Weiss-Str. 12, TU Darmstadt, 64287 Darmstadt, Germany.
| | - Herbert Plenio
- Organometallic Chemistry, Alarich-Weiss-Str. 12, TU Darmstadt, 64287 Darmstadt, Germany.
| |
Collapse
|
23
|
Bergmann M, Savka R, Foro S, Plenio H. Synthesis of an
ortho
‐Methyl‐
N
,
N′
‐bis(triptycenyl) N‐Heterocyclic Carbene Ligand and Its Metal Complexes. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700793] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Marvin Bergmann
- Organometallic Chemistry TU Darmstadt Alarich‐Weiss‐Str. 12 64287 Darmstadt Germany
| | - Roman Savka
- Organometallic Chemistry TU Darmstadt Alarich‐Weiss‐Str. 12 64287 Darmstadt Germany
| | - Sabine Foro
- Department of Materials Science TU Darmstadt Alarich‐Weiss‐Str. 2 64287 Darmstadt Germany
| | - Herbert Plenio
- Organometallic Chemistry TU Darmstadt Alarich‐Weiss‐Str. 12 64287 Darmstadt Germany
| |
Collapse
|
24
|
Savka R, Bergmann M, Kanai Y, Foro S, Plenio H. Triptycene-Based Chiral andmeso-N-Heterocyclic Carbene Ligands and Metal Complexes. Chemistry 2016; 22:9667-75. [DOI: 10.1002/chem.201601474] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Roman Savka
- Organometallic Chemistry; TU Darmstadt; Alarich-Weiss-Strasse 12 64287 Darmstadt Germany
| | - Marvin Bergmann
- Organometallic Chemistry; TU Darmstadt; Alarich-Weiss-Strasse 12 64287 Darmstadt Germany
| | - Yuki Kanai
- Organometallic Chemistry; TU Darmstadt; Alarich-Weiss-Strasse 12 64287 Darmstadt Germany
| | - Sabine Foro
- Department of Materials Science; TU Darmstadt; Alarich-Weiss-Strasse 2 64287 Darmstadt Germany
| | - Herbert Plenio
- Organometallic Chemistry; TU Darmstadt; Alarich-Weiss-Strasse 12 64287 Darmstadt Germany
| |
Collapse
|
25
|
Perfetto A, Bertolasi V, Costabile C, Paradiso V, Caruso T, Longo P, Grisi F. Methyl and phenyl substituent effects on the catalytic behavior of NHC ruthenium complexes. RSC Adv 2016. [DOI: 10.1039/c6ra20608e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
NHCs with different combinations of methyl and phenyl substituents produce ruthenium second generation catalysts with different RCM behavior.
Collapse
Affiliation(s)
- Alessandra Perfetto
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| | - Valerio Bertolasi
- Dipartimento di Scienze Chimiche e Farmaceutiche and Centro di Strutturistica Diffrattometrica
- Università di Ferrara
- I-44121 Ferrara
- Italy
| | - Chiara Costabile
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| | - Veronica Paradiso
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| | - Tonino Caruso
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| | - Pasquale Longo
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| | - Fabia Grisi
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”
- Università di Salerno
- I-84084 Fisciano
- Italy
| |
Collapse
|