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González-Fernández E, Marinus N, Dhankhar J, Linden A, Čorić I. Control over Anion Coordination on Pd(II), Cu(I), and Ag(I) with Regioisomeric Phosphine-Carboxylate Ligands. Chemistry 2024; 30:e202401215. [PMID: 38688855 DOI: 10.1002/chem.202401215] [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: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
The coordination of anionic donors is involved at various stages of catalytic cycles in transition-metal catalysis, but control over the spatial positioning of anions around a metal center is a challenge in coordination chemistry. Here we show that regioisomeric phosphine-carboxylate ligands provide spatial anion control on palladium(II) centers by favoring either κ2, cis-κ1, or trans-κ1 coordination of the carboxylate donor. Additionally, the palladium(II) carboxylates, which contain a methyl donor, upon protonation, deliver metal-alkyl complexes that feature a coordinated carboxylic acid. Such complexes can be considered as models for the minima that follow the concerted metalation-deprotonation transition state for C-H activation. The predictability of the coordination modes is further demonstrated on silver(I) and copper(I) centers, for which less common structures of mononuclear and dinuclear complexes can be obtained by using spatial anion control. Our results demonstrate the potential for spatial control over carboxylate anions in coordination chemistry.
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Affiliation(s)
- Elisa González-Fernández
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Nittert Marinus
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Jyoti Dhankhar
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Anthony Linden
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Ilija Čorić
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
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2
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Muzart J. Palladium Catalysis: Dependence of the Efficiency of C-N Bond Formation on Carboxylate Ligand and Metal Carboxylate or Carboxylic Acid Additive. ACS OMEGA 2024; 9:12292-12306. [PMID: 38524407 PMCID: PMC10955574 DOI: 10.1021/acsomega.4c00468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 03/26/2024]
Abstract
The Pd-catalyzed inter- and intramolecular reactions of nitrogen compounds are often carried out with palladium carboxylates, sometimes in the presence of carboxylic acids or alkali metal carboxylates. This Mini-Review highlights the dependence of the reaction efficiency on the nature of the ligand and the carboxylate additives. The proposed reaction mechanisms are presented with, as far as possible, personal comments.
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Affiliation(s)
- Jacques Muzart
- Institut de Chimie Moléculaire
de Reims, UMR 7312, CNRS, Université de Reims Champagne-Ardenne, B.P. 1039, 51687 Reims Cedex 2, France
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3
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Cervantes‐Reyes A, Saxl T, Stein PM, Rudolph M, Rominger F, Asiri AM, Hashmi ASK. Expanded Ring NHC Silver Carboxylate Complexes as Efficient and Reusable Catalysts for the Carboxylative Cyclization of Unsubstituted Propargylic Derivatives. CHEMSUSCHEM 2021; 14:2367-2374. [PMID: 33687152 PMCID: PMC8252382 DOI: 10.1002/cssc.202002822] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/28/2021] [Indexed: 06/05/2023]
Abstract
Stabilized by a bulky N-heterocyclic carbene [BP DPr, 1,3-bis(2,6-diisopropylphenyl)-1,3-diazonine-2-ylidene] ligand, new silver carboxylate complexes of the form BP DPrAgO2 C-R (R=Me, Ph) have been synthesized and fully characterized in solution and in the solid state and implemented as sole catalysts (base-, additive-, and, in some cases, solvent-free) in the challenging fixation of carbon dioxide to unsubstituted propargylic derivatives for the synthesis of oxazolidinones and α-methylene cyclic carbonates. Derived from X-ray diffraction studies, the molecular geometry and the concept of buried volume were employed to describe the structural and steric features of these silver complexes. Their stability and efficiency as catalysts have been demonstrated by the synthesis of 29 carboxylation products (72-98 % yield) at low catalyst loadings (0.01-1.5 mol%). Characteristics are high turnover numbers (up to 9400), catalyst recyclability (up to 96 % yield after the 7th cycle with no decomposition of the silver complex), and the possibility to scale-up the reaction.
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Affiliation(s)
| | - Tobias Saxl
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Philipp M. Stein
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Matthias Rudolph
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Frank Rominger
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Abdullah M. Asiri
- Chemistry DepartmentFaculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi Arabia
| | - A. Stephen K. Hashmi
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
- Chemistry DepartmentFaculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi Arabia
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4
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Stegner PC, Eyselein J, Ballmann GM, Langer J, Schmidt J, Harder S. Calcium catalyzed enantioselective intramolecular alkene hydroamination with chiral C2-symmetric bis-amide ligands. Dalton Trans 2021; 50:3178-3185. [PMID: 33594995 DOI: 10.1039/d1dt00173f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chiral building block (R)-(+)-2,2'-diamino-1,1'-binaphthyl, (R)-BINAM, which is often used as backbone in privileged enantioselective catalysts, was converted to a series of N-substituted proligands R1-H2 (R = CH2tBu, C(H)Ph2, PPh2, dibenzosuberane, 8-quinoline). After double deprotonation with strong Mg or Ca bases, a series of alkaline earth (Ae) metal catalysts R1-Ae·(THF)n was obtained. Crystal structures of these C2-symmetric catalysts have been analyzed by quadrant models which show that the ligands with C(H)Ph2, dibenzosuberane and 8-quinoline substituents should give the best steric discrimination for the enantioselective intramolecular alkene hydroamination (IAH) of the aminoalkenes H2C[double bond, length as m-dash]CHCH2CR'2CH2NH2 (CR'2 = CPh2, CCy or CMe2). The dianionic R12- ligand in R1-Ae·(THF)n functions as reagent that deprotonates the aminoalkene substrate, while the monoanionic (R1-H)- ligand formed in this reaction functions as a chiral spectator ligand that controls the enantioselectivity of the ring closure reaction. Depending on the substituent R in the BINAM ligand, full cyclization of aminoalkenes to chiral pyrrolidine products as fast as 5 minutes was observed. Product analysis furnished enantioselectivities up to 57% ee, which marks the highest enantioselectivity reported for Ca catalyzed IAH. Higher selectivities are impeded by double protonation of the R12- ligand leading to complete loss of chiral information in the catalytically active species.
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Affiliation(s)
- Philipp C Stegner
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Jonathan Eyselein
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Gerd M Ballmann
- 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
| | - Jochen Schmidt
- 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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Gangwar MK, Butcher RJ. Axially chiral bis-1,2,3-Triazol-4-ylidene–Ag(I)-MIC and, bis-Au(I)-MIC complexes of (R)-BINOL and (-)-Menthol scaffold: Synthesis, structure, and characterizations. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2020.121626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hylland KT, Øien‐Ødegaard S, Tilset M. The Suzuki–Miyaura Cross‐Coupling as the Key Step in the Synthesis of 2‐Aminobiphenyls and 2,2'‐Diaminobiphenyls: Application in the Synthesis of Schiff Base Complexes of Zn. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
| | - Sigurd Øien‐Ødegaard
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
| | - Mats Tilset
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
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Cervantes‐Reyes A, Rominger F, Hashmi ASK. Sterically Demanding Ag I and Cu I N-Heterocyclic Carbene Complexes: Synthesis, Structures, Steric Parameters, and Catalytic Activity. Chemistry 2020; 26:5530-5540. [PMID: 32104933 PMCID: PMC7216994 DOI: 10.1002/chem.202000600] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/27/2020] [Indexed: 12/13/2022]
Abstract
The synthesis and full characterization of new air-stable AgI and CuI complexes bearing structurally bulky expanded-ring N-heterocyclic carbene (erNHC) ligands is presented. The condensation of protonated NHC salts with Ag2 O afforded a collection of AgI complexes, and their first use as ligand transfer reagents led to novel isostructural CuI or AuI complexes. In situ deprotonation of the NHC salts in the presence of a copper(I) source, provides a library of new CuI complexes. The solid-state structures feature large N-CNHC -N angles (118-128°) and almost identical angles between the aryl groups on the nitrogen atoms and the plane of the N-C-N unit of the carbene (i.e. torsion angles close to 0°). Among the steric parameters, the percent buried volume (%Vbur ) values span easily in the 50-57 % range, and that one of (9-Dipp)CuBr complex (%Vbur =57.5) overcomes to other known erNHC-metal complexes reported to date. Preliminary catalytic experiments in the copper-catalyzed coupling between N-tosylhydrazone and phenylacetylene, afforded 76-93 % product at the 0.5-2.5 mol % catalyst loading, proving the stability of CuI erNHC complexes at elevated temperatures (100 °C).
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Affiliation(s)
| | - Frank Rominger
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - A. Stephen K. Hashmi
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
- Chemistry DepartmentFaculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi Arabia
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9
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Montanaro S, Wright IA, Batsanov AS, Bryce MR. Synthesis of Tetracyclic 2,3-Dihydro-1,3-diazepines from a Dinitrodibenzothiophene Derivative. J Org Chem 2018; 83:12320-12326. [PMID: 30247912 DOI: 10.1021/acs.joc.8b02029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Triply fused 1,3-diazepine derivatives have been obtained by acidic reduction of rotationally locked and sterically hindered nitro groups in the presence of an aldehyde or ketone. The nitro groups are sited on adjacent rings of a dicyanodibenzothiophene-5,5-dioxide, which also displays fully reversible two-electron-accepting behavior. The synthesis, crystallographically determined molecular structures, and aspects of the electronic properties of these new molecules are presented.
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Affiliation(s)
- Stephanie Montanaro
- Department of Chemistry , Durham University , Durham , DH1 3LE , United Kingdom.,Department of Chemistry , Loughborough University , Loughborough , LE11 3TU , United Kingdom
| | - Iain A Wright
- Department of Chemistry , Loughborough University , Loughborough , LE11 3TU , United Kingdom
| | - Andrei S Batsanov
- Department of Chemistry , Durham University , Durham , DH1 3LE , United Kingdom
| | - Martin R Bryce
- Department of Chemistry , Durham University , Durham , DH1 3LE , United Kingdom
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10
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Synthesis of New C2-Symmetric Six-Membered NHCs and Their Application for the Asymmetric Diethylzinc Addition of Arylaldehydes. Catalysts 2018. [DOI: 10.3390/catal8020046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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11
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New C 2 -symmetric six-membered carbene ligands incorporating two hydroxyl groups for palladium-catalyzed deprotonative-cross-coupling processes (DCCP) of sp 3 C–H bonds in diarylmethanes. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.09.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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12
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A novel ditopic ring-expanded N-heterocyclic carbene ligand-assisted Suzuki-Miyaura coupling reaction in aqueous media. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.07.096] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Wang C, Wu E, Pu L. Enantioselective Fluorescent Recognition by Using a 1,1′-Binaphthyl-2,2′-diamine Derivative. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chao Wang
- Department of Chemistry; University of Virginia; 22904 Charlottesville Virginia USA
| | - Elaine Wu
- Department of Chemistry; University of Virginia; 22904 Charlottesville Virginia USA
| | - Lin Pu
- Department of Chemistry; University of Virginia; 22904 Charlottesville Virginia USA
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14
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Pérez-Briso C, Gallego AM, Martín-Alvarez JM, Martínez-Ilarduya JM, Espinet P. Polymer [Pd(CH2SO2C6H4Me)2]n, a precursor to remarkably stable Pd organometallics. Dalton Trans 2017; 46:8083-8090. [DOI: 10.1039/c7dt00904f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stable (arylsulfonyl)alkylpalladium complexes obtained from the polymer [Pd(CH2SO2C6H4Me)2]n undergo cis-to-trans isomerization in order to produce systems with stronger hydrogen bonds.
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Affiliation(s)
- Celeste Pérez-Briso
- IU CINQUIMA/Química Inorgánica
- Facultad de Ciencias
- Universidad de Valladolid
- 47071 Valladolid
- Spain
| | - Ana M. Gallego
- IU CINQUIMA/Química Inorgánica
- Facultad de Ciencias
- Universidad de Valladolid
- 47071 Valladolid
- Spain
| | - Jose M. Martín-Alvarez
- IU CINQUIMA/Química Inorgánica
- Facultad de Ciencias
- Universidad de Valladolid
- 47071 Valladolid
- Spain
| | | | - Pablo Espinet
- IU CINQUIMA/Química Inorgánica
- Facultad de Ciencias
- Universidad de Valladolid
- 47071 Valladolid
- Spain
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15
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16
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Wurm T, Mulks F, Böhling CRN, Riedel D, Zargaran P, Rudolph M, Rominger F, Hashmi ASK. Synthesis of Different Classes of Six-Membered Gold(I) NHC Complexes by the Isonitrile Route. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00023] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | | | | | | | | | | | - A. Stephen K. Hashmi
- Chemistry
Department, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia
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17
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Iannucci G, Iuliano A. Asymmetric activation of the tropos biphenyldiamidophosphite moiety: Synthesis and complexation to rhodium of a deoxycholic acid derived diamidophosphite. J Organomet Chem 2016. [DOI: 10.1016/j.jorganchem.2016.01.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Banach Ł, Guńka PA, Buchowicz W. Half-sandwich nickel complexes with ring-expanded NHC ligands – synthesis, structure and catalytic activity in Kumada–Tamao–Corriu coupling. Dalton Trans 2016; 45:8688-92. [DOI: 10.1039/c5dt04663g] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report the synthesis and catalytic properties of novel [Ni(Cp)(X)(NHC)] complexes with ring-expanded NHC ligands of six-, seven-, and eight-membered heterocycles.
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Affiliation(s)
- Ł. Banach
- Faculty of Chemistry
- Warsaw University of Technology
- 00-664 Warsaw
- Poland
| | - P. A. Guńka
- Faculty of Chemistry
- Warsaw University of Technology
- 00-664 Warsaw
- Poland
| | - W. Buchowicz
- Faculty of Chemistry
- Warsaw University of Technology
- 00-664 Warsaw
- Poland
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19
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Schmidt A, Wiechmann S, Otto CF. N-Heterocyclic Carbenes. ADVANCES IN HETEROCYCLIC CHEMISTRY 2016. [DOI: 10.1016/bs.aihch.2016.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Novel C2-symmetric six-membered NHCs for asymmetric copper-catalysed conjugate addition of Grignard reagents to 3-methylhexenone. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.03.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Wezeman T, Hu Y, McMurtrie J, Bräse S, Masters KS. Synthesis of Non-Symmetrical and Atropisomeric Dibenzo[1,3]diazepines: Pd/CPhos-Catalysed Direct Arylation of Bis-Aryl Aminals. Aust J Chem 2015. [DOI: 10.1071/ch15465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Pd/CPhos-catalysis provides direct arylation/cyclisation of methylene-linked bis-anilines to dibenzo[1,3]diazepines v, which are both non-(C2)-symmetrical and axially chiral. Synthesis of the direct arylation substrates commences with substitution of (N-acyl)anilines to methylene methyl sulfide derivatives, followed by halogenation/de-thiomethylation to N-(chloromethyl)anilines. These are substituted with a second aniline derivative, allowing modular preparation of (ortho-halo)aryl-aminal-linked arenes 4. The C–H functionalising direct arylation conditions were adapted from Fagnou and co-workers: substrates and potassium carbonate were heated in dimethylacetamide in the presence of palladium acetate and an electron-rich and sterically hindered biarylphosphine ligand, here CPhos 5. These conditions delivered the C1-(a)symmetric dibenzo[1,3]diazepine targets, which, due to torsion around the axis of the newly formed biaryl bond, are also intrinsically atropisomeric. The axially twisted scaffold is known to impart special properties to ligands/catalysts when the products are further converted into the corresponding seven-membered ring-containing N-heterocyclic carbenes (e.g. xii and xiv).
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22
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Yang L, Zhang X, Mao P, Xiao Y, Bian H, Yuan J, Mai W, Qu L. NCN pincer palladium complexes based on 1,3-dipicolyl-3,4,5,6-tetrahydropyrimidin-2-ylidenes: synthesis, characterization and catalytic activities. RSC Adv 2015. [DOI: 10.1039/c5ra01706h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
NCN pincer six-membered NHC palladium complexes were synthesized, characterized and used in Heck reaction of aryl bromides with olefines.
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Affiliation(s)
- Liangru Yang
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Xinchi Zhang
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Pu Mao
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Yongmei Xiao
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Huanyu Bian
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Jinwei Yuan
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Wenpeng Mai
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
| | - Lingbo Qu
- School of Chemistry and Chemical Engineering
- Henan University of Technology
- Zhengzhou 450001
- P. R. China
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Ananikov VP, Khemchyan LL, Ivanova YV, Bukhtiyarov VI, Sorokin AM, Prosvirin IP, Vatsadze SZ, Medved'ko AV, Nuriev VN, Dilman AD, Levin VV, Koptyug IV, Kovtunov KV, Zhivonitko VV, Likholobov VA, Romanenko AV, Simonov PA, Nenajdenko VG, Shmatova OI, Muzalevskiy VM, Nechaev MS, Asachenko AF, Morozov OS, Dzhevakov PB, Osipov SN, Vorobyeva DV, Topchiy MA, Zotova MA, Ponomarenko SA, Borshchev OV, Luponosov YN, Rempel AA, Valeeva AA, Stakheev AY, Turova OV, Mashkovsky IS, Sysolyatin SV, Malykhin VV, Bukhtiyarova GA, Terent'ev AO, Krylov IB. Development of new methods in modern selective organic synthesis: preparation of functionalized molecules with atomic precision. RUSSIAN CHEMICAL REVIEWS 2014. [DOI: 10.1070/rc2014v83n10abeh004471] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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GANGWAR MANOJKUMAR, KALITA ALOKCH, GHOSH PRASENJIT. Palladium complexes of a new type of N-heterocyclic carbene ligand derived from a tricyclic triazolooxazine framework. J CHEM SCI 2014. [DOI: 10.1007/s12039-014-0705-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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25
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Yang P, Xiang Y, Lin Z, Bassil BS, Cao J, Fan L, Fan Y, Li MX, Jiménez-Lozano P, Carbó JJ, Poblet JM, Kortz U. Alkaline earth guests in polyoxopalladate chemistry: from nanocube to nanostar via an open-shell structure. Angew Chem Int Ed Engl 2014; 53:11974-8. [PMID: 25220307 DOI: 10.1002/anie.201407090] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Indexed: 11/05/2022]
Abstract
The three novel, discrete palladium(II)-oxo clusters [CaPd12O8(PhAsO3)8](6-) (CaPd12), [SrPd12O6(OH)3(PhAsO3)6(OAc)3](4-) (SrPd12), and [BaPd15O10(PhAsO3)10](8-) (BaPd15) encapsulating alkaline earth metal ions were prepared and fully characterized by a multitude of solution and solid-state physicochemical techniques. We have discovered a structure-directing template effect induced by the respective size of the alkaline earth guest ion, which determines the detailed condensation arrangement of the peripheral Pd(II)-oxo shell. The unprecedented SrPd12 with an open-shell type structure is of particular importance and reflects a successful strategy for deliberate design of new structural classes of polyoxo-noble-metalates. Furthermore, the unusual acetate-water ligand exchange phenomenon renders SrPd12 as a promising candidate for noble-metal-based catalysis.
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Affiliation(s)
- Peng Yang
- Jacobs University, School of Engineering and Science, P.O. Box 750561, 28725 Bremen (Germany) http://www.jacobs-university.de/ses/ukortz
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Yang P, Xiang Y, Lin Z, Bassil BS, Cao J, Fan L, Fan Y, Li MX, Jiménez-Lozano P, Carbó JJ, Poblet JM, Kortz U. Erdalkalimetalle als Gastionen in der Polyoxopalladatchemie: vom Nanowürfel über eine offenschalige Struktur zum Nanostern. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201407090] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Naumann S, Buchmeiser MR. Liberation of N-heterocyclic carbenes (NHCs) from thermally labile progenitors: protected NHCs as versatile tools in organo- and polymerization catalysis. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00344f] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The thermally triggered release of catalytically active, free NHCs from various heat-sensitive progenitors is discussed.
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Affiliation(s)
- Stefan Naumann
- Institute of Polymer Chemistry
- University of Stuttgart
- D-70569 Stuttgart, Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry
- University of Stuttgart
- D-70569 Stuttgart, Germany
- Institute of Textile Chemistry and Chemical Fibres
- , Germany
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Naumann S, Schmidt FG, Speiser M, Böhl M, Epple S, Bonten C, Buchmeiser MR. Anionic Ring-Opening Homo- and Copolymerization of Lactams by Latent, Protected N-Heterocyclic Carbenes for the Preparation of PA 12 and PA 6/12. Macromolecules 2013. [DOI: 10.1021/ma4018586] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stefan Naumann
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | | | - Maria Speiser
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Margit Böhl
- Institute of Textile
Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
| | - Stefan Epple
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstrasse
70, D-70199 Stuttgart, Germany
| | - Christian Bonten
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstrasse
70, D-70199 Stuttgart, Germany
| | - Michael R. Buchmeiser
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
- Institute of Textile
Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
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Budagumpi S, Haque RA, Endud S, Rehman GU, Salman AW. Biologically Relevant Silver(I)-N-Heterocyclic Carbene Complexes: Synthesis, Structure, Intramolecular Interactions, and Applications. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300483] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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30
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Phukan AK, Guha AK, Sarmah S. Ligand Properties of Boron-Substituted Five-, Six-, and Seven-Membered Heterocyclic Carbenes: A Theoretical Study. Organometallics 2013. [DOI: 10.1021/om400162a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ashwini K. Phukan
- Department
of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India
- Institut für Anorganische
Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Ankur Kanti Guha
- Department
of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India
| | - Satyajit Sarmah
- Department
of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India
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31
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Page MJ, Lu WY, Poulten RC, Carter E, Algarra AG, Kariuki BM, Macgregor SA, Mahon MF, Cavell KJ, Murphy DM, Whittlesey MK. Three-Coordinate Nickel(I) Complexes Stabilised by Six-, Seven- and Eight-Membered Ring N-Heterocyclic Carbenes: Synthesis, EPR/DFT Studies and Catalytic Activity. Chemistry 2013; 19:2158-67. [DOI: 10.1002/chem.201202950] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Indexed: 11/07/2022]
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Sereda O, Clemens N, Heckel T, Wilhelm R. Imidazolinium and amidinium salts as Lewis acid organocatalysts. Beilstein J Org Chem 2012; 8:1798-803. [PMID: 23209514 PMCID: PMC3511014 DOI: 10.3762/bjoc.8.205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 09/17/2012] [Indexed: 11/23/2022] Open
Abstract
The application of imidazolinium and amidinium salts as soft Lewis acid organocatalysts is described. These salts were suitable catalysts for the activation of unsaturated thioesters in a Diels-Alder reaction and in the ring opening of thiiranes and epoxides. The products were isolated in good yields. The mild catalysts did not cause desulfurization of the products containing a thiol or thiocarbonyl group.
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Affiliation(s)
- Oksana Sereda
- Institute of Organic Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Nicole Clemens
- Institute of Organic Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Tatjana Heckel
- Department of Chemistry, University of Paderborn, 33098 Paderborn, Germany
| | - René Wilhelm
- Institute of Organic Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
- Department of Chemistry, University of Paderborn, 33098 Paderborn, Germany
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Novel Nonsymmetrically p-Benzyl-Substituted (Benz)imidazole N-Heterocyclic Carbene-Silver(I) Acetate Complexes: Synthesis and Biological Evaluation. ACTA ACUST UNITED AC 2012. [DOI: 10.1155/2012/121540] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Nonsymmetrically substituted N-heterocyclic carbene (NHC) precursors 1a–d and 3a–d were synthesised by first reacting 1H-(benz)imidazole with p-cyanobenzyl bromide to give 4-(1H-imidazole-1-ylmethyl)benzonitrile (1) and 4-(1H-benzimidazole-1-ylmethyl)benzonitrile (3) and afterwards introducing benzyl bromide, 1-(bromomethyl)-4-methylbenzene, 1-(bromomethyl)-4-methoxybenzene, and methyl 4-(bromomethyl)benzoate. The NHC-silver(I) acetate complexes (1-benzyl-3-(4-cyanobenzyl)-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2a), (1-(4-cyanobenzyl)-3-(4-methylbenzyl)-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2b), (1-(4-cyanobenzyl)-3-[4-(methoxycarbonyl)benzyl]-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2c), (1-benzyl-3-(4-cyanobenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4a), (1-(4-cyanobenzyl)-3-(4-methylbenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4b), (1-(4-cyanobenzyl)-3-(4-methoxybenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4c), and (1-(4-cyanobenzyl)-3-[4-(methoxycarbonyl)benzyl]-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4d) were yielded by reacting these NHC precursors with silver(I) acetate. The silver(I) acetate complex 4b was characterised by single crystal X-ray diffraction. Preliminary in vitro antibacterial studies against the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli, using the Kirby-Bauer disc diffusion method, were carried out on the seven NHC-silver(I) acetate complexes 2a–c and 4a–d. Also the IC50 values of these seven complexes were determined by an MTT-based assay against the human renal cancer cell line Caki-1. The complexes 2a–c and 4a–c revealed the following IC50 values, respectively, 25 (±1), 15 (±2), 5.4 (±0.8), 16 (±2), 7.1 (±1), 20 (±4), and 14 (±1) μM.
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35
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Paulose TAP, Wu SC, Olson JA, Chau T, Theaker N, Hassler M, Quail JW, Foley SR. Bis-diimidazolylidine complexes of nickel: Investigations into nickel catalyzed coupling reactions. Dalton Trans 2012; 41:251-60. [DOI: 10.1039/c1dt10858a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Lu WY, Cavell KJ, Wixey JS, Kariuki B. First Examples of Structurally Imposing Eight-Membered-Ring (Diazocanylidene) N-Heterocyclic Carbenes: Salts, Free Carbenes, and Metal Complexes. Organometallics 2011. [DOI: 10.1021/om200467x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wei Y. Lu
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - Kingsley J. Cavell
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - James S. Wixey
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - Benson Kariuki
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
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37
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Li XL, Huang JH, Yang LM. Iron(III)-Promoted Oxidative Coupling of Naphthylamines: Synthetic and Mechanistic Investigations. Org Lett 2011; 13:4950-3. [DOI: 10.1021/ol202058r] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Xin-Le Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), Laboratory of New Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China, and Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin-Hua Huang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Laboratory of New Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China, and Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Lian-Ming Yang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Laboratory of New Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China, and Graduate School of Chinese Academy of Sciences, Beijing 100049, China
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38
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McDonald RI, Liu G, Stahl SS. Palladium(II)-catalyzed alkene functionalization via nucleopalladation: stereochemical pathways and enantioselective catalytic applications. Chem Rev 2011; 111:2981-3019. [PMID: 21428440 PMCID: PMC3076534 DOI: 10.1021/cr100371y] [Citation(s) in RCA: 1051] [Impact Index Per Article: 80.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Richard I McDonald
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
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39
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Benhamou L, Chardon E, Lavigne G, Bellemin-Laponnaz S, César V. Synthetic routes to N-heterocyclic carbene precursors. Chem Rev 2011; 111:2705-33. [PMID: 21235210 DOI: 10.1021/cr100328e] [Citation(s) in RCA: 557] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Laure Benhamou
- LCC (Laboratoire de chimie de coordination), CNRS, 205 route de Narbonne, F-31077 Toulouse, France
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40
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Jahnke MC, Ekkehardt Hahn F. Introduction to N-Heterocyclic Carbenes: Synthesis and Stereoelectronic Parameters. N-HETEROCYCLIC CARBENES 2010. [DOI: 10.1039/9781849732161-00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are cyclic compounds containing a divalent carbon atom bound to at least one nitrogen atom within the heterocycle. Variation of the size of the carbene ring, the substituents on the nitrogen atoms or the additional atoms within the heterocycle lead to an array of different NHCs exhibiting a broad range of electronic properties. Their ability to act as donors and the resulting stable bounds to most transition metals make them excellent ligands in coordination chemistry. In addition, free NHCs have found applications as organocatalysts in metal free chemical transformations. In this Chapter synthetic procedures leading to different NHCs and important structural and electronic features of this class of compounds are discussed.
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Affiliation(s)
- Mareike C. Jahnke
- Institut für Anorganische und Analytische Chemie Westfälische Wilhelms-Universität Münster, Corrensstrasse 30 D-48149 Münster Germany
| | - F. Ekkehardt Hahn
- Institut für Anorganische und Analytische Chemie Westfälische Wilhelms-Universität Münster, Corrensstrasse 30 D-48149 Münster Germany
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41
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Binobaid A, Iglesias M, Beetstra D, Dervisi A, Fallis I, Cavell KJ. Donor-Functionalised Expanded Ring N-Heterocyclic Carbenes: Highly Effective Ligands in Ir-Catalysed Transfer Hydrogenation. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000680] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Affiliation(s)
- Todd W. Hudnall
- Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew G. Tennyson
- Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Christopher W. Bielawski
- Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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43
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Affiliation(s)
- Yves Canac
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, 31077 Toulouse, France, Fax: +33‐5‐61553003
- Université de Toulouse, UPS, INP, LCC, 31077 Toulouse, France
| | - Remi Chauvin
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, 31077 Toulouse, France, Fax: +33‐5‐61553003
- Université de Toulouse, UPS, INP, LCC, 31077 Toulouse, France
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44
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Iglesias M, Beetstra DJ, Cavell KJ, Dervisi A, Fallis IA, Kariuki B, Harrington RW, Clegg W, Horton PN, Coles SJ, Hursthouse MB. Expanded-Ring and Backbone-Functionalised N-Heterocyclic Carbenes. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.200901182] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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45
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Armstrong R, Ecott C, Mas-Marzá E, Page MJ, Mahon MF, Whittlesey MK. Ring-Expanded N-Heterocyclic Carbene Complexes of Ruthenium. Organometallics 2010. [DOI: 10.1021/om901044u] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert Armstrong
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Christopher Ecott
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Elena Mas-Marzá
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Michael J. Page
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
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Siemeling U, Färber C, Leibold M, Bruhn C, Mücke P, Winter RF, Sarkar B, von Hopffgarten M, Frenking G. Six-Membered N-Heterocyclic Carbenes with a 1,1′-Ferrocenediyl Backbone: Bulky Ligands with Strong Electron-Donor Capacity and Unusual Non-Innocent Character. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900863] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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47
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Six- and seven-membered ring carbenes: Rational synthesis of amidinium salts, generation of carbenes, synthesis of Ag(I) and Cu(I) complexes. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.03.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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48
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Scarborough CC, Bergant A, Sazama GT, Guzei IA, Spencer LC, Stahl SS. Synthesis of Pd Complexes Bearing an Enantiomerically-Resolved Seven-Membered N-Heterocyclic Carbene Ligands and Initial Studies of their Use in Asymmetric Wacker-Type Oxidative Cyclization Reactions. Tetrahedron 2009; 65:5084-5092. [PMID: 20161255 DOI: 10.1016/j.tet.2009.04.072] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The development of enantiomerically-resolved, axially-chiral seven-membered N-heterocyclic carbene ((7)NHC) ligands for palladium is described. These (7)NHC ligands are derived from enatiomerically pure 2,2'-diamino-6,6'-dimethylbiphenyl, which is transformed via a synthetic sequence consisting of ortho-arylation, N-alkylation, and cyclization to afford seven-membered-ring amidinium salts. Synthesis of the 7-membered amidinium salts benefits from microwave irradiation, and in-situ metalation of the amidinium salts yields (7)NHC-Pd(II) complexes. The chiral (7)NHC-Pd complexes were examined as chiral catalysts under aerobic conditions in two intramolecular oxidative amination reactions of alkenes. In one case, enantioselectivities up to 63% e.e. were obtained, while the other substrate underwent cyclization to afford essentially racemic products. The catalytic data compare favorably to results obtained with a Pd(II) catalyst bearing a chiral five-membered-ring NHC ligand and, thereby, highlight the potential significance of this new class of chiral NHC ligands.
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Iglesias M, Beetstra DJ, Kariuki B, Cavell KJ, Dervisi A, Fallis IA. Synthesis and Structural Features of Rhodium Complexes of Expanded Ring N-Heterocyclic Carbenes. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200801179] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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50
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Scarborough CC, McDonald RI, Hartmann C, Sazama GT, Bergant A, Stahl SS. Steric modulation of chiral biaryl diamines via Pd-catalyzed directed C-H arylation. J Org Chem 2009; 74:2613-5. [PMID: 19219972 DOI: 10.1021/jo802632v] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Palladium-catalyzed directed arylation of 2,2'-diacetamidobiaryls with aryl iodides provides efficient access to chiral ortho-substituted biaryl diamines. Aryl iodides with para- and meta-substituents are tolerated. Deprotection of the acetyl groups under basic conditions furnishes the free diamines, which should find broad utility in asymmetric catalysis.
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