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Vermersch F, Wang VT, Abdellaoui M, Jazzar R, Bertrand G. Ambiphilicity of ring-expanded N-heterocyclic carbenes. Chem Sci 2024; 15:3707-3710. [PMID: 38455021 PMCID: PMC10915854 DOI: 10.1039/d3sc04543a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 01/18/2024] [Indexed: 03/09/2024] Open
Abstract
N-heterocyclic carbenes, such as imidazole-2-ylidenes and imidazolin-2-ylidenes, the popular class of singlet carbenes introduced by Arduengo in 1991 have not been shown to be ambiphilic owing to the two σ-withdrawing, π-donating amino groups flanking the carbene centre. However, our experimental data suggest that ring-expanded N-heterocyclic carbenes (RE-NHCs), especially the seven and eight membered rings, are significantly ambiphilic. Our results also show that the steric environment in RE-NHCs can become a determining factor for controlling the E-H bond activation.
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Affiliation(s)
- François Vermersch
- UCSD-CNRS Joint Research Chemistry Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093-0358 USA
| | - Victor T Wang
- UCSD-CNRS Joint Research Chemistry Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093-0358 USA
| | - Mehdi Abdellaoui
- UCSD-CNRS Joint Research Chemistry Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093-0358 USA
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Chemistry Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093-0358 USA
| | - Guy Bertrand
- UCSD-CNRS Joint Research Chemistry Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093-0358 USA
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2
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Hussein AA, Ariffin A. Remote Steric and Electronic Effects of N-Heterocyclic Carbene Ligands on Alkene Reactivity and Regioselectivity toward Hydrocupration Reactions: The Role of Expanded-Ring N-Heterocyclic Carbenes. J Org Chem 2023; 88:13009-13021. [PMID: 37649423 DOI: 10.1021/acs.joc.3c01121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The remote groups in N-heterocyclic carbene (NHC) ligands have a significant influence on metal-catalyzed reactions. We examine how remote bulkiness, electronic groups, and expanded-ring NHCs (ER-NHCs) influence alkene reactivity and regioselectivity toward hydrocupration using density functional theory calculations. The impact of remote steric bulkiness on the Cu-H insertion rate is analyzed, revealing a strong correlation between the steric substituent constant and rate ratio, where a bulky group increases the rate due to reduced steric effects in the transition state (TS). The steric properties of the examined catalysts (with a remote group R2 = CPh3, CHPh2, CH2Ph, CH3, and H) and their corresponding TSs are found to be modulated greatly by the remote steric substitution group and the ring size of the NHC ligand. Enhanced bulkiness enhances the nucleophilic Cu-H moiety. The remote electronic groups have a smaller impact on insertion barrier compared to that of steric hindrance. Furthermore, ER-NHC exploration indicates that NHCs with over five-membered rings have a significantly negative influence on the reaction rate. Finally, with a highly bulky group (R2 = CPh3), anti-Markovnikov insertion preference is attributed to high interaction energy and improved steric properties. Overall, our findings here provide valuable insights for the development of a more effective catalyst in metal-catalyzed reactions.
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Affiliation(s)
- Aqeel A Hussein
- Department of Medical Laboratory Science, College of Science, Komar University of Science and Technology, Sulaymaniyah, Kurdistan Region 46001, Iraq
- Department of Biology, College of Science, Al-Qasim Green University, Al-Qassim, Babylon 51013, Iraq
| | - Azhar Ariffin
- Department of Chemistry, Faculty of Science, University Malaya, Kuala Lumpur 50603, Malaysia
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3
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Ma Y, Ali HS, Hussein AA. A mechanistic study on the gold(i)-catalyzed cyclization of propargylic amide: revealing the impact of expanded-ring N-heterocyclic carbenes. Catal Sci Technol 2022. [DOI: 10.1039/d1cy01617b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory (DFT) was applied to understand the mechanistic pathway of the gold(i)-catalyzed cyclization of propargylic amide, and to reveal the impact of expanded-ring N-heterocyclic carbenes.
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Affiliation(s)
- Yumiao Ma
- BSJ Institute, Haidian, Beijing, 100084, People's Republic of China
- Hangzhou Yanqu Information Technology Co., Ltd., Xixi Legu Creative Pioneering Park, No. 712 Wen'er West Road, Xihu District, Hangzhou City, Zhejiang Province, 310003, People's Republic of China
| | - Hafiz Saqib Ali
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Rd, Kings Buildings, EH9 3FJ Edinburgh, UK
| | - Aqeel A. Hussein
- Department of Pharmacy, College of Medicine, Komar University of Science and Technology, Sulaymaniyah, Kurdistan Region, Iraq
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4
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Ma X, Guillet SG, Liu Y, Cazin CSJ, Nolan SP. Simple synthesis of [Ru(CO 3)(NHC)( p-cymene)] complexes and their use in transfer hydrogenation catalysis. Dalton Trans 2021; 50:13012-13019. [PMID: 34581364 DOI: 10.1039/d1dt02098f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A novel, efficient and facile protocol for the synthesis of a series of [Ru(NHC)(CO3)(p-cymene)] complexes is reported. This family of Ru-NHC complexes was obtained from imidazol(in)ium tetrafluoroborate or imidazolium hydrogen carbonate salts in moderate to excellent yields, employing sustainable weak base. The ruthenium complexes were successfully utilized in the transfer hydrogenation of ketones as highly active multifunctional catalysts.
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Affiliation(s)
- Xinyuan Ma
- Department of Chemistry and Centre for Sustainable Chemistry Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium.
| | - Sébastien G Guillet
- Department of Chemistry and Centre for Sustainable Chemistry Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium.
| | - Yaxu Liu
- Department of Chemistry and Centre for Sustainable Chemistry Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium.
| | - Catherine S J Cazin
- Department of Chemistry and Centre for Sustainable Chemistry Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium.
| | - Steven P Nolan
- Department of Chemistry and Centre for Sustainable Chemistry Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium.
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5
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Synthesis and coordination chemistry of silver(I), gold(I) and gold(III) complexes with picoline-functionalized benzimidazolin-2-ylidene ligands. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2021. [DOI: 10.1515/znb-2021-0087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The reactions of N-alkyl-N′-picolyl-benzimidazolium bromides or N,N′-dipicolyl-benzimidazolium bromide with silver oxide yielded the silver dicarbene complexes of the type [Ag(NHC)2][AgBr2] 1–4 (NHC = picoline-functionalized benzimidazolin-2-ylidene). The silver complexes 1–4 have been used in carbene transfer reactions to yield the gold(I) complexes of the type [AuCl(NHC)] 5–8 in good yields. A halide exchange at the metal center of complexes 5–8 with lithium bromide yielded the gold bromide complexes 9–12. Finally, the oxidation of the gold(I) centers in complexes 9–12 with elemental bromine gave the gold(III) complexes of the type [AuBr3(NHC)] 13–16. Molecular structures of selected Au(I) and Au(III) complexes have been determined by X-ray diffraction studies.
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6
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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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7
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Hall JW, Bouchet D, Mahon MF, Whittlesey MK, Cazin CSJ. Synthetic Access to Ring-Expanded N-Heterocyclic Carbene (RE-NHC) Copper Complexes and Their Performance in Click Chemistry. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jonathan W. Hall
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Damien Bouchet
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University, Krijgslaan 283 (S3), Ghent 9000, Belgium
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | | | - Catherine S. J. Cazin
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University, Krijgslaan 283 (S3), Ghent 9000, Belgium
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8
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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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9
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10
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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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11
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Gold(I) Complexes with Eight‐Membered NHC Ligands: Synthesis, Structures and Catalytic Activity. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000281] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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Konstandaras N, Dunn MH, Luis ET, Cole ML, Harper JB. The pK a values of N-aryl imidazolinium salts, their higher homologues, and formamidinium salts in dimethyl sulfoxide. Org Biomol Chem 2020; 18:1910-1917. [PMID: 32095802 DOI: 10.1039/d0ob00036a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A series of imidazolinium salts, their six-, seven- and eight-membered homologues, and the related formamidinium salts were prepared, and their pKa values were determined in DMSO at 25 °C using the bracketing indicator method. The effect of each type of structural variation on the acidity of each salt was considered, particularly noting the importance of ring size and the effect of the steric and electronic nature of the N-aryl substituents. The effect of a cyclic structure was also probed through comparing the cyclic systems with the corresponding formamidinium salts, noting the importance of conformational flexibility in the latter cases. Along with allowing choice of appropriate bases for deprotonation of these species, it is anticipated that the data presented will aid in the understanding of the nucleophilicity, and potentially catalytic efficacy, of the corresponding carbenes.
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Affiliation(s)
- Nicholas Konstandaras
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
| | - Michelle H Dunn
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
| | - Ena T Luis
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
| | - Marcus L Cole
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
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13
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Kumar A, Singh C, Tinnermann H, Huynh HV. Gold(I) and Gold(III) Complexes of Expanded-Ring N-Heterocyclic Carbenes: Structure, Reactivity, and Catalytic Applications. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00718] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anuj Kumar
- Department of Chemistry, National University of Singapore, Science Drive 3, Singapore 117543
| | - Chandan Singh
- Department of Chemistry, National University of Singapore, Science Drive 3, Singapore 117543
| | - Hendrik Tinnermann
- Department of Chemistry, National University of Singapore, Science Drive 3, Singapore 117543
| | - Han Vinh Huynh
- Department of Chemistry, National University of Singapore, Science Drive 3, Singapore 117543
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14
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Cervantes‐Reyes A, Rominger F, Rudolph M, Hashmi ASK. Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands. Chemistry 2019; 25:11745-11757. [PMID: 31310385 PMCID: PMC6852534 DOI: 10.1002/chem.201902458] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Indexed: 02/02/2023]
Abstract
Nine- and ten-membered N-heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro-ligands 2 a-h were prepared by the reaction of readily available N,N'-diarylformamidines with bis-electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a-h with tBuOK in the presence of AuCl(SMe2 ) provided fast access to NHC-gold(I) complexes 3-10. These new NHC-gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid-state structures reveal high steric hindrance around the metal atom (%Vbur up to 53.0) which is caused by their expanded-ring architecture.
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Affiliation(s)
| | - Frank Rominger
- Organisch-Chemisches InstitutHeidelberg UniversityIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Matthias Rudolph
- 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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15
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Kumar A, Yuan D, Huynh HV. Stereoelectronic Profiling of Expanded-Ring N-Heterocyclic Carbenes. Inorg Chem 2019; 58:7545-7553. [PMID: 31074971 DOI: 10.1021/acs.inorgchem.9b00786] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heterobis(carbene) complexes of palladium(II) and gold(I) containing expanded-ring N-heterocyclic carbenes (erNHCs) have been prepared in order to study their electronic properties. erNHCs with mesityl substituents were found to exhibit anisotropic interferences, which hampered ranking of their donicities by 13C NMR spectroscopy. The anisotropy effects were found to be stronger in the linear gold complexes, where a smaller coordination number allows the wingtips to spread out more. erNHCs with flexible N-benzyl groups are more suitable, and their donor strengths were found to gradually increase from five- to seven-membered heterocycles. The same trend can also be obtained by comparing the 1 J(C-H) coupling constants of the respective salts, although significant differences between seven- and eight-membered erNHCs could not be detected. The % Vbur values of erNHCs obtained from structures of their palladium and gold complexes revealed that the anisotropic interferences increase with overall steric bulk.
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Affiliation(s)
- Anuj Kumar
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543
| | - Dan Yuan
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Dushu Lake Campus , Soochow University , Suzhou 215123 , People's Republic of China
| | - Han Vinh Huynh
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543
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16
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Wallbaum L, Weismann D, Löber D, Bruhn C, Prochnow P, Bandow JE, Siemeling U. Stable and Persistent Acyclic Diaminocarbenes with Cycloalkyl Substituents and Their Transformation to β-Lactams by Uncatalysed Carbonylation with CO. Chemistry 2019; 25:1488-1497. [PMID: 30408240 DOI: 10.1002/chem.201805307] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/07/2018] [Indexed: 01/07/2023]
Abstract
Four new acyclic diaminocarbenes (ADACs), viz. [(cyclo-Cn H2n-1 )2 N]2 C (n=5-7) and iPr2 N-C-N(cyclo-C6 H11 )2 , were synthesised by reacting the corresponding formamidinium hexafluorophosphates with NaN(SiMe3 )2 . Their nucleophilicities and electrophilicities were respectively judged from the 1 JCH values determined for the N2 CH unit of the corresponding formamidinium cations and from the 77 Se NMR chemical shifts of the selenourea derivatives obtained from the reaction of elemental selenium with the corresponding ADACs. An ambiphilic profile essentially identical to that of the "Alder carbene" (iPr2 N)2 C was found in each case. Similar to the latter carbene, the new ADACs undergo a well-defined thermal decomposition by β-fragmentation, affording an alkene and a formamidine. The stabilities of [(cyclo-Cn H2n-1 )2 N]2 C depend strongly on the value of n, following the order 6>5>7, with the latter congener being too unstable for isolation. [(cyclo-C6 H11 )2 N]2 C shows no thermal decomposition at room temperature in solution and is thus significantly more stable than (iPr2 N)2 C. The stability of iPr2 N-C-N(cyclo-C6 H11 )2 is intermediate between that of (iPr2 N)2 C and [(cyclo-C6 H11 )2 N]2 C, its β-fragmentation selectively affording propene and iPrN=CH-N(cyclo-C6 H11 )2 . [(cyclo-Cn H2n-1 )2 N]2 C (n=5-7) react readily with CO under mild conditions, selectively affording trisubstituted spirocyclic β-lactam derivatives with an antimicrobial activity spectrum similar to that of penicillin G.
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Affiliation(s)
- Lars Wallbaum
- Institute of Chemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132, Kassel, Germany
| | - Daniel Weismann
- Institute of Chemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132, Kassel, Germany
| | - Dennis Löber
- Institute of Chemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132, Kassel, Germany
| | - Clemens Bruhn
- Institute of Chemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132, Kassel, Germany
| | - Pascal Prochnow
- Biology of Microorganisms, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Julia E Bandow
- Biology of Microorganisms, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Ulrich Siemeling
- Institute of Chemistry, University of Kassel, Heinrich-Plett-Straße 40, 34132, Kassel, Germany
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17
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Cationic versus anionic Pt complex: The performance analysis of a hybrid-capacitor, DFT calculation and electrochemical properties. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.10.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Teng Q, Wu W, Duong HA, Huynh HV. Ring-expanded N-heterocyclic carbenes as ligands in iron-catalysed cross-coupling reactions of arylmagnesium reagents and aryl chlorides. Chem Commun (Camb) 2018; 54:6044-6047. [PMID: 29799033 DOI: 10.1039/c8cc01808a] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The structure-activity relationship of expanded-ring N-heterocyclic carbenes (NHCs) in the iron-catalysed Kumada aryl-aryl coupling reaction was explored. This was achieved by comparing the catalytic performance of Fe-NHC catalysts generated in situ containing NHCs that differ in steric bulk. In particular, the influences of ring sizes (5-8) and N-aryl substituents were explored in terms of spectroscopic and structural features, which affect their %Vbur values. The three best performing ligands were found on a diagonal of a 5 × 4 structural matrix revealing an optimal steric bulk and significant influences of subtle steric variations on the catalytic activities.
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Affiliation(s)
- Qiaoqiao Teng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
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19
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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
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20
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Chesnokov GA, Topchiy MA, Dzhevakov PB, Gribanov PS, Tukov AA, Khrustalev VN, Asachenko AF, Nechaev MS. Eight-membered-ring diaminocarbenes bearing naphthalene moiety in the backbone: DFT studies, synthesis of amidinium salts, generation of free carbene, metal complexes, and solvent-free copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Dalton Trans 2018; 46:4331-4345. [PMID: 28281713 DOI: 10.1039/c6dt04484k] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A new type of eight-membered ring N-heterocyclic carbene (NHC) bearing a rigid naphthalene moiety in the backbone is reported for the first time. Stereoelectronic properties of 4,5-dihydro-1H-naphtho[1,8-ef][1,3]diazocin-3(2H)-ylidene (NaphtDHD) and smaller ring NHCs were theoretically studied at the DFT level. Amidinium salts were prepared from corresponding amidines and dibromides. Free carbene NaphtDHD-Dipp (Dipp = 2,6-diisopropylphenyl) was generated in solution by treatment of the corresponding salt with LiHMDS. It is stable in solution at low temperatures, while decomposing rapidly at room temperature. Silver(i) and copper(i) complexes were synthesized and structurally characterized in the solid state. The copper(i) complex [(NaphtDHD-Mes)CuBr] (Mes = mesityl, 2,4,6-trimethylphenyl) exhibits high catalytic activity in alkyne-azide cycloaddition (CuAAC) reaction under solvent-free conditions.
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Affiliation(s)
- Gleb A Chesnokov
- M. V. Lomonosov Moscow State University, Leninskie Gory 1 (3), Moscow, 119991, Russia. Mikhail S. Nechaev
| | - Maxim A Topchiy
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia and A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street 28, Moscow, 119991, Russia
| | - Pavel B Dzhevakov
- M. V. Lomonosov Moscow State University, Leninskie Gory 1 (3), Moscow, 119991, Russia. Mikhail S. Nechaev and A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia
| | - Pavel S Gribanov
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia
| | - Aleksandr A Tukov
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia
| | - Victor N Khrustalev
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street 28, Moscow, 119991, Russia and Department of Inorganic Chemistry, Peoples' Friendship University of Russia, Miklukho-Maklay Street 6, Moscow, 117198, Russia
| | - Andrey F Asachenko
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia
| | - Mikhail S Nechaev
- M. V. Lomonosov Moscow State University, Leninskie Gory 1 (3), Moscow, 119991, Russia. Mikhail S. Nechaev and A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prospect 29, Moscow, 119991, Russia
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21
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Idrees KB, Rutledge WJ, Roberts SA, Rajaseelan E. [(1,2,5,6-η)-Cycloocta-1,5-diene](1-ethyl-3-isopropyl-1,3-imidazol-2-ylidene-κ C2)(triphenylphosphane-κ P)iridium(I) tetrafluoridoborate. IUCRDATA 2017. [DOI: 10.1107/s2414314617014110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In the title compound, [Ir(C8H12)(C8H14N2)(C18H15P)]BF4, the cationic complex has the anticipated square-planar geometry. The asymmetric unit comprises the iridium complex and one tetrafluoridoborate anion. The space group is non-centrosymmetric, with the Flack parameter of 0.007 (3) well determined, and confirms the hand for the complex cation. This compound shows promising catalytic activity in transfer hydrogenation reactions.
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22
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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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23
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Karaca EÖ, Akkoç M, Öz E, Altin S, Dorcet V, Roisnel T, Gürbüz N, Çelik Ö, Bayri A, Bruneau C, Yaşar S, Özdemir I. Ring-expanded iridium and rhodiumN-heterocyclic carbene complexes: a comparative DFT study of heterocycle ring size and metal center diversity. J COORD CHEM 2017. [DOI: 10.1080/00958972.2017.1287906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- E. Ö. Karaca
- Department of Chemistry, İnönü University, Malatya, Turkey
| | - M. Akkoç
- Department of Chemistry, İnönü University, Malatya, Turkey
| | - E. Öz
- Department of Physics, İnönü University, Malatya, Turkey
| | - S. Altin
- Department of Physics, İnönü University, Malatya, Turkey
| | - V. Dorcet
- Université de Rennes, UMR 6226: CNRS Sciences Chimiques de Rennes, Rennes, France
| | - T. Roisnel
- Université de Rennes, UMR 6226: CNRS Sciences Chimiques de Rennes, Rennes, France
| | - N. Gürbüz
- Department of Chemistry, İnönü University, Malatya, Turkey
| | - Ö. Çelik
- Department of Physics, Dicle University, Diyarbakır, Turkey
| | - A. Bayri
- Department of Physics, İnönü University, Malatya, Turkey
| | - C. Bruneau
- Université de Rennes, UMR 6226: CNRS Sciences Chimiques de Rennes, Rennes, France
| | - S. Yaşar
- Department of Chemistry, İnönü University, Malatya, Turkey
| | - I. Özdemir
- Department of Chemistry, İnönü University, Malatya, Turkey
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24
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Pelties S, Carter E, Folli A, Mahon MF, Murphy DM, Whittlesey MK, Wolf R. Influence of Ring-Expanded N-Heterocyclic Carbenes on the Structures of Half-Sandwich Ni(I) Complexes: An X-ray, Electron Paramagnetic Resonance (EPR), and Electron Nuclear Double Resonance (ENDOR) Study. Inorg Chem 2016; 55:11006-11017. [PMID: 27731984 DOI: 10.1021/acs.inorgchem.6b01540] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Potassium graphite reduction of the half-sandwich Ni(II) ring-expanded diamino/diamidocarbene complexes CpNi(RE-NHC)Br gave the Ni(I) derivatives CpNi(RE-NHC) (where RE-NHC = 6-Mes (1), 7-Mes (2), 6-MesDAC (3)) in yields of 40%-50%. The electronic structures of paramagnetic 1-3 were investigated by CW X-/Q-band electron paramagnetic resonance (EPR) and Q-band 1H electron nuclear double resonance (ENDOR) spectroscopy. While small variations in the g-values were observed between the diaminocarbene complexes 1 and 2, pronounced changes in the g-values were detected between the almost isostructural species (1) and diamidocarbene species (3). These results highlight the sensitivity of the EPR g-tensor to changes in the electronic structure of the Ni(I) centers generated by incorporation of heteroatom substituents onto the backbone ring positions. Variable-temperature EPR analysis also revealed the presence of a second Ni(I) site in 3. The experimental g-values for these two Ni(I) sites detected by EPR in frozen solutions of 3 are consistent with resolution on the EPR time scale of the disordered components evident in the X-ray crystallographically determined structure and the corresponding density functional theory (DFT)-calculated g-tensor. Q-band 1H ENDOR measurements revealed a small amount of unpaired electron spin density on the Cp rings, consistent with the calculated SOMO of complexes 1-3. The magnitude of the 1H A values for 3 were also notably larger, compared to 1 and 2, again highlighting the influence of the diamidocarbene on the electronic properties of 3.
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Affiliation(s)
- Stefan Pelties
- Institute of Inorganic Chemistry, University of Regensburg , 93040 Regensburg, Germany
| | - Emma Carter
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Andrea Folli
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Mary F Mahon
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, United Kingdom
| | - Damien M Murphy
- School of Chemistry, Cardiff University , Park Place, Cardiff CF10 3AT, United Kingdom
| | - Michael K Whittlesey
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, United Kingdom
| | - Robert Wolf
- Institute of Inorganic Chemistry, University of Regensburg , 93040 Regensburg, Germany
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25
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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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26
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Jordan AJ, Wyss CM, Bacsa J, Sadighi JP. Synthesis and Reactivity of New Copper(I) Hydride Dimers. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Abraham J. Jordan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Chelsea M. Wyss
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - John Bacsa
- X-ray Crystallography
Center, Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Joseph P. Sadighi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
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27
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Andrada DM, Holzmann N, Hamadi T, Frenking G. Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules. Beilstein J Org Chem 2015; 11:2727-36. [PMID: 26877795 PMCID: PMC4734353 DOI: 10.3762/bjoc.11.294] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/11/2015] [Indexed: 11/23/2022] Open
Abstract
Fifteen cyclic and acylic carbenes have been calculated with density functional theory at the BP86/def2-TZVPP level. The strength of the internal X→p(π) π-donation of heteroatoms and carbon which are bonded to the C(II) atom is estimated with the help of NBO calculations and with an energy decomposition analysis. The investigated molecules include N-heterocyclic carbenes (NHCs), the cyclic alkyl(amino)carbene (cAAC), mesoionic carbenes and ylide-stabilized carbenes. The bonding analysis suggests that the carbene centre in cAAC and in diamidocarbene have the weakest X→p(π) π-donation while mesoionic carbenes possess the strongest π-donation.
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Affiliation(s)
- Diego M Andrada
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
| | - Nicole Holzmann
- Laboratoire International Associé Centre National de la Recherche Scientifique - UMR 7565, Université de Lorraine, 54506 Vandoeuvre-lès-Nancy, France
| | - Thomas Hamadi
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
| | - Gernot Frenking
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
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28
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Collins LR, Riddlestone IM, Mahon MF, Whittlesey MK. A Comparison of the Stability and Reactivity of Diamido‐ and Diaminocarbene Copper Alkoxide and Hydride Complexes. Chemistry 2015; 21:14075-84. [DOI: 10.1002/chem.201502476] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Indexed: 02/05/2023]
Affiliation(s)
- Lee R. Collins
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (UK), Fax: (+44) 1225‐386‐231
| | - Ian M. Riddlestone
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (UK), Fax: (+44) 1225‐386‐231
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (UK), Fax: (+44) 1225‐386‐231
| | - Michael K. Whittlesey
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (UK), Fax: (+44) 1225‐386‐231
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29
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Giner EA, Santiago A, Gómez-Gallego M, Ramírez de Arellano C, Poulten RC, Whittlesey MK, Sierra MA. Mono- and Bimetallic Zwitterionic Chromium(0) and Tungsten(0) Allenyls. Inorg Chem 2015; 54:5450-61. [DOI: 10.1021/acs.inorgchem.5b00492] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elena A. Giner
- Departamento de
Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
- Centro de Innovación
en Química
Avanzada, ORFEO−CINQA, Madrid, Spain
| | - Alicia Santiago
- Departamento de
Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
- Centro de Innovación
en Química
Avanzada, ORFEO−CINQA, Madrid, Spain
| | - Mar Gómez-Gallego
- Departamento de
Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
- Centro de Innovación
en Química
Avanzada, ORFEO−CINQA, Madrid, Spain
| | - Carmen Ramírez de Arellano
- Departamento de Química Orgánica, Facultad
de Química, Universidad de Valencia, 46100-Valencia, Spain
- Centro de Innovación
en Química
Avanzada, ORFEO−CINQA, Madrid, Spain
| | - Rebecca C. Poulten
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K
| | | | - Miguel A. Sierra
- Departamento de
Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
- Centro de Innovación
en Química
Avanzada, ORFEO−CINQA, Madrid, Spain
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30
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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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31
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Roth T, Vasilenko V, Benson CGM, Wadepohl H, Wright DS, Gade LH. Extending N-heterocyclic carbene ligands into the third dimension: a new type of hybrid phosphazane/NHC system. Chem Sci 2015; 6:2506-2510. [PMID: 29308160 PMCID: PMC5647813 DOI: 10.1039/c4sc03966a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/13/2015] [Indexed: 11/24/2022] Open
Abstract
A simple, "click" synthetic approach to a new type of hybrid phosph(III)azane/NHC system is described. The presence of the phosphazane P2N2 ring unit, with P atoms flanking the NCN fragment and with this ring perpendicular to the binding site of the NHC, provides unique opportunities for modifying the electronic and steric character of these carbenes.
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Affiliation(s)
- Torsten Roth
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 270 , 69120 Heidelberg , Germany .
| | - Vladislav Vasilenko
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 270 , 69120 Heidelberg , Germany .
| | - Callum G M Benson
- Chemistry Department , Cambridge University , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 270 , 69120 Heidelberg , Germany .
| | - Dominic S Wright
- Chemistry Department , Cambridge University , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - Lutz H Gade
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 270 , 69120 Heidelberg , Germany .
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32
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Jahnke MC, Hahn FE. Complexes Bearing Protic N-Heterocyclic Carbenes: Synthesis and Applications. CHEM LETT 2015. [DOI: 10.1246/cl.141052] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Mareike C. Jahnke
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster
| | - F. Ekkehardt Hahn
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster
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33
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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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34
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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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35
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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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36
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Phillips N, Dodson T, Tirfoin R, Bates JI, Aldridge S. Expanded-ring N-heterocyclic carbenes for the stabilization of highly electrophilic gold(I) cations. Chemistry 2014; 20:16721-31. [PMID: 25336057 DOI: 10.1002/chem.201404939] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Indexed: 12/31/2022]
Abstract
Strategies for the synthesis of highly electrophilic Au(I) complexes from either hydride- or chloride-containing precursors have been investigated by employing sterically encumbered Dipp-substituted expanded-ring NHCs (Dipp=2,6-iPr2 C6 H3 ). Thus, complexes of the type (NHC)AuH have been synthesised (for NHC=6-Dipp or 7-Dipp) and shown to feature significantly more electron-rich hydrides than those based on ancillary imidazolylidene donors. This finding is consistent with the stronger σ-donor character of these NHCs, and allows for protonation of the hydride ligand. Such chemistry leads to the loss of dihydrogen and to the trapping of the [(NHC)Au](+) fragment within a dinuclear gold cation containing a bridging hydride. Activation of the hydride ligand in (NHC)AuH by B(C6 F5 )3 , by contrast, generates a species (at low temperatures) featuring a [HB(C6 F5 )3 ](-) fragment with spectroscopic signatures similar to the "free" borate anion. Subsequent rearrangement involves BC bond cleavage and aryl transfer to the carbophilic metal centre. Under halide abstraction conditions utilizing Na[BAr(f) 4 ] (Ar(f) =C6 H3 (CF3 )2 -3,5), systems of the type [(NHC)AuCl] (NHC=6-Dipp or 7-Dipp) generate dinuclear complexes [{(NHC)Au}2 (μ-Cl)](+) that are still electrophilic enough at gold to induce aryl abstraction from the [BAr(f) 4 ](-) counterion.
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Affiliation(s)
- Nicholas Phillips
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR (UK)
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37
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Blase V, Flores-Figueroa A, Schulte to Brinke C, Hahn FE. Template Synthesis of Tetracarbene Platinum(II) Complexes with Five- and Six-Membered-Ring N-Heterocyclic Carbenes. Organometallics 2014. [DOI: 10.1021/om5006947] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Verena Blase
- Institut für Anorganische
und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Aarón Flores-Figueroa
- Institut für Anorganische
und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Christian Schulte to Brinke
- 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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38
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Bernhammer JC, Chong NX, Jothibasu R, Zhou B, Huynh HV. Palladium(II) Complexes Bearing an Indazole-Derived N-Heterocyclic Carbene and Phosphine Coligands as Catalysts for the Sonogashira Coupling and the Hydroamination of Alkynes. Organometallics 2014. [DOI: 10.1021/om500566n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan C. Bernhammer
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Ning Xi Chong
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Ramasamy Jothibasu
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Binbin Zhou
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Han Vinh Huynh
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
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39
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Collins LR, Rookes TM, Mahon MF, Riddlestone IM, Whittlesey MK. Use of Ring-Expanded Diamino- and Diamidocarbene Ligands in Copper Catalyzed Azide–Alkyne “Click” Reactions. Organometallics 2014. [DOI: 10.1021/om5004732] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Lee R. Collins
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K
| | - Thomas M. Rookes
- 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
| | - Ian M. Riddlestone
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K
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40
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Dunsford JJ, Cavell KJ. Pd–PEPPSI-Type Expanded Ring N-Heterocyclic Carbene Complexes: Synthesis, Characterization, and Catalytic Activity in Suzuki–Miyaura Cross Coupling. Organometallics 2014. [DOI: 10.1021/om5003107] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jay J. Dunsford
- School
of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, U.K
| | - Kingsley J. Cavell
- School
of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, U.K
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41
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Yaşar S, Çekirdek S, Özdemir İ. New Bisbenzimidazolin-2-Ylidene Salts asN-Heterocyclic Dicarbene Precursors: Synthesis, Characterization, and Involvement in Palladium-Catalyzed Suzuki Reactions. HETEROATOM CHEMISTRY 2014. [DOI: 10.1002/hc.21148] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Sedat Yaşar
- Department of Chemistry; Faculty of Science and Art; Gaziosmanpaşa University; 60150 Tokat Turkey
- Department of Chemistry; Catalysis, Research and Applied Center; Inönü University; 44280 Malatya Turkey
| | - Suzan Çekirdek
- Department of Chemistry; Faculty of Science and Art; Gaziosmanpaşa University; 60150 Tokat Turkey
| | - İsmail Özdemir
- Department of Chemistry; Catalysis, Research and Applied Center; Inönü University; 44280 Malatya Turkey
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42
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Phillips N, Tirfoin R, Aldridge S. Probing the Limits of Ligand Steric Bulk: Backbone CH Activation in a Saturated N-Heterocyclic Carbene. Chemistry 2014; 20:3825-30. [DOI: 10.1002/chem.201304243] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/11/2013] [Indexed: 11/08/2022]
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43
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Dunsford JJ, Tromp DS, Cavell KJ, Elsevier CJ, Kariuki BM. N-alkyl functionalised expanded ring N-heterocyclic carbene complexes of rhodium(I) and iridium(I): structural investigations and preliminary catalytic evaluation. Dalton Trans 2014; 42:7318-29. [PMID: 23292451 DOI: 10.1039/c2dt32823b] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of new N-alkyl functionalised 6- and 7-membered expanded ring N-heterocyclic carbene (NHC) pro-ligands 3-6 and their corresponding complexes of rhodium(I) and iridium(I), [M(NHC)(COD)Cl] 7-14 and [M(NHC)(CO)2Cl] 15-22 are described. The complexes have been characterised by (1)H and (13)C{(1)H} NMR, mass spectrometry, IR and X-ray diffraction. It is noted from X-ray diffraction studies that the N-alkyl substituents are found to orientate themselves away from the metal centre due to unfavourable steric interactions resulting in low percent buried volume (%V(bur)) values in the solid state. The heterocycle ring size is also found to dictate the spatial orientation of the N-alkyl substituents in the neopentyl functionalised derivatives 10 and 14. The 7-membered derivative 14 allows for a conformational 'twist' of the heterocycle ring with the N-alkyl substituents adopting a mutually trans configuration with respect to each other, while the more rigid 6-membered system 10 does not allow for this conformational 'twist' and consequently the N-alkyl substituents adopt a mutually cis configuration. The σ-donor function of this new class of expanded ring NHC ligand has also been probed by measured IR stretching frequencies of the [M(NHC)(CO)2Cl] complexes 15-22. A preliminary catalytic survey of the hydrogenation of functionalised alkenes with molecular hydrogen under mild conditions has also been undertaken with complex , affording an insight into the application of large ring NHC ancillary ligands bearing N-alkyl substituents in hydrogenation transformations.
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Affiliation(s)
- Jay J Dunsford
- School of Chemistry, Main Building, Cardiff University, Cardiff, CF10 3AT Wales, UK
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44
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Rittinghaus S, Färber C, Bruhn C, Siemeling U. Unsymmetrical N-heterocyclic carbenes with a 1,1′-ferrocenediyl backbone. Dalton Trans 2014; 43:3508-20. [DOI: 10.1039/c3dt52669k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
N-Substituents have only a marginal influence on the electronic properties, but a strong influence on the steric properties of ferrocene-based NHC ligands, which therefore offer great potential for rational fine-tuning.
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Affiliation(s)
| | | | - Clemens Bruhn
- Institute of Chemistry
- University of Kassel
- 34132 Kassel, Germany
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45
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Phillips N, Tang CY, Tirfoin R, Kelly MJ, Thompson AL, Gutmann MJ, Aldridge S. Modulating reactivity in iridium bis(N-heterocyclic carbene) complexes: influence of ring size on E–H bond activation chemistry. Dalton Trans 2014; 43:12288-98. [DOI: 10.1039/c4dt01398k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Critical influence of NHC ring size: highly labile [Ir(5-Mes)2(H)2]+can only be studied by trapping experiments, while [Ir(6-Mes)2(H)2]+and [Ir(6-Xyl)2(H)2]+are air/moisture stable.
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Affiliation(s)
- Nicholas Phillips
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
| | - Christina Y. Tang
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
| | - Rémi Tirfoin
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
| | - Michael J. Kelly
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
| | - Amber L. Thompson
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
| | | | - Simon Aldridge
- Inorganic Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford, UK
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46
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Harkness MB, Alvarado E, Badaj AC, Skrela BC, Fan L, Lavoie GG. Coordination and Reactivity Study of Group 4 and 10 Transition Metal Complexes of N-Imidazol-2-ylidene-N′-p-tolylureate and Thioureate Ligands. Organometallics 2013. [DOI: 10.1021/om400220v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Michael B. Harkness
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
| | - Edwin Alvarado
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
| | - Anna C. Badaj
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
| | - Barbara C. Skrela
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
| | - Louie Fan
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
| | - Gino G. Lavoie
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario,
M3J 1P3, Canada
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47
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Ung G, Soleilhavoup M, Bertrand G. Gold(III)- versus gold(I)-induced cyclization: synthesis of six-membered mesoionic carbene and acyclic (aryl)(heteroaryl) carbene complexes. Angew Chem Int Ed Engl 2013; 52:758-61. [PMID: 23169762 PMCID: PMC3712865 DOI: 10.1002/anie.201207961] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 10/25/2012] [Indexed: 12/17/2022]
Abstract
The golden state: selective 5-exo- and 6-endo-cyclizations of an alkynyl benzothioamide have been achieved. The selectivity is controlled by the oxidation state of the gold precursor (+I or +III), yielding two new types of carbene ligand: an (aryl)(heteroaryl)carbene and a six-membered mesoionic carbene. Mes=2,4,6-trimethylphenyl.
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Affiliation(s)
- Gaël Ung
- UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0343 (USA)
| | - Michele Soleilhavoup
- UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0343 (USA)
| | - Guy Bertrand
- UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0343 (USA)
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48
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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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49
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Borguet Y, Zaragoza G, Demonceau A, Delaude L. Assessing the ligand properties of 1,3-dimesitylbenzimidazol-2-ylidene in ruthenium-catalyzed olefin metathesis. Dalton Trans 2013; 42:7287-96. [DOI: 10.1039/c2dt31520c] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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50
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Nelson DJ, Nolan SP. Quantifying and understanding the electronic properties of N-heterocyclic carbenes. Chem Soc Rev 2013; 42:6723-53. [DOI: 10.1039/c3cs60146c] [Citation(s) in RCA: 808] [Impact Index Per Article: 73.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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