51
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Jin P, Yang L, Liu C, Chen M, Hou Q, Li L, Zhao Y. A comparative study on the N-heterocyclic carbene adducts of Ih-C60, D5h-C70 and Sc3N@Ih-C80. Phys Chem Chem Phys 2017; 19:17598-17606. [DOI: 10.1039/c7cp02696j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The exclusive formations of the normal nNHC-C60/70 and abnormal aNHC-Sc3N@Ih-C80 complexes in two recent experiments were suggested to be thermodynamically and kinetically controlled, respectively.
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Affiliation(s)
- Peng Jin
- Key Laboratory for New Type of Functional Materials in Hebei Province
- School of Materials Science and Engineering
- Hebei University of Technology
- Tianjin 300130
- P. R. China
| | - Le Yang
- Key Laboratory for New Type of Functional Materials in Hebei Province
- School of Materials Science and Engineering
- Hebei University of Technology
- Tianjin 300130
- P. R. China
| | - Chang Liu
- Key Laboratory for New Type of Functional Materials in Hebei Province
- School of Materials Science and Engineering
- Hebei University of Technology
- Tianjin 300130
- P. R. China
| | - Muqing Chen
- Department of Materials Physics
- School of Physics and Mechanical & Electronical Engineering
- Hubei University of Education
- Wuhan 430205
- P. R. China
| | - Qinghua Hou
- Key Laboratory for New Type of Functional Materials in Hebei Province
- School of Materials Science and Engineering
- Hebei University of Technology
- Tianjin 300130
- P. R. China
| | - Lanlan Li
- Key Laboratory for New Type of Functional Materials in Hebei Province
- School of Materials Science and Engineering
- Hebei University of Technology
- Tianjin 300130
- P. R. China
| | - Yujun Zhao
- Key Laboratory for Green Chemical Technology of Ministry of Education
- Collaborative Innovation Centre of Chemical Science and Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 30072
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52
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Swarnakar AK, Ferguson MJ, McDonald R, Rivard E. Azido- and amido-substituted gallium hydrides supported by N-heterocyclic carbenes. Dalton Trans 2017; 46:1406-1412. [DOI: 10.1039/c6dt04595b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of azido- and amido-gallanes supported by hindered N-heterocyclic carbene donors is reported.
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Affiliation(s)
| | | | - Robert McDonald
- Department of Chemistry
- University of Alberta
- Edmonton
- Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry
- University of Alberta
- Edmonton
- Canada T6G 2G2
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53
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Elmer LM, Kehr G, Daniliuc CG, Siedow M, Eckert H, Tesch M, Studer A, Williams K, Warren TH, Erker G. The Chemistry of a Non-Interacting Vicinal Frustrated Phosphane/Borane Lewis Pair. Chemistry 2016; 23:6056-6068. [PMID: 27925311 DOI: 10.1002/chem.201603954] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/23/2016] [Indexed: 12/14/2022]
Abstract
The dimesitylphosphinocyclopentene/HB(C6 F5 )2 -derived vicinal trans-1,2-P/B frustrated Lewis pair (FLP) 4 shows no direct phosphane-borane interaction. Toward some reagents it behaves similar to an intermolecular FLP; it cleaves dihydrogen, deprotonates terminal alkynes, and adds to organic carbonyl compounds including CO2 . It shows typical intramolecular FLP reaction modes (cooperative 1,1-additions) to mesityl azide, to carbon monoxide, and to NO. The latter reaction yields a persistent P/B FLPNO nitroxide radical, which undergoes H-atom abstraction reactions. The FLP 4 serves as a template for the CO reduction by [HB(C6 F5 )2 ] to generate a FLP-η2 -formylborane. The formylborane moiety is removed from the FLP template by reaction with pyridine to yield a genuine pyridine stabilized formylborane that undergoes characteristic borane carbaldehyde reactions (Wittig olefination, imine formation). Most new products were characterized by X-ray diffraction.
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Affiliation(s)
- Lisa-Maria Elmer
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Melanie Siedow
- Institut für Physikalische Chemie, Universutät Münster, Corrensstraße 28/30, 48149, Münster, Germany
| | - Hellmut Eckert
- Institut für Physikalische Chemie, Universutät Münster, Corrensstraße 28/30, 48149, Münster, Germany.,Instituto de Física Sao Carlos, Universidade de Sao Paulo, CP 369, 13560-970, Sao Carlos, SP, Brasil
| | - Matthias Tesch
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Kamille Williams
- Georgetown University, Department of Chemistry, Box 571227, Washington DC, 20057-1227, USA
| | - Timothy H Warren
- Georgetown University, Department of Chemistry, Box 571227, Washington DC, 20057-1227, USA
| | - Gerhard Erker
- Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149, Münster, Germany
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54
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Winkler A, Freytag M, Jones PG, Tamm M. Isolation and Reactivity of a FrustratedN-Heterocyclic Carbene-Borane. Z Anorg Allg Chem 2016. [DOI: 10.1002/zaac.201600290] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Andrea Winkler
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Matthias Freytag
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Peter G. Jones
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
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55
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Uzelac M, Armstrong DR, Kennedy AR, Hevia E. Understanding the Subtleties of Frustrated Lewis Pair Activation of Carbonyl Compounds by N-Heterocyclic Carbene/Alkyl Gallium Pairings. Chemistry 2016; 22:15826-15833. [DOI: 10.1002/chem.201603597] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Marina Uzelac
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - David R. Armstrong
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Eva Hevia
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
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56
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Yin Q, Kemper S, Klare HFT, Oestreich M. Boron Lewis Acid-Catalyzed Hydroboration of Alkenes with Pinacolborane: BAr F3 Does What B(C 6 F 5 ) 3 Cannot Do! Chemistry 2016; 22:13840-13844. [PMID: 27447683 DOI: 10.1002/chem.201603466] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Indexed: 11/06/2022]
Abstract
The transition-metal-free hydroboration of various alkenes with pinacolborane (HBpin) initiated by tris[3,5-bis(trifluoromethyl)phenyl]borane (BArF3 ) is reported. The choice of the boron Lewis acid is crucial as the more prominent boron Lewis acid tris(pentafluorophenyl)borane (B(C6 F5 )3 ) is reluctant to react. Unlike B(C6 F5 )3 , BArF3 is found to engage in substituent redistribution with HBpin, resulting in the formation of ArF Bpin and the electron-deficient diboranes [H2 BArF ]2 and [(ArF )(H)B(μ-H)2 BArF2 ]. These in situ-generated hydroboranes undergo regioselective hydroboration of styrene derivatives as well as aliphatic alkenes with cis diastereoselectivity. Another ligand metathesis of these adducts with HBpin subsequently affords the corresponding HBpin-derived anti-Markovnikov adducts. The reactive hydroboranes are regenerated in this step, thereby closing the catalytic cycle.
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Affiliation(s)
- Qin Yin
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Sebastian Kemper
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany.
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany.
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57
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Kelch H, Kachel S, Celik MA, Schäfer M, Wennemann B, Radacki K, Petrov AR, Tamm M, Braunschweig H. Elucidating the Reactivity of Vicinal Dicarbenoids: From Lewis Adduct Formation to B−C Bond Activation. Chemistry 2016; 22:13815-13818. [DOI: 10.1002/chem.201603234] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Hauke Kelch
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Stephanie Kachel
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Mehmet Ali Celik
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Marius Schäfer
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Benedikt Wennemann
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Alex R. Petrov
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie; Julius-Maximilians Universität Würzburg; Am Hubland 97074 Würzburg Germany
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58
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Igarashi A, Kolychev EL, Tamm M, Nomura K. Synthesis of (Imido)Vanadium(V) Dichloride Complexes Containing Anionic N-Heterocyclic Carbenes That Contain a Weakly Coordinating Borate Moiety: New MAO-Free Ethylene Polymerization Catalysts. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00200] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Atsushi Igarashi
- Department
of Chemistry, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Eugene L. Kolychev
- Institut
für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Institut
für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Kotohiro Nomura
- Department
of Chemistry, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji, Tokyo 192-0397, Japan
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59
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Lawrence EJ, Clark ER, Curless LD, Courtney JM, Blagg RJ, Ingleson MJ, Wildgoose GG. Metal-free electrocatalytic hydrogen oxidation using frustrated Lewis pairs and carbon-based Lewis acids. Chem Sci 2016; 7:2537-2543. [PMID: 28660024 PMCID: PMC5477046 DOI: 10.1039/c5sc04564a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/06/2016] [Indexed: 02/04/2023] Open
Abstract
Whilst hydrogen is a potentially clean fuel for energy storage and utilisation technologies, its conversion to electricity comes at a high energetic cost. This demands the use of rare and expensive precious metal electrocatalysts. Electrochemical-frustrated Lewis pairs offer a metal-free, CO tolerant pathway to the electrocatalysis of hydrogen oxidation. They function by combining the hydrogen-activating ability of frustrated Lewis pairs (FLPs) with electrochemical oxidation of the resultant hydride. Here we present an electrochemical-FLP approach that utilises two different Lewis acids - a carbon-based N-methylacridinium cation that possesses excellent electrochemical attributes, and a borane that exhibits fast hydrogen cleavage kinetics and functions as a "hydride shuttle". This synergistic interaction provides a system that is electrocatalytic with respect to the carbon-based Lewis acid, decreases the required potential for hydrogen oxidation by 1 V, and can be recycled multiple times.
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Affiliation(s)
- Elliot J Lawrence
- Energy & Materials Laboratory , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Ewan R Clark
- School of Chemistry , University of Manchester , Oxford Road , Manchester M13 9PL , UK .
| | - Liam D Curless
- School of Chemistry , University of Manchester , Oxford Road , Manchester M13 9PL , UK .
| | - James M Courtney
- Energy & Materials Laboratory , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Robin J Blagg
- Energy & Materials Laboratory , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Michael J Ingleson
- School of Chemistry , University of Manchester , Oxford Road , Manchester M13 9PL , UK .
| | - Gregory G Wildgoose
- Energy & Materials Laboratory , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
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60
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Swarnakar AK, Ferguson MJ, McDonald R, Rivard E. Transition metal-mediated donor-acceptor coordination of low-oxidation state Group 14 element halides. Dalton Trans 2016; 45:6071-8. [PMID: 26373599 DOI: 10.1039/c5dt03018h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity of tungsten carbonyl adducts of Group 14 element (Ge, Sn and Pb) dihalides towards the metal-based donors (η(5)-C5H5)Rh(PMe2Ph)2 and Pt(PCy3)2 was examined. When (η(5)-C5H5)Rh(PMe2Ph)2 was treated with the Lewis acid supported Ge(ii) complex, THF·GeCl2·W(CO)5, cyclopentadienyl ring activation occurred, whereas the analogous Lewis acidic units SnCl2·W(CO)5 and PbCl2 form direct adducts with the Rh complex to yield Rh-Sn and Rh-Pb dative bonds. Attempts to prepare metal coordinated element(ii) hydrides by adding hydride sources to the above mentioned rhodium-E(ii) halide complexes were unsuccessful; in each case insoluble products were formed along with regeneration of free (η(5)-C5H5)Rh(PMe2Ph)2. In a parallel study, ECl2·W(CO)5 (E = Ge or Sn) groups were shown to participate in E-Cl oxidation addition chemistry with (Cy3P)2Pt to give the formal Pt(ii) complexes ClPt(PCy3)2ECl·W(CO)5.
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Affiliation(s)
- Anindya K Swarnakar
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2.
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2.
| | - Robert McDonald
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2.
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2.
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61
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Winkler A, Brandhorst K, Freytag M, Jones PG, Tamm M. Palladium(II) Complexes with Anionic N-Heterocyclic Carbene–Borate Ligands as Catalysts for the Amination of Aryl Halides. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00217] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrea Winkler
- Institut für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig, Germany
| | - Kai Brandhorst
- Institut für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig, Germany
| | - Matthias Freytag
- Institut für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig, Germany
| | - Peter G. Jones
- Institut für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Institut für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig, Germany
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62
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Liu M, Nieger M, Hübner EG, Schmidt A. Formation of N-Heterocyclic Carbenes by Tautomerization of Mesomeric Betaines: Cyclic Boron Adducts and Palladium Complexes From 2-(Imidazolium-1-yl)phenolates. Chemistry 2016; 22:5416-24. [PMID: 26929134 DOI: 10.1002/chem.201505042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/09/2022]
Abstract
2-(Imidazolium-1-yl)phenolates are conjugated heterocyclic mesomeric betaines in tautomeric equilibrium with the corresponding N-heterocyclic carbenes (NHCs), 3-(2-hydroxyphenyl)-imidazol-2-ylidenes. The carbene tautomers can be trapped as thiones (X-ray analysis). Moreover, bis(triphenylphosphine)palladium(II) dichloride in THF trapped the carbene tautomer as a palladium complex without participation of the phenolate group (X-ray analysis). The corresponding anionic NHCs, 2-phenolate-substituted imidazol-2-ylidenes, can be trapped by triethylborane or triphenylborane to form 4,4-diethyl- or 4,4-diphenyl-4H-benzo[e]imidazo[2,1-c][1,4,2]oxaza-borininium-4-ides, respectively (two X-ray analyses). These tricyclic systems are the first representatives of a new heterocyclic ring system. The results of DFT calculations concerning the HOMO/LUMO profiles and partial charges are also presented.
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Affiliation(s)
- Ming Liu
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834
| | - Martin Nieger
- University of Helsinki, Laboratory of Inorganic Chemistry, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), 00014, Helsinki, Finland
| | - Eike G Hübner
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834
| | - Andreas Schmidt
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834.
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63
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Engesser TA, Lichtenthaler MR, Schleep M, Krossing I. Reactive p-block cations stabilized by weakly coordinating anions. Chem Soc Rev 2016; 45:789-899. [PMID: 26612538 PMCID: PMC4758321 DOI: 10.1039/c5cs00672d] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/12/2022]
Abstract
The chemistry of the p-block elements is a huge playground for fundamental and applied work. With their bonding from electron deficient to hypercoordinate and formally hypervalent, the p-block elements represent an area to find terra incognita. Often, the formation of cations that contain p-block elements as central ingredient is desired, for example to make a compound more Lewis acidic for an application or simply to prove an idea. This review has collected the reactive p-block cations (rPBC) with a comprehensive focus on those that have been published since the year 2000, but including the milestones and key citations of earlier work. We include an overview on the weakly coordinating anions (WCAs) used to stabilize the rPBC and give an overview to WCA selection, ionization strategies for rPBC-formation and finally list the rPBC ordered in their respective group from 13 to 18. However, typical, often more organic ion classes that constitute for example ionic liquids (imidazolium, ammonium, etc.) were omitted, as were those that do not fulfill the - naturally subjective -"reactive"-criterion of the rPBC. As a rule, we only included rPBC with crystal structure and only rarely refer to important cations published without crystal structure. This collection is intended for those who are simply interested what has been done or what is possible, as well as those who seek advice on preparative issues, up to people having a certain application in mind, where the knowledge on the existence of a rPBC that might play a role as an intermediate or active center may be useful.
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Affiliation(s)
- Tobias A. Engesser
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Martin R. Lichtenthaler
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Mario Schleep
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
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64
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Thakur A, Vardhanapu PK, Vijaykumar G, Kumar Hota P, Mandal SK. Abnormal N-Heterocyclic-Carbene-Mediated Fixation of CO2and N2O, and the Activation of Tetrahydrofuran and Tetrahydrothiophene under Ambient Conditions. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501303] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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65
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Zhang J, Franz M, Hübner E, Schmidt A. N-Heterocyclic carbenes by tautomerization of mesomeric betaines. Thione, selenone, and borane adduct formations of imidazolium-isocytosinates. Tetrahedron 2016. [DOI: 10.1016/j.tet.2015.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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66
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Ai P, Danopoulos AA, Braunstein P. Transition metal (Rh and Fe) complexes and main-group (Se and B) adducts with N,N′-diphosphanyl NHC ligands: a study of stereoelectronic properties. Dalton Trans 2016; 45:4771-9. [DOI: 10.1039/c6dt00318d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The reactions ofN,N′-bis(di-tert-butylphosphanyl)-imidazole-2-ylidene (PCNHCP) with [Rh(μ-Cl)(COD)]2, [Rh(μ-Cl)(CO)2]2, [Fe4Cl8(THF)6], elemental Se and [(C6F5)BO]3, have been investigated to evaluate the stereoelectronic properties of this hybrid ligand.
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Affiliation(s)
- Pengfei Ai
- Laboratoire de Chimie de Coordination
- Institut de Chimie (UMR 7177 CNRS)
- Université de Strasbourg
- 67081 Strasbourg Cedex
- France
| | - Andreas A. Danopoulos
- Laboratoire de Chimie de Coordination
- Institut de Chimie (UMR 7177 CNRS)
- Université de Strasbourg
- 67081 Strasbourg Cedex
- France
| | - Pierre Braunstein
- Laboratoire de Chimie de Coordination
- Institut de Chimie (UMR 7177 CNRS)
- Université de Strasbourg
- 67081 Strasbourg Cedex
- France
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67
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Pal A, Vanka K. Small Molecule Activation by Constrained Phosphorus Compounds: Insights from Theory. Inorg Chem 2015; 55:558-65. [PMID: 26700074 DOI: 10.1021/acs.inorgchem.5b01074] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amrita Pal
- Physical Chemistry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Kumar Vanka
- Physical Chemistry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
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68
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Wang S, Wang X. Imidazolatsysteme zur CO2
-Abscheidung und photochemischen Reduktion. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507145] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sibo Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry; Fuzhou University; Fuzhou 350002 China
| | - Xinchen Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry; Fuzhou University; Fuzhou 350002 China
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69
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Wang S, Wang X. Imidazolium Ionic Liquids, Imidazolylidene Heterocyclic Carbenes, and Zeolitic Imidazolate Frameworks for CO2
Capture and Photochemical Reduction. Angew Chem Int Ed Engl 2015; 55:2308-20. [DOI: 10.1002/anie.201507145] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/10/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Sibo Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry; Fuzhou University; Fuzhou 350002 China
| | - Xinchen Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry; Fuzhou University; Fuzhou 350002 China
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70
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Uzelac M, Hernán-Gómez A, Armstrong DR, Kennedy AR, Hevia E. Rational synthesis of normal, abnormal and anionic NHC-gallium alkyl complexes: structural, stability and isomerization insights. Chem Sci 2015; 6:5719-5728. [PMID: 29910864 PMCID: PMC5975842 DOI: 10.1039/c5sc02086g] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 07/03/2015] [Indexed: 11/21/2022] Open
Abstract
Advancing the rational design of main-group N-heterocyclic carbene complexes, this study reports the synthesis, X-ray crystallographic and NMR spectroscopic characterisation of a novel series of Ga complexes containing neutral or anionic NHC ligands using the unsaturated carbene IPr (IPr = 1,3-bis-(2,6-di-isopropylphenyl)imidazol-2-ylidene). Starting from normal adduct GaR3·IPr (1) (R = CH2SiMe3), the addition of polar LiR led to the formation of NHC-stabilised gallate species IPr·LiGaR4 (2), resulting from co-complexation of the single-metal species. Contrastingly, reversing the order of addition of these organometallic reagents, by treating unsaturated free IPr, first with LiR followed by GaR3, furnished novel heteroleptic gallate (THF)2Li[:C{[N(2,6-iPr2C6H3)]2CHCGa(CH2SiMe3)3}] (3), which contains an anionic NHC ligand acting as an unsymmetrical bridge between the two metals, coordinating through its abnormal C4 position to Ga and through its normal C2 position to Li. Electrophilic interception studies of 3 using methyl triflate (MeOTf), methanol and imidazolium salt (IMes·HCl) led to the isolation and structural elucidation of the two novel neutral abnormal NHC (aNHC) complexes [CH3C{[N(2,6-iPr2C6H3)]2CHCGa(CH2SiMe3)3}] (4) and aIPr·GaR3 (5) (aIPr = HC{[N(2,6-iPr2C6H3)]2CHC}). These studies disclose the preference of the anionic IPr ligand present in 3 to react with electrophiles via its C2 position, leaving its Ga-C4 bond intact. Abnormal complex 5 can also be accessed by a thermally induced rearrangement of its normal isomer 1. Combining NMR spectroscopic and kinetic studies with DFT calculations, new light has been shed on this intriguing transformation, which suggests that it occurs via a dissociative mechanism, highlighting the importance of the donor ability of the solvent used in these thermal isomerizations as well as the steric bulk of the substituents on the NHC and the Ga reagent. These findings intimate that relief of the steric hindrance around Ga by forming an abnormal complex is a key driving force behind these rearrangements.
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Affiliation(s)
- Marina Uzelac
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Alberto Hernán-Gómez
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - David R Armstrong
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Alan R Kennedy
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Eva Hevia
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
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71
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Hoshimoto Y, Kinoshita T, Ohashi M, Ogoshi S. A Strategy to Control the Reactivation of Frustrated Lewis Pairs from Shelf-Stable Carbene Borane Complexes. Angew Chem Int Ed Engl 2015; 54:11666-71. [PMID: 26315680 PMCID: PMC4600235 DOI: 10.1002/anie.201505974] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Indexed: 12/03/2022]
Abstract
N-Phosphine oxide substituted imidazolylidenes (PoxIms) have been synthesized and fully characterized. These species can undergo significant changes to the spatial environment surrounding their carbene center through rotation of the phosphine oxide moiety. Either classical Lewis adducts (CLAs) or frustrated Lewis pairs (FLPs) are thus formed with B(C6F5)3 depending on the orientation of the phosphine oxide group. A strategy to reactivate FLPs from CLAs by exploiting molecular motions that are responsive to external stimuli has therefore been developed. The reactivation conditions were successfully controlled by tuning the strain in the PoxIm–B(C6F5)3 complexes so that reactivation only occurred above ambient temperature.
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Affiliation(s)
- Yoichi Hoshimoto
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan). .,Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan).
| | - Takuya Kinoshita
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)
| | - Masato Ohashi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)
| | - Sensuke Ogoshi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan). .,JST, ACT-C, Suita, Osaka 565-0871 (Japan).
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72
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Pérez P, Yepes D, Jaque P, Chamorro E, Domingo LR, Rojas RS, Toro-Labbé A. A computational and conceptual DFT study on the mechanism of hydrogen activation by novel frustrated Lewis pairs. Phys Chem Chem Phys 2015; 17:10715-25. [PMID: 25812082 DOI: 10.1039/c5cp00306g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A computational and conceptual density functional theory (DFT) study on the mechanism of molecular hydrogen activation by a set of three frustrated Lewis pairs (FLPs) was performed at the ωB97X-D/6-311G(d,p) level of theory. A reduced model and other two prototypes derived from experimental data, based on the donor nitrogen and acceptor boron atoms, were used. Analysis based on the energy results, geometries and the global electron density transfer at the TSs made it possible to obtain some interesting conclusions: (i) despite the well-known very low reactivity of molecular hydrogen, the catalytic effectiveness of the three FLPs produces reactions with almost unappreciable activation energies; (ii) the reactions, being exothermic, follow a one-step mechanism via polarised TSs; (iii) there are neither substituent effects on the kinetics nor on the thermodynamics of these reactions; (iv) the activation of molecular hydrogen seems to be attained when the N-B distance in the FLP derivatives is around 2.74 Å; and (v) the proposed FLP model is consistent with the behaviour of the experimental prototypes. Finally, the ability of the three FLPs as efficient catalysts was evaluated studying the hydrogenation of acetylene to yield ethylene.
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Affiliation(s)
- Patricia Pérez
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Laboratorio de Química Teórica, Av. República 275, 8370146 Santiago, Chile.
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73
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Hoshimoto Y, Kinoshita T, Ohashi M, Ogoshi S. A Strategy to Control the Reactivation of Frustrated Lewis Pairs from Shelf-Stable Carbene Borane Complexes. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505974] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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74
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Yang S, Zhang C. Theoretical Investigation of Obtaining Compounds with Planar Tetracoordinate Carbons by Frustrated Lewis Pairs. J Phys Chem A 2015. [PMID: 26218898 DOI: 10.1021/acs.jpca.5b06449] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ten derivatives of 2-borabicyclo[1.1.0]but-1(3)-ene (1a-1j) with different degrees of frustration have been investigated using density functional theory. Moreover, 1a-1j as Lewis bases were used to form Lewis adducts C3X2BYH/B(C6F5)3 (2a-2j) with Lewis acid B(C6F5)3. Optimized geometries and the thermodynamic properties of giving the Lewis adducts C3X2BYH/B(C6F5)3 reveal that 2a-2j are frustrated Lewis pairs (FLPs). Their reactivity of activating H2 and HF show that 2a-2j are unfavorable to heterolytically cleave H2, whereas 2c-2j can cleave HF to form [C3X2BYH](+)[FB(C6F5)3](-). In addition, we found the structures of [C3X2BYH](+) in [C3X2BYH](+)[FB(C6F5)3](-) contained a planar tetracoordinate carbon (ptC). Therefore, a new method of obtaining main group element compounds with ptC by using FLPs was presented.
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75
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Affiliation(s)
- Douglas W. Stephan
- Department of Chemistry, University of Toronto, 80 St. George
Street, Toronto, Ontario, Canada M5S 3H6
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76
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Blagg RJ, Lawrence EJ, Resner K, Oganesyan VS, Herrington TJ, Ashley AE, Wildgoose GG. Exploring structural and electronic effects in three isomers of tris{bis(trifluoromethyl)phenyl}borane: towards the combined electrochemical-frustrated Lewis pair activation of H2. Dalton Trans 2015. [PMID: 26215924 DOI: 10.1039/c5dt01918d] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Three structural isomers of tris{bis(trifluoromethyl)phenyl}borane have been studied as the acidic component of frustrated Lewis pairs. While the 3,5-substituted isomer is already known to heterolytically cleave H2 to generate a bridging-hydride; ortho-substituents in the 2,4- and 2,5-isomers quench such reactivity through electron donation into the vacant boron pz orbital and steric blocking of the boron centre; as shown by electrochemical, structural and computational studies. Electrochemical studies of the corresponding borohydrides identify that the two-electron oxidation of terminal-hydrides occurs at more positive potentials than observed for [HB(C6F5)3](-), while the bridging-hydride oxidizes at a higher potential still, comparable to that of free H2.
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Affiliation(s)
- Robin J Blagg
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK.
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77
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Swarnakar AK, Hering-Junghans C, Nagata K, Ferguson MJ, McDonald R, Tokitoh N, Rivard E. Encapsulating Inorganic Acetylene, HBNH, Using Flanking Coordinative Interactions. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201504867] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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78
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Swarnakar AK, Hering-Junghans C, Nagata K, Ferguson MJ, McDonald R, Tokitoh N, Rivard E. Stabilisierung von anorganischem Acetylen, HBNH, mithilfe flankierender koordinativer Wechselwirkungen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504867] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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79
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Stephan DW, Erker G. Chemie frustrierter Lewis-Paare: Entwicklung und Perspektiven. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201409800] [Citation(s) in RCA: 481] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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80
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Stephan DW, Erker G. Frustrated Lewis pair chemistry: development and perspectives. Angew Chem Int Ed Engl 2015; 54:6400-41. [PMID: 25974714 DOI: 10.1002/anie.201409800] [Citation(s) in RCA: 1298] [Impact Index Per Article: 144.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Indexed: 12/17/2022]
Abstract
Frustrated Lewis pairs (FLPs) are combinations of Lewis acids and Lewis bases in solution that are deterred from strong adduct formation by steric and/or electronic factors. This opens pathways to novel cooperative reactions with added substrates. Small-molecule binding and activation by FLPs has led to the discovery of a variety of new reactions through unprecedented pathways. Hydrogen activation and subsequent manipulation in metal-free catalytic hydrogenations is a frequently observed feature of many FLPs. The current state of this young but rapidly expanding field is outlined in this Review and the future directions for its broadening sphere of impact are considered.
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Affiliation(s)
- Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, Ontario M5S3H6 (Canada).
| | - Gerhard Erker
- Organisch Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstr. 40, 48149 Münster (Germany).
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81
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Johnstone MD, Schwarze EK, Clever GH, Pfeffer FM. Inside Cover: Modular Synthesis of Linear Bis- and Tris-monodentate Fused [6]Polynorbornane-Based Ligands and their Assembly into Coordination Cages (Chem. Eur. J. 10/2015). Chemistry 2015. [DOI: 10.1002/chem.404242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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82
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Abstract
CONSPECTUS: Frustrated Lewis pair (FLP) chemistry has emerged in the past decade as a strategy that enables main-group compounds to activate small molecules. This concept is based on the notion that combinations of Lewis acids and bases that are sterically prevented from forming classical Lewis acid-base adducts have Lewis acidity and basicity available for interaction with a third molecule. This concept has been applied to stoichiometric reactivity and then extended to catalysis. This Account describes three examples of such developments: hydrogenation, hydroamination, and CO2 reduction. The most dramatic finding from FLP chemistry was the discovery that FLPs can activate H2, thus countering the long-existing dogma that metals are required for such activation. This finding of stoichiometric reactivity was subsequently evolved to employ simple main-group species as catalysts in hydrogenations. While the initial studies focused on imines, subsequent studies uncovered FLP catalysts for a variety of organic substrates, including enamines, silyl enol ethers, olefins, and alkynes. Moreover, FLP reductions of aromatic anilines and N-heterocycles have been developed, while very recent extensions have uncovered the utility of FLP catalysts for ketone reductions. FLPs have also been shown to undergo stoichiometric reactivity with terminal alkynes. Typically, either deprotonation or FLP addition reaction products are observed, depending largely on the basicity of the Lewis base. While a variety of acid/base combinations have been exploited to afford a variety of zwitterionic products, this reactivity can also be extended to catalysis. When secondary aryl amines are employed, hydroamination of alkynes can be performed catalytically, providing a facile, metal-free route to enamines. In a similar fashion, initial studies of FLPs with CO2 demonstrated their ability to capture this greenhouse gas. Again, modification of the constituents of the FLP led to the discovery of reaction systems that demonstrated stoichiometric reduction of CO2 to either methanol or CO. Further modification led to the development of catalytic systems for the reduction of CO2 by hydrosilylation and hydroboration or deoxygenation. As each of these areas of FLP chemistry has advanced from the observation of unusual stoichiometric reactions to catalytic processes, it is clear that the concept of FLPs provides a new strategy for the design and application of main-group chemistry and the development of new metal-free catalytic processes.
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Affiliation(s)
- Douglas W. Stephan
- Department of Chemistry, University of Toronto, 80 St. George
Street, Toronto, Ontario, Canada M5S 3H6
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83
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Chen J, Chen EYX. Lewis Pair Polymerization of Acrylic Monomers byN-Heterocyclic Carbenes and B(C6F5)3. Isr J Chem 2015. [DOI: 10.1002/ijch.201400136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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84
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Lawrence EJ, Blagg RJ, Hughes DL, Ashley AE, Wildgoose GG. A combined "electrochemical-frustrated lewis pair" approach to hydrogen activation: surface catalytic effects at platinum electrodes. Chemistry 2015; 21:900-6. [PMID: 25382457 PMCID: PMC4316182 DOI: 10.1002/chem.201404242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Indexed: 11/11/2022]
Abstract
Herein, we extend our "combined electrochemical-frustrated Lewis pair" approach to include Pt electrode surfaces for the first time. We found that the voltammetric response of an electrochemical-frustrated Lewis pair (FLP) system involving the B(C6 F5 )3 /[HB(C6 F5 )3 ](-) redox couple exhibits a strong surface electrocatalytic effect at Pt electrodes. Using a combination of kinetic competition studies in the presence of a H atom scavenger, 6-bromohexene, and by changing the steric bulk of the Lewis acid borane catalyst from B(C6 F5 )3 to B(C6 Cl5 )3 , the mechanism of electrochemical-FLP reactions on Pt surfaces was shown to be dominated by hydrogen-atom transfer (HAT) between Pt, [PtH] adatoms and transient [HB(C6 F5 )3 ](⋅) electrooxidation intermediates. These findings provide further insight into this new area of combining electrochemical and FLP reactions, and proffers additional avenues for exploration beyond energy generation, such as in electrosynthesis.
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Affiliation(s)
- Elliot J Lawrence
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ (UK)
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85
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86
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Silva Valverde MF, Theuergarten E, Bannenberg T, Freytag M, Jones PG, Tamm M. Frustrated N-heterocyclic carbene–silylium ion Lewis pairs. Dalton Trans 2015; 44:9400-8. [DOI: 10.1039/c5dt01362c] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The reaction of a sterically demanding NHC affords frustrated carbene-trimethylsilylium ion pairs, which exhibit FLP-type reactivity such as carbon dioxide fixation and metal–halide bond activation.
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Affiliation(s)
- Miguel F. Silva Valverde
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
| | - Eileen Theuergarten
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
| | - Thomas Bannenberg
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
| | - Matthias Freytag
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
| | - Peter G. Jones
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
| | - Matthias Tamm
- Technische Universität Braunschweig
- Institut für Anorganische und Analytische Chemie
- 38106 Braunschweig
- Germany
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87
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Liu M, Nieger M, Schmidt A. Mesomeric betaine – N-heterocyclic carbene interconversions of 1,2,4-triazolium-phenolates. Sulfur, selenium, and borane adduct formation. Chem Commun (Camb) 2015; 51:477-9. [DOI: 10.1039/c4cc08032g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Triazolium-phenolates form carbenic tautomers which can be trapped with boranes as a new heterocyclic ring system.
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Affiliation(s)
- Ming Liu
- Clausthal University of Technology
- Institute of Organic Chemistry
- D-38678 Clausthal-Zellerfeld
- Germany
| | - Martin Nieger
- Laboratory of Inorganic Chemistry
- Department of Chemistry
- University of Helsinki
- FIN-00014 Helsinki
- Finland
| | - Andreas Schmidt
- Clausthal University of Technology
- Institute of Organic Chemistry
- D-38678 Clausthal-Zellerfeld
- Germany
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88
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Schneider H, Schmidt D, Radius U. A Facile Route to Backbone-Tethered N-Heterocyclic Carbene (NHC) Ligands via NHC to aNHC Rearrangement in NHC Silicon Halide Adducts. Chemistry 2014; 21:2793-7. [DOI: 10.1002/chem.201406264] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Indexed: 11/06/2022]
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89
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Rocchigiani L. Experimental Insights into the Structure and Reactivity of Frustrated Lewis Pairs. Isr J Chem 2014. [DOI: 10.1002/ijch.201400139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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90
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Das Neves Gomes C, Blondiaux E, Thuéry P, Cantat T. Metal-free reduction of CO2 with hydroboranes: two efficient pathways at play for the reduction of CO2 to methanol. Chemistry 2014; 20:7098-106. [PMID: 24771681 DOI: 10.1002/chem.201400349] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Indexed: 11/10/2022]
Abstract
Guanidines and amidines prove to be highly efficient metal-free catalysts for the reduction of CO2 to methanol with hydroboranes such as 9-borabicyclo[3.3.1]nonane (9-BBN) and catecholborane (catBH). Nitrogen bases, such as 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (Me-TBD), and 1,8-diazabicycloundec-7-ene (DBU), are active catalysts for this transformation and Me-TBD can catalyze the reduction of CO2 to methoxyborane at room temperature with TONs and TOFs of up to 648 and 33 h(-1) (25 °C), respectively. Formate HCOOBR2 and acetal H2C(OBR2)2 derivatives have been identified as reaction intermediates in the reduction of CO2 with R2BH, and the first C-H-bond formation is rate determining. Experimental and computational investigations show that TBD and Me-TBD follow distinct mechanisms. The N-H bond of TBD is reactive toward dehydrocoupling with 9-BBN and affords a novel frustrated Lewis pair (FLP) that can activate a CO2 molecule and form the stable adduct 2, which is the catalytically active species and can facilitate the hydride transfer from the boron to the carbon atoms. In contrast, Me-TBD promotes the reduction of CO2 through the activation of the hydroborane reagent. Detailed DFT calculations have shown that the computed energy barriers for the two mechanisms are consistent with the experimental findings and account for the reactivity of the different boron reductants.
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Affiliation(s)
- Christophe Das Neves Gomes
- CEA, IRAMIS, NIMBE, CNRS UMR 3299, 91191 Gif-sur-Yvette (France) http://iramis.cea.fr/Pisp/thibault.cantat/index.htm
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91
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Yang L, Wang H. Recent advances in carbon dioxide capture, fixation, and activation by using N-heterocyclic carbenes. CHEMSUSCHEM 2014; 7:962-998. [PMID: 24644039 DOI: 10.1002/cssc.201301131] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Indexed: 06/03/2023]
Abstract
In the last two decades, CO2 emission has caused a lot of environmental problems. To mitigate the concentration of CO2 in the atmosphere, various strategies have been implemented, one of which is the use of N-heterocyclic carbenes (NHCs) and related complexes to accomplish the capture, fixation, and activation of CO2 effectively. In this review, we summarize CO2 capture, fixation, and activation by utilizing NHCs and related complexes; homogeneous reactions and their reaction mechanisms are discussed. Free NHCs and NHC salts can capture CO2 in both direct and indirect ways to form imidazolium carboxylates, and they can also catalyze the reaction of aromatic aldehydes with CO2 to form carboxylic acids and derivatives. Moreover, associated with transition metals (TMs), NHCs can form NHC-TM complexes to transform CO2 into industrial acid or esters. Non-metal-NHC complexes can also catalyze the reactions of silicon and boron complexes with CO2 . In addition, catalytic cycloaddition of epoxides with CO2 is another effective function of NHC complexes, and NHC ionic liquids perform excellently in this aspect.
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Affiliation(s)
- Longhua Yang
- Institute for Advanced Study, Department of Chemistry, Nanchang University, Xuefu Dadao 999, Nanchang City, Jiangxi Province, 330031 (PR China)
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92
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Erdmann M, Wiegand T, Blumenberg J, Eckert H, Ren J, Daniliuc CG, Kehr G, Erker G. Formation, structural characterization, and reactions of a unique cyclotrimeric vicinal Lewis pair containing (C6F5)2P-Lewis base and (C6F5)BH-Lewis acid components. Dalton Trans 2014; 43:15159-69. [DOI: 10.1039/c4dt02081b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A unique vicinal Lewis pair cyclotrimer has been synthesized and characterized with respect to its structure and reactivity.
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Affiliation(s)
- Markus Erdmann
- Organisch-Chemisches Institut
- WWU Münster
- D 48149 Münster, Germany
| | - Thomas Wiegand
- Institut für Physikalische Chemie and Graduate School of Chemistry
- WWU Münster
- D 48149 Münster, Germany
| | - Jonas Blumenberg
- Organisch-Chemisches Institut
- WWU Münster
- D 48149 Münster, Germany
| | - Hellmut Eckert
- Institut für Physikalische Chemie and Graduate School of Chemistry
- WWU Münster
- D 48149 Münster, Germany
| | - Jinjun Ren
- Institut für Physikalische Chemie and Graduate School of Chemistry
- WWU Münster
- D 48149 Münster, Germany
| | | | - Gerald Kehr
- Organisch-Chemisches Institut
- WWU Münster
- D 48149 Münster, Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut
- WWU Münster
- D 48149 Münster, Germany
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93
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Stephan DW, Erker G. Frustrated Lewis pair chemistry of carbon, nitrogen and sulfur oxides. Chem Sci 2014. [DOI: 10.1039/c4sc00395k] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Frustrated Lewis pairs have been used to activate a variety of small molecules.
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Affiliation(s)
| | - Gerhard Erker
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität
- 48149 Münster, German
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94
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Herrington TJ, Ward BJ, Doyle LR, McDermott J, White AJP, Hunt PA, Ashley AE. Bypassing a highly unstable frustrated Lewis pair: dihydrogen cleavage by a thermally robust silylium–phosphine adduct. Chem Commun (Camb) 2014; 50:12753-6. [DOI: 10.1039/c4cc05905k] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The thermally robust silylium complex [iPr3Si–PtBu3]+[B(C6F5)4]− (1) activates H2/D2 at 90 °C (PhCl). However, experimental evidence and DFT calculations show no evidence for dissociation into the separated Lewis pair.
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Affiliation(s)
| | - Bryan J. Ward
- Department of Chemistry
- Imperial College London
- London SW7 2AZ, U.K
| | | | - Joe McDermott
- Department of Chemistry
- Imperial College London
- London SW7 2AZ, U.K
| | | | - Patricia A. Hunt
- Department of Chemistry
- Imperial College London
- London SW7 2AZ, U.K
| | - Andrew E. Ashley
- Department of Chemistry
- Imperial College London
- London SW7 2AZ, U.K
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95
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Arnold PL, Marr IA, Zlatogorsky S, Bellabarba R, Tooze RP. Activation of carbon dioxide and carbon disulfide by a scandium N-heterocyclic carbene complex. Dalton Trans 2014; 43:34-7. [DOI: 10.1039/c3dt52762j] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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96
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Li H, Aquino AJA, Cordes DB, Hung-Low F, Hase WL, Krempner C. A Zwitterionic Carbanion Frustrated by Boranes – Dihydrogen Cleavage with Weak Lewis Acids via an “Inverse” Frustrated Lewis Pair Approach. J Am Chem Soc 2013; 135:16066-9. [DOI: 10.1021/ja409330h] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hui Li
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
| | - Adelia J. A. Aquino
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
| | - David B. Cordes
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
| | - Fernando Hung-Low
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
| | - William L. Hase
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
| | - Clemens Krempner
- Texas Tech University, Department of Chemistry & Biochemistry, Box 41061, Lubbock, Texas 79409-1061, United States
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97
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Lu Z, Wang Y, Liu J, Lin YJ, Li ZH, Wang H. Synthesis and Reactivity of the CO2 Adducts of Amine/Bis(2,4,6-tris(trifluoromethyl)phenyl)borane Pairs. Organometallics 2013. [DOI: 10.1021/om4007246] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Zhenpin Lu
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Yuwen Wang
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Jia Liu
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Yue-jian Lin
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Zhen Hua Li
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Huadong Wang
- Shanghai
Key Laboratory of Molecular Catalysis and Innovative Material, Department
of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
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98
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Kolychev EL, Kronig S, Brandhorst K, Freytag M, Jones PG, Tamm M. Iridium(I) Complexes with Anionic N-Heterocyclic Carbene Ligands as Catalysts for the Hydrogenation of Alkenes in Nonpolar Media. J Am Chem Soc 2013; 135:12448-59. [DOI: 10.1021/ja406529c] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Eugene L. Kolychev
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
| | - Sabrina Kronig
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
| | - Kai Brandhorst
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
| | - Matthias Freytag
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
| | - Peter G. Jones
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring
30, 38106 Braunschweig
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99
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Sen TK, Sau SC, Mukherjee A, Hota PK, Mandal SK, Maity B, Koley D. Abnormal N-heterocyclic carbene main group organometallic chemistry: a debut to the homogeneous catalysis. Dalton Trans 2013; 42:14253-60. [DOI: 10.1039/c3dt51802g] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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100
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