1
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Ruppert H, Meister A, Pfretzschner R, Vieira AF, Greb L. Concatenating Structural Constraint Effects at Tin for the Sequential Generation, Stabilization, and Transfer of Acyclic Aminocarbenes. J Am Chem Soc 2024; 146. [PMID: 38604608 PMCID: PMC11048120 DOI: 10.1021/jacs.4c02446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024]
Abstract
Structural constraint approaches have been employed toward different ends in recent years, from augmenting the nucleophilicity in pyramidalized low-valent p-block compounds to enhancing the Lewis acidities at planarized tetravalent p-block elements. While previous studies exploited these effects separately, this work introduces a strategy to concatenate structural constraint approaches at individual stages of a reaction sequence in a row to unlock a synthetic path unattainable by conventional methodologies. The boosted nucleophilicity resulting from the constrained tetracoordinated calix[4]pyrrolato stannate(II) dianion enables the reductive formation of sterically unprotected acyclic aminocarbenes. These amino carbenes are stabilized at the concomitantly formed square-planar stannane(IV) as air-stable adducts. Transfer of the carbenes onto copper(I) by cooperativity of the calix[4]pyrrole ligand finalizes this protocol to hitherto unreported yet prototypical carbene complexes. Detailed spectroscopic and quantum theoretical analyses establish the synergy of structural constraints and element-ligand cooperation as the linchpin to this reaction path and its selectivity.
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Affiliation(s)
- Heiko Ruppert
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
| | - Arne Meister
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
| | - Ronja Pfretzschner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
| | - André Faria Vieira
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
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2
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Leung JN, Huynh HV. Design of a Mesoionic Janus-type Dicarbene. J Am Chem Soc 2024; 146:3622-3626. [PMID: 38306245 DOI: 10.1021/jacs.3c13284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2024]
Abstract
A versatile synthetic strategy for the preparation of homo- and heterobimetallic complexes bearing an unprecedented mesoionic Janus-type diNHC is presented. Moreover, its electronic property is evaluated, and a preliminary catalytic application in the direct diarylation of 1-methylpyrrole is demonstrated.
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Affiliation(s)
- Jia Nuo Leung
- Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, Singapore 117453, Republic of Singapore
| | - Han Vinh Huynh
- Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, Singapore 117453, Republic of Singapore
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3
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Kumar S, Patra DK, Rit A. Heterobimetallic Complexes Bridged by an Unsymmetrical Bis(NHC) Ligand: Study of Enhanced Catalytic Activity in Tandem Transformations and Understanding of Cooperativity between the Metal Centers. Chemistry 2023; 29:e202302180. [PMID: 37702918 DOI: 10.1002/chem.202302180] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/12/2023] [Accepted: 09/12/2023] [Indexed: 09/14/2023]
Abstract
The bis(azolium) salt [L1-H2 ]Br2 was found to serve as a suitable platform for accessing the heterobimetallic IrIII -M (M=PdII /AuI ) and PdII -IrIII complexes. Initially, selective mono-metalation of [L1-H2 ]Br2 yielded an orthometalated IrIII - or non-orthometalated PdII -complex. Sequential metalation of the mono-IrIII complex resulted in the formation of heterobimetallic IrIII -PdII /AuI complexes. Similarly, a distinct heterobimetallic PdII -IrIII complex was synthesized starting from the mono-PdII complex. Further, the corresponding homobimetallic IrIII -IrIII and PdII -PdII complexes were directly obtained from [L1-H2 ]Br2 . Additionally, monometallic PdII and IrIII analogues were synthesized from [L2-H]Br and [L3-H]Br, respectively. The heterobimetallic IrIII -PdII and PdII -IrIII complexes were then evaluated as catalysts in various one-pot tandem catalytic reactions in which they demonstrated superior activity than the mixtures of both their corresponding homobimetallic IrIII -IrIII /PdII -PdII and monometallic IrIII /PdII counterparts, under the constant concentrations of metal centers. Moreover, while comparing complexes IrIII -PdII and PdII -IrIII , the former exhibits higher activity in all the studied reactions. All these findings suggest the presence of some form of cooperativity between the two metal centers (Ir and Pd) connected by a single ligand framework in IrIII -PdII and PdII -IrIII complex, with IrIII -PdII displaying better cooperativity that has been validated by electrochemical, NMR, and DFT studies.
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Affiliation(s)
- Shashi Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Deeptesh K Patra
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
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4
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Löwe P, Wünsche MA, Purtscher FRS, Gamper J, Hofer TS, Wilm LFB, Röthel MB, Dielmann F. Terminal methylene phosphonium ions: precursors for transient monosubstituted phosphinocarbenes. Chem Sci 2023; 14:7928-7935. [PMID: 37502319 PMCID: PMC10370551 DOI: 10.1039/d3sc02899b] [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: 06/06/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
Isolable singlet carbenes are among the most important tools in chemistry, but generally require the interaction of two substituents with the electron deficient carbon atom. We herein report a synthetic approach to monosubstituted phosphinocarbenes via deprotonation of hitherto unknown diprotic terminal methylene phosphonium ions. Two methylene phosphonium salts bearing bulky N-heterocyclic imine substituents at the phosphorus atom were isolated and fully characterized. Deprotonation studies indicate the formation of transient monosubstituted carbenes that undergo intermolecular cycloadditions or intramolecular Buchner ring expansion to afford a cycloheptatriene derivative. The reaction mechanism of the latter transformation was elucidated using DFT calculations, which reveal the ambiphilic nature of the phosphinocarbene enabling the insertion into the aromatic C-C bond. Additional computational studies on the role of substituent effects are presented.
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Affiliation(s)
- Pawel Löwe
- Instutut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 28/30 48149 Münster Germany
| | - Marius A Wünsche
- Instutut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 28/30 48149 Münster Germany
| | - Felix R S Purtscher
- Institute of General, Inorganic and Theoretical Chemistry Leopold-Franzens-Universität Innsbruck Innrain 80-82 6020 Innsbruck Austria
| | - Jakob Gamper
- Institute of General, Inorganic and Theoretical Chemistry Leopold-Franzens-Universität Innsbruck Innrain 80-82 6020 Innsbruck Austria
| | - Thomas S Hofer
- Institute of General, Inorganic and Theoretical Chemistry Leopold-Franzens-Universität Innsbruck Innrain 80-82 6020 Innsbruck Austria
| | - Lukas F B Wilm
- Instutut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 28/30 48149 Münster Germany
| | - Maike B Röthel
- Institute of General, Inorganic and Theoretical Chemistry Leopold-Franzens-Universität Innsbruck Innrain 80-82 6020 Innsbruck Austria
| | - Fabian Dielmann
- Instutut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 28/30 48149 Münster Germany
- Institute of General, Inorganic and Theoretical Chemistry Leopold-Franzens-Universität Innsbruck Innrain 80-82 6020 Innsbruck Austria
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5
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Pellitero MA, Jensen IM, Dominique NL, Ekowo LC, Camden JP, Jenkins DM, Arroyo-Currás N. Stability of N-Heterocyclic Carbene Monolayers under Continuous Voltammetric Interrogation. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37449918 PMCID: PMC10377464 DOI: 10.1021/acsami.3c06148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are promising monolayer-forming ligands that can overcome limitations of thiol-based monolayers in terms of stability, surface functionality, and reactivity across a variety of transition-metal surfaces. Recent publications have reported the ability of NHCs to support biomolecular receptors on gold substrates for sensing applications and improved tolerance to prolonged biofluid exposure relative to thiols. However, important questions remain regarding the stability of these monolayers when subjected to voltage perturbations, which is needed for applications with electrochemical platforms. Here, we investigate the ability of two NHCs, 1,3-diisopropylbenzimidazole and 5-(ethoxycarbonyl)-1,3-diisopropylbenzimidazole, to form monolayers via self-assembly from methanolic solutions of their trifluoromethanesulfonate salts. We compare the electrochemical behavior of the resulting monolayers relative to that of benchmark mercaptohexanol monolayers in phosphate-buffered saline. Within the -0.15 to 0.25 V vs Ag|AgCl voltage window, NHC monolayers are stable on gold surfaces, wherein they electrochemically perform like thiol-based monolayers and undergo similar reorganization kinetics, displaying long-term stability under incubation in buffered media and under continuous voltammetric interrogation. At negative voltages, NHC monolayers cathodically desorb from the electrode surface at lower bias (-0.1 V) than thiol-based monolayers (-0.5 V). At voltages more positive than 0.25 V, NHC monolayers anodically desorb from electrode surfaces at similar voltages to thiol-based monolayers. These results highlight new limitations to NHC monolayer stability imposed by electrochemical interrogation of the underlying gold electrodes. Our results serve as a framework for future optimization of NHC monolayers on gold for electrochemical applications, as well as structure-functionality studies of NHCs on gold.
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Affiliation(s)
- Miguel Aller Pellitero
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Isabel M Jensen
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Nathaniel L Dominique
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Lilian Chinenye Ekowo
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jon P Camden
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David M Jenkins
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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6
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Majumder A, Naskar R, Roy P, Mondal B, Garai S, Maity R. A naphthalene-based heterobimetallic triazolylidene Ir III/Pd II complex: regioselective to regiospecific C-H activation, tandem catalysis and a copper-free Sonogashira reaction. Dalton Trans 2023; 52:2272-2281. [PMID: 36723111 DOI: 10.1039/d2dt03508a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Heterobimetallic complexes featuring mesoionic carbene (MIC) donor ligands are gaining enormous popularity in tandem catalysis owing to the combined action of two different metal centers during catalysis. A rare version of the heterobimetallic PdII/IrIII complex possessing a cyclometalated mesoionic carbene (MIC) ligand is presented along with the analogous homodinuclear PdII complex. A sterically controlled regiospecific cyclometalation towards the formation of a six-membered ring complex over a five-membered ring complex has been performed using a naphthalene-based bis-MIC ligand platform. The interplay between regioselective vs. regiospecific C-H bond activation for the synthesis of cyclometalated IrIII complexes has also been demonstrated using the corresponding naphthyl-derived mono-imidazolylidene ligand. Both homodinuclear PdII and heterobimetallic PdII/IrIII complexes have been characterized using standard spectroscopic techniques including 1H, 13C{1H}, 2D correlation NMR spectroscopy and ESI mass spectrometry. The structure of the cyclometalated heterobimetallic complex has been established by single crystal XRD. The heterobimetallic complex has been employed as a pre-catalyst in the tandem Suzuki-Miyaura/transfer hydrogenation reaction and the homobimetallic PdII complex has been successfully employed as a catalyst in both the Sonogashira coupling and α-arylation of 1-methyl-2-oxindole.
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Affiliation(s)
- Adhir Majumder
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Rajat Naskar
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Pallabi Roy
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Bhaskar Mondal
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Somenath Garai
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh, India
| | - Ramananda Maity
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
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7
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Hashikawa Y, Sadai S, Okamoto S, Murata Y. Near-Infrared-Absorbing Chiral Open [60]Fullerenes. Angew Chem Int Ed Engl 2023; 62:e202215380. [PMID: 36357327 DOI: 10.1002/anie.202215380] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Indexed: 11/12/2022]
Abstract
Though [60]fullerene is an achiral molecular nanocarbon with Ih symmetry, it could attain an inherent chirality depending upon a functionalization pattern. The conventional chiral induction of C60 relies mainly upon a multiple addition affording a mixture of achiral and chiral isomers while their chiral function would be largely offset by the existence of pseudo-mirror plane(s). These are major obstacles to proceed further study on fullerene chirality and yet leave its understanding elusive. Herein, we showcase a carbene-mediated synthesis of C1 -symmetric chiral open [60]fullerenes showing an intense far-red to near-infrared absorption. The large dissymmetry factor of |gabs |=0.12 was achieved at λ=820 nm for circular dichroism in benzonitrile. This is, in general, unachievable by other small chiral organic molecules, demonstrating the potential usage of open [60]fullerenes as novel types of chiral chromophores.
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Affiliation(s)
- Yoshifumi Hashikawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Shumpei Sadai
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Shu Okamoto
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Yasujiro Murata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
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8
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Tan C, Tinnermann H, Wee V, Tan S, Sung S, Wang Q, Young RD. Synthesis of bimetallic rhodium phosphinine complexes with enhanced catalytic activity towards alkyne hydrosilylation. J Organomet Chem 2023. [DOI: 10.1016/j.jorganchem.2023.122617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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9
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Eder T, Buß F, Wilm LFB, Seidl M, Podewitz M, Dielmann F. Oxidative Fluorination of Selenium and Tellurium Compounds using a Thermally Stable Phosphonium SF 5 - Salt Accessible from SF 6. Angew Chem Int Ed Engl 2022; 61:e202209067. [PMID: 36018610 PMCID: PMC9826459 DOI: 10.1002/anie.202209067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Indexed: 01/11/2023]
Abstract
Fluorinated group 16 moieties are attractive building blocks in synthetic chemistry but only few synthetic methods are available to prepare them. Herein, we report a new oxidative fluorination reagent capable of stabilizing reactive fluorinated anions. It consists of an SF5 - anion and a chemically inert phosphonium cation and is exceptionally thermally stable. Accordingly, it was used to generate the SeF5 - and TeF5 - anions from the elemental chalcogens and to prepare the unknown tetrafluoro(phenyl)-λ5 -selenate PhSeF4 - and -tellurate PhTeF4 - from the corresponding diphenyl dichalcogenides. In addition, we show that further derivatization of [PhTeF4 ]- by oxidation to trans-PhTeF4 O- and subsequent alkylation gives access to a new class of trans-(alkoxy)(phenyl)tetrafluoro-λ6 -tellanes (trans-PhTeF4 OR), thus providing an approach to introduce the functional group into organic molecules.
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Affiliation(s)
- Tobias Eder
- Institute of GeneralInorganic and Theoretical ChemistryLeopold-Franzens-Universität InnsbruckInnrain 80–826020InnsbruckAustria,Institute of Inorganic and Analytical ChemistryWestfälische Wilhelms-Universität MünsterCorrensstrasse 28–3048149MünsterGermany
| | - Florenz Buß
- Institute of Inorganic and Analytical ChemistryWestfälische Wilhelms-Universität MünsterCorrensstrasse 28–3048149MünsterGermany
| | - Lukas F. B. Wilm
- Institute of Inorganic and Analytical ChemistryWestfälische Wilhelms-Universität MünsterCorrensstrasse 28–3048149MünsterGermany
| | - Michael Seidl
- Institute of GeneralInorganic and Theoretical ChemistryLeopold-Franzens-Universität InnsbruckInnrain 80–826020InnsbruckAustria
| | - Maren Podewitz
- Institute of Materials ChemistryTU WienGetreidemarkt 91060ViennaAustria
| | - Fabian Dielmann
- Institute of GeneralInorganic and Theoretical ChemistryLeopold-Franzens-Universität InnsbruckInnrain 80–826020InnsbruckAustria
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10
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He C, Si DH, Huang YB, Cao R. A CO 2 -Masked Carbene Functionalized Covalent Organic Framework for Highly Efficient Carbon Dioxide Conversion. Angew Chem Int Ed Engl 2022; 61:e202207478. [PMID: 35789079 DOI: 10.1002/anie.202207478] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 01/06/2023]
Abstract
Free N-heterocyclic carbenes (NHCs) are generally prepared by treatment of imidazolium precursors with strong alkali reagents, which usually produces inactive NHC dimers. This treatment would destroy porous supports and thus make supported NHC catalysts difficult to recovery and reuse. Herein, we report the first stable CO2 -masked N-heterocyclic carbenes (NHCs) grafted on a porous crystalline covalent organic framework (COF). The stable NHC-CO2 moieties in the COF-NHC-CO2 could be transformed in situ into isolated NHCs by heating, which exhibit superior catalytic performances in hydrosilylation and N-formylation reactions with CO2 . The NHC sites can reversibly form NHC-CO2 and thus can be easily recycled and reused while maintaining excellent catalytic activity. Density functional theory calculations revealed that NHC sites can be fully exposed after removal of CO2 -masks and rapidly react with silanes, which endows COF-NHC with high catalytic activity.
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Affiliation(s)
- Chang He
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Duan-Hui Si
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
| | - Yuan-Biao Huang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Rong Cao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, 350108, P. R. China
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11
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Eder T, Buß F, Wilm LFB, Seidl M, Podewitz M, Dielmann F. Oxidative Fluorination of Selenium and Tellurium Compounds using a Thermally Stable Phosphonium SF5‐ Salt Accessible from SF6. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Tobias Eder
- Leopold Franzens Universität für Innsbruck: Universitat Innsbruck Inorganic Chemistry AUSTRIA
| | - Florenz Buß
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Inorganic Chemistry GERMANY
| | - Lukas F. B. Wilm
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Inorganic Chemistry GERMANY
| | - Michael Seidl
- Leopold Franzens Universität für Innsbruck: Universitat Innsbruck Inorganic Chemistry AUSTRIA
| | - Maren Podewitz
- TU Wien: Technische Universitat Wien Institute of Materials Chemistry AUSTRIA
| | - Fabian Dielmann
- Universitat Innsbruck Fakultat fur Chemie und Pharmazie Institut für Allgemeine, Anorganische und Theoretische Chemie Innrain 80-82 6020 Innsbruck AUSTRIA
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12
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Böhme MD, Eder T, Röthel MB, Dutschke PD, Wilm LFB, Hahn FE, Dielmann F. Synthesis of N-Heterocyclic Carbenes and Their Complexes by Chloronium Ion Abstraction from 2-Chloroazolium Salts Using Electron-Rich Phosphines. Angew Chem Int Ed Engl 2022; 61:e202202190. [PMID: 35230738 PMCID: PMC9401039 DOI: 10.1002/anie.202202190] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Indexed: 12/18/2022]
Abstract
N‐Heterocyclic carbenes (NHCs) are commonly prepared by deprotonation of azolium salts using strong anionic bases. This reaction is often unselective, yielding alkali metal NHC complexes or dimerized NHCs. Alternatively, free NHCs are obtained by the dechlorination of 2‐chloroazolium salts using electron‐rich phosphines. PPh3, PCy3, and PtBu3 are unsuitable for Cl+ abstraction, while the sterically encumbered tris(1,3‐tert‐butylimidazolidin‐2‐ylidenamino)phosphine 1 selectively removes Cl+ from 2‐chloroazolium salts. Since bulky 1 does not bind to metal complexes, it was used for the preparation of NHC complexes via in situ Cl+ abstraction from 2‐chloroazolium salts. The dechlorination was employed for the site‐selective monometallation with IrI, IrIII, RhI, RhIII, and RuII of a bis‐NHC precursor composed of a 2‐chlorobenzimidazolium and a 2‐chlorobenzimidazole group, followed by the preparation of the heterobimetallic IrIII/PdII complex [18](BF4)2 by a dechlorination/oxidative addition reaction sequence.
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Affiliation(s)
- Matthias D Böhme
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 39, 48149, Münster, Germany
| | - Tobias Eder
- Institute of General and Theoretical Chemistry, Leopold-Franzens Universität Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Maike B Röthel
- Institute of General and Theoretical Chemistry, Leopold-Franzens Universität Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Patrick D Dutschke
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 39, 48149, Münster, Germany
| | - Lukas F B Wilm
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 39, 48149, Münster, Germany
| | - F Ekkehardt Hahn
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 39, 48149, Münster, Germany
| | - Fabian Dielmann
- Institute of General and Theoretical Chemistry, Leopold-Franzens Universität Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
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13
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He C, Si DH, Huang YB, Cao R. A CO2‐Masked Carbene Functionalized Covalent Organic Framework for Highly Efficient Carbon Dioxide Conversion. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chang He
- Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter State key laboratory of structural chemistry CHINA
| | - Duan-Hui Si
- Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter State key laboratory of structural chemistry CHINA
| | - Yuan-Biao Huang
- Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter State key laboratory of structural chemistry CHINA
| | - Rong Cao
- Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter State Key Laboratory of Structural Chemistry YangQiao street NO. 155Gulou District 350002 Fuzhou CHINA
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