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Farkas V, Csókás D, Erdélyi Á, Turczel G, Bényei A, Nagy T, Kéki S, Pápai I, Tuba R. "Inverted" Cyclic(Alkyl)(Amino)Carbene (CAAC) Ruthenium Complex Catalyzed Isomerization Metathesis (ISOMET) of Long Chain Olefins to Propylene at Low Ethylene Pressure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400118. [PMID: 38482751 PMCID: PMC11109630 DOI: 10.1002/advs.202400118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/20/2024] [Indexed: 05/23/2024]
Abstract
Isomerization Metathesis (ISOMET) reaction is an emerging tool for "open loop" chemical recycling of polyethylene to propylene. Novel, latent N-Alkyl substituted Cyclic(Alkyl)(Amino)Carbene (CAAC)-ruthenium catalysts (5a-Ru, 3b-Ru - 6c-Ru) are developed rendering "inverted" chemical structure while showing enhanced ISOMET activity in combination with (RuHCl)(CO)(PPh3)3 (RuH) double bond isomerization co-catalyst. Systematic investigations reveal that the steric hindrance of the substituents on nitrogen and carbon atom adjacent to carbene moiety in the CAAC ligand have significantly improved the catalytic activity and robustness. In contrast to the NHC-Ru and CAAC-Ru catalyst systems known so far, these systems show higher isomerization metathesis (ISOMET) activity (TON: 7400) on the model compound 1-octadecene at as low as 3.0 bar optimized pressure, using technical grade (3.0) ethylene. The propylene content formed in the gas phase can reach up to 20% by volume.
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Affiliation(s)
- Vajk Farkas
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
- Department of Organic Chemistry and TechnologyBudapest University of Technology and EconomicsSzent Gellért tér 4BudapestH‐1111Hungary
| | - Dániel Csókás
- Institute of Organic ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
| | - Ádám Erdélyi
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
- Research Centre for BiochemicalEnvironmental and Chemical EngineeringDepartment of MOL Hydrocarbon and Coal ProcessingUniversity of PannoniaEgyetem u. 10VeszprémH‐8210Hungary
| | - Gábor Turczel
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
| | - Attila Bényei
- Department of Physical ChemistryFaculty of Science and TechnologyUniversity of DebrecenEgyetem tér 1DebrecenH‐4032Hungary
| | - Tibor Nagy
- Department of Applied ChemistryFaculty of Science and TechnologyUniversity of DebrecenEgyetem tér 1DebrecenH‐4032Hungary
| | - Sándor Kéki
- Department of Applied ChemistryFaculty of Science and TechnologyUniversity of DebrecenEgyetem tér 1DebrecenH‐4032Hungary
| | - Imre Pápai
- Institute of Organic ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
| | - Róbert Tuba
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesMagyar tudósok körútja 2BudapestH‐1117Hungary
- Research Centre for BiochemicalEnvironmental and Chemical EngineeringDepartment of MOL Hydrocarbon and Coal ProcessingUniversity of PannoniaEgyetem u. 10VeszprémH‐8210Hungary
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2
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Nayak MK, Elvers BJ, Mehta S, Krummenacher I, Mondal A, Braunschweig H, Schulzke C, Ravat P, Jana A. Bis-[cyclic(alkyl)(amino)carbene]-derived diradicals. Chem Commun (Camb) 2024; 60:1739-1742. [PMID: 38240479 DOI: 10.1039/d3cc05779h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Crystalline polymeric structures of trans-1,4-cyclohexylene bridged N-tethered bis-CAACs in the form of their LiOTf adducts were synthesized and isolated. These were further used as building blocks for the synthesis of crystalline (amino)(carboxy)-based diradicals. The triplet diradical character of these compounds was unambiguously confirmed by the presence of a half-field signal in their EPR spectra. Theoretical calculations show that the singlet state is marginally more stable than the triplet state.
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Affiliation(s)
- Mithilesh Kumar Nayak
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India.
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India.
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
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3
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Saha P, Chrysochos N, Elvers BJ, Pätsch S, Uddin SI, Krummenacher I, Nandeshwar M, Mishra A, Raman KV, Rajaraman G, Prabusankar G, Braunschweig H, Ravat P, Schulzke C, Jana A. Bis-Olefin Based Crystalline Schlenk Hydrocarbon Diradicals with a Triplet Ground State. Angew Chem Int Ed Engl 2023; 62:e202311868. [PMID: 37646230 DOI: 10.1002/anie.202311868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 09/01/2023]
Abstract
A modular approach for the synthesis of isolable crystalline Schlenk hydrocarbon diradicals from m-phenylene bridged electron-rich bis-triazaalkenes as synthons is reported. EPR spectroscopy confirms their diradical nature and triplet electronic structure by revealing a half-field signal. A computational analysis confirms the triplet state to be the ground state. As a proof-of-principle for the modular methodology, the 4,6-dimethyl-m-phenylene was further utilized as a coupling unit between two alkene motifs. The steric conjunction of the 4,6-dimethyl groups substantially twists the substituents at the nonbonding electron bearing centers relative to the central coupling m-phenylene motif. As a result, the spin delocalization is decreased and the exchange coupling between the two unpaired spins, hence, significantly reduced. Notably, 108 years after Schlenk's m-phenylene-bis(diphenylmethyl) synthesis as a diradical, for the first time we were able to isolate its derivative with the same spacer, i.e. m-phenylene, between two radical centers in a crystalline form.
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Affiliation(s)
- Priyanka Saha
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, 17489, Greifswald, Germany
| | - Sebastian Pätsch
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, 17489, Greifswald, Germany
| | - Sk Imraj Uddin
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Muneshwar Nandeshwar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, 502284, India
| | - Anshika Mishra
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
| | - Karthik V Raman
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
| | - Ganesan Prabusankar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, 502284, India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Prince Ravat
- Institute of Organic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, 17489, Greifswald, Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500046, India
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4
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Chrysochos N, Pätsch S, Elvers BJ, Krummenacher I, Nandeshwar M, Prabusankar G, Braunschweig H, Schulzke C, Ravat P, Jana A. Introducing an orthogonally polarized electron-rich alkene: synthesis of a zwitterionic boron-containing π-conjugated system. Chem Commun (Camb) 2023; 59:12350-12353. [PMID: 37767978 DOI: 10.1039/d3cc03975g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
The synthesis of an alkene is reported which is concurrently twisted (twist angle = 86.6(8)°), push-pull (dipole moment = 7.48 D), and electron-rich (E1/2 = -1.45 V and -0.52 V vs. Fc/Fc+) in nature, comprising a unique trinity combination for the alkene class of compounds. Subsequently, this newly synthesized alkene-motif was used as a donor for the synthesis of a zwitterionic boron-containing π-conjugated compound (dipole moment = 12.17 D) through an intramolecular charge transfer process exploiting the π-conjugated donor-acceptor system.
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Affiliation(s)
- Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
| | - Sebastian Pätsch
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Muneshwar Nandeshwar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502284, India.
| | - Ganesan Prabusankar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502284, India.
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
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5
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Nayak MK, Sarkar P, Elvers BJ, Mehta S, Zhang F, Chrysochos N, Krummenacher I, Vijayakanth T, Narayanan RS, Dolai R, Roy B, Malik V, Rawat H, Mondal A, Boomishankar R, Pati SK, Braunschweig H, Schulzke C, Ravat P, Jana A. A bis-NHC-CAAC dimer derived dicationic diradical. Chem Sci 2022; 13:12533-12539. [PMID: 36382295 PMCID: PMC9629079 DOI: 10.1039/d2sc03937k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/21/2022] [Indexed: 08/11/2023] Open
Abstract
The isolation of carbon-centered diradicals is always challenging due to synthetic difficulties and their limited stability. Herein we report the synthesis of a trans-1,4-cyclohexylene bridged bis-NHC-CAAC dimer derived thermally stable dicationic diradical. The diradical character of this compound was confirmed by EPR spectroscopy. The variable temperature EPR study suggests the singlet state to be marginally more stable than the triplet state (2J = -5.5 cm-1 (ΔE ST = 0.065 kJ mol-1)). The presence of the trans-1,4-cyclohexylene bridge is instrumental for the successful isolation of this dicationic diradical. Notably, in the case of ethylene or propylene bridged bis-NHC-CAAC dimers, the corresponding dicationic diradicals are transient and rearrange to hydrogen abstracted products.
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Affiliation(s)
| | - Pallavi Sarkar
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Fangyuan Zhang
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Thangavel Vijayakanth
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | | | - Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Biswarup Roy
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Vishal Malik
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Hemant Rawat
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Ramamoorthy Boomishankar
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | - Swapan K Pati
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
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6
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Madron du Vigné A, Cramer N. Chiral Cyclic Alkyl Amino Carbene (CAAC) Transition-Metal Complexes: Synthesis, Structural Analysis, and Evaluation in Asymmetric Catalysis. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adrien Madron du Vigné
- Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), SB-ISIC, BCH 4305, 1015 Lausanne, Switzerland
| | - Nicolai Cramer
- Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), SB-ISIC, BCH 4305, 1015 Lausanne, Switzerland
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7
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Breitwieser K, Bahmann H, Weiss R, Munz D. Gauging Radical Stabilization with Carbenes. Angew Chem Int Ed Engl 2022; 61:e202206390. [PMID: 35796423 PMCID: PMC9545232 DOI: 10.1002/anie.202206390] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Indexed: 11/29/2022]
Abstract
Carbenes, including N-heterocyclic carbene (NHC) ligands, are used extensively to stabilize open-shell transition metal complexes and organic radicals. Yet, it remains unknown, which carbene stabilizes a radical well and, thus, how to design radical-stabilizing C-donor ligands. With the large variety of C-donor ligands experimentally investigated and their electronic properties established, we report herein their radical-stabilizing effect. We show that radical stabilization can be understood by a captodative frontier orbital description involving π-donation to- and π-donation from the carbenes. This picture sheds a new perspective on NHC chemistry, where π-donor effects usually are assumed to be negligible. Further, it allows for the intuitive prediction of the thermodynamic stability of covalent radicals of main group- and transition metal carbene complexes, and the quantification of redox non-innocence.
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Affiliation(s)
- Kevin Breitwieser
- Coordination ChemistrySaarland UniversityCampus C4.166123SaarbrückenGermany
| | - Hilke Bahmann
- Physical and Theoretical ChemistrySaarland UniversityCampus B2.266123SaarbrückenGermany
| | - Robert Weiss
- Organische ChemieFriedrich-Alexander-Universität (FAU) Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
| | - Dominik Munz
- Coordination ChemistrySaarland UniversityCampus C4.166123SaarbrückenGermany
- Inorganic and General ChemistryFriedrich-Alexander-Universität (FAU) Erlangen-NürnbergEgerlandstr. 191058ErlangenGermany
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8
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Breitwieser K, Bahmann H, Weiss R, Munz D. Gauging Radical Stabilization with Carbenes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kevin Breitwieser
- Saarland University: Universitat des Saarlandes Coordination Chemistry GERMANY
| | - Hilke Bahmann
- Saarland University: Universitat des Saarlandes Theoretical Chemistry GERMANY
| | - Robert Weiss
- FAU Erlangen Nuremberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Organic Chemistry GERMANY
| | - Dominik Munz
- Universitat des Saarlandes Inorganic Chemistry: Coordination Chemistry Campus C 4.1 66123 Saarbrücken GERMANY
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9
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Puerta Lombardi BM, Pezoulas ER, Suvinen RA, Harrison A, Dubrawski ZS, Gelfand BS, Tuononen HM, Roesler R. Bis[cyclic (alkyl)(amino)carbene] isomers: Stable trans-bis(CAAC) versus facile olefin formation for cis-bis(CAAC). Chem Commun (Camb) 2022; 58:6482-6485. [PMID: 35583166 DOI: 10.1039/d2cc01476a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isomeric bis(aldiminium) salts with a 1,4-cyclohexylene framework were synthesized. The first isolable bis(CAAC) was prepared from the trans-stereoisomer and its ditopic ligand competency was proven by conversion to iridium(I) and rhodium(I) complexes. Upon deprotonation, the cis-isomer yielded an electron rich olefin via a classic, proton-catalyzed pathway. The CC bond formation from the desired cis-bis(CAAC) was shown to be thermodynamically very favorable and to involve a small activation barrier. Compounds that can be described as insertion products of the cis-bis(CAAC) into the E-H bonds of NH3, CH3CN and H2O were also identified.
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Affiliation(s)
- Braulio M Puerta Lombardi
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
| | - Ethan R Pezoulas
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
| | - Roope A Suvinen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland.
| | - Alexander Harrison
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
| | - Zachary S Dubrawski
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
| | - Benjamin S Gelfand
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
| | - Heikki M Tuononen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland.
| | - Roland Roesler
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
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10
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Maiti A, Elvers BJ, Bera S, Lindl F, Krummenacher I, Ghosh P, Braunschweig H, Yildiz CB, Schulzke C, Jana A. Disclosing Cyclic(Alkyl)(Amino)Carbenes as One-Electron Reductants: Synthesis of Acyclic(Amino)(Aryl)Carbene-Based Kekulé Diradicaloids. Chemistry 2022; 28:e202104567. [PMID: 35262232 PMCID: PMC9321839 DOI: 10.1002/chem.202104567] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/10/2022]
Abstract
Herein, we disclose cyclic(alkyl)(amino)carbenes (CAACs) to be one-electron reductants under the formation of a transient radical cation as indicated by EPR spectroscopy. The disclosed CAAC reducing reactivity was used to synthesize acyclic(amino)(aryl)carbene-based Thiele and Chichibabin hydrocarbons, a new class of Kekulé diradicaloids. The results demonstrate CAACs to be potent organic reductants. Notably, the acyclic(amino)(aryl)carbene-based Chichibabin's hydrocarbon shows an appreciable population of the triplet state at room temperature, as evidenced by both variable-temperature NMR and EPR spectroscopy.
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Affiliation(s)
- Avijit Maiti
- Tata Institute of Fundamental Research Hyderabad GopanpallyHyderabad500046, TelanganaIndia
| | - Benedict J. Elvers
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Straße 417489GreifswaldGermany
| | - Sachinath Bera
- Department of ChemistryRamakrishna Mission Residential College NarendrapurKolkata700103India
- Shahid Matangini Hazra Govt General Degree College for Women TamlukPurba Medinipur721649India
| | - Felix Lindl
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Prasanta Ghosh
- Department of ChemistryRamakrishna Mission Residential College NarendrapurKolkata700103India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Cem B. Yildiz
- Department of Aromatic and Medicinal PlantsAksaray UniversityAksaray68100Turkey
| | - Carola Schulzke
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Straße 417489GreifswaldGermany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad GopanpallyHyderabad500046, TelanganaIndia
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11
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Vermersch F, Oliveira L, Hunter J, Soleilhavoup M, Jazzar R, Bertrand G. Cyclic (Alkyl)(amino)carbenes: Synthesis of Iminium Precursors and Structural Properties. J Org Chem 2022; 87:3511-3518. [PMID: 35133152 DOI: 10.1021/acs.joc.1c03075] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using readily available preallylated aldehydes, we report a simple and divergent synthesis of cyclic (alkyl)(amino)carbene (CAAC) iminium precursors. Using a combination of crystallographic data and steric maps, we further elaborate on the specific steric properties of CAAC ligands with respect to state-of-the-art phosphine and carbene ligands.
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Affiliation(s)
- François Vermersch
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Luana Oliveira
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Joseph Hunter
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Michele Soleilhavoup
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
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Kumar R, Chandra S, Nayak MK, Singha Hazari A, Elvers BJ, Schulzke C, Sarkar B, Jana A. An Air-Stable Alkene-Derived Organic Radical Cation. ACS OMEGA 2022; 7:837-843. [PMID: 35036750 PMCID: PMC8757455 DOI: 10.1021/acsomega.1c05479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 10/27/2021] [Indexed: 06/14/2023]
Abstract
Alkenes are known to undergo oxidation to radical cations and dications. The radical cations are often highly reactive and not stable under air. Herein, we report the synthesis, isolation, characterization, and molecular structure of an alkene-derived radical cation A, which is stable in air both in the solid state and in solution. The access to this compound was facilitated from E-diamino tri-substituted alkene B as a synthon for the synthesis of A through one-electron oxidation. The E-diamino tri-substituted alkene B was synthesized by the two-electron reduction of N,N'-1,2-propylene-bridged bis-2-phenyl-pyrrolinium cation C. Under two-electron oxidation, alkene B transforms back to cation C involving a double carbocation rearrangement.
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Affiliation(s)
- Rahul Kumar
- Tata
Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Shubhadeep Chandra
- Universität
Stuttgart, Fakultät Chemie, Lehrstuhl für Anorganische
Koordinationschemie, Institut für
Anorganische Chemie, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Mithilesh Kumar Nayak
- Tata
Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Arijit Singha Hazari
- Universität
Stuttgart, Fakultät Chemie, Lehrstuhl für Anorganische
Koordinationschemie, Institut für
Anorganische Chemie, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Benedict J. Elvers
- Institut
für Biochemie, Universität
Greifswald, Felix-Hausdorff-Straße 4, Greifswald D-17489, Germany
| | - Carola Schulzke
- Institut
für Biochemie, Universität
Greifswald, Felix-Hausdorff-Straße 4, Greifswald D-17489, Germany
| | - Biprajit Sarkar
- Universität
Stuttgart, Fakultät Chemie, Lehrstuhl für Anorganische
Koordinationschemie, Institut für
Anorganische Chemie, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Anukul Jana
- Tata
Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
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Cyclic (alkyl)(amino)carbene (CAAC) ligands: Electronic structure and application as chemically- and redox-non-innocent ligands and chromophores. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2022. [DOI: 10.1016/bs.adomc.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Kundu A, Chandra S, Mandal D, Neuman NI, Mahata A, Anga S, Rawat H, Pal S, Schulzke C, Sarkar B, Chandrasekhar V, Jana A. Twisted Push-Pull Alkenes Bearing Geminal Cyclicdiamino and Difluoroaryl Substituents. J Org Chem 2021; 86:12683-12692. [PMID: 34473501 DOI: 10.1021/acs.joc.1c01201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The systematic combination of N-heterocyclic olefins (NHOs) with fluoroarenes resulted in twisted push-pull alkenes. These alkenes carry electron-donating cyclicdiamino substituents and two electron-withdrawing fluoroaryl substituents in the geminal positions. The synthetic method can be extended to a variety of substituted push-pull alkenes by varying the NHO as well as the fluoroarenes. Solid-state molecular structures of these molecules reveal a notable elongation of the central C-C bond and a twisted geometry in the alkene motif. Absorption properties were investigated with UV-vis spectroscopy. The redox properties of the twisted push-pull alkenes were probed with electrochemistry as well as UV-vis/NIR and EPR spectroelectrochemistry, while the electronic structures were computationally evaluated and validated.
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Affiliation(s)
- Abhinanda Kundu
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Shubhadeep Chandra
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Debdeep Mandal
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Nicolás I Neuman
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.,Instituto de Desarrollo Tecnológico para la Industria Química, CCT Santa Fe CONICET-UNL, Colectora Ruta Nacional 168, Paraje El Pozo, 3000 Santa Fe, Argentina
| | - Alok Mahata
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Srinivas Anga
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Hemant Rawat
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Sudip Pal
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489 Greifswald, Germany
| | - Biprajit Sarkar
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | | | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, Telangana, India
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Messelberger J, Kumar M, Goodner SJ, Munz D. Wanzlick's equilibrium in tri- and tetraaminoolefins. Org Chem Front 2021. [DOI: 10.1039/d1qo01320c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
How to isolate small carbenes, previously reported to from dimers instantaneously, and how to split triaminoolefins into free carbenes.
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Affiliation(s)
- Julian Messelberger
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
| | - Manoj Kumar
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
| | - Stephen J. Goodner
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
- Friedrich-Alexander Universität Erlangen-Nürnberg, Department of Chemistry and Pharmacy: Chair of Inorganic and General Chemistry, Egerlandstraße 1, D-91058 Erlangen, Germany
| | - Dominik Munz
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
- Friedrich-Alexander Universität Erlangen-Nürnberg, Department of Chemistry and Pharmacy: Chair of Inorganic and General Chemistry, Egerlandstraße 1, D-91058 Erlangen, Germany
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