1
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Blechschmidt DR, Mergendahl C, Kass SR. Metallocenium incorporated charge-enhanced thiourea catalysts. Org Biomol Chem 2024; 22:1788-1793. [PMID: 38343361 DOI: 10.1039/d3ob02007j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Several metallocenium derivatives were prepared including N-ferrocenium-N'-phenylthiourea tetrakis-[3,5-bis(trifluoromethyl)phenyl]borate (BArF4, 4a), N-methylferrocenium-N'-phenylthiourea BArF4 (4b) and N-cobaltocenium-N'-phenylthiourea BArF4 (5). These compounds are competent catalysts for the Friedel-Crafts alkylation of indoles with trans-β-nitrostyrenes, and are much more active than their reduced non-charged forms. The iron derivatives are less stable than the cobalt analog and were generated and used in situ whereas the cobalt-containing thiourea was isolated and characterized by X-ray crystallography. All three of these metallocenium salts have Lewis and Brønsted acidic sites which were exploited in tandem to afford charge-activated catalysts.
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Affiliation(s)
- Daniel R Blechschmidt
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
| | - Cal Mergendahl
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
| | - Steven R Kass
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
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2
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Carter C, Kratish Y, Marks TJ. Influence of Rare-Earth Ion Radius on Metal-Metal Charge Transfer in Trinuclear Mixed-Valent Complexes. Inorg Chem 2023; 62:4799-4813. [PMID: 36921086 DOI: 10.1021/acs.inorgchem.2c03973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
We report the synthesis and characterization of a highly conjugated bisferrocenyl pyrrolediimine ligand, Fc2PyrDIH (1), and its trinuclear complexes with rare earth ions─(Fc2PyrDI)M(N(TMS)2)2 (2-M, M = Sc, Y, Lu, La). Crystal structures, nuclear magnetic resonance (NMR) spectra, and ultraviolet/visible/near-infrared (UV/vis-NIR) data are presented. The latter are in good agreement with DFT calculations, illuminating the impact of the rare earth ionic radius on NIR charge transfer excitations. For [2-Sc]+, the charge transfer is at 11,500 cm-1, while for [2-Y]+, only a d-d transition at 8000 cm-1 is observed. Lu has an ionic radius in between Sc and Y, and the [2-Lu]+ complex exhibits both transitions. From time-dependent density functional theory (TDDFT) analysis, we assign the 11,500 cm-1 transition as a mixture of metal-to-ligand charge transfer (MLCT) and metal-to-metal charge transfer (MMCT), rather than pure metal-to-metal CT because it has significant ligand character. Typically, the ferrocenes moieties have high rotational freedom in bis-ferrocenyl mixed valent complexes. However, in the present (Fc2PyrDI)M(N(TMS)2)2 complexes, ligand-ligand repulsions lock the rotational freedom so that rare-earth ionic radius-dependent geometric differences increasingly influence orbital overlap as the ionic radius falls. The Marcus-Hush coupling constant HAB trends as [2-Sc]+ > [2-Lu]+ > [2-Y]+.
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Affiliation(s)
- Cole Carter
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Yosi Kratish
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Tobin J Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
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3
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Park J, Son J. Cobalt‐Catalyzed C(sp2)–O Bond Formation by Directing Group Assisted C–H Activation. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200465] [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]
Affiliation(s)
- Jinhwan Park
- Dong-A University Chemical Engineering KOREA, REPUBLIC OF
| | - Jongwoo Son
- Dong-A University Chemistry 550beon-gil, Nakdong-daero 49315 Busan KOREA, REPUBLIC OF
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4
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Rupf SM, Dimitrova IS, Schröder G, Malischewski M. Preparation and One-Electron Oxidation of Decabromoferrocene. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Susanne M. Rupf
- Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
| | | | - Gabriel Schröder
- Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
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5
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Evans DM, Hughes DD, Murphy PJ, Horton PN, Coles SJ, de Biani FF, Corsini M, Butler IR. Synthetic Route to 1,1′,2,2′-Tetraiodoferrocene That Avoids Isomerization and the Electrochemistry of Some Tetrahaloferrocenes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel M. Evans
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, U.K
| | - David D. Hughes
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, U.K
| | - Patrick J. Murphy
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, U.K
| | - Peter N. Horton
- EPSRC National Crystallography Centre, University of Southampton, Southampton SO17 1BJ. U.K
| | - Simon J. Coles
- EPSRC National Crystallography Centre, University of Southampton, Southampton SO17 1BJ. U.K
| | - Fabrizia Fabrizi de Biani
- Dipartimento di Biotecnologie Chimica e Farmacia and C.I.R.C.M.S.B., Università di Siena Via Aldo Moro, 53100 Siena, Italy
| | - Maddalena Corsini
- Dipartimento di Biotecnologie Chimica e Farmacia and C.I.R.C.M.S.B., Università di Siena Via Aldo Moro, 53100 Siena, Italy
| | - Ian R. Butler
- Department of Electronic Engineering and Computer Science, Bangor University, Bangor, Gwynedd LL57 2DG, U.K
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6
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Metzelaars M, Schleicher S, Hattori T, Borca B, Matthes F, Sanz S, Bürgler DE, Rawson J, Schneider CM, Kögerler P. Cyclophane with eclipsed pyrene units enables construction of spin interfaces with chemical accuracy. Chem Sci 2021; 12:8430-8437. [PMID: 34221324 PMCID: PMC8221062 DOI: 10.1039/d1sc01036k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Advanced functionality in molecular electronics and spintronics is orchestrated by exact molecular arrangements at metal surfaces, but the strategies for constructing such arrangements remain limited. Here, we report the synthesis and surface hybridization of a cyclophane that comprises two pyrene groups fastened together by two ferrocene pillars. Crystallographic structure analysis revealed pyrene planes separated by ∼352 pm and stacked in an eclipsed geometry that approximates the rare configuration of AA-stacked bilayer graphene. We deposited this cyclophane onto surfaces of Cu(111) and Co(111) at submonolayer coverage and studied the resulting hybrid entities with scanning tunnelling microscopy (STM). We found distinct characteristics of this cyclophane on each metal surface: on non-magnetic Cu(111), physisorption occurred and the two pyrene groups remained electronically coupled to each other; on ferromagnetic Co(111) nanoislands, chemisorption occurred and the two pyrene groups became electronically decoupled. Spin-polarized STM measurements revealed that the ferrocene groups had spin polarization opposite to that of the surrounding Co metal, while the pyrene stack had no spin polarization. Comparisons to the non-stacked analogue comprising only one pyrene group bolster our interpretation of the cyclophane's STM features. The design strategy presented herein can be extended to realize versatile, three-dimensional platforms in single-molecule electronics and spintronics. A chemical strategy for the bottom-up construction of 3D spin interfaces is presented. Scanning tunnelling microscopy reveals distinct electronic features of a cyclophane with precisely designed pi-stacking on ferromagnetic Co(111) nanoislands.![]()
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Affiliation(s)
- Marvin Metzelaars
- Institute of Inorganic Chemistry, RWTH Aachen University 52074 Aachen Germany
| | | | - Takuma Hattori
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Bogdana Borca
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany .,National Institute of Materials Physics Atomistilor 405A, Magurele 077125 Ilfov Romania
| | - Frank Matthes
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Sergio Sanz
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Daniel E Bürgler
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Jeff Rawson
- Institute of Inorganic Chemistry, RWTH Aachen University 52074 Aachen Germany.,Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Claus M Schneider
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
| | - Paul Kögerler
- Institute of Inorganic Chemistry, RWTH Aachen University 52074 Aachen Germany.,Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich 52428 Jülich Germany
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7
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Schmiel S, Butenschön H. New π‐Extended 1,1′‐Disubstituted Ferrocenes with Thioate and Dithioate End Groups. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sinem‐Fatma Schmiel
- Institut für Organische Chemie Leibniz Universität Hannover Schneiderberg 1B 30167 Hannover Germany
| | - Holger Butenschön
- Institut für Organische Chemie Leibniz Universität Hannover Schneiderberg 1B 30167 Hannover Germany
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8
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Bennett TLR, Wilkinson LA, Lok JMA, O’Toole RCP, Long NJ. Synthesis, Electrochemistry, and Optical Properties of Highly Conjugated Alkynyl-Ferrocenes and -Biferrocenes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00098] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Troy L. R. Bennett
- Department of Chemistry, Imperial College London, MSRH, White City Campus, London W12 0BZ, U.K
| | - Luke A. Wilkinson
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Jasmine M. A. Lok
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | | | - Nicholas J. Long
- Department of Chemistry, Imperial College London, MSRH, White City Campus, London W12 0BZ, U.K
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9
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Klett J. Structural Motifs of Alkali Metal Superbases in Non-coordinating Solvents. Chemistry 2021; 27:888-904. [PMID: 33165981 PMCID: PMC7839563 DOI: 10.1002/chem.202002812] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/23/2020] [Indexed: 12/13/2022]
Abstract
Lochmann-Schlosser superbases (LSB) are a standard reagent in synthetic chemistry to achieve an exchange of a proton on an organic framework with an alkali metal cation, which in turn can be replaced by a wide range of electrophilic groups. In standard examples, the deprotonating reagent consists of an equimolar mixture of n-butyllithium and potassium t-butoxide. However, the nature of the reactive species could not be pinned down either for this composition or for similar mixtures with comparable high reactivity. Despite the poor solubility and the fierce reactivity, some insights into this mixture were achieved by some indirect results, comparison with chemically related systems, or skillful deductions. Recent results, mainly based on new soluble compounds, delivered structural evidence. These new insights lead to advanced and more detailed conclusions about the interplay of the involved components.
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Affiliation(s)
- Jan Klett
- Institut für Anorganische Chemie und Analytische ChemieJohannes Gutenberg-Universität MainzDuesbergweg 10–1455128MainzGermany
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10
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Butler IR, Beaumont M, Bruce MI, Zaitseva NN, Iggo JA, Robertson C, Horton PN, Coles SJ. Synthesis and Structures of 1,1′,2-Tribromoferrocene, 1,1′,2,2′-Tetrabromoferrocene, 1,1′,2,2′-Tetrabromoruthenocene: Expanding the Range of Precursors for the Metallocene Chemist’s Toolkit. Aust J Chem 2021. [DOI: 10.1071/ch19184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The synthesis, characterisation, and isolation of 1,1′,2-tribromoferrocene and 1,1′,2,2′-tetrabromoferrocene, which are key synthons in ferrocene chemistry, are described. These compounds are prepared using α-halide assisted lithiation. The crystal structures of 1,1′,2-tribromoferrocene, 1,1′,2,2′-tetrabromoferrocene, 1,1′-dibromoruthenocene, and 1,1′,2,2′-tetrabromoruthenocene have been determined and are reported together with a brief discussion of the intramolecular forces involved in the crystal structures.
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11
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Carter C, Kratish Y, Jurca T, Gao Y, Marks TJ. Bis-Ferrocenyl-Pyridinediimine Trinuclear Mixed-Valent Complexes with Metal-Binding Dependent Electronic Coupling: Synthesis, Structures, and Redox-Spectroscopic Characterization. J Am Chem Soc 2020; 142:18715-18729. [DOI: 10.1021/jacs.0c10015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Cole Carter
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Yosi Kratish
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Titel Jurca
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Yanshan Gao
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Tobin J. Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
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12
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Butler IR, Mehdar YTH, Al-Taie ZS. The self-indicating preparation of bromoferrocenes from stannylferrocenes and an improved synthesis of di-iodoferrocene. Heliyon 2020; 6:e04824. [PMID: 32954028 PMCID: PMC7486603 DOI: 10.1016/j.heliyon.2020.e04824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/01/2020] [Accepted: 08/26/2020] [Indexed: 11/26/2022] Open
Abstract
A simple method for the preparation of bromoferrocenes from stannylferrocenes is described: the preparation of 1,1′-dibromoferrocene is used as an example. Stannylferrocenes are reacted with bromine directly in dichloromethane to give bromoferrocenes in a self-indicating titration reaction. Also, an enhanced method of removal of the highly soluble organotin tin by-products formed in the preparation of 1,1′-diiodoferrocene from 1,1′-tri-n-butylstannylferrocene is reported allowing the preparation of large-scale quantities of 1,1′-diiodoferrocene, which is one of the most important starting materials in ferrocene chemistry.
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Affiliation(s)
- Ian R Butler
- Department of Electrical and Electronic Engineering, Bangor University, Bangor, Gwynedd, LL57 1UT, UK
| | - Yassin T H Mehdar
- Department of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Zahraa S Al-Taie
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
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13
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Gottwald D, Yuan Q, Speck M, Mahrholdt J, Korb M, Schreiter K, Spange S, Lang H. Synthesis and (spectro)electrochemistry of 1′,1′′′-disubstituted biferrocenes. J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2020.121447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Roemer M, Wild DA, Sobolev AN, Skelton BW, Nealon GL, Piggott MJ, Koutsantonis GA. Carbon-Rich Trinuclear Octamethylferrocenophanes. Inorg Chem 2019; 58:3789-3799. [DOI: 10.1021/acs.inorgchem.8b03389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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15
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Halogen and Hydrogen Bonding Interplay in the Crystal Packing of Halometallocenes. Molecules 2018; 23:molecules23112959. [PMID: 30428578 PMCID: PMC6278450 DOI: 10.3390/molecules23112959] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/30/2018] [Accepted: 11/08/2018] [Indexed: 11/17/2022] Open
Abstract
This paper focuses in the influence of halogen atoms in the design and structural control of the crystal packing of Group VIII halogenated metallocenes. The study is based on the present knowledge on new types of intermolecular contacts such as halogen (X⋯X, C-X⋯H, C-X⋯π), π⋯π, and C-H⋯π interactions. The presence of novel C-H⋯M interactions is also discussed. Crystal packings are analysed after database search on this family of compounds. Results are supported by ab initio calculations on electrostatic charge distributions; Hirshfeld analysis is also used to predict the types of contacts to be expected in the molecules. Special attention is given to the competition among hydrogen and halogen interactions, mainly its influence on the nature and geometric orientations of the different supramolecular motifs. Supramolecular arrangements of halogenated metallocenes and Group IV di-halogenated bent metallocenes are also compared and discussed. Analysis supports halogen bonds as the predominant interactions in defining the crystal packing of bromine and iodine 1,1′-halometallocenes.
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16
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Gadhachanda VR, Eastman KJ, Wang Q, Phadke AS, Patel D, Yang W, Marlor CW, Deshpande M, Huang M, Wiles JA. Ferrocene-based inhibitors of hepatitis C virus replication that target NS5A with low picomolar in vitro antiviral activity. Bioorg Med Chem Lett 2018; 28:3463-3471. [PMID: 30290989 DOI: 10.1016/j.bmcl.2018.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/13/2018] [Accepted: 09/17/2018] [Indexed: 01/23/2023]
Abstract
An unprecedented series of organometallic HCV (hepatitis C virus) NS5A (nonstructural 5A protein) replication complex inhibitors that incorporates a 1,1'-ferrocenediyl scaffold was explored. This scaffold introduces the elements of linear flexibility and non-planar topology that are unconventional for this class of inhibitors. Data from 2-D NMR spectroscopic analyses of these complexes in solution support an anti (unstacked) arrangement of the pharmacophoric groups. Several complexes demonstrate single-digit picomolar in vitro activity in an HCV genotype-1b replicon system. One complex to arise from this investigation (10a) exhibits exceptional picomolar activity against HCV genotype 1a and 1b replicons, low hepatocellular cytotoxicity, and good pharmacokinetic properties in rat.
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Affiliation(s)
- Venkat R Gadhachanda
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Kyle J Eastman
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Qiuping Wang
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Avinash S Phadke
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Dharaben Patel
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Wengang Yang
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Christopher W Marlor
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Milind Deshpande
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Mingjun Huang
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States
| | - Jason A Wiles
- Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, CT 06511, United States.
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17
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Roemer M, Donnadieu B, Nijhuis CA. Functionalized 1′-Substituted Iodoferrocenes and Their Pd-Catalyzed Heck Cross-Coupling Reactions. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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Inkpen MS, Du S, Hildebrand M, White AJP, Harrison NM, Albrecht T, Long NJ. The Unusual Redox Properties of Fluoroferrocenes Revealed through a Comprehensive Study of the Haloferrocenes. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00811] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael S. Inkpen
- Department
of Chemistry, Imperial College London, London, SW7 2AZ, U.K
| | - Shuoren Du
- Department
of Chemistry, Imperial College London, London, SW7 2AZ, U.K
- College
of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | | | | | | | - Tim Albrecht
- Department
of Chemistry, Imperial College London, London, SW7 2AZ, U.K
| | - Nicholas J. Long
- Department
of Chemistry, Imperial College London, London, SW7 2AZ, U.K
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19
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Zirakzadeh A, Herlein A, Groß MA, Mereiter K, Wang Y, Weissensteiner W. Halide-Mediated Ortho-Deprotonation Reactions Applied to the Synthesis of 1,2- and 1,3-Disubstituted Ferrocene Derivatives. Organometallics 2015; 34:3820-3832. [PMID: 26294806 PMCID: PMC4534838 DOI: 10.1021/acs.organomet.5b00464] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Indexed: 11/29/2022]
Abstract
![]()
The ortho-deprotonation
of halide-substituted
ferrocenes by treatment with lithium tetramethylpiperidide (LiTMP)
has been investigated. Iodo-, bromo-, and chloro-substituted ferrocenes
were easily deprotonated adjacent to the halide substituents. The
synthetic applicability of this reaction was, however, limited by
the fact that, depending on the temperature and the degree of halide
substitution, scrambling of both iodo and bromo substituents at the
ferrocene core took place. Iodoferrocenes could not be transformed
selectively into ortho-substituted iodoferrocenes
since, in the presence of LiTMP, the iodo substituents scrambled efficiently
even at −78 °C, and this process had occurred before electrophiles
had been added. Bromoferrocene and certain monobromo-substituted derivatives,
however, could be efficiently ortho-deprotonated
at low temperature and reacted with a number of electrophiles to afford
1,2- and 1,2,3-substituted ferrocene derivatives. For example, 2-bromo-1-iodoferrocene
was synthesized by ortho-deprotonation of bromoferrocene
and reaction with the electrophiles diiodoethane and diiodotetrafluoroethane,
respectively. In this and related cases the iodide scrambling process
and further product deprotonation due to the excess LiTMP could be
suppressed efficiently by running the reaction at low temperature
and in inverse mode. In contrast to the low-temperature process, at
room temperature bromo substituents in bromoferrocenes scrambled in
the presence of LiTMP. Chloro- and 1,2-dichloroferrocene could be ortho-deprotonated selectively, but in neither case was
scrambling of a chloro substituent observed. As a further application
of this ortho-deprotonation reaction, a route for
the synthesis of 1,3-disubstituted ferrocenes was developed. 1,3-Diiodoferrocene
was accessible from bromoferrocene in four steps. On a multigram scale
an overall yield of 41% was achieved. 1,3-Diiodoferrocene was further
transformed into symmetrically 1,3-disubstituted ferrocenes (1,3-R2Fc; R = CHO, COOEt, CN, CH=CH2).
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Affiliation(s)
- Afrooz Zirakzadeh
- Institute of Organic Chemistry, University of Vienna , Währinger Straße 38, A-1090 Vienna, Austria ; Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163, A-1060 Vienna, Austria
| | - Alexander Herlein
- Institute of Organic Chemistry, University of Vienna , Währinger Straße 38, A-1090 Vienna, Austria
| | - Manuela A Groß
- Institute of Organic Chemistry, University of Vienna , Währinger Straße 38, A-1090 Vienna, Austria ; Department of Chemistry, University of Cambridge , Lensfield Road, CB2 1EW Cambridge, U.K
| | - Kurt Mereiter
- Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9/164, A-1060 Vienna, Austria
| | - Yaping Wang
- College of Pharmaceutical Sciences, Capital Medical University, Beijing , No. 10 Xitoutiao, You An Men Beijing 100069, People's Republic of China
| | - Walter Weissensteiner
- Institute of Organic Chemistry, University of Vienna , Währinger Straße 38, A-1090 Vienna, Austria
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