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Mlostoń G, Urbaniak K, Palusiak M, Witczak ZJ, Würthwein EU. (3+2)-Cycloadditions of Levoglucosenone (LGO) with Fluorinated Nitrile Imines Derived from Trifluoroacetonitrile: An Experimental and Computational Study. Molecules 2023; 28:7348. [PMID: 37959767 PMCID: PMC10647924 DOI: 10.3390/molecules28217348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
The in situ-generated N-aryl nitrile imines derived from trifluoroacetonitrile smoothly undergo (3+2)-cycloadditions onto the enone fragment of the levoglucosenone molecule, yielding the corresponding, five-membered cycloadducts. In contrast to the 'classic' C(Ph),N(Ph) nitrile imine, reactions with fluorinated C(CF3),N(Ar) analogues lead to stable pyrazolines in a chemo- and stereoselective manner. Based on the result of X-ray single crystal diffraction analysis, their structures were established as exo-cycloadducts with the location of the N-Ar terminus of the 1,3-dipole at the α-position of the enone moiety. The DFT computation demonstrated that the observed reaction pathway results from the strong dominance of kinetic control over thermodynamic control.
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Affiliation(s)
- Grzegorz Mlostoń
- Department of Organic & Applied Chemistry, Faculty of Chemistry, University of Lodz, Tamka 12, PL-91-403 Lodz, Poland;
| | - Katarzyna Urbaniak
- Department of Organic & Applied Chemistry, Faculty of Chemistry, University of Lodz, Tamka 12, PL-91-403 Lodz, Poland;
| | - Marcin Palusiak
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163/165, PL-90-236 Lodz, Poland;
| | - Zbigniew J. Witczak
- Department of Pharmaceutical Sciences, Nesbitt School of Pharmacy, Wilkes University, 84 W. South Street, Wilkes-Barre, PA 18766, USA;
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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2
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Winge T, Schepmann D, Schmidt J, Daniliuc C, Würthwein EU, Wünsch B. Diastereoselective synthesis and structure-affinity relationships of σ1 receptor ligands with spirocyclic scaffold. Org Biomol Chem 2023; 21:7730-7752. [PMID: 37691601 DOI: 10.1039/d3ob01169k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Spirocyclic scaffolds play an increasing role in drug discovery as they define a rigid three-dimensional space to increase specific interactions with protein binding sites. Herein, a spirocyclic center was introduced into the lead compound 1 to rigidify its flexible benzylaminoethyl side chain. The key step of the synthesis was the reaction of different α,β-unsaturated amides 6 and 13-16 with methyl acrylate in the presence of TBDMSOTf. DFT calculations explain the mechanism of this transformation as concerted Diels-Alder reaction (functionals B3LYP and TPSS) or double (aza)-Michael addition (functionals PBE and wB97X-D). After separation of the diastereomeric spirocyclic products 8 and 17-20, LiAlH4 reduction provided the spirocyclic hydroxymethyl piperidines 21a,b-25a,b showing low nanomolar σ1 affinity (Ki < 100 nM). trans-Configured ligands (a-series) showed higher or equal σ1 affinity and higher selectivity over σ2 receptors and GluN2B-NMDA receptors than their cis-configured analogs (b-series). The additional hydroxymethyl moiety brings the log D7.4 value in a promising range. The high σ1 affinity (Ki = 3.6 nM) and the low lipophilicity result in the highest lipophilic ligand efficiency for the dispiro compound 23a (LLE = 6.0). The spirocyclic compounds reported herein and in particular the dispiro compound 23a demonstrate that ligands containing a large number of sp3 C-atoms possess favorable pharmacological (σ1 receptor affinity, receptor selectivity) and physicochemical properties (log D7.4 value) resulting in promising LLE.
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Affiliation(s)
- Tobias Winge
- Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, D-48149 Münster, Germany.
| | - Dirk Schepmann
- Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, D-48149 Münster, Germany.
| | - Judith Schmidt
- Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, D-48149 Münster, Germany.
| | - Constantin Daniliuc
- Universität Münster, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Corrensstraße 40, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Universität Münster, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Corrensstraße 40, D-48149 Münster, Germany
| | - Bernhard Wünsch
- Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, D-48149 Münster, Germany.
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3
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Kurzawa T, Zimmer R, Würthwein EU, Reissig HU. The Boekelheide Rearrangement of Pyrimidine N-oxides as a Case Study of Closed or Open Shell Reactions - Experimental and Computational Evidence for the Participation of Radical Intermediates. Chemistry 2023; 29:e202204015. [PMID: 36780139 DOI: 10.1002/chem.202204015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/14/2023]
Abstract
In a case study, the acetic anhydride-promoted reaction of a model pyrimidine N-oxide to the corresponding 4-acetoxymethyl-substituted pyrimidine derivative (Boekelheide rearrangement) was investigated in detail by experiment and quantum chemical calculations. The reaction conditions were varied and several side products formed in low to moderate yields were identified. These experiments indicate that a (pyrimidin-4-yl)methyl radical is one of the key species of the rearrangement. This interpretation was supported by the fact that rearrangements performed in solvents which can easily lose hydrogen atoms, afford considerable quantities of products incorporating the solvent. With TEMPO the key radical could be trapped. Other carboxylic acid anhydrides confirm the conclusion that the Boekelheide rearrangement of the model pyrimidine N-oxide proceeds, at least in part, via radical intermediates. The high level closed and open shell quantum chemical calculations show that concerted [3,3]-sigmatropic rearrangements or stepwise processes, either via ion pairs or via radicals, are energetically feasible.
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Affiliation(s)
- Timon Kurzawa
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195, Berlin, Germany
| | - Reinhold Zimmer
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195, Berlin, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and, Center for Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Hans-Ulrich Reissig
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195, Berlin, Germany
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4
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Steinert K, Berg N, Kalinin DV, Jagels A, Würthwein EU, Humpf HU, Kalinina S. Semisynthetic Approach toward Biologically Active Derivatives of Phenylspirodrimanes from S. chartarum. ACS Omega 2022; 7:45215-45230. [PMID: 36530258 PMCID: PMC9753195 DOI: 10.1021/acsomega.2c05681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
The phenylspirodrimanes (PSDs) from Stachybotrys chartarum represent a structurally diverse group of meroterpenoids, which, on the one hand, exhibit a structural exclusivity since their occurrence is not known for any other species and, on the other hand, offer access to chemically and biologically active compounds. In this study, phenylspirodrimanes 1-3 were isolated from S. chartarum and their water-mediated Cannizzaro-type transformation was investigated using quantum chemical DFT calculations substantiated by LC-MS and NMR experiments. Considering the inhibitory activity of PSDs against proteolytic enzymes and their modulatory effect on plasminogen, PSDs 1-3 were used as a starting material for the synthesis of their corresponding biologically active lactams. To access the library of the PSD derivatives and screen them against physiologically relevant serine proteases, a microscale semisynthetic approach was developed. This allowed us to generate the library of 35 lactams, some of which showed the inhibitory activity against physiologically relevant serine proteases such as thrombin, FXIIa, FXa, and trypsin. Among them, the agmatine-derived lactam 16 showed the highest inhibitory activity against plasma coagulation factors and demonstrated the anticoagulant activity in two plasma coagulation tests. The semisynthetic lactams were significantly less toxic compared to their parental natural PSDs.
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Affiliation(s)
- Katharina Steinert
- Institut
für Lebensmittelchemie, Westfälische
Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Nina Berg
- Institut
für Lebensmittelchemie, Westfälische
Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Dmitrii V. Kalinin
- Institut
für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Annika Jagels
- The
Whitney Laboratory for Marine Bioscience, Department of Chemistry, University of Florida, St. Augustine, Florida 32080, United States
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches
Institut and Center for Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Hans-Ulrich Humpf
- Institut
für Lebensmittelchemie, Westfälische
Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Svetlana Kalinina
- Institut
für Lebensmittelchemie, Westfälische
Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
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5
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Lünne F, Köhler J, Stroh C, Müller L, Daniliuc CG, Mück-Lichtenfeld C, Würthwein EU, Esselen M, Humpf HU, Kalinina SA. Insights into Ergochromes of the Plant Pathogen Claviceps purpurea. J Nat Prod 2021; 84:2630-2643. [PMID: 34553942 DOI: 10.1021/acs.jnatprod.1c00264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Claviceps purpurea is an ergot fungus known for its neurotropic alkaloids, which have been identified as the main cause of ergotism, a livestock and human disease triggered by ergot consumption. Tetrahydroxanthone dimers, the so-called ergopigments, presumably also contribute to this toxic effect. Overexpression of the cluster-specific transcription factor responsible for the formation of these pigments in C. purpurea led to the isolation of three new metabolites (8-10). The new pigments were characterized utilizing HRMS, NMR techniques, and CD spectroscopy and shown to be xanthone dimers. Secalonic acid A and its 2,4'- and 4,4'-linked isomers were also isolated, and their absolute configuration was investigated. The contribution of secalonic acid A, its isomers, and new metabolites to the toxicity of C. purpurea was investigated in HepG2 and CCF-STTG1 cells. Along with cytotoxic properties, secalonic acid A was found to inhibit topoisomerase I and II activity.
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Affiliation(s)
- Friederike Lünne
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Jens Köhler
- Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, 48149 Münster, Germany
| | - Christina Stroh
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Lena Müller
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Constantin G Daniliuc
- Organisch-chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Melanie Esselen
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Hans-Ulrich Humpf
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
| | - Svetlana A Kalinina
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 45, 48149 Münster, Germany
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6
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Mlostoń G, Urbaniak K, Sobiecka M, Heimgartner H, Würthwein EU, Zimmer R, Lentz D, Reissig HU. Hetero-Diels-Alder Reactions of In Situ-Generated Azoalkenes with Thioketones; Experimental and Theoretical Studies. Molecules 2021; 26:2544. [PMID: 33925483 PMCID: PMC8123831 DOI: 10.3390/molecules26092544] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 11/18/2022] Open
Abstract
The hetero-Diels-Alder reactions of in situ-generated azoalkenes with thioketones were shown to offer a straightforward method for an efficient and regioselective synthesis of scarcely known N-substituted 1,3,4-thiadiazine derivatives. The scope of the method was fairly broad, allowing the use of a series of aryl-, ferrocenyl-, and alkyl-substituted thioketones. However, in the case of N-tosyl-substituted cycloadducts derived from 1-thioxo-2,2,4,4-tetramethylcyclobutan-3-one and the structurally analogous 1,3-dithione, a more complicated pathway was observed. By elimination of toluene sulfinic acid, the initially formed cycloadducts afforded 2H-1,3,4-thiadiazines as final products. Advanced DFT calculations revealed that the observed high regioselectivity was due to kinetic reaction control and that the (4 + 2)-cycloadditions of sterically less unhindered thiones occurred via highly unsymmetric transition states with shorter C..S-distances (2.27-2.58 Å) and longer N..C-distances (3.02-3.57 Å). In the extreme case of the sterically very hindered 2,2,4,4-tetramethylcyclobutan-1,3-dione-derived thioketones, a zwitterionic intermediate with a fully formed C‒S bond was detected, which underwent ring closure to the 1,3,4-thiadiazine derivative in a second step. For the hypothetical formation of the regioisomeric 1,2,3-thiadiazine derivatives, the DFT calculations proposed more symmetric transition states with considerably higher energies.
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Affiliation(s)
- Grzegorz Mlostoń
- Department of Organic and Applied Chemistry, Faculty of Chemistry, University of Lodz, 12 Tamka Street, 91-403 Lodz, Poland; (K.U.); (M.S.)
| | - Katarzyna Urbaniak
- Department of Organic and Applied Chemistry, Faculty of Chemistry, University of Lodz, 12 Tamka Street, 91-403 Lodz, Poland; (K.U.); (M.S.)
| | - Malwina Sobiecka
- Department of Organic and Applied Chemistry, Faculty of Chemistry, University of Lodz, 12 Tamka Street, 91-403 Lodz, Poland; (K.U.); (M.S.)
| | - Heinz Heimgartner
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland;
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
| | - Reinhold Zimmer
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany; (R.Z.); (D.L.)
| | - Dieter Lentz
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany; (R.Z.); (D.L.)
| | - Hans-Ulrich Reissig
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany; (R.Z.); (D.L.)
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7
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Tendyck JC, Klöcker H, Schürmann L, Würthwein EU, Hepp A, Layh M, Uhl W. Aspects of Phosphaallene Chemistry: Heat-Induced Formation of 1,2-Dihydrophosphetes by Intramolecular Nucleophilic Aromatic Substitution and Photochemical Generation of Tricyclic Phosphiranes. J Org Chem 2020; 85:14315-14332. [PMID: 32022561 DOI: 10.1021/acs.joc.9b03056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
3H-Phosphaallenes are accessible on a new and facile route and show a fascinating chemical behavior. The thermally induced rearrangement of Mes*P═C═C(H)R' (R' = tBu, Ad) afforded by C-H activation, isobutene elimination, and C-C and P-H bond formation bicyclic 1-benzo-dihydrophosphetes (2) with PC3 heterocycles. DFT calculations suggest a mechanism with intramolecular nucleophilic aromatic substitution and replacement of an alkyl group by the nucleophilic α-C atom of the phosphaallene. These bicycles formed W(CO)5 complexes (3) or afforded 1,2-dihydrophosphetes with P-bound alkenyl groups by catalyst-free hydrophosphination of alkynes (4 and 5). The resulting bulky phosphines formed complexes with IrCp*Cl2, RuCl2, AuCl, or CuO3SCF3. The Ru atom is coordinated by the P atom and a phenyl group. Irradiation of TripP═C═C(H)tBu led by the insertion of the central C atom of the P═C═C group into the α-C-H bond of an iPr substituent and by C-C and P-C bond formation to a new isomer of phosphaallenes, 10, which features a strained PC2 heterocycle. It formed adducts with M(CO)5 (M = Cr, Mo, W) and AuCl and reacted with SO2Cl2 by cleavage of one of the phosphirane P-C bonds to yield PC4 or PC5 heterocycles. Hydrolysis yielded a PC5 compound with a P(O)Cl group.
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Affiliation(s)
- Jonas C Tendyck
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Hans Klöcker
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Lina Schürmann
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
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8
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Mallick S, Würthwein EU, Studer A. Synthesis of Alkyl Silanes via Reaction of Unactivated Alkyl Chlorides and Triflates with Silyl Lithium Reagents. Org Lett 2020; 22:6568-6572. [PMID: 32806169 DOI: 10.1021/acs.orglett.0c02337] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The reaction of unactivated secondary and primary alkyl chlorides as well as primary alkyl triflates with silyl lithium reagents to access tetraorganosilanes is reported. These nucleophilic substitutions proceed in the absence of any transition metal catalyst under mild conditions in moderate to very good yields. The silyl lithium reagents are readily generated from the corresponding commercially available chlorosilanes. Enantioenriched secondary alkyl chlorides react with high stereospecificity under inversion of configuration.
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Affiliation(s)
- Shubhadip Mallick
- Institute of Organic Chemistry, Westfälische Wilhelms University, Corrensstraße 40, 48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Institute of Organic Chemistry, Westfälische Wilhelms University, Corrensstraße 40, 48149 Münster, Germany
| | - Armido Studer
- Institute of Organic Chemistry, Westfälische Wilhelms University, Corrensstraße 40, 48149 Münster, Germany
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9
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Brand A, Hepp A, Würthwein EU, Uhl W. Tridentate Ligand with Three Carbanions as Donor Atoms: Formation of Dinuclear, Heptacyclic Complexes of Boron, Aluminum, or Gallium with B–C–B, Al–C–Al, or Ga–C–Ga Three-Center–Two-Electron Bonds. Inorg Chem 2020; 59:5558-5563. [DOI: 10.1021/acs.inorgchem.0c00254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander Brand
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Universität Münster, Corrensstraße 40, D-48149 Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
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10
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Pleschka D, Uebing M, Lange M, Hepp A, Wübker AL, Hansen MR, Würthwein EU, Uhl W. Al/P- and Ga/P-Based Frustrated Lewis Pairs and Electronically Unsaturated Substrates: Ring Cleavage and Ring Closure, C-C and C-N Bond Formation. Chemistry 2019; 25:9315-9325. [PMID: 31081975 DOI: 10.1002/chem.201901659] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Indexed: 12/20/2022]
Abstract
Al/P- and Ga/P-based frustrated Lewis pairs (FLPs) reacted with an azirine under mild conditions under cleavage of the heterocycle on two different positions. Opening of the C-C bond yielded an unusual nitrile-ylide adduct in which a C-N moiety coordinated to the FLP backbone. Cleavage of a C-N bond afforded the thermodynamically favored enamine adduct with the N atom bound to P and Al or Ga atoms. Ring closure was observed upon treatment of an Al/P FLP with electronically unsaturated substrates (4-(1-cyclohexenyl)-1-aza-but-1-en-3-ynes) and yielded by C-N bond formation hexahydroquinoline derivatives, which coordinated to the FLP through P-C and Al-C bonds. Diphenylcyclopropenone showed a diverse reactivity, which depending on steric shielding and the polarizing effect of Al or Ga atoms afforded different products. An AltBu2 /P FLP yielded an adduct with the C=O group coordinated to P and Al. The dineopentyl derivative gave an equilibrium mixture consisting of a similar product and a simple adduct with O bound to Al and a three-coordinate P atom. Both compounds co-crystallize. The Ga/P FLP only formed the simple adduct with the same substrate. Rearrangement resulted in all cases in C3 -ring cleavage and migration of a mesityl group from P to a former ring C atom by C-C bond formation. Diphenylthiocyclopropenone (evidence for the presence of P=C bonds) and an imine derivative afforded similar products.
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Affiliation(s)
- Damian Pleschka
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Marten Uebing
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Merten Lange
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Anna-Lena Wübker
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Michael Ryan Hansen
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and Center for Multiscale Theory, and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
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11
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Mallick S, Xu P, Würthwein EU, Studer A. Silyldefluorination of Fluoroarenes by Concerted Nucleophilic Aromatic Substitution. Angew Chem Int Ed Engl 2018; 58:283-287. [DOI: 10.1002/anie.201808646] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/10/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Shubhadip Mallick
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC); Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Pan Xu
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC); Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC); Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation (CMTC); Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
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12
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Lange M, Tendyck JC, Wegener P, Hepp A, Würthwein EU, Uhl W. Reactions of an Aluminium/Phosphorus Frustrated Lewis Pair (FLP) with α,β-Unsaturated Carbonyl Compounds: FLPs as Efficient Two-Electron Reductants with the Formation of Enolates, a cis-Enediolate, and an Allene. Chemistry 2018; 24:12856-12868. [PMID: 29337388 DOI: 10.1002/chem.201706089] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Indexed: 01/14/2023]
Abstract
The Al/P-based frustrated Lewis pair (FLP) Mes2 P-C(AltBu)2 =C(H)Ph (1; Mes=mesityl) reacted as an efficient two-electron reductant with benzil to afford a cis-enediolate that was coordinated to the FLP through P-O and Al-O bonds and the formation of a seven-membered heterocycle (2). The phosphorus atom is oxidised from +III to +V. Similar heterocycles (3 a to 3 f) were formed if 1 was treated with various enones (acrolein, acrylate, acrylamide). The resulting enolates are bound to the FLP through P-C and Al-O bonds. Cyclopropenone gave an adduct (4) with the C=O bond coordinated by P and Al. Ynones gave a fascinating variety of different structures. 1,3-Diphenylprop-2-yn-1-one afforded a remarkable allene-type moiety with two cumulated C=C bonds (5); 3-hexyn-2-one yielded a ligand with two conjugated C=C bonds by C-H bond activation at the carbonyl methyl group (7); and 4-(trimethylsilyl)-3-butyn-2-one reacted by C-H bond cleavage, formation of an enolate group with a terminal C=C bond, and shift of the proton to the P atom (8). The C≡C bond was not affected. Allene compound 5 rearranged at elevated temperature and in daylight through the formation of a tricyclic compound by C-H bond activation and C-C bond formation. DFT calculations on this unusual rearrangement suggest insertion of the central allene C atom into the C-H bond of a methyl group and the intermediate formation of a C3 ring.
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Affiliation(s)
- Merten Lange
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Jonas C Tendyck
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Philipp Wegener
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut and Center for, Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
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13
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Keweloh L, Aders N, Hepp A, Pleschka D, Würthwein EU, Uhl W. A P-H functionalized Al/P-based frustrated Lewis pair - hydrophosphination of nitriles, ring opening with cyclopropenones and evidence of P[double bond, length as m-dash]C double bond formation. Dalton Trans 2018; 47:8402-8417. [PMID: 29893387 DOI: 10.1039/c8dt01836g] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Hydroalumination of R-P(H)-C[triple bond, length as m-dash]C-tBu with bulky H-Al[CH(SiMe3)2]2 afforded the new P-H functionalized Al/P-based frustrated Lewis pair R-P(H)-C[[double bond, length as m-dash]C(H)-tBu]-AlR2 [R = CH(SiMe3)2; FLP 7]. A weak adduct of 7 with benzonitrile (8) was detected by NMR spectroscopy, but could not be isolated. tert-Butyl isocyanide afforded a similar, but isolable adduct (9), in which the isocyanide C atom was coordinated to aluminium. The unique reactivity of 7 became evident from its reactions with the heteroatom substituted nitriles PhO-C[triple bond, length as m-dash]N, PhCH2S-C[triple bond, length as m-dash]N and H8C4N-C[triple bond, length as m-dash]N. Hydrophosphination of the C[triple bond, length as m-dash]N triple bonds afforded imines at room temperature which were coordinated to the FLP by Al-N and P-C bonds to yield AlCPCN heterocycles (10 to 12). These processes depend on substrate activation by the FLP. Diphenylcyclopropenone and its sulphur derivative reacted with 7 by addition of the P-H bond to a C-C bond of the strained C3 ring and ring opening to afford the fragment (Z)-Ph-C(H)[double bond, length as m-dash]C(Ph)-C-X-Al (X = O, S). The C-O or C-S groups were coordinated to the FLP to yield AlCPCX heterocycles (13 and 14). The thiocarbonyl derived compound 14 contains an internally stabilized phosphenium cation with a localized P[double bond, length as m-dash]C bond, a trigonal planar coordinated P atom and a short P[double bond, length as m-dash]C distance (168.9 pm). Insight into formation mechanisms, the structural and energetic properties of FLP 7 and compounds 13 and 14 was gained by quantum chemical DFT calculations.
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Affiliation(s)
- Lukas Keweloh
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany.
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14
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Dahlkamp JM, Tolzmann M, Lucchesi R, Daniliuc CG, Wibbeling B, Uhl W, Würthwein EU. Chemoselective Hydroalumination of 1-Aza-but-1-en-3-ynes ( C-Iminoalkynes): Formation of Propargylamines by Imine Reduction and of 5-Aluminazoles and 1-Aza-butadienes by Anti-Michael Attack. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- J. Matthias Dahlkamp
- Organisch Chemisches Institut der Universität Münster and Center for Multiscale Theory and Computation (CMTC), Corrensstrasse 40, D-48149 Münster, Germany
| | - Michael Tolzmann
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Ralph Lucchesi
- Organisch Chemisches Institut der Universität Münster and Center for Multiscale Theory and Computation (CMTC), Corrensstrasse 40, D-48149 Münster, Germany
| | - Constantin-Gabriel Daniliuc
- Organisch Chemisches Institut der Universität Münster and Center for Multiscale Theory and Computation (CMTC), Corrensstrasse 40, D-48149 Münster, Germany
| | - Birgit Wibbeling
- Organisch Chemisches Institut der Universität Münster and Center for Multiscale Theory and Computation (CMTC), Corrensstrasse 40, D-48149 Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch Chemisches Institut der Universität Münster and Center for Multiscale Theory and Computation (CMTC), Corrensstrasse 40, D-48149 Münster, Germany
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15
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Affiliation(s)
- Paul Bunse
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster; Corrensstraße 48 48149 Münster Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut der Westfälischen Wilhelms-Universität Münster and Center for Multiscale Theory and Computation (CMTC); Corrensstraße 40 48149 Münster Germany
| | - Bernhard Wünsch
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster; Corrensstraße 48 48149 Münster Germany
- Cells-in-Motion Cluster of Excellence (EXC; Westfälische Wilhelms-Universität Münster; 1003 - CiM) Münster Germany
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16
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Xu P, Würthwein EU, Daniliuc CG, Studer A. Transition-Metal-Free Ring-Opening Silylation of Indoles and Benzofurans with (Diphenyl-tert-butylsilyl)lithium. Angew Chem Int Ed Engl 2017; 56:13872-13875. [PMID: 28885762 DOI: 10.1002/anie.201707309] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/25/2017] [Indexed: 11/09/2022]
Abstract
A practical method is presented for ring opening various indoles and benzofurans with concomitant stereoselective silylation using readily generated (diphenyl-tert-butylsilyl)lithium to afford ortho-β-silylvinylanilines or -phenols. Dearomatization of the heteroarene core proceeds in the absence of any transition-metal catalyst through addition of a silyl anion and a subsequent stereoselective β-elimination. DFT calculations provide insight into the mechanism. Functionalizing C-X bond cleavage of heteroarenes is rare and generally requires transition-metal catalysts.
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Affiliation(s)
- Pan Xu
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149, Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149, Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149, Münster, Germany
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17
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Hokamp T, Dewanji A, Lübbesmeyer M, Mück-Lichtenfeld C, Würthwein EU, Studer A. Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane. Angew Chem Int Ed Engl 2017; 56:13275-13278. [PMID: 28841248 PMCID: PMC5698765 DOI: 10.1002/anie.201706534] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Indexed: 11/24/2022]
Abstract
A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4‐dioxane as reagents and 1,10‐phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
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Affiliation(s)
- Tobias Hokamp
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Abhishek Dewanji
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
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18
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Hokamp T, Dewanji A, Lübbesmeyer M, Mück-Lichtenfeld C, Würthwein EU, Studer A. Radikalische Hydrodehalogenierung von Arylbromiden und -chloriden mit Natriumhydrid und 1,4-Dioxan. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tobias Hokamp
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Abhishek Dewanji
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Armido Studer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
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19
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Martinewski K, Holtrichter-Rößmann T, Rösener C, Hepp A, Würthwein EU, Uhl W. Cooperative Activation of Isocyanates by Al-N-Based Active Lewis Pairs and the Generation of a C 5 Chain by Simultaneous Formation of Two C-C Bonds. Chemistry 2017; 23:6129-6141. [PMID: 28079943 DOI: 10.1002/chem.201604630] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Indexed: 11/08/2022]
Abstract
The active Al/N Lewis pair, (Me3 C)2 Al-C(SiMe3 )=C(H)-N(CHMe-CH2 )2 CH2 (2), reacted with isocyanates to afford a fascinating variety of products. One equivalent of Ph-N=C=O yielded by the release of H-C≡C-SiMe3 an urea-type ligand which coordinated the Al atom in a chelating manner (4). Dipp-N=C=O gave a similar product, but the bulky substituent hindered the approach of the N-aryl group to Al. A situation similar to that of frustrated Lewis pairs resulted in the coordination of the alkyne to the Al and N atoms (6) by C-H bond activation. Dual insertion was observed upon treatment of 2 with two equivalents of isocyanates (8 to 11). The preferred formation of cyclic oligomers is prevented by the specific cooperative properties of the Lewis pair. A metal-free dimeric isocyanate (13) was formed by hydrolysis. Replacement of the CMe3 groups in 2 by less bulky isobutyl groups (7) afforded the insertion of two isocyanate molecules into the Al-vinyl bonds without alkyne elimination. The resulting highly functionalised compound had a chain formed by two isocyanates and the organic backbone of the Lewis pair. Me3 C-N=C=O and 2 afforded a unique compound (14) in which an isocyanate ligand connects two molecules of 2 by the release of dimethylpiperidine. The combination of a C1 building block and two C2 groups gave an unsaturated branched C5 moiety by the simultaneous formation of two C-C bonds. The molecular structure showed an interaction between an Al atom and a C-C π-bond.
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Affiliation(s)
- Katharina Martinewski
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Thorsten Holtrichter-Rößmann
- Organisch-chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Christian Rösener
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut and Center for Multiscale Theory and Computation (CMTC), Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany
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20
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Abstract
The kinetics of the reactions of the vinyl cations 2 [Ph2C═C+-(4-MeO-C6H4)] and 3 [Me2C═C+-(4-MeO-C6H4)] (generated by laser flash photolysis) with diverse nucleophiles (e.g., pyrroles, halide ions, and solvents containing variable amounts of water or alcohol) have been determined photometrically. It was found that the reactivity order of the nucleophiles toward these vinyl cations is the same as that toward diarylcarbenium ions (benzhydrylium ions). However, the reaction rates of vinyl cations are affected only half as much by variation of the nucleophiles as those of the benzhydrylium ions. For that reason, the relative reactivities of vinyl cations and benzhydrylium ions depend strongly on the nature of the nucleophiles. It is shown that vinyl cations 2 and 3 react, respectively, 227 and 14 times more slowly with trifluoroethanol than the parent benzhydrylium ion (Ph)2CH+, even though in solvolysis reactions (80% aqueous ethanol at 25 °C) the vinyl bromides leading to 2 and 3 ionize much more slowly (half-lives 1.15 yrs and 33 days) than (Ph)2CH-Br (half-life 23 s). The origin of this counterintuitive phenomenon was investigated by high-level MO calculations. We report that vinyl cations are not exceptionally high energy intermediates, and that high intrinsic barriers for the sp2 ⇌ sp rehybridizations account for the general phenomenon that vinyl cations are formed slowly by solvolytic cleavage of vinyl derivatives, and are also consumed slowly by reactions with nucleophiles.
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Affiliation(s)
- Peter A Byrne
- Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, 81377 München, Germany
| | - Shinjiro Kobayashi
- Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, 81377 München, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität , 48149 Münster, Germany
| | - Johannes Ammer
- Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, 81377 München, Germany
| | - Herbert Mayr
- Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, 81377 München, Germany
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21
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Uhl W, Wegener P, Layh M, Hepp A, Würthwein EU. Reaction of an Al/P-based frustrated Lewis pair with benzophenone: formation of adducts and aluminium alcoholates via β-hydride elimination. Zeitschrift für Naturforschung B 2016. [DOI: 10.1515/znb-2016-0118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Abstract
Treatment of the Al/P-based frustrated Lewis pair (FLP) Mes2P–C(Al
t
Bu2)=C(H)-Ph (1) with benzophenone afforded the simple 1:1 adduct (4) with a O=CPh2 molecule coordinated to the aluminum atom by an Al←O donor-acceptor bond. Steric repulsion may prevent an interaction between the electrophilic carbonyl carbon atom and the Lewis-basic phosphorus atom. 4 is unstable in solution at room temperature, the coordination to aluminium increases the polarisation of the carbonyl group and favours its reduction. As suggested by quantum chemical calculations, a C–H bond of a
t
Bu group approaches the electrophilic center and facilitates β-hydride elimination with the release of isobutene and the formation of an Al–OCHPh2 ligation. An intact O=CPh2 molecule completes the coordination sphere of the metal atom (5). The second
t
Bu group at aluminium reacts similarly by the selective formation of an Al(OCHPh2)2 moiety (6). The thermodynamics of adduct formation and the mechanism of the hydride shift have been evaluated by quantum chemical DFT calculations.
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Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Philipp Wegener
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut der Universität Münster, Corrensstraße 40, 48149 Münster, Germany
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22
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Holtrichter-Rößmann T, Häger I, Daniliuc CG, Fröhlich R, Bergander K, Troll C, Rieger B, Rojas RS, Würthwein EU. Catalytically Active N-Acylamidine–Zirconium Complexes: Synthesis, Structures, and Application in Ethylene Polymerization. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thorsten Holtrichter-Rößmann
- Organisch-Chemisches
Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
- Chemtura Organometallics GmbH, Ernst Schering Straße 14, D-59192 Bergkamen, Germany
| | - Ina Häger
- Organisch-Chemisches
Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | | | - Roland Fröhlich
- Organisch-Chemisches
Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Klaus Bergander
- Organisch-Chemisches
Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Carsten Troll
- WACKER-Lehrstuhl
für Makromolekulare Chemie, Technische Universität München, Lichtenbergstraße 4, D-85747 Garching, Germany
| | - Bernhard Rieger
- WACKER-Lehrstuhl
für Makromolekulare Chemie, Technische Universität München, Lichtenbergstraße 4, D-85747 Garching, Germany
| | - René S. Rojas
- Departamento
de Química Inorgánica, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago-22, Chile
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches
Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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23
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Wrobel AJ, Lucchesi R, Wibbeling B, Daniliuc CG, Fröhlich R, Würthwein EU. 1,3,5-Triazapentadienes by Nucleophilic Addition to 1,3- and 1,4-Dinitriles-Sterically Constrained Examples by Incorporation into Cyclic Peripheries: Synthesis, Aggregation, and Photophysical Properties. J Org Chem 2016; 81:2849-63. [PMID: 26987891 DOI: 10.1021/acs.joc.6b00126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1,3,5-Triazapentadienes usually show U- or twisted S-shaped conformations along the N-C-N-C-N skeleton due to dominating n/π* interactions. If, however, the 1,3,5-triazapentadiene unit is part of a ring, its W conformation might be restricted to the plane. Here, we describe the synthesis of 13 new 1,3,5-triazapentadienes 10-12, which are sterically restrained by incorporation into six- or seven-membered ring systems, by addition of a lithiated primary amine or hydrazine 5 to a dinitrile 7, 8, or 9 with the two cyano groups in 1,3 or 1,4 distance. These novel compounds show very strong tendency for aggregation due to hydrogen bonding, especially to form homodimers as seen from X-ray data in the solid state. Additional hydrogen bonding generates also linear chains in the crystal. Several of the new compounds show fluorescence in solution. Quantum chemical DFT calculations were used for evaluation of the dimerization energies and for interpretation of the photophysical properties.
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Affiliation(s)
- Agnes Johanna Wrobel
- Organisch-Chemisches Institut der Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | - Ralph Lucchesi
- Organisch-Chemisches Institut der Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | - Birgit Wibbeling
- Organisch-Chemisches Institut der Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | | | - Roland Fröhlich
- Organisch-Chemisches Institut der Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut der Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
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24
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Keweloh L, Klöcker MSH, Würthwein EU, Uhl W. Ein P-H-funktionalisiertes Al/P-basiertes frustriertes Lewis-Paar: Substrataktivierung und selektiver Wasserstofftransfer. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511048] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lukas Keweloh
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstraße 30 48149 Münster Deutschland
| | - M Sc. Hans Klöcker
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstraße 30 48149 Münster Deutschland
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität Münster; Corrensstraße 40 48149 Münster Deutschland
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstraße 30 48149 Münster Deutschland
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25
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Keweloh L, Klöcker H, Würthwein EU, Uhl W. A P−H Functionalized Al/P Frustrated Lewis Pair: Substrate Activation and Selective Hydrogen Transfer. Angew Chem Int Ed Engl 2016; 55:3212-5. [DOI: 10.1002/anie.201511048] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Lukas Keweloh
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstrasse 30 48149 Münster Germany
| | - Hans Klöcker
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstrasse 30 48149 Münster Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut; Westfälische Wilhelms-Universität Münster; Corrensstrasse 40 48149 Münster Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstrasse 30 48149 Münster Germany
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26
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Schulte A, Janich S, Würthwein EU, Saito S, Wünsch B. Investigation of the Corey Bromolactamization withN-Functionalized Allylamines. J Heterocycl Chem 2015. [DOI: 10.1002/jhet.2493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Adrian Schulte
- Institut für Pharmazeutische und Medizinische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstr. 48 48149 Münster Germany
| | - Simon Janich
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität Münster; Corrensstr. 40 48149 Münster Germany
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität Münster; Corrensstr. 40 48149 Münster Germany
| | - Susumu Saito
- Research Center for Materials Science; Nagoya University; Chikusa Nagoya 464-8602 Japan
| | - Bernhard Wünsch
- Institut für Pharmazeutische und Medizinische Chemie; Westfälische Wilhelms-Universität Münster; Corrensstr. 48 48149 Münster Germany
- Cells-in-Motion Cluster of Excellence (EXC 1003-CiM); Westfälische Wilhelms-Universität Münster; Corrensstr. 48 48149 Münster Germany
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27
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von Bargen KW, Niehaus EM, Krug I, Bergander K, Würthwein EU, Tudzynski B, Humpf HU. Isolation and Structure Elucidation of Fujikurins A-D: Products of the PKS19 Gene Cluster in Fusarium fujikuroi. J Nat Prod 2015; 78:1809-1815. [PMID: 26192387 DOI: 10.1021/np5008137] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fusarium fujikuroi is a member of the Gibberella fujikuroi species complex and well known for the production of gibberellins and mycotoxins including fusarins and fusaric acid. A recent genome sequencing study revealed that the fungus has the genetic potential to produce many more secondary metabolites than have been reported. This paper describes the structure elucidation of the products of the cryptic and silent PKS19 gene cluster that were recently identified (fujikurins A-D). We present the complete NMR data for the structure elucidation of the main compound fujikurin D, which shows tautomeric 1,3-diketo elements. The different tautomeric structures could be confirmed using quantum chemical calculations. Additionally, the structures of the minor compounds fujikurins A-C were elucidated by high-resolution mass spectrometric fragmentation experiments. It emerged that fujikurin A was identical to the bioactive compound CR377 of the taxonomically unclassified Fusarium strain CR377, while fujikurins B-D have not been reported from other fungi.
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Affiliation(s)
| | - Eva-Maria Niehaus
- Institute of Molecular Biology and Biotechnology of Fungi, Westfälische Wilhelms-Universität Münster , Schlossplatz 8, 48143 Münster, Germany
| | - Isabel Krug
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstraße 45, 48149 Münster, Germany
| | - Klaus Bergander
- Institute of Organic Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstraße 40, 48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Institute of Organic Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstraße 40, 48149 Münster, Germany
| | - Bettina Tudzynski
- Institute of Molecular Biology and Biotechnology of Fungi, Westfälische Wilhelms-Universität Münster , Schlossplatz 8, 48143 Münster, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstraße 45, 48149 Münster, Germany
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28
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Uhl W, Wegener P, Würthwein EU. Dehydrochlorination of Carboxylic Acid Chlorides by an Aluminum/Phosphorus-Based Frustrated Lewis Pair and the Formation of Ketene Adducts. Z Anorg Allg Chem 2015. [DOI: 10.1002/zaac.201500519] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Jin X, Willeke M, Lucchesi R, Daniliuc CG, Fröhlich R, Wibbeling B, Uhl W, Würthwein EU. Hydroalumination of Ketenimines and Subsequent Reactions with Heterocumulenes: Synthesis of Unsaturated Amide Derivatives and 1,3-Diimines. J Org Chem 2015; 80:6062-75. [PMID: 26031425 DOI: 10.1021/acs.joc.5b00466] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The series of differently substituted ketenimines 1 was hydroluminated using di-iso-butyl aluminum hydride. For the sterically congested ketenimine 1a, preferred hydroalumination of the C═N-bond was proven by X-ray crystallography (compound 5a). In situ treatment of the hydroaluminated ketenimines 5 with various heterocumulenes like carbodiimides, isocycanates, isothiocyanates and ketenimines as electrophiles and subsequent hydrolytic workup resulted in novel enamine derived amide species in case of N-attack (sterically less hindered ketenimines) under formation of a new C-N-bond or in 1,3-diimines by C-C-bond-formation in case of bulky substituents at the ketenimine-nitrogen atom. Furthermore, domino reactions with more than 1 equiv of the electrophile or by subsequent addition of two different electrophiles are possible and lead to polyfunctional amide derivatives of the biuret type which are otherwise not easily accessible.
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Affiliation(s)
- Xing Jin
- †Organisch Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Matthias Willeke
- ‡Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Ralph Lucchesi
- †Organisch Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | | | - Roland Fröhlich
- †Organisch Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Birgit Wibbeling
- †Organisch Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Werner Uhl
- ‡Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- †Organisch Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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30
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Stopka T, Marzo L, Zurro M, Janich S, Würthwein EU, Daniliuc CG, Alemán J, Mancheño OG. Oxidative CH Bond Functionalization and Ring Expansion with TMSCHN2: A Copper(I)-Catalyzed Approach to Dibenzoxepines and Dibenzoazepines. Angew Chem Int Ed Engl 2015; 54:5049-53. [DOI: 10.1002/anie.201411726] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Indexed: 12/14/2022]
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31
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Uhl W, Pelties S, Tannert J, Ravoo BJ, Würthwein EU. Germacyclobutenes: generation by 1,1-carbalumination or 1,1-carbagallation and their photophysical properties. Chemistry 2015; 21:2629-37. [PMID: 25522339 DOI: 10.1002/chem.201405739] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Indexed: 11/07/2022]
Abstract
Aluminium- and gallium-functionalised alkenylalkynylgermanes, R(1) 2 Ge(C≡C-R(2) )[C{E(CMe3 )2 }=C(H)-R(2) ] (E=Al, Ga), exhibit a close contact between the coordinatively unsaturated Al or Ga atoms and the α-C atoms of the intact ethynyl groups. These interactions activate the Ge-C(alkynyl) bonds and favour the thermally induced insertion of these C atoms into the E-C(vinyl) bonds by means of 1,1-carbalumination or 1,1-carbagallation reactions. For the first time the latter method was shown to be a powerful alternative to known metallation processes. Germacyclobutenes with an unsaturated GeC3 heterocycle and endo- and exocyclic C=C bonds resulted from concomitant Ge-C bond formation to the β-C atoms of the alkynyl groups. These heterocyclic compounds show an interesting photoluminescence behaviour with Stokes shifts of >110 nm. The fascinating properties are based on extended π-delocalisation including σ*-orbitals localised at Ge and Al. High-level quantum chemical DFT and TD-DFT calculations for an Al compound were applied to elucidate their absorption and emission properties. They revealed a biradical excited state with the transfer of a π-electron into the empty p-orbital at Al and a pyramidalisation of the metal atom.
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Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, 48149 Münster (Germany), Fax: (+49) 251-8336660.
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32
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Uhl W, Wegener P, Layh M, Hepp A, Würthwein EU. Chalcogen Capture by an Al/P-Based Frustrated Lewis Pair: Formation of Al-E-P Bridges and Intermolecular Tellurium–Tellurium Interactions. Organometallics 2015. [DOI: 10.1021/om501206p] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße
30, D-48149 Münster, Germany
| | - Philipp Wegener
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße
30, D-48149 Münster, Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße
30, D-48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße
30, D-48149 Münster, Germany
| | - Ernst-Ulrich Würthwein
- Organisch-chemisches Institut der Universität Münster, Corrensstraße 40, D-48149 Münster, Germany
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33
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Glotzbach C, Gödeke N, Fröhlich R, Daniliuc CG, Saito S, Yamaguchi S, Würthwein EU. Fluorescent benzene-centered mono-, bis- and tris-triazapentadiene–boron complexes. Dalton Trans 2015; 44:9659-71. [DOI: 10.1039/c5dt00908a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Uhl W, Appelt C, Wollschläger A, Hepp A, Würthwein EU. An Al/P-based frustrated Lewis pair as an efficient ambiphilic ligand: coordination of boron trihalides, rearrangement, and formation of HBX₂ complexes (X = Br, I). Inorg Chem 2014; 53:8991-9. [PMID: 25144381 DOI: 10.1021/ic5009126] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The Al/P-based frustrated Lewis pair (FLP) Mes2P-C(═CH-Ph)-Al(CMe3)2 (1) reacted with boron halides BX3 (X = F, Cl, Br, I) as an ambiphilic ligand to form complexes (2-5) in which the boron atoms were coordinated to phosphorus and one of the halogen atoms to aluminum. Nonplanar five-membered heterocycles resulted that had five different ring atoms (AlCPBX). The distance of the bridging halogen atoms to the AlCPB plane increased steadily with the radius of the halogen atoms. Only the BF3 adduct showed a dynamic behavior in solution at room temperature with equivalent tert-butyl or mesityl groups in the NMR spectra, while in other cases, the rigid conformation led to the magnetic inequivalence of the substituents at Al and P with well-resolved signals for each group. The BBr3 and BI3 complexes underwent in solution at room temperature a spontaneous stereoselective rearrangement with the concomitant release of isobutene. The obtained products, Mes2P-(μ-C═CH-Ph)(μ-HBX2)-AlX(CMe3) (6 and 7) may be viewed as unique adducts of a modified new Al/P-based FLP, Mes2P-C(═CH-Ph)-AlX(CMe3) (X = Br, I), with dihalogenboranes, HBX2. The trapped boranes are either completely unknown (X = I) or unstable in the free form. Quantum-chemical calculations suggest an ionic rearrangement mechanism via the formation of a borenium cation, β-hydride elimination, and hydride transfer. The bromine migration from boron to aluminum corresponds to a formal suprafacial 1,3-sigmatropic rearrangement.
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Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstraße 30, D-48149 Münster, Germany
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35
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Uhl W, Bohnemann J, Layh M, Würthwein EU. Hydroalumination of a Chlorotrialkynylsilane: Spontaneous Stepwise 1,3-Dyotropic Rearrangement via an Intermediate Silyl Cation. Chemistry 2014; 20:8771-81. [DOI: 10.1002/chem.201402713] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Indexed: 11/10/2022]
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Reichardt C, Würthwein EU. Synthesen mit aliphatischen Dialdehyden, XXXV. Synthesen mit 1- und 2-Adamantylmalonaldehyd/ Syntheses with Aliphatic Dialdehydes, XXXV. Syntheses with 1- and 2-Adamantyl Malonaldehyde. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znb-1982-0918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The reaction of 1- (1) and 2-adamantyl malonaldehyde (2) with suitable electrophiles and nucleophiles yields adainantyl-substituted open-chain (3-5), carbocyclic (6) as well as heterocyclic compounds (7-19) with peculiar properties due to the presence of the lipophilic adamantyl group. The tetrazolo[1,5-a]pyrimidine (16) exhibits a solvent-dependent tetrazolo-azido valence isomerization reaction.
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Affiliation(s)
- Christian Reichardt
- Fachbereich Chemie der Universität Marburg, Hans-Meerwein-Straße, D-3550 Marburg
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37
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Peikert M, Chen X, Chi L, Brezesinski G, Janich S, Würthwein EU, Schäfer HJ. Phase behavior and molecular packing of octadecyl phenols and their methyl ethers at the air/water interface. Langmuir 2014; 30:5780-9. [PMID: 24401011 DOI: 10.1021/la404340h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Noncovalent molecular interactions, such as hydrogen bonding and van der Waals forces, play an important role in self-assembling to supramolecular structures. To study these forces, we chose monolayers at the air/water interface to limit the possible arrangements of the interacting molecules. Furthermore, monolayers provide useful tools to understand and study interactions between molecules in a controlled and fundamental way. The phase behavior and molecular packing of the phenols 1-(4-hydroxyphenyl)-octadecane (5a), 1-(3,4-dihydroxyphenyl)-octadecane (6), and 1-(2,3,4-trihydroxyphenyl)-octadecane (3) and their methyl ethers in monolayers at the air/water interface have been examined by π/A isotherms, Brewster angle microscopy (BAM), grazing incidence X-ray diffraction (GIXD) measurements, and density functional theory (DFT) calculations. The phenols are synthesized by Friedel-Crafts acylation of methoxybenzenes, hydrogenation of the resulting aryl ketones, and cleavage of the aryl methyl ethers. In the π/A isotherms and in BAM, the phenols show patches of the solid condensed phase at large molecular areas and the monolayers collapse at high pressures. Furthermore, the dimensions of the unit cell obtained by GIXD measurements are compatible with an arrangement of the phenyl rings that allows one aryl ring to interact with four adjacent phenyl rings in an edge-to-face arrangement, which leads to a significant binding energy. The experimental data are in good agreement with DFT calculations of 2D crystalline benzene and p-cresol arrangements. The enhanced monolayer stability of phenol 5a can be explained by hydrogen bonds of the hydroxyl group with water and van der Waals forces between the alkyl chains and aryl-aryl interactions.
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Affiliation(s)
- Miroslawa Peikert
- Organisch-Chemisches Institut der Westfälischen Wilhelms-Universität, Correns-Str. 40, 48149 Münster, Germany
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Neue B, Wakamiya A, Fröhlich R, Wibbeling B, Yamaguchi S, Würthwein EU. Modification and Unexpected Reactivity of 2-Borylbenzaldimines: Acylated and Silylated Derivatives as Well as Dimeric Compounds. J Org Chem 2013; 78:11747-55. [DOI: 10.1021/jo401748d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Benedikt Neue
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Atsushi Wakamiya
- Institute for Chemical Research, Kyoto University Uji,
Gokasho, Kyoto 611-0011, Japan
| | - Roland Fröhlich
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Birgit Wibbeling
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate
School of
Science, Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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39
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Hengesbach F, Jin X, Hepp A, Wibbeling B, Würthwein EU, Uhl W. Activation of Isocyanates and Carbon Dioxide by a Monomeric Aluminium Hydrazide as an Active Lewis Pair. Chemistry 2013; 19:13901-9. [PMID: 24038438 DOI: 10.1002/chem.201302179] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Frank Hengesbach
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstrasse 30, 48149 Münster (Germany)
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40
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Neue B, Reiermann R, Fröhlich R, Wibbeling B, Bergander K, Würthwein EU. Isocyanide Cyclization Reactions: 4-Methylene-4H-benzo[d][1,3]oxazine, 3-Benzyl-4-methylene-3,4-dihydroquinazolines and 3-(4-Benzyl)-3H-quinazolin-4-ones - Experiment and Theory. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300293] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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41
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Holtrichter-Rößmann T, Isermann J, Rösener C, Cramer B, Daniliuc CG, Kösters J, Letzel M, Würthwein EU, Uhl W. Ein Al-N-basiertes Lewis-Paar als effektiver Katalysator für die Oligomerisierung von Cyanamiden - Bildung von acyclischen C-N-Oligomeren anstelle von thermodynamisch begünstigten cyclischen Trimeren. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301970] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Holtrichter-Rößmann T, Isermann J, Rösener C, Cramer B, Daniliuc CG, Kösters J, Letzel M, Würthwein EU, Uhl W. An Aluminum-Nitrogen Based Lewis Pair as an Effective Catalyst for the Oligomerization of Cyanamides: Formation of Acyclic CN Oligomers Instead of Thermodynamically Favored Cyclic Aromatic Trimers. Angew Chem Int Ed Engl 2013; 52:7135-8. [DOI: 10.1002/anie.201301970] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/23/2013] [Indexed: 11/06/2022]
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Hellmann J, Rhotert I, Westenberg H, Fröhlich R, Wibbeling B, Uhl W, Würthwein EU. N-Acyl- andN-Sulfonylformamidines from Cyanamides and Carbodiimides by Hydroalumination and Subsequent Treatment with Electrophiles. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300208] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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44
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Glotzbach C, Kauscher U, Voskuhl J, Kehr NS, Stuart MCA, Fröhlich R, Galla HJ, Ravoo BJ, Nagura K, Saito S, Yamaguchi S, Würthwein EU. Fluorescent Modular Boron Systems Based on NNN- and ONO-Tridentate Ligands: Self-Assembly and Cell Imaging. J Org Chem 2013; 78:4410-8. [DOI: 10.1021/jo4003745] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Christoph Glotzbach
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
| | - Ulrike Kauscher
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
| | - Jens Voskuhl
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
| | - N. Seda Kehr
- Physical Institute, Westfälische Wilhelms-Universität, Heisenbergstrasse
11, 48149 Münster, Germany
| | - Marc C. A. Stuart
- Biophysical Chemistry, Biomolecular Sciences and Biotechnology Institute,
9747 AG Groningen, The Netherlands
| | - Roland Fröhlich
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
| | - Hans J. Galla
- Biochemistry Institute, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Str.
2, 48149 Münster, Germany
| | - Bart Jan Ravoo
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
| | - Kazuhiko Nagura
- Department of Chemistry, Graduate
School of Science, Nagoya University, Furo,
Chikusa, Nagoya 464-8602, Japan
| | - Shohei Saito
- Department of Chemistry, Graduate
School of Science, Nagoya University, Furo,
Chikusa, Nagoya 464-8602, Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate
School of Science, Nagoya University, Furo,
Chikusa, Nagoya 464-8602, Japan
| | - Ernst-Ulrich Würthwein
- Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr.
40, 48149 Münster, Germany
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45
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Meyer C, Neue B, Schepmann D, Yanagisawa S, Yamaguchi J, Würthwein EU, Itami K, Wünsch B. Improvement of σ1 receptor affinity by late-stage C-H-bond arylation of spirocyclic lactones. Bioorg Med Chem 2013; 21:1844-56. [PMID: 23462714 DOI: 10.1016/j.bmc.2013.01.038] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/14/2013] [Accepted: 01/18/2013] [Indexed: 11/16/2022]
Abstract
The direct C-H-bond arylation of the complex spirocyclic lactones 13, 14, and 18 allows the introduction of diverse aryl moieties in the last step of the synthesis. A selective α-arylation of the thiophene moiety was performed with the catalytic system PdCl2/2,2'-bipyridyl/Ag2CO3, whereas the β-position of the thiophene ring was addressed by using the alternative catalytic system PdCl2/P[OCH(CF3)2]3/Ag2CO3. Due to electronic and steric reasons the arylation of the five-membered lactone 18 occurred in both α-positions providing 4'-mono-, 6'-mono- and 4',6'-diarylated thiophenes 22-26a-c. Compounds with an additional aryl moiety at the 'upper left (top)' position (1'-position of 13, 3'-position of 14, 4'-position of 18) showed increased σ1 affinity compared to the non-arylated parent compounds. A phenyl moiety at the 'left' position (2'-position in 20a) also increased the σ1 affinity but to a lower extent. A considerable reduction of σ1 affinity was observed after introducing an aryl moiety in 6'-position of 18, which might result from shielding the tertiary amine, which is crucial for interaction with the σ1 receptor. The discussion of the experimental results is supported by high-level quantum chemical DFT-calculations of the NBO-charges of 13 and 18 and the relative energies of the related arylated products.
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Affiliation(s)
- Christina Meyer
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen, Wilhelms-Universität Münster, Hittorfstraße 58-62, D-48149 Münster, Germany
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46
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Banert K, Ihle A, Kuhtz A, Penk E, Saha B, Würthwein EU. Generation of highly strained 2,3-bridged 2H-azirines via cycloaddition reactions of 2-azidobuta-1,3-dienes and photolysis of the resulting cyclic vinyl azides. Tetrahedron 2013. [DOI: 10.1016/j.tet.2012.12.054] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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Erdmann M, Rösener C, Holtrichter-Rößmann T, Daniliuc CG, Fröhlich R, Uhl W, Würthwein EU, Kehr G, Erker G. Functional group chemistry at intramolecular frustrated Lewis pairs: substituent exchange at the Lewis acid site with 9-BBN. Dalton Trans 2013; 42:709-18. [DOI: 10.1039/c2dt31737k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Kösterke T, Kösters J, Würthwein EU, Mück-Lichtenfeld C, Schulte to Brinke C, Lahoz F, Hahn FE. Synthesis of Complexes Containing an Anionic NHC Ligand with an Unsubstituted Ring-Nitrogen Atom. Chemistry 2012; 18:14594-8. [DOI: 10.1002/chem.201202973] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Indexed: 11/07/2022]
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49
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Narayan R, Daniliuc CG, Würthwein EU. Preparation of NH-Pyrroles under Superelectrophilic Conditions by an Aza-Nazarov Reaction Cascade with Indole as Neutral Leaving Group: Experiment and Theory. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200913] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Kleigrewe K, Aydin F, Hogrefe K, Piecuch P, Bergander K, Würthwein EU, Humpf HU. Structure elucidation of new fusarins revealing insights in the rearrangement mechanisms of the Fusarium mycotoxin fusarin C. J Agric Food Chem 2012; 60:5497-5505. [PMID: 22540270 DOI: 10.1021/jf3009469] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Fusarin C is a Fusarium mycotoxin that rearranges under reversed phase chromatographic conditions. In this study, the rearrangement of fusarin C was examined in detail, and the formation of fusarins under different conditions was optimized. All relevant fusarins including (10Z)-, (8Z)-, and (6Z)-fusarin C were isolated and identified by NMR. To confirm the involvement of the 2-pyrrolidone ring in the rearrangement of fusarin C, 15-methoxy-fusarin C was synthesized. For the first time, the structure of open-chain fusarin C was elucidated, and on the basis of these data, the rearrangement product of fusarin C was identified as epi-fusarin C. The results were confirmed by detailed NMR measurements and density functional theory calculations. Furthermore, a new fusarin C like metabolite, which was named dihydrofusarin C, was detected by analysis of the crude extract of fusarin C with high-performance liquid chromatography coupled to UV and Fourier transform mass spectrometry.
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Affiliation(s)
- Karin Kleigrewe
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Münster, Germany
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