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Eisele NF, Rahrt R, Giachanou L, Shikho F, Koszinowski K. Gas-Phase Alkali-Metal Cation Affinities of Stabilized Enolates. Chemistry 2023; 29:e202302540. [PMID: 37752885 DOI: 10.1002/chem.202302540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 09/28/2023]
Abstract
The chemistry of alkali-metal enolates is dominated by ion pairing. To improve our understanding of the intrinsic interactions between the alkali-metal cations and the enolate anions, we have applied Cooks' kinetic method to determine relative M+ (M=Li, Na, K) affinities of the stabilized enolates derived from acetylacetone, ethyl acetoacetate, diethyl malonate, ethyl cyanoacetate, 2-cyanoacetamide, and methyl malonate monoamide in the gas phase. Quantum chemical calculations support the experimental results and moreover afford insight into the structures of the alkali-metal enolate complexes. The affinities decrease with increasing size of the alkali-metal cations, reflecting weaker electrostatic interactions and lower charge densities of the free M+ ions. For the different enolates, a comparison of their coordinating abilities is complicated by the fact that some of the free anions undergo conformational changes resulting in stabilizing intramolecular interactions. If these complicating effects are disregarded, the M+ affinities correlate with the electron density of the chelating functionalities, that is, the carbonyl and/or the nitrile groups of the enolates. A comparison with the known association constants of the corresponding alkali-metal enolates in solution points to the importance of solvation effects for these systems.
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Affiliation(s)
- Niklas F Eisele
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Rene Rahrt
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Lamprini Giachanou
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Fadi Shikho
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
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2
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Yoshimura T, Onda KI, Matsuo JI. Asymmetric Cycloaddition Reactions of Aryne Intermediates with a Chiral Carbon-Carbon Axis: Syntheses of Axially Chiral Biaryl Compounds. Org Lett 2023. [PMID: 38055630 DOI: 10.1021/acs.orglett.3c03983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
An asymmetric synthesis via an axially chiral arylaryne intermediate was developed. A cycloaddition reaction with various arynophiles was used to obtain chiral biaryl compounds while preserving the enantiomeric excess (ee) of a precursor even though the reaction proceeds through an arylaryne intermediate, whose chirality decreases on a time-dependent basis. High chiral transfer from a precursor to a product was observed not only at low temperature (-78 °C) but also at room temperature.
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Affiliation(s)
- Tomoyuki Yoshimura
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Ken-Ichi Onda
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Jun-Ichi Matsuo
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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3
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de Giovanetti M, Hopen Eliasson SH, Castro AC, Eisenstein O, Cascella M. Morphological Plasticity of LiCl Clusters Interacting with Grignard Reagent in Tetrahydrofuran. J Am Chem Soc 2023. [PMID: 37471267 PMCID: PMC10401704 DOI: 10.1021/jacs.3c04238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Ab initio molecular dynamics simulations are used to explore tetrahydrofuran (THF) solutions containing pure LiCl and LiCl with CH3MgCl, as model constituents of the turbo Grignard reagent. LiCl aggregates as Li4Cl4, which preferentially assumes compact cubane-like conformations. In particular, an open-edge pseudotetrahedral frame is promoted by solvent-assisted Li-Cl bond cleavage. Among the Grignard species involved in the Schlenk equilibrium, LiCl prefers to coordinate MgCl2 through μ2-Cl bridges. Using a 1:1 Li:Mg ratio, the plastic tetranuclear LiCl cluster decomposes to a highly solvated mixed LiCl·MgCl2 aggregate with prevalent Li-(μ2-Cl)2-Mg rings and linear LiCl entities. The MgCl2-assisted disaggregation of Li4Cl4 occurs through transient structures analogous to those detected for pure LiCl in THF, also corresponding to moieties observed in the solid state. This study identifies a synergistic role of LiCl for the determination of the compounds present in turbo Grignard solutions. LiCl shifts the Schlenk equilibrium promoting a higher concentration of dialkylmagnesium, while decomposing into smaller, more soluble, mixed Li:Mg:Cl clusters.
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Affiliation(s)
- Marinella de Giovanetti
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
| | - Sondre H Hopen Eliasson
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
| | - Abril C Castro
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
| | - Odile Eisenstein
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
- ICGM, University Montpellier, CNRS, ENSCM, 34090 Montpellier, France
| | - Michele Cascella
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
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4
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Sandulenko IV, Kovaleva ES, Zelentsova MV, Ambartsumyan AA, Gorlov SN, Danshina AA, Aysin RR, Moiseev SK. Control of the diastereoselectivity at C(20) in the formation of C(21)-fluorinated thevinols. Org Biomol Chem 2023; 21:1440-1449. [PMID: 36651056 DOI: 10.1039/d2ob02144g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A method is reported to control the stereoselectivity at C(20) in the syntheses of 20-R-21,21,21-trifluorothevinols (12), the opioid ligands incorporating fluorine atoms within the pharmacophore associated with the surroundings of the C(20) carbon atom. The C(20)-alcohols 12 can be prepared either by reaction of 21,21,21-trifluorothevinone (9) with RM (R = alkyl; M = Li, MgX) or by reaction of thevinone (2) and related non-fluorinated ketones with CF3SiMe3. In general, alcohols 12 were formed as mixtures of the C(20)-epimers, with the major epimers of the alcohols obtained from the aforementioned reactions exploiting RLi vs. CF3SiMe3 with opposite absolute configurations at C(20). Some individual C(20)-epimers of the fluorinated alcohols 12 were isolated from the reaction mixtures in pure form by trivial crystallization. The reactions of the ketones with RMgX (R ≠ Me) and RLi (R = tertiary or secondary alkyl) resulted in the reduction of the carbonyl function to produce the secondary alcohols 11a,b rather than the tertiary alcohols 12. The additives of the salts were found to affect the composition of the products in the reactions of 9 with alkyl organomagnesium and organolithium reagents.
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Affiliation(s)
- Irina V Sandulenko
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia.
| | - Ekaterina S Kovaleva
- D. I. Mendeleev University of Chemical Technology of Russia, Miusskaya Sq., 9, Moscow 125047, Russia
| | - Maria V Zelentsova
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia.
| | - Asmik A Ambartsumyan
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia.
| | - Sergey N Gorlov
- Faculty of the Fundamental Physical and Chemical Engineering, Lomonosov Moscow State University, Leninskiye Gory 1-51, Moscow 119991, Russia
| | - Anastasia A Danshina
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia. .,Moscow Institute of Physics and Technology (National Research University), Institutskiy per., 9, Dolgoprudny, 3, Russia
| | - Rinat R Aysin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia. .,Moscow Institute of Physics and Technology (National Research University), Institutskiy per., 9, Dolgoprudny, 3, Russia
| | - Sergey K Moiseev
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, build. 1, ul. Vavilova 28, Moscow 119334, Russia.
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5
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Influence of reaction conditions on kumada catalytic transfer polymerization for synthesis of poly(p-phenylene) for organic semiconductors. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03261-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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6
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Bole LJ, Tortajada A, Hevia E. Enhancing Metalating Efficiency of the Sodium Amide NaTMP in Arene Borylation Applications. Angew Chem Int Ed Engl 2022; 61:e202204262. [PMID: 35420221 PMCID: PMC9323492 DOI: 10.1002/anie.202204262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Indexed: 12/12/2022]
Affiliation(s)
- Leonie J. Bole
- Departement für Chemie, Biochemie und Pharmazie Universität Bern Freiestrasse 3 3012 Bern Switzerland
| | - Andreu Tortajada
- Departement für Chemie, Biochemie und Pharmazie Universität Bern Freiestrasse 3 3012 Bern Switzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmazie Universität Bern Freiestrasse 3 3012 Bern Switzerland
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7
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Bole L, Tortajada A, Hevia E. Enhancing Metalating Efficiency of the Sodium Amide NaTMP in Arene Borylation Applications. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Leonie Bole
- Universitat Bern Department of Chemistry, Biochemistry and Pharmaceutical Sciences SWITZERLAND
| | - Andreu Tortajada
- Universitat Bern Department of Chemistry, Biochemistry and Pharmaceutical Sciences SWITZERLAND
| | - Eva Hevia
- Universitat Bern Department of Chemistry and Biochemistry Freiestrasse 3 3012 Bern SWITZERLAND
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8
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Mix A, Lamm JH, Schwabedissen J, Gebel E, Stammler HG, Mitzel NW. Monitoring dynamic pre-crystallization aggregation processes in solution by VT-DOSY-NMR spectroscopy. Chem Commun (Camb) 2022; 58:3465-3468. [PMID: 35014642 DOI: 10.1039/d1cc05925d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Equimolar mixtures of pyridine (Py) with para-halotetrafluoropyridine (BrTFP and ITFP) were investigated by VT-diffusion NMR experiments. The formation of a halogen-bond-stabilized ITFP·Py complex was detected upon cooling a solution in methylcyclohexane-d14 to 260 K; this allows monitoring a halogen-bond-driven aggregation process preceding crystallization in solution.
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Affiliation(s)
- Andreas Mix
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
| | - Jan-Hendrik Lamm
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
| | - Jan Schwabedissen
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
| | - Erich Gebel
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
| | - Hans-Georg Stammler
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
| | - Norbert W Mitzel
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS) and Centre for Molecular Materials (CM2), Universitätsstr. 25, Bielefeld D-33615, Germany.
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9
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Bondarenko AA, Vlasova YS, Polynski MV, Ilyushenkova VV, Ananikov VP. Towards determining molecular structure with ESI-MS backed by computational methods: structures of subnanoclusters of Pd and Cu chlorides, ion dynamics in vacuum, and challenges to the methodology. Inorg Chem Front 2022. [DOI: 10.1039/d2qi01098d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Determining most stable structures of sub-nanoscale ionic clusters in ESI-MS spectra with quantum chemical modeling.
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Affiliation(s)
- Anton A. Bondarenko
- Saint Petersburg State University, Universitetsky Prospect 26, Saint Petersburg 198504, Russia
| | - Yulia S. Vlasova
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia
- MSU, Faculty of Chemistry, Leninskiye Gory 1-3, Moscow 119991, Russia
| | - Mikhail V. Polynski
- Saint Petersburg State University, Universitetsky Prospect 26, Saint Petersburg 198504, Russia
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia
- MSU, Faculty of Chemistry, Leninskiye Gory 1-3, Moscow 119991, Russia
| | - Valentina V. Ilyushenkova
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia
| | - Valentine P. Ananikov
- Saint Petersburg State University, Universitetsky Prospect 26, Saint Petersburg 198504, Russia
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia
- MSU, Faculty of Chemistry, Leninskiye Gory 1-3, Moscow 119991, Russia
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10
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The Structure of Bis(catecholato)silanes: Phase Adaptation by Dynamic Covalent Chemistry of the Si-O Bond. J Am Chem Soc 2021; 143:18784-18793. [PMID: 34699725 DOI: 10.1021/jacs.1c09746] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Catechols occupy a unique role in the structural, bio-, and geochemistry of silicon. Although a wealth of knowledge exists on their hypercoordinate complexes, the structure of tetracoordinate bis(catecholato)silane, Si(catH)2 1, has been enigmatic since its first report in 1951. Indeed, the claim of a planar-tetracoordinated silicon in 1 triggered a prominent debate, which is unsettled to this day. Herewith, we present a comprehensive structural study on 1 and derivatives in the gas phase by electron diffraction, in a neon matrix by IR spectroscopy, in solution by diffusion NMR spectroscopy, and in the solid-state by X-ray diffraction and MAS NMR spectroscopy, complemented by high-level quantum-chemical computations. The compound exhibits unprecedented phase adaptation. In the gas phase, the monomeric bis(catecholato)silane is tetrahedral, but in the condensed phase, it is metastable toward oligomerization up to a degree controllable by the type of catechol, temperature, and concentration. For the first time, spectroscopic evidence is obtained for a rapid Si-O σ-bond metathesis reaction. Hence, this study sorts out a long-lasting debate and confirms dynamic covalent features for our Earth's crust's most abundant chemical bond.
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11
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Auth T, Grabarics M, Schlangen M, Pagel K, Koszinowski K. Modular Ion Mobility Calibrants for Organometallic Anions Based on Tetraorganylborate Salts. Anal Chem 2021; 93:9797-9807. [PMID: 34227799 DOI: 10.1021/acs.analchem.1c01333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Organometallics are widely used in catalysis and synthesis. Their analysis relies heavily on mass spectrometric methods, among which traveling-wave ion mobility spectrometry (TWIMS) has gained increasing importance. Collision cross sections (CCS) obtainable by TWIMS significantly aid the structural characterization of ions in the gas phase, but for organometallics, their accuracy has been limited by the lack of appropriate calibrants. Here, we propose tetraorganylborates and their alkali-metal bound oligomers [Mn-1(BR4)n]- (M = Li, Na, K, Rb, Cs; R = aryl, Et; n = 1-6) as calibrants for electrospray ionization (ESI) TWIMS. These species chemically resemble typical organometallics and readily form upon negative-ion mode ESI of solutions of alkali-metal tetraorganylborates. By combining different tetraorganylborate salts, we have generated a large number of anions in a modular manner and determined their CCS values by drift-tube ion mobility spectrometry (DTIMS) (DTCCSHe = 81-585, DTCCSN2 = 130-704 Å2). In proof-of-concept experiments, we then applied these DTCCS values to the calibration of a TWIMS instrument and analyzed phenylcuprate and argentate anions, [Lin-1MnPh2n]- and [MnPhn+1]- (M = Cu, Ag), as prototypical reactive organometallics. The TWCCSN2 values derived from TWIMS measurements are in excellent agreement with those determined by DTIMS (<2% relative difference), demonstrating the effectiveness of the proposed calibration scheme. Moreover, we used theoretical methods to predict the structures and CCS values of the anions considered. These predictions are in good agreement with the experimental results and give further insight into the trends governing the assembly of tetraorganylborate, cuprate, and argentate oligomers.
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Affiliation(s)
- Thomas Auth
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, Göttingen 37077, Germany
| | - Márkó Grabarics
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Molekülphysik, Faradayweg 4-6, Berlin 14195, Germany
| | - Maria Schlangen
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, Berlin 10623, Germany
| | - Kevin Pagel
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Molekülphysik, Faradayweg 4-6, Berlin 14195, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, Göttingen 37077, Germany
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12
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Bartolo ND, Demkiw KM, Valentín EM, Hu CT, Arabi AA, Woerpel KA. Diastereoselective Additions of Allylmagnesium Reagents to α-Substituted Ketones When Stereochemical Models Cannot Be Used. J Org Chem 2021; 86:7203-7217. [PMID: 33978419 DOI: 10.1021/acs.joc.1c00553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The stereoselectivities of reactions of allylmagnesium reagents with chiral ketones cannot be easily explained by stereochemical models. Competition experiments indicate that the complexation step is not reversible, so nucleophiles cannot access the widest range of possible encounter complexes and therefore cannot be analyzed easily using available models. Nevertheless, additions of allylmagnesium reagents to a ketone can still be stereoselective provided that the carbonyl group adopts a conformation that leads to one face being completely blocked from the approach of the allylmagnesium reagent.
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Affiliation(s)
- Nicole D Bartolo
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Krystyna M Demkiw
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Elizabeth M Valentín
- St. Mary's College of California, 1928 St. Marys Road, Moraga, California 94575, United States
| | - Chunhua T Hu
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Alya A Arabi
- Biochemistry Department, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates.,Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - K A Woerpel
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
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13
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Deuker M, Yang Y, O’Hair RAJ, Koszinowski K. Tetraorganylargentate(III) Complexes: Key Intermediates in Silver-Mediated Cross-Coupling Reactions. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Marius Deuker
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - Yang Yang
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Richard A. J. O’Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
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14
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Eisele NF, Koszinowski K. Direct Detection of Free and Counterion-Bound Carbanions by Electrospray-Ionization Mass Spectrometry. J Org Chem 2021; 86:3750-3757. [PMID: 33599503 DOI: 10.1021/acs.joc.0c02504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We propose electrospray-ionization (ESI) mass spectrometry as a robust and powerful method for the in situ analysis of carbanions. ESI mass spectrometry selectively probes the charged components of the sampled solution and, thus, is ideally suited for the detection of free carbanions. We demonstrate the potential of this method by analyzing acetonitrile solutions of 15 different carbon acids AH, whose acidities cover a range of 11.1 ≤ pKa(DMSO) ≤ 29.5. After treatment with KOtBu as a strong base, all but the two least acidic compounds were successfully detected as free carbanions A- and/or as potassium-bound aggregates [Kn-1An]-. The association equilibria can be shifted toward smaller aggregates and free carbanions by the addition of the crown ether 18-crown-6, which facilitates the evaluation of the mass spectra. When KOtBu was replaced by other bases (LiOH, LiNiPr2, NaH, NaOH, KOH, NBu4OH) or when tetrahydrofuran or methanol was used as a solvent, carbanions were also successfully observed. For further demonstrating the utility of the proposed method, we applied it to the analysis of the Michael addition of deprotonated dimedone to butenone. ESI mass spectrometry allowed us to follow the decrease of the reactant carbanion and the buildup of the product carbanion in time.
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Affiliation(s)
- Niklas F Eisele
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
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15
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Planas F, Kohlhepp SV, Huang G, Mendoza A, Himo F. Computational and Experimental Study of Turbo-Organomagnesium Amide Reagents: Cubane Aggregates as Reactive Intermediates in Pummerer Coupling. Chemistry 2021; 27:2767-2773. [PMID: 33044772 PMCID: PMC7898302 DOI: 10.1002/chem.202004164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/08/2020] [Indexed: 11/07/2022]
Abstract
The dynamic equilibria of organomagnesium reagents are known to be very complex, and the relative reactivity of their components is poorly understood. Herein, a combination of DFT calculations and kinetic experiments is employed to investigate the detailed reaction mechanism of the Pummerer coupling between sulfoxides and turbo-organomagnesium amides. Among the various aggregates studied, unprecedented heterometallic open cubane structures are demonstrated to yield favorable barriers through a concerted anion-anion coupling/ S-O cleavage step. Beyond a structural curiosity, these results introduce open cubane organometallics as key reactive intermediates in turbo-organomagnesium amide mixtures.
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Affiliation(s)
- Ferran Planas
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Stefanie V Kohlhepp
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Genping Huang
- Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, P. R. China
| | - Abraham Mendoza
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Fahmi Himo
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
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16
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Desaintjean A, Haupt T, Bole LJ, Judge NR, Hevia E, Knochel P. Regioselective Bromine/Magnesium Exchange for the Selective Functionalization of Polyhalogenated Arenes and Heterocycles. Angew Chem Int Ed Engl 2021; 60:1513-1518. [PMID: 33079466 PMCID: PMC7839478 DOI: 10.1002/anie.202012496] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Indexed: 12/20/2022]
Abstract
Using the bimetallic combination sBu2 Mg⋅2 LiOR (R=2-ethylhexyl) in toluene enables efficient and regioselective Br/Mg exchanges with various dibromo-arenes and -heteroarenes under mild reaction conditions and provides bromo-substituted magnesium reagents. Assessing the role of Lewis donor additives in these reactions revealed that N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDTA) finely tunes the regioselectivity of the Br/Mg exchange on dibromo-pyridines and quinolines. Combining spectroscopic with X-ray crystallographic studies, light has been shed on the mixed Li/Mg constitution of the organometallic intermediates accomplishing these transformations. These systems reacted effectively with a broad range of electrophiles, including allyl bromides, ketones, aldehydes, and Weinreb amides in good yields.
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Affiliation(s)
- Alexandre Desaintjean
- Ludwig-Maximilians-Universität MünchenDepartment ChemieButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Tobias Haupt
- Ludwig-Maximilians-Universität MünchenDepartment ChemieButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Leonie J. Bole
- Department für Chemie und BiochemieUniversität Bern3012BernSwitzerland
| | - Neil R. Judge
- Department für Chemie und BiochemieUniversität Bern3012BernSwitzerland
| | - Eva Hevia
- Department für Chemie und BiochemieUniversität Bern3012BernSwitzerland
| | - Paul Knochel
- Ludwig-Maximilians-Universität MünchenDepartment ChemieButenandtstrasse 5–13, Haus F81377MünchenGermany
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17
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Desaintjean A, Haupt T, Bole LJ, Judge NR, Hevia E, Knochel P. Regioselektiver Brom/Magnesium‐Austausch für die selektive Funktionalisierung von polyhalogenierten Arenen und Heterozyklen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202012496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Alexandre Desaintjean
- Ludwig-Maximilians-Universität München Department Chemie Butenandtstraße 5–13, Haus F 81377 München Deutschland
| | - Tobias Haupt
- Ludwig-Maximilians-Universität München Department Chemie Butenandtstraße 5–13, Haus F 81377 München Deutschland
| | - Leonie J. Bole
- Department für Chemie und Biochemie Universität Bern 3012 Bern Schweiz
| | - Neil R. Judge
- Department für Chemie und Biochemie Universität Bern 3012 Bern Schweiz
| | - Eva Hevia
- Department für Chemie und Biochemie Universität Bern 3012 Bern Schweiz
| | - Paul Knochel
- Ludwig-Maximilians-Universität München Department Chemie Butenandtstraße 5–13, Haus F 81377 München Deutschland
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18
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Kolter M, Koszinowski K. Second Comes First: Switching Elementary Steps in Palladium-Catalyzed Cross-Coupling Reactions. Chemistry 2020; 26:12212-12218. [PMID: 32428266 PMCID: PMC7540703 DOI: 10.1002/chem.202001041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/11/2020] [Indexed: 12/13/2022]
Abstract
The electron-poor palladium(0) complex L3 Pd (L=tris[3,5-bis(trifluoromethyl)phenyl]phosphine) reacts with Grignard reagents RMgX and organolithium compounds RLi via transmetalation to furnish the anionic organopalladates [L2 PdR]- , as shown by negative-ion mode electrospray-ionization mass spectrometry. These palladates undergo oxidative additions of organyl halides R'X (or related SN 2-type reactions) followed by further transmetalation. Gas-phase fragmentation of the resulting heteroleptic palladate(II) complexes results in the reductive elimination of the cross-coupling products RR'. This reaction sequence corresponds to a catalytic cycle, in which the order of the elementary steps of transmetalation and oxidative addition is switched relative to that of palladium-catalyzed cross-coupling reactions proceeding via neutral intermediates. An attractive feature of the palladate-based catalytic system is its ability to mediate challenging alkyl-alkyl coupling reactions. However, the poor stability of the phosphine ligand L against decomposition reactions has so far prevented its successful use in practical applications.
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Affiliation(s)
- Marlene Kolter
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
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19
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Münch A, Knauer L, Ott H, Sindlinger C, Herbst-Irmer R, Strohmann C, Stalke D. Insight into the Bonding and Aggregation of Alkyllithiums by Experimental Charge Density Studies and Energy Decomposition Analyses. J Am Chem Soc 2020; 142:15897-15906. [PMID: 32811141 DOI: 10.1021/jacs.0c06035] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this Article, the organolithiums [((-)-sparteine)LitBu] (1), [(ABCO)LitBu]2 (2), and [(ABCO)2(LiiPr)4] (3) are investigated by means of experimental and theoretical charge density determination to elucidate the nature of the Li-C and Li-N bonds. Furthermore, the valence shell charge concentrations (VSCCs) in the nonbonding region of the deprotonated Cα-atom will provide some insight on the localization of the carbanionic lone pair. Analysis of the electron density (ρ(rBCP)), Laplacian (∇2ρ(rBCP)), and the energy decomposition (EDA) confirmed that the Li-C/N bond exhibits astonishingly similar characteristics, to reveal an increasingly polar contact with decreasing aggregate size. This explains former observations on the incorporation of halide salts in organolithium reagents. Furthermore, it could be shown that the bonding properties of the iPr group are similar to those of the tBu substituent. The accuracy of fit to all previously determined properties in organolithiums is remarkable.
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Affiliation(s)
- Annika Münch
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Lena Knauer
- Institut für Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Straβe 6, Dortmund 44227, Germany
| | - Holger Ott
- Bruker AXS GmbH, Östliche Rheinbrückenstraβe 49, Karlsruhe 76187, Germany
| | - Christian Sindlinger
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Carsten Strohmann
- Institut für Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Straβe 6, Dortmund 44227, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
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20
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Evans R. The interpretation of small molecule diffusion coefficients: Quantitative use of diffusion-ordered NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 117:33-69. [PMID: 32471534 DOI: 10.1016/j.pnmrs.2019.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 06/11/2023]
Abstract
Measuring accurate molecular self-diffusion coefficients, D, by nuclear magnetic resonance (NMR) techniques has become routine as hardware, software and experimental methodologies have all improved. However, the quantitative interpretation of such data remains difficult, particularly for small molecules. This review article first provides a description of, and explanation for, the failure of the Stokes-Einstein equation to accurately predict small molecule diffusion coefficients, before moving on to three broadly complementary methods for their quantitative interpretation. Two are based on power laws, but differ in the nature of the reference molecules used. The third addresses the uncertainties in the Stokes-Einstein equation directly. For all three methods, a wide range of examples are used to show the range of chemistry to which diffusion NMR can be applied, and how best to implement the different methods to obtain quantitative information from the chemical systems studied.
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Affiliation(s)
- Robert Evans
- Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, United Kingdom.
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21
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Colas K, Dos Santos ACVD, Mendoza A. i-Pr 2NMgCl·LiCl Enables the Synthesis of Ketones by Direct Addition of Grignard Reagents to Carboxylate Anions. Org Lett 2019; 21:7908-7913. [PMID: 31513423 DOI: 10.1021/acs.orglett.9b02899] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The direct preparation of ketones from carboxylate anions is greatly limited by the required use of organolithium reagents or activated acyl sources that need to be independently prepared. Herein, a specific magnesium amide additive is used to activate and control the addition of more tolerant Grignard reagents to carboxylate anions. This strategy enables the modular synthesis of ketones from CO2 and the preparation of isotopically labeled pharmaceutical building blocks in a single operation.
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Affiliation(s)
- Kilian Colas
- Department of Organic Chemistry , Stockholm University , Arrhenius Laboratory , 106 91 Stockholm , Sweden
| | - A Catarina V D Dos Santos
- Department of Organic Chemistry , Stockholm University , Arrhenius Laboratory , 106 91 Stockholm , Sweden
| | - Abraham Mendoza
- Department of Organic Chemistry , Stockholm University , Arrhenius Laboratory , 106 91 Stockholm , Sweden
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22
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Yu M, Strotman NA, Savage SA, Leung S, Ramirez A. A Practical and Robust Multistep Continuous Process for Manufacturing 5-Bromo- N-( tert-butyl)pyridine-3-sulfonamide. Org Process Res Dev 2019. [DOI: 10.1021/acs.oprd.9b00254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Miao Yu
- Chemical & Synthetic Development, Global Product Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Neil A. Strotman
- Chemical & Synthetic Development, Global Product Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Scott A. Savage
- Chemical & Synthetic Development, Global Product Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Simon Leung
- Research and Development External Manufacturing, Global Product Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Antonio Ramirez
- Chemical & Synthetic Development, Global Product Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
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23
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Kreyenschmidt F, Meurer SE, Koszinowski K. Mechanisms of Cobalt/Phosphine-Catalyzed Cross-Coupling Reactions. Chemistry 2019; 25:5912-5921. [PMID: 30734379 DOI: 10.1002/chem.201805964] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Indexed: 01/09/2023]
Abstract
>The combination of CoCl2 with bidentate phosphines is known to catalyze challenging cross-coupling and Heck-type reactions, but the mechanisms of these valuable transformations have not been established. Here, we use electrospray-ionization mass spectrometry to intercept the species formed in these reactions. Our results indicate that a sequence of transmetalation, reductive elimination, and redox disproportionation convert the cobalt(II) precatalyst into low-valent cobalt complexes. These species readily transfer single electrons to alkyl bromides, which thereupon dissociate into alkyl radicals and Br- . In cross-coupling reactions, the alkyl radicals add to the cobalt catalyst to form observable heteroleptic complexes, which release the coupling products through reductive eliminations. In the Heck-type reactions, the low abundance of newly formed ionic species renders the analysis more difficult. Nonetheless, our results also point to the occurrence of single-electron transfer processes and the involvement of radicals in these transformations.
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Affiliation(s)
- Friedrich Kreyenschmidt
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Selim E Meurer
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
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24
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Bodach A, Hebestreit R, Bolte M, Fink L. Syntheses and Crystal Structures of Phenyl-Lithium Derivatives. Inorg Chem 2018; 57:9079-9085. [PMID: 30009594 DOI: 10.1021/acs.inorgchem.8b01041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although organolithium compounds have been studied and applied for ∼100 years, only few crystal structures of pure, unsolvated organolithium compounds have been reported so far. Therefore, several phenyl-lithium derivatives were synthesized by lithium-halogen exchange reactions, yielding fairly soluble polymers in the cases of 4- and 2-methylphenyl-lithium ( p-TolLi and o-TolLi). Their crystal structures have been determined by X-ray powder diffraction. Remarkably, o-TolLi crystallizes in the noncentrosymmetric space group P212121 with two independent monomers, whereas the crystal structure of p-TolLi is described in spacegroup P21/ a. In contrast, no polymer of 5- m-XyLi (3,5-dimethyl-phenyl-lithium) could be observed, but single crystals of a [(5- m-XyLi)3(MTBE)3LiBr] adduct were isolated (MTBE = methyl- tert-butylether). This gives hints on the nature of lithium-halogen exchange reactions. Steric and electronic effects of the phenyl-lithium substitution are further discussed in conjunction with related compounds.
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Affiliation(s)
- Alexander Bodach
- Institut für Anorganische und Analytische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt/Main , Germany
| | - René Hebestreit
- Institut für Anorganische und Analytische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt/Main , Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt/Main , Germany
| | - Lothar Fink
- Institut für Anorganische und Analytische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt/Main , Germany
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25
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Parchomyk T, Demeshko S, Meyer F, Koszinowski K. Oxidation States, Stability, and Reactivity of Organoferrate Complexes. J Am Chem Soc 2018; 140:9709-9720. [PMID: 29991250 DOI: 10.1021/jacs.8b06001] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have applied a combination of electrospray-ionization mass spectrometry, electrical conductivity measurements, and Mössbauer spectroscopy to identify and characterize the organoferrate species R nFe m- formed upon the transmetalation of iron precursors (Fe(acac)3, FeCl3, FeCl2, Fe(OAc)2) with Grignard reagents RMgX (R = Me, Et, Bu, Hex, Oct, Dec, Me3SiCH2, Bn, Ph, Mes, 3,5-(CF3)2-C6H3; X = Cl, Br) in tetrahydrofuran. The observed organoferrates show a large variety in their aggregation (1 ≤ m ≤ 8) and oxidation states (I to IV), which are chiefly determined by the nature of their organyl groups R. In numerous cases, the addition of a bidentate amine or phosphine changes the distributions of organoferrates and affects their stability. Besides undergoing efficient intermolecular exchange processes, several of the probed organoferrates react with organyl (pseudo)halides R'X (R' = Et, iPr, Bu, Ph, p-Tol; X = Cl, Br, I, OTf) to afford heteroleptic complexes of the type R3FeR'-. Gas-phase fragmentation of most of these complexes results in reductive eliminations of the coupling products RR' (or, alternatively, of R2). This finding indicates that iron-catalyzed cross-coupling reactions may proceed via such heteroleptic organoferrates R3FeR'- as intermediates. Gas-phase fragmentation of other organoferrate complexes leads to β-hydrogen eliminations, the loss of arenes, and the expulsion of organyl radicals. The operation of both one- and two-electron processes is consistent with previous observations and contributes to the formidable complexity of organoiron chemistry.
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Affiliation(s)
- Tobias Parchomyk
- Institut für Organische und Biomolekulare Chemie , Universität Göttingen , Tammannstraße 2 , 37077 Göttingen , Germany
| | - Serhiy Demeshko
- Institut für Anorganische Chemie , Universität Göttingen , Tammannstraße 4 , 37077 Göttingen , Germany
| | - Franc Meyer
- Institut für Anorganische Chemie , Universität Göttingen , Tammannstraße 4 , 37077 Göttingen , Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie , Universität Göttingen , Tammannstraße 2 , 37077 Göttingen , Germany
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26
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Bachmann S, Gernert B, Stalke D. Solution structures of alkali metal cyclopentadienides in THF estimated by ECC-DOSY NMR-spectroscopy (incl. software). Chem Commun (Camb) 2018; 52:12861-12864. [PMID: 27731871 DOI: 10.1039/c6cc07273a] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In this paper we present the aggregational motifs of the widely used alkali-metal cyclopentadienides (CpLi, CpNa, CpK, CpRb, CpCs) in THF-d8 solution estimated by ECC-DOSY NMR spectroscopy. They form monomeric contact ion pairs (CIPs) in THF-d8 solution, whereas in NH3 solvent-separated ion pairs (SSIPs) are observed. The applicability of ECC-DOSY is further advanced by introducing ECC-MW estimation software.
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Affiliation(s)
- Sebastian Bachmann
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 4, D-37077, Göttingen, Germany.
| | - Björn Gernert
- Institut für Betriebssysteme und Rechnerverbund, TU Braunschweig, Mühlenpfordstraße 23, Braunschweig, D-38106, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 4, D-37077, Göttingen, Germany.
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27
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García-Valle FM, Tabernero V, Cuenca T, Cano J, Mosquera MEG. Schiff-base -ate derivatives with main group metals: generation of a tripodal aluminate metalloligand. Dalton Trans 2018; 47:6499-6506. [DOI: 10.1039/c8dt00835c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A new type of -ate derivatives is described, where the alkali metal exerts a strong influence on the final outcome.
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Affiliation(s)
- Francisco M. García-Valle
- Departamento de Química Orgánica y Química Inorgánica
- Instituto de Investigacion en Química “Andres M. del Río” (IQAR) Universidad de Alcalá
- 28871-Alcala de Henares
- Spain
| | - Vanessa Tabernero
- Departamento de Química Orgánica y Química Inorgánica
- Instituto de Investigacion en Química “Andres M. del Río” (IQAR) Universidad de Alcalá
- 28871-Alcala de Henares
- Spain
| | - Tomás Cuenca
- Departamento de Química Orgánica y Química Inorgánica
- Instituto de Investigacion en Química “Andres M. del Río” (IQAR) Universidad de Alcalá
- 28871-Alcala de Henares
- Spain
| | - Jesús Cano
- Departamento de Química Orgánica y Química Inorgánica
- Instituto de Investigacion en Química “Andres M. del Río” (IQAR) Universidad de Alcalá
- 28871-Alcala de Henares
- Spain
| | - Marta E. G. Mosquera
- Departamento de Química Orgánica y Química Inorgánica
- Instituto de Investigacion en Química “Andres M. del Río” (IQAR) Universidad de Alcalá
- 28871-Alcala de Henares
- Spain
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28
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Raţ CI, Soran A, Varga RA, Silvestru C. C–H Bond Activation Mediated by Inorganic and Organometallic Compounds of Main Group Metals. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2018. [DOI: 10.1016/bs.adomc.2018.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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29
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Kreyenschmidt F, Koszinowski K. Low-Valent Ate Complexes Formed in Cobalt-Catalyzed Cross-Coupling Reactions with 1,3-Dienes as Additives. Chemistry 2017; 24:1168-1177. [PMID: 29110364 DOI: 10.1002/chem.201704547] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Indexed: 12/23/2022]
Abstract
The combination of CoCl2 and 1,3-dienes is known to catalyze challenging alkyl-alkyl cross-coupling reactions between Grignard reagents and alkyl halides, but the mechanism of these valuable transformations remains speculative. Herein, electrospray-ionization mass spectrometry is used to identify and characterize the elusive intermediates of these and related reactions. The vast majority of detected species contain low-valent cobalt(I) centers and diene molecules. Charge tagging, deuterium labeling, and gas-phase fragmentation experiments elucidate the likely origin of these species and show that the diene not only binds to Co as a π ligand, but also undergoes migratory insertion reactions into Co-H and Co-R bonds. The resulting species have a strong tendency to form anionic cobalt(I) ate complexes, the superior nucleophilicity of which should render them highly reactive toward electrophilic substrates and, thus, presumably is the key to the high catalytic efficiency of the system under investigation. Upon the reaction of the in situ formed cobalt(I) ate complexes with organyl halides, only the final cross-coupling product could be detected, but no cobalt(III) species. This finding implies that this reaction step proceeds in a direct manner without any intermediate or, alternatively, that it involves an intermediate with a very short lifetime.
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Affiliation(s)
- Friedrich Kreyenschmidt
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
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30
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Vulovic B, Cinderella AP, Watson DA. Palladium-Catalyzed Cross-Coupling of Monochlorosilanes And Grignard Reagents. ACS Catal 2017; 7:8113-8117. [PMID: 29868244 PMCID: PMC5984048 DOI: 10.1021/acscatal.7b03465] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Using a palladium catalyst supported by DrewPhos, the alkylation of monochlorosilanes with primary and secondary alkyl-magnesium halides is now possible. Arylation with sterically demanding aromatic magnesium halides is also enabled. This transformation overcomes the high bond strength of the Si-Cl bond (113 kcal/mol) and is a rare example of a transition-metal catalyzed process involving its activation. Due to the availability of both chlorosilanes and organomagnesium halide reagents, this method allows for the preparation of a wide range of alkyl and aryl silanes.
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Affiliation(s)
| | | | - Donald A. Watson
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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31
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Kreyenschmidt AK, Bachmann S, Niklas T, Stalke D. Molecular Weight Estimation of Molecules Incorporating Heavier Elements from van-der-Waals Corrected ECC-DOSY. ChemistrySelect 2017. [DOI: 10.1002/slct.201701497] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anne-Kathrin Kreyenschmidt
- Institut für Anorganische Chemie der; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen
| | - Sebastian Bachmann
- Institut für Anorganische Chemie der; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen
| | - Thomas Niklas
- Institut für Anorganische Chemie der; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen
| | - Dietmar Stalke
- Institut für Anorganische Chemie der; Georg-August-Universität Göttingen; Tammannstraße 4 37077 Göttingen
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32
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Uzelac M, Kennedy AR, Hevia E. Trans-Metal-Trapping Meets Frustrated-Lewis-Pair Chemistry: Ga(CH 2SiMe 3) 3-Induced C-H Functionalizations. Inorg Chem 2017; 56:8615-8626. [PMID: 28485929 PMCID: PMC5549243 DOI: 10.1021/acs.inorgchem.7b00549] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Merging two topical themes in main-group chemistry, namely, cooperative bimetallics and frustrated-Lewis-pair (FLP) activity, this Forum Article focuses on the cooperativity-induced outcomes observed when the tris(alkyl)gallium compound GaR3 (R = CH2SiMe3) is paired with the lithium amide LiTMP (TMP = 2,2,6,6-tetramethylpiperidide) or the sterically hindered N-heterocyclic carbene (NHC) 1,3-bis(tert-butyl)imidazol-2-ylidene (ItBu). When some previously published work are drawn together with new results, unique tandem reactivities are presented that are driven by the steric mismatch between the individual reagents of these multicomponent reagents. Thus, the LiTMP/GaR3 combination, which on its own fails to form a cocomplex, functions as a highly regioselective base (LiTMP)/trap (GaR3) partnership for the metalation of N-heterocycles such as diazines, 1,3-benzoazoles, and 2-picolines in a trans-metal-trapping (TMT) process that stabilizes the emerging sensitive carbanions. Taking advantage of related steric incompatibility, a novel monometallic FLP system pairing GaR3 with ItBu has been developed for the activation of carbonyl compounds (via C═O insertion) and other molecules with acidic hydrogen atoms such as phenol and phenylacetylene. Shedding new light on how these non-cocomplexing partnerships operate and showcasing the potential of gallium reagents to engage in metalation reactions or FLP activations, areas where the use of this group 13 metal is scant, this Forum Article aims to stimulate more interest and activity toward the advancement of organogallium chemistry.
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Affiliation(s)
- Marina Uzelac
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
| | - Eva Hevia
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
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Read JA, Yang Y, Woerpel KA. Additions of Organomagnesium Halides to α-Alkoxy Ketones: Revision of the Chelation-Control Model. Org Lett 2017; 19:3346-3349. [DOI: 10.1021/acs.orglett.7b01161] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jacquelyne A. Read
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Yingying Yang
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - K. A. Woerpel
- Department of Chemistry, New York University, New York, New York 10003, United States
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Muñoz MT, Barandika G, Bazán B, Cuenca T, Mosquera MEG. Aluminum Alkali Metalate Derivatives: Factors Driving the Final Nuclearity in the Crystal Form. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201601428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- M. Teresa Muñoz
- Organic and Inorganic Chemistry Department University of Alcalá Campus Universitario 28805 Alcalá de Henares Madrid Spain
| | - Gotzone Barandika
- Inorganic Chemistry Department University of the Basque Country UPV/EHU Barrio Sarriena s/n 48940 Leioa Spain
- BCMaterials Parque Tecnológico de Zamudio Ibaizabal Bidea, Edificio 500‐Planta 1 48160 Derio Spain
| | - Begoña Bazán
- BCMaterials Parque Tecnológico de Zamudio Ibaizabal Bidea, Edificio 500‐Planta 1 48160 Derio Spain
- Mineralogy and Petrology Department University of the Basque Country UPV/EHU Barrio Sarriena s/n 48940 Leioa Spain
| | - Tomás Cuenca
- Organic and Inorganic Chemistry Department University of Alcalá Campus Universitario 28805 Alcalá de Henares Madrid Spain
| | - Marta E. G. Mosquera
- Organic and Inorganic Chemistry Department University of Alcalá Campus Universitario 28805 Alcalá de Henares Madrid Spain
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Büschelberger P, Gärtner D, Reyes‐Rodriguez E, Kreyenschmidt F, Koszinowski K, Jacobi von Wangelin A, Wolf R. Alkene Metalates as Hydrogenation Catalysts. Chemistry 2017; 23:3139-3151. [PMID: 28026060 PMCID: PMC5861671 DOI: 10.1002/chem.201605222] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Indexed: 11/09/2022]
Abstract
First-row transition-metal complexes hold great potential as catalysts for hydrogenations and related reductive reactions. Homo- and heteroleptic arene/alkene metalates(1-) (M=Co, Fe) are a structurally distinct catalyst class with good activities in hydrogenations of alkenes and alkynes. The first syntheses of the heteroleptic cobaltates [K([18]crown-6)][Co(η4 -cod)(η2 -styrene)2 ] (5) and [K([18]crown-6)][Co(η4 -dct)(η4 -cod)] (6), and the homoleptic complex [K(thf)2 ][Co(η4 -dct)2 ] (7; dct=dibenzo[a,e]cyclooctatetraene, cod=1,5-cyclooctadiene), are reported. For comparison, two cyclopentadienylferrates(1-) were synthesized according to literature procedures. The isolated and fully characterized monoanionic complexes were competent precatalysts in alkene hydrogenations under mild conditions (2 bar H2 , r.t., THF). Mechanistic studies by NMR spectroscopy, ESI mass spectrometry, and poisoning experiments documented the operation of a homogeneous mechanism, which was initiated by facile redox-neutral π-ligand exchange with the substrates followed by H2 activation. The substrate scope of the investigated precatalysts was also extended to polar substrates (ketones and imines).
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Affiliation(s)
- Philipp Büschelberger
- Institute of Inorganic ChemistryUniversity of RegensburgUniversitätsstr. 3193040RegensburgGermany
| | - Dominik Gärtner
- Institute of Organic ChemistryUniversity of Regensburg93040RegensburgGermany
| | | | - Friedrich Kreyenschmidt
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstr. 237077GöttingenGermany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstr. 237077GöttingenGermany
| | | | - Robert Wolf
- Institute of Inorganic ChemistryUniversity of RegensburgUniversitätsstr. 3193040RegensburgGermany
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Koszinowski K, Lissy F. ESI activity of Br⁻, BF₄⁻ , ClO₄⁻ and BPh₄⁻ anions in the presence of Li⁺ and NBu⁴⁺ counter-ions. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:144-151. [PMID: 28098404 DOI: 10.1002/jms.3911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/12/2017] [Accepted: 01/14/2017] [Indexed: 06/06/2023]
Abstract
To improve our understanding of the electrospray ionization (ESI) process, we have subjected equimolar mixtures of salts A+ X- (A+ = Li+ , NBu4+ ; X- = Br- , ClO4- , BF4- , BPh4- ) in different solvents (CH3 CN, tetrahydrofuran, CH3 OH, H2 O) to negative-ion mode ESI and analyzed the relative ESI activity of the different anionic model analytes. The ESI activity of the large and hydrophobic BPh4- ion greatly exceeds that of the smaller and more hydrophilic anions Br- , ClO4- and BF4- , which we ascribe to its higher surface activity. Moreover, the ESI activity of the anions is modulated by the action of the counter-ions and their different tendency toward ion pairing. The tendency toward ion pairing can be reduced by the addition of the chelating ligands 12-crown-4 and 2.2.1 cryptand and is, although to a smaller degree, further influenced by the variation of the solvent. Complementary electrical conductivity measurements afford additional information on the interactions of the ionic constituents of the sample solutions. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- K Koszinowski
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - F Lissy
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
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Parchomyk T, Koszinowski K. Solution and Gas-Phase Reactivity of Me12
Fe8
−
and Related Cluster Ions. Chemistry 2017; 23:3213-3219. [DOI: 10.1002/chem.201605602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Tobias Parchomyk
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstr. 2 37077 Göttingen Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstr. 2 37077 Göttingen Germany
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Parchomyk T, Koszinowski K. Ate Complexes in Iron-Catalyzed Cross-Coupling Reactions. Chemistry 2016; 22:15609-15613. [DOI: 10.1002/chem.201603574] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Indexed: 12/27/2022]
Affiliation(s)
- Tobias Parchomyk
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstr. 2 37077 Göttingen Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstr. 2 37077 Göttingen Germany
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Yu G, Clive DLJ. Formation of meta-Substituted Phenols by Transition Metal-Free Aromatization: Use of 2-Bromocyclohex-2-en-1-ones. J Org Chem 2016; 81:8470-84. [PMID: 27563935 DOI: 10.1021/acs.joc.6b01653] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Addition of Grignard or other organometallic reagents to 2-halocyclohex-2-en-1-ones bearing an alkyl or aryl group at C-5, followed by mild acid treatment and exposure to 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) at room temperature, generates meta-substituted phenols in which the newly introduced meta substituent originates from the Grignard reagent. The range of effective organometallic reagents includes alkyl, allyl, alkynyl, aryl, and heteroaryl compounds including those with fluorine substituents. The initial halocyclohexenone can be deprotonated at C-6 and reacted with carbon, fluorine, or sulfur electrophiles before the Grignard addition so as to generate highly substituted phenols.
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Affiliation(s)
- Guojun Yu
- Chemistry Department, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Derrick L J Clive
- Chemistry Department, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
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