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Kulsha AV, Ivashkevich OA, Lyakhov DA, Michels D. Strong Bases Design: Key Techniques and Stability Issues. Int J Mol Sci 2024; 25:8716. [PMID: 39201404 PMCID: PMC11354936 DOI: 10.3390/ijms25168716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2024] [Revised: 08/06/2024] [Accepted: 08/08/2024] [Indexed: 09/02/2024] Open
Abstract
Theoretical design of molecular superbases has been attracting researchers for more than twenty years. General approaches were developed to make the bases potentially stronger, but less attention was paid to the stability of the predicted structures. Hence, only a small fraction of the theoretical research has led to positive experimental results. Possible stability issues of extremely strong bases are extensively studied in this work using quantum chemical calculations on a high level of theory. Several step-by-step design examples are discussed in detail, and general recommendations are given to avoid the most common stability problems. New potentially stable structures are theoretically studied to demonstrate the future prospects of molecular superbases design.
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Affiliation(s)
- Andrey V. Kulsha
- Chemical Department, Belarusian State University, 14 Leningradskaya Str., 220006 Minsk, Belarus;
| | - Oleg A. Ivashkevich
- Research Institute for Physical Chemical Problems, Belarusian State University, 14 Leningradskaya Str., 220006 Minsk, Belarus
| | - Dmitry A. Lyakhov
- Computer, Electrical and Mathematical Science and Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia; (D.A.L.); (D.M.)
| | - Dominik Michels
- Computer, Electrical and Mathematical Science and Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia; (D.A.L.); (D.M.)
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2
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Bousselat A, Rouden J, Blanchet J. From Building Blocks to Catalysts: The Underinvestigated Potential of Boronic Acid Esters. J Org Chem 2024; 89:11009-11013. [PMID: 38995625 DOI: 10.1021/acs.joc.4c00775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Lewis acids are crucial in chemistry, with applications in pharmaceuticals, agrochemicals, and materials science. In main-group chemistry, they offer alternatives to transition metals, prompting our study of halogenated boronic acid esters (BAEs). Although BAEs are well-known, their catalytic potential has been overlooked. Our investigation found their Lewis acidity superior to that of boron trifluoride and comparable to that of tris(pentafluorophenyl)borane. Additionally, their catalysis of the Sakurai allylation of aldehydes has been documented, paving the way for future advancements.
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Affiliation(s)
- Ava Bousselat
- LCMT, ENSICAEN, UNICAEN et CNRS, 6 bd du Maréchal Juin, 14050 Caen, France
| | - Jacques Rouden
- LCMT, ENSICAEN, UNICAEN et CNRS, 6 bd du Maréchal Juin, 14050 Caen, France
| | - Jérôme Blanchet
- LCMT, ENSICAEN, UNICAEN et CNRS, 6 bd du Maréchal Juin, 14050 Caen, France
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3
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Song Z, Wang X, Feng W, Armand M, Zhou Z, Zhang H. Designer Anions for Better Rechargeable Lithium Batteries and Beyond. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310245. [PMID: 38839065 DOI: 10.1002/adma.202310245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 04/17/2024] [Indexed: 06/07/2024]
Abstract
Non-aqueous electrolytes, generally consisting of metal salts and solvating media, are indispensable elements for building rechargeable batteries. As the major sources of ionic charges, the intrinsic characters of salt anions are of particular importance in determining the fundamental properties of bulk electrolyte, as well as the features of the resulting electrode-electrolyte interphases/interfaces. To cope with the increasing demand for better rechargeable batteries requested by emerging application domains, the structural design and modifications of salt anions are highly desired. Here, salt anions for lithium and other monovalent (e.g., sodium and potassium) and multivalent (e.g., magnesium, calcium, zinc, and aluminum) rechargeable batteries are outlined. Fundamental considerations on the design of salt anions are provided, particularly involving specific requirements imposed by different cell chemistries. Historical evolution and possible synthetic methodologies for metal salts with representative salt anions are reviewed. Recent advances in tailoring the anionic structures for rechargeable batteries are scrutinized, and due attention is paid to the paradigm shift from liquid to solid electrolytes, from intercalation to conversion/alloying-type electrodes, from lithium to other kinds of rechargeable batteries. The remaining challenges and key research directions in the development of robust salt anions are also discussed.
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Affiliation(s)
- Ziyu Song
- Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Xingxing Wang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Wenfang Feng
- Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Michel Armand
- Centre for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Albert Einstein 48, Vitoria-Gasteiz, 01510, Spain
| | - Zhibin Zhou
- Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Heng Zhang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
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4
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Krieft J, Trapp PC, Vishnevskiy YV, Neumann B, Stammler HG, Lamm JH, Mitzel NW. A geminal antimony(iii)/phosphorus(iii) frustrated Lewis pair. Chem Sci 2024; 15:12118-12125. [PMID: 39092119 PMCID: PMC11290451 DOI: 10.1039/d4sc02785j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/29/2024] [Indexed: 08/04/2024] Open
Abstract
The geminal Lewis pair (F5C2)2SbCH2P(tBu)2 (1) was prepared by reacting (F5C2)2SbCl with LiCH2P(tBu)2. Despite its extremely electronegative pentafluoroethyl substituents, the neutral 1 exhibits a relatively soft acidic antimony function according to the HSAB concept (hard-soft acid-base). These properties lead to a reversibility in the binding of CS2 to 1, as observed by VT-NMR spectroscopy, while no reaction with CO2 is observed. The reaction behaviour towards heterocumulenes and the specific interaction situation in the CS2 adduct were analysed by quantum chemical calculations. The FLP-type reactivity of 1 has also been demonstrated by reaction with a variety of small molecules (SO2, PhNCO, PhNCS, (MePh2P)AuCl). The reactions of 1 with PhNCO and PhNCS led to different types of cyclic addition products: PhNCO adds with its N[double bond, length as m-dash]C bond and PhNCS adds preferentially with its C[double bond, length as m-dash]S bond. The reaction of 1 with (MePh2P)AuCl gave an adduct {[(F5C2)2SbCH2(tBu)2P]2Au}+ with a clamp-like structure binding a chloride anion by its two antimony atoms in chelate mode. Compound 1 and its adducts have been characterised by X-ray diffraction experiments, multinuclear NMR spectroscopy, elemental analyses and computational calculations (DFT, QTAIM, IQA).
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Affiliation(s)
- Jonas Krieft
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Pia C Trapp
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Yury V Vishnevskiy
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Beate Neumann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Hans-Georg Stammler
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Jan-Hendrik Lamm
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
| | - Norbert W Mitzel
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25 Bielefeld 33615 Germany
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5
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Wenger JS, Johnstone TC. A Sterically Accessible Monomeric Stibine Oxide Activates Organotetrel(IV) Halides, Including C-F and Si-F Bonds. J Am Chem Soc 2024; 146:19350-19359. [PMID: 38959432 PMCID: PMC11258792 DOI: 10.1021/jacs.4c05394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/05/2024]
Abstract
Phosphine oxides and arsine oxides are common laboratory reagents with diverse applications that stem from the chemistry exhibited by these monomeric species. Stibine oxides are, in contrast, generally dimeric or oligomeric species because of the reactivity-quenching self-association of the highly polarized stiboryl (Sb=O/Sb+-O-) group. We recently isolated Dipp3SbO (Dipp = 2,6-diisopropylphenyl), the first example of a kinetically stabilized monomeric stibine oxide, which exists as a bench-stable solid and bears an unperturbed stiboryl group. Herein, we report the isolation of Mes3SbO (Mes = mesityl), in which the less bulky substituents maintain the monomeric nature of the compound but unlock access to a wider range of reactivity at the unperturbed stiboryl group relative to Dipp3SbO. Mes3SbO was found to be a potent Lewis base in the formation of adducts with the main-group Lewis acids PbMe3Cl and SnMe3Cl. The accessible Lewis acidity at the Sb atom results in a change in the reactivity with GeMe3Cl, SiMe3Cl, and CPh3Cl. With these species, Mes3SbO formally adds the E-Cl (E = Ge, Si, C) bond across the unsaturated stiboryl group to form a 5-coordinate stiborane. The biphilicity of Mes3SbO is sufficiently potent to activate even the C-F and Si-F bonds of C(p-MeOPh)3F and SiEt3F, respectively. These results mark a significant contribution to an increasingly rich literature on the reactivity of polar, unsaturated main-group motifs. Furthermore, these results highlight the utility of a kinetic stabilization approach to access unusual bonding motifs with unquenched reactivity that can be leveraged for small-molecule activation.
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Affiliation(s)
- John S. Wenger
- Department of Chemistry and
Biochemistry, University of California Santa
Cruz, Santa
Cruz, California 95064, United States
| | - Timothy C. Johnstone
- Department of Chemistry and
Biochemistry, University of California Santa
Cruz, Santa
Cruz, California 95064, United States
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6
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Franke M, Ens T, Mix A, Neumann B, Stammler HG, Mitzel NW. Host-guest chemistry of tridentate Lewis acids based on tribenzotriquinacene. Dalton Trans 2024; 53:11970-11980. [PMID: 38961795 DOI: 10.1039/d4dt01558d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Flexible poly-Lewis acids (PLA) based on the tribenzotriquinacene (TBTQ) scaffold have been synthesised. Hydrosilylation of 4b,8b,12b-triallyltribenzotriquinacene and subsequent exchange of the chlorine substituents with weaker coordinating triflate groups afforded a novel triple silyl-functionalised PLA. By regioselective hydroboration of triallyl-TBTQ with various organoboranes, PLAs with different Lewis acidities were obtained. The synthesised PLAs were combined with neutral bases in host-guest experiments. DOSY NMR spectroscopy was performed to elucidate the complexation process in solution. These experiments revealed a highly dynamic interaction between the boron-functionalised PLA and triazine. However, the addition of one equivalent of tris(dimethylphosphino(methyl))phenylsilane led to the formation of a 1 : 1 adduct, which was confirmed by diffusion experiments.
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Affiliation(s)
- Maurice Franke
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Tobin Ens
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Andreas Mix
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Beate Neumann
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Hans-Georg Stammler
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Norbert W Mitzel
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
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7
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Krieft J, Neumann B, Stammler HG, Mitzel NW. Oxidation-dependent Lewis acidity in chalcogen adducts of Sb/P frustrated Lewis pairs. Dalton Trans 2024; 53:11762-11768. [PMID: 38938114 DOI: 10.1039/d4dt01591f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
The reactions of the frustrated Lewis pair (F5C2)2SbCH2P(tBu)2 with oxygen, sulphur, selenium and tellurium led to the mono-oxidation products (F5C2)2SbCH2P(E)(tBu)2 (E = O, S, Se, Te). Further oxidation of these chalcogen adducts with tetrachloro-ortho-benzoquinone (o-chloranil) gave (F5C2)2Sb(CH2)(μ-E)P(tBu)2·CatCl (CatCl = o-O2C6Cl4) with a central four-membered ring heterocycle for E = O, S, and Se. For E = Te the elimination of elemental tellurium led to an oxidation product with two equivalents of o-chloranil, (F5C2)2SbCH2P(tBu)2·2CatCl, which is also accessible by reaction of (F5C2)2SbCH2P(tBu)2 with o-chloranil. The synthesised compounds were characterised by NMR spectroscopy and X-ray structure analyses, and the structural properties were analysed in the light of the altered Lewis acidity due to the oxidation of the antimony atoms.
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Affiliation(s)
- Jonas Krieft
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Beate Neumann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Hans-Georg Stammler
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Norbert W Mitzel
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
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8
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Durfy CS, Zurakowski JA, Drover MW. A Blueprint for Secondary Coordination Sphere Editing: Approaches Toward Lewis-Acid Assisted Carbon Dioxide Co-Activation. CHEMSUSCHEM 2024; 17:e202400039. [PMID: 38358843 DOI: 10.1002/cssc.202400039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/17/2024]
Abstract
Carbon dioxide (CO2) is a potent greenhouse gas of environmental concern. Seeking to offer a solution to the "CO2-problem", the chemistry community has turned a focus toward transition metal complexes which can activate, reduce, and convert CO2 into carbon-based products. The design of such systems involves judicious selection of both metal and accompanying donor ligand; in part, these efforts are motivated by biological metalloenzymes that undertake similar transformations. As a design element, metal-ligand cooperativity, which leverages intramolecular interactions between a transition metal and an adjacent secondary ligand site, has been acknowledged as a vitally important component by the CO2 activation community. These systems offer a "push-pull" style of activation where electron density is chaperoned onto CO2 with an accompanying electrophile, such as a Lewis-acid, playing the role of acceptor. This pairing allows for the stabilization of reactive CxHyOz-containing intermediates and can bias CO2 product selectivity. In the laboratory, chemists can test hypotheses and ideas, enabling rationalization of why a given pairing of transition metal/Lewis-acid leads to selective CO2 reduction outcomes. This Concept identifies literature examples and highlights key design properties, allowing interested contributors to design, create, and implement novel systems for productive transformations of a small molecule (CO2) with huge potential impact.
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Affiliation(s)
- Connor S Durfy
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7
| | - Joseph A Zurakowski
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7
- Department of Chemistry and Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, Canada, N9B 3P4
| | - Marcus W Drover
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7
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9
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Zhang Z, Sheetz EG, Pink M, Yamamoto N, Flood AH. Cone Angles Quantify and Predict the Affinity and Reactivity of Anion Complexes between Trifluoroborates and Rigid Macrocycles. Angew Chem Int Ed Engl 2024:e202409070. [PMID: 38969622 DOI: 10.1002/anie.202409070] [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: 05/13/2024] [Revised: 07/04/2024] [Accepted: 07/05/2024] [Indexed: 07/07/2024]
Abstract
Steric manipulation is a known concept in molecular recognition but there is currently no linear free energy relationship correlating sterics to the stability of receptor-anion complexes nor to the reactivity of the bound anion. By analogy to Tolman cone angles in cation coordination chemistry, we explore how to define and correlate cone angles of organo-trifluoroborates (R-BF3 -) to the affinities observed for cyanostar-anion binding. We extend the analogy to a rare investigation of the anion's reactivity and how it changes upon binding. The substituent on the anion is used to define the cone angle, θ. A series of 10 anions were studied including versions with ethynyl, ethylene, and ethyl substituents to tune steric bulk across the sp, sp2 and sp3 hybridized α-carbons bearing 0, 1 and 2 hydrogen atoms. A linear relationship between affinity and cone angle is observed for anions bearing substituents larger than the -BF3 - headgroup. This correlation predicted affinities of two new anions to within ±5 %. We explored how complexation affects the reactivity of fluoride exchange. The yield of fluoride transfer from R-BF3 - to Lewis acid triphenylborane is correlated with cone angle. We predict that other rigid macrocycles, like commercially available bambusuril, could follow these trends.
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Affiliation(s)
- Zhao Zhang
- Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States
| | - Edward G Sheetz
- Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States
| | - Maren Pink
- Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States
| | - Nobuyuki Yamamoto
- Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States
| | - Amar H Flood
- Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States
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10
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Schepper J, Orthaber A, Pammer F. Tetrazole-Functionalized Organoboranes Exhibiting Dynamic Intramolecular N→B-Coordination and Cyanide-Selective Anion Binding. Chemistry 2024; 30:e202401466. [PMID: 38708576 DOI: 10.1002/chem.202401466] [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: 04/15/2024] [Revised: 04/25/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
Starting from two different cyano-functionalized organoboranes, we demonstrate that 1,3-dipolar [3+2] azide-nitrile cycloaddition can serve to generate libraries of alkyl-tetrazole-functionalized compounds capable of intramolecular N→B-Lewis adduct formation. Due to the relatively low basicity of tetrazoles, structures can be generated that exhibit weak and labile N→B-coordination. The reaction furnishes 1- and 2-alkylated regio-isomers that exhibit different effective Lewis-acidities at the boron centers, and vary in their optical absorption and fluorescence properties. Indeed, we identified derivatives capable of selectively binding cyanide over fluoride, as confirmed by 11B NMR. This finding demonstrates the potentialities of this synthetic strategy to systematically fine-tune the properties of lead structures that are of interest as chemical sensors.
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Affiliation(s)
- Jonas Schepper
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Andreas Orthaber
- Department of Chemistry - Ångström laboratories, Uppsala University, BOX 523, 75120, Uppsala, Sweden
| | - Frank Pammer
- Helmholtz Institute Ulm, Karlsruhe Institute for Technology, Helmholtzstrasse 11, 89081, Ulm, Germany
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11
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Brzeski J. Can H 2 be Superacidic? A Computational Study of Triel-Bonded Brønsted Acids. J Phys Chem A 2024; 128:5009-5020. [PMID: 38869476 PMCID: PMC11215784 DOI: 10.1021/acs.jpca.4c02663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/25/2024] [Accepted: 05/29/2024] [Indexed: 06/14/2024]
Abstract
The abundance of XIII group element compounds in science and industry together with their electron-deficient character gives rise to their influence on properties of the systems they interact with. This paper is an attempt to assess the strength, nature, and effect of formation of a triel bond on acidity. A wide set of Brønsted acids among others comprising hydrocarbons, halogen hydrides, and amines bonded with B, Al, and Ga trifluorides forming HX/TF3 was selected for the research. Various computational approaches (e.g., MP2, GFN2-xTB, SAPT2 + 3(CCD)δMP2, quantum theory of atoms in molecules analysis, and density overlap regions indicator) are used to describe the triel-bonded systems. Among other things, it was found that the electrostatics may not be the dominant contribution to the triel binding in some cases. Additionally, it was established that even weak Brønsted acids such as C2H2 or H2 may be superacidic if bonded to a Lewis acid (TF3) that is strong enough. The calculations indicate a significant covalent character of some of the studied HX/TF3 triel-bonded systems. Moreover, the effect of solvation of HX with TF3 as well as that of the reverse process on the acidity of the resulting system is thoroughly described.
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Affiliation(s)
- Jakub Brzeski
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
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12
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Wingering PMR, Krämer F, Dilanas MEA, Ruiz-Martínez C, Fernández I, Breher F. Structure and Solution Behavior of Rare-Earth-Metal Complexes with Tripodal N-Donor Ligands. Chemistry 2024; 30:e202400781. [PMID: 38668679 DOI: 10.1002/chem.202400781] [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: 02/26/2024] [Indexed: 06/27/2024]
Abstract
Rare-earth-metal complexes (Ln=Y, La, Ce, Sm and Lu) of tripodal N-donor ligands respecting the CHON principle have been synthetized and characterized. The selectivity of the ligands through the lanthanide cations was investigated and related to their donor strength.
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Affiliation(s)
- Perrine M R Wingering
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Felix Krämer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Melina E A Dilanas
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Cristina Ruiz-Martínez
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Ctra. Sacramento s/n, 04120, Almería, Spain
| | - Ignacio Fernández
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Ctra. Sacramento s/n, 04120, Almería, Spain
| | - Frank Breher
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
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13
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Wegener D, Pérez-Bitrián A, Limberg N, Wiesner A, Hoffmann KF, Riedel S. A Highly Sterically Encumbered Boron Lewis Acid Enabled by an Organotellurium-Based Ligand. Chemistry 2024; 30:e202401231. [PMID: 38625061 DOI: 10.1002/chem.202401231] [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: 04/06/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/17/2024]
Abstract
Lewis acidic boron compounds are ubiquitous in chemistry due to their numerous applications, yet tuning and optimizing their properties towards different purposes is still a challenging field of research. In this work, the boron-based Lewis acid B[OTeF3(C6F5)2]3 was synthesized by reaction of the teflate derivative HOTeF3(C6F5)2 with BCl3 or BCl3 ⋅ SMe2. This new compound presents a remarkably high thermal stability up to 300 °C, as well as one of the most sterically encumbered boron centres known in the literature. Theoretical and experimental methods revealed that B[OTeF3(C6F5)2]3 exhibits a comparable Lewis acidity to that of the well-known B(C6F5)3. The affinity of B[OTeF3(C6F5)2]3 towards pyridine was accessed by Isothermal Titration Calorimetry (ITC) and compared to that of B(OTeF5)3 and B(C6F5)3. The ligand-transfer reactivity of this new boron compound towards different fluorides was demonstrated by the formation of an anionic Au(III) complex and a hypervalent iodine(III) species.
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Affiliation(s)
- Daniel Wegener
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Alberto Pérez-Bitrián
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
- Current address: Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Niklas Limberg
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Anja Wiesner
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Kurt F Hoffmann
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Sebastian Riedel
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
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14
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Golz P, Shakeri K, Maas L, Balizs M, Pérez-Bitrián A, Kemmler HD, Kleoff M, Voßnacker P, Christmann M, Riedel S. Silver(i) Perfluoroalcoholates: Synthesis, Structure, and their Use as Transfer Reagents. Chemistry 2024; 30:e202400861. [PMID: 38607245 DOI: 10.1002/chem.202400861] [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: 02/29/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/13/2024]
Abstract
Herein we report a general access to silver(i) perfluoroalcoholates, their structure in the solid state and in solution, and their use as transfer reagents. The silver(i) perfluoroalcoholates are prepared by the reaction of AgF with the corresponding perfluorinated carbonyl compounds in acetonitrile and are stable for a prolonged time at -18 °C. X-ray analysis of single crystals of perfluoroalcoholate species showed that two Ag(i) centers are bridged by the alcoholate ligands. In acetonitrile solution, Ag[OCF3] forms different structures as indicated by IR spectroscopy. Furthermore, the silver(i) perfluoroalcoholates can be used as easy-to-handle transfer reagents for the synthesis of Cu[OCF3], Cu[OC2F5], [PPh4][Au(CF3)3(OCF3)], and fluorinated alkyl ethers.
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Affiliation(s)
- Paul Golz
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Kamar Shakeri
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Lilian Maas
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Marius Balizs
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Alberto Pérez-Bitrián
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Helen D Kemmler
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Merlin Kleoff
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Patrick Voßnacker
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Mathias Christmann
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Sebastian Riedel
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstr. 34/36, 14195, Berlin, Germany
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15
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Réant BLL, Whitehead GFS, Mehta M. Zintl Clusters as a Platform for Lewis Acid Catalysis. Inorg Chem 2024. [PMID: 38814137 DOI: 10.1021/acs.inorgchem.4c00433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Clusters of the main group elements phosphorus and arsenic, commonly categorized as Zintl clusters, have been known for over a century. And, only now is the application of these systems as catalysts for organic synthesis being investigated. In this work, boranes are tethered via an aliphatic linker to Zintl-based clusters and their Lewis acidity is examined experimentally, by the Gutmann-Beckett test and competency in the hydroborative reduction of six organic substrates, as well as computationally, by fluoride ion affinity and hydride ion affinity methods. The effects of tuning the aliphatic linker length, substituents at the boron, and changing the cluster from a seven-atom phosphorus system to a seven-atom arsenic system on reactivity are studied.
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Affiliation(s)
- Benjamin L L Réant
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - George F S Whitehead
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Meera Mehta
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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16
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Schlögl J, Goldammer O, Bader J, Emmerling F, Riedel S. Introducing AFS ([Al(SO 3F) 3] x) - a thermally stable, readily available, and catalytically active solid Lewis superacid. Chem Sci 2024; 15:8038-8044. [PMID: 38817578 PMCID: PMC11134397 DOI: 10.1039/d4sc01753f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 05/01/2024] [Indexed: 06/01/2024] Open
Abstract
Common Lewis superacids often suffer from low thermal stability or complicated synthetic protocols, requiring multi-step procedures and expensive starting materials. This prevents their large-scale application. Herein, the easy and comparably cheap synthesis of high-purity aluminium tris(fluorosulfate) ([Al(SO3F)3]x, AFS) is presented. All starting materials are commercially available and no work-up is required. The superacidity of this thermally stable, polymeric Lewis acid is demonstrated using both theoretical and experimental methods. Furthermore, its synthetic and catalytic applicability, e.g. in bond heterolysis reactions and C-F bond activations, is shown.
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Affiliation(s)
- Johanna Schlögl
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34/36 14195 Berlin Germany
| | - Ole Goldammer
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34/36 14195 Berlin Germany
| | - Julia Bader
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34/36 14195 Berlin Germany
| | - Franziska Emmerling
- Department Materials Chemistry, Federal Institute for Material Research and Testing Richard-Willstätter-Straße 11 12489 Berlin Germany
| | - Sebastian Riedel
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34/36 14195 Berlin Germany
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17
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Erdmann P, Schmitt M, Sigmund LM, Krämer F, Breher F, Greb L. How to Deal with Charge in the Ranking of Lewis Acidity: Critical Evaluation of an Extensive Set of Cationic Lewis Acids. Angew Chem Int Ed Engl 2024; 63:e202403356. [PMID: 38478925 DOI: 10.1002/anie.202403356] [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: 02/17/2024] [Indexed: 04/09/2024]
Abstract
The quantification of Lewis acidity is of fundamental and applied importance in chemistry. However, if neutral and charged Lewis acids are compared, a coherent ranking has been elusive, and severe uncertainties were accepted. With this study, we present a systematic computational analysis of Lewis base affinities of 784 mono-, di- and tricationic Lewis acids and their comparison with 149 representative neutral Lewis acids. Evaluating vacuum fluoride ion affinities (FIA) reveals a charge-caused clustering that prohibits any meaningful ranking. Instead, solvation-corrected FIAsolv is identified as a metric that overcomes charge sensitivity in a balanced manner, allowing for a coherent evaluation of Lewis acidity across varying charge states. Analyzing the impact of molecular volume on solvation-induced FIA damping provides rationales for fundamental trends and guidelines for the choice or design of neutral and cationic Lewis acids in the condensed phase. Exploring alternative scales, explicit counteranion effects, and selected experimental case studies reaffirms the advantages of solvation-corrected FIAsolv as the most versatile and practical approach for the quantitative ranking of general (thermodynamic) Lewis acidity.
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Affiliation(s)
- Philipp Erdmann
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Manuel Schmitt
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Lukas M Sigmund
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Felix Krämer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Frank Breher
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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18
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O'Donnell F, Wetmore SD, Gerken M. Fluoride-Ion Donor Properties of AsF 5. Inorg Chem 2024; 63:7619-7630. [PMID: 38629175 DOI: 10.1021/acs.inorgchem.3c04143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2024]
Abstract
Arsenic pentafluoride undergoes ligand-induced autoionization in the presence of 1,10-phenanthroline (phen) in a SO2ClF solution to form the donor-stabilized [AsF4(phen)][AsF6] salt. Reacting [AsF4(phen)][AsF6] with the strong Lewis acid SbF5·SO2 yields the mixed arsenic-antimony salt [AsF4(phen)][Sb2F11]. These salts are the first examples of crystallographically characterized donor-stabilized [AsF4]+ cations. The analogous reaction of AsF5 and 2,2'-bipyridine (bipy) does not result in autoionization but leads to the formation of the neutral 2:1 adduct (AsF5)2·bipy. The gas-phase and solution fluoride-ion affinities of [AsF4]+ and [SbF4]+ were calculated, revealing them to be incredibly strong Lewis acids. Density functional theory calculations and natural bond orbital analysis show that significant electron-pair donation from phen to the As center in [AsF4(phen)]+ occurs and quenches the extreme electrophilicity of the [AsF4]+ cation.
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Affiliation(s)
- Felix O'Donnell
- Canadian Centre for Research in Advanced Fluorine Technologies and Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge T1K 3M4, Canada
| | - Stacey D Wetmore
- Canadian Centre for Research in Advanced Fluorine Technologies and Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge T1K 3M4, Canada
| | - Michael Gerken
- Canadian Centre for Research in Advanced Fluorine Technologies and Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge T1K 3M4, Canada
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19
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Coburger P, Buzanich AG, Emmerling F, Abbenseth J. Combining geometric constraint and redox non-innocence within an ambiphilic PBiP pincer ligand. Chem Sci 2024; 15:6036-6043. [PMID: 38665539 PMCID: PMC11040644 DOI: 10.1039/d4sc00197d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/16/2024] [Indexed: 04/28/2024] Open
Abstract
The synthesis of the first pincer ligand featuring a strictly T-shaped group 15 element and its coordination behaviour towards transition metals is described. The platform is itself derived from a trianionic redox non-innocent NNN scaffold. In addition to providing a rigid coordination environment to constrain a Bi centre in a T-shaped geometry to manipulate its frontier molecular orbital constitution, the NNN chelate displays highly covalent bonding towards the geometrically constrained Bi centre. The formation of intriguing ambiphilic Bi-M bonding interactions is demonstrated upon formation of a pincer complex as well as a multimetallic cluster. All compounds are comprehensively characterised by spectroscopic methods including X-ray Absorption Near Edge Structure (XANES) spectroscopy and complemented by DFT calculations.
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Affiliation(s)
- Peter Coburger
- Department of Inorganic Chemistry, Technische Universität München Lichtenbergstr. 4 85747 Garching Germany
| | - Ana Guilherme Buzanich
- Department of Materials Chemistry, Federal Institute for Materials Research and Testing Richard-Willstätter-Str. 11 12489 Berlin Germany
| | - Franziska Emmerling
- Department of Materials Chemistry, Federal Institute for Materials Research and Testing Richard-Willstätter-Str. 11 12489 Berlin Germany
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Josh Abbenseth
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
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20
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Ferrer M, Alkorta I, Elguero J, Oliva-Enrich JM. A multi-FLP approach for CO 2 capture: investigating nitrogen, boron, phosphorus and aluminium doped nanographenes and the influence of a sodium cation. Phys Chem Chem Phys 2024; 26:12433-12443. [PMID: 38596872 DOI: 10.1039/d4cp00496e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The reactivity of B3N3-doped hexa-cata-hexabenzocoronene (B3N3-NG), Al3N3-NG, B3P3-NG and Al3P3-NG, models of doped nanographenes (NGs), towards carbon dioxide was studied with density functional theory (DFT) calculations at the M06-2X/6-311++G(3df,3pd)//M06-2X/6-31+G* level of theory. The NG systems exhibit a poly-cyclic poly-frustrated Lewis pair (FLP) nature, featuring multiple Lewis acid/Lewis base pairs on their surface enabling the capture of several CO2 molecules. The capture of CO2 by these systems was investigated within two scenarios: (A) sequential capture of up to three CO2 molecules and (B) capture of CO2 molecules in the presence of a sodium cation. The resulting adducts were analyzed in terms of the activation barriers and relative stabilities. The presence of aluminium atoms changes the asynchrony of the reaction favoring the aluminium-oxygen bond and influences the regioselectivity of the multi-capture. A cooperative effect is predicted due to π-electron delocalization, with the sodium cation stabilizing the stationary points and favoring the addition of CO2 to the NGs.
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Affiliation(s)
- Maxime Ferrer
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain.
- PhD Program in Theoretical Chemistry and Computational Modeling, Doctoral School, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain.
| | - José Elguero
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain.
| | - Josep M Oliva-Enrich
- Instituto de Química-Física Blas Cabrera (CSIC), Serrano, 119, E-28006 Madrid, Spain
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21
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Sigmund LM, S SS, Albers A, Erdmann P, Paton RS, Greb L. Predicting Lewis Acidity: Machine Learning the Fluoride Ion Affinity of p-Block-Atom-Based Molecules. Angew Chem Int Ed Engl 2024; 63:e202401084. [PMID: 38452299 DOI: 10.1002/anie.202401084] [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: 01/19/2024] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024]
Abstract
"How strong is this Lewis acid?" is a question researchers often approach by calculating its fluoride ion affinity (FIA) with quantum chemistry. Here, we present FIA49k, an extensive FIA dataset with 48,986 data points calculated at the RI-DSD-BLYP-D3(BJ)/def2-QZVPP//PBEh-3c level of theory, including 13 different p-block atoms as the fluoride accepting site. The FIA49k dataset was used to train FIA-GNN, two message-passing graph neural networks, which predict gas and solution phase FIA values of molecules excluded from training with a mean absolute error of 14 kJ mol-1 (r2=0.93) from the SMILES string of the Lewis acid as the only input. The level of accuracy is notable, given the wide energetic range of 750 kJ mol-1 spanned by FIA49k. The model's value was demonstrated with four case studies, including predictions for molecules extracted from the Cambridge Structural Database and by reproducing results from catalysis research available in the literature. Weaknesses of the model are evaluated and interpreted chemically. FIA-GNN and the FIA49k dataset can be reached via a free web app (www.grebgroup.de/fia-gnn).
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Affiliation(s)
- Lukas M Sigmund
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Shree Sowndarya S
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Andreas Albers
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Philipp Erdmann
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Robert S Paton
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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22
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Garg A, Haswell A, Hopkinson MN. C-F Bond Insertion: An Emerging Strategy for Constructing Fluorinated Molecules. Chemistry 2024; 30:e202304229. [PMID: 38270496 DOI: 10.1002/chem.202304229] [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: 12/19/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 01/26/2024]
Abstract
C-F Insertion reactions, where an organic fragment formally inserts into a carbon-fluorine bond in a substrate, are highly attractive, yet largely unexplored, methods to prepare valuable fluorinated molecules. The inherent strength of C-F bonds and the resulting need for a large thermodynamic driving force to initiate C-F cleavage often leads to sequestering of the released fluoride in an unreactive by-product. Recently, however, several groups have succeeded in overcoming this challenge, opening up the study of C-F insertion as an efficient and highly atom-economical approach to prepare fluorinated compounds. In this article, the recent breakthroughs are discussed focusing on the key conceptual advances that allowed for both C-F bond cleavage and subsequent incorporation of the released fluoride into the product.
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Affiliation(s)
- Arushi Garg
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
| | - Alex Haswell
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
| | - Matthew N Hopkinson
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, NE1 7RU, Newcastle Upon Tyne, UK
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23
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Schulte Y, Wölper C, Rupf SM, Malischewski M, SantaLucia DJ, Neese F, Haberhauer G, Schulz S. Structural characterization and reactivity of a room-temperature-stable, antiaromatic cyclopentadienyl cation salt. Nat Chem 2024; 16:651-657. [PMID: 38225271 DOI: 10.1038/s41557-023-01417-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 12/07/2023] [Indexed: 01/17/2024]
Abstract
The singlet states of cyclopentadienyl (Cp) cations are considered as true prototypes of an antiaromatic system. Unfortunately, their high intrinsic reactivity inhibited their isolation in the solid state as a salt, and controlled reactions are also scarce. Here we present the synthesis and solid state structure of the room-temperature-stable Cp cation salt [Cp(C6F5)5]+[Sb3F16]-. Although the aromatic triplet state of the [Cp(C6F5)5]+ cation is energetically favoured in the gas phase according to quantum chemical calculations, coordination of the cation by either [Sb3F16]- or C6F6 in the crystal lattice stabilizes the antiaromatic singlet state, which is present in the solid state. The calculated hydride and fluoride ion affinities of the [Cp(C6F5)5]+ cation are higher than those of the perfluorinated tritylium cation [C(C6F5)3]+. Reactions of [Cp(C6F5)5]+[Sb3F16]- with CO, which probably yields the corresponding carbonyl complex, and of radical Cp(C6F5)5∙ with selected model substrates (Cp2Fe, (Ph3C∙)2 and Cp*Al) are also presented.
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Affiliation(s)
- Yannick Schulte
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Christoph Wölper
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Susanne M Rupf
- Institute of Inorganic Chemistry, Freie Universität Berlin, Berlin, Germany
| | | | | | - Frank Neese
- Max-Planck Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
| | - Gebhard Haberhauer
- Institute of Organic Chemistry, University of Duisburg-Essen, Essen, Germany.
| | - Stephan Schulz
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Essen, Germany.
- Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Duisburg, Germany.
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24
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Samudrala K, Akram MO, Dutton JL, Martin CD, Conley MP. Formation of Strong Boron Lewis Acid Sites on Silica. Inorg Chem 2024; 63:4939-4946. [PMID: 38451151 PMCID: PMC10951953 DOI: 10.1021/acs.inorgchem.3c04121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/08/2024]
Abstract
Bis(1-methyl-ortho-carboranyl)borane (HBMeoCb2) is a very strong Lewis acid that reacts with the isolated silanols present on silica partially dehydroxylated at 700 °C (SiO2-700) to form the well-defined Lewis site MeoCb2B(OSi≡) (1) and H2. 11B{1H} magic-angle spinning (MAS) nuclear magnetic resonance (NMR) data of 1 are consistent with that of a three-coordinate boron site. Contacting 1 with O═PEt3 (triethylphosphine oxide TEPO) and measuring 31P{1H} MAS NMR spectra show that 1 preserves the strong Lewis acidity of HBMeoCb2. Hydride ion affinity and fluoride ion affinity calculations using small molecules analogs of 1 also support the strong Lewis acidity of the boron sites in this material. Reactions of 1 with Cp2Hf(13CH3)2 show that the Lewis sites are capable of abstracting methide groups from Hf to form [Cp2Hf-13CH3][H313C-B(MeoCb2)OSi≡], but with a low overall efficiency.
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Affiliation(s)
| | - Manjur O. Akram
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Jason L. Dutton
- Department
of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Caleb D. Martin
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Matthew P. Conley
- Department
of Chemistry, University of California, Riverside, California 92521, United States
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25
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Yoneda N, Iyama H, Nagata T, Katahira M, Ishii Y, Tada K, Matsumoto K, Hagiwara R. Fluoride Ion in Alcohols: Isopropanol vs Hexafluoroisopropanol. J Phys Chem Lett 2024; 15:1677-1685. [PMID: 38315662 DOI: 10.1021/acs.jpclett.3c03619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
The utility of alcohol as a hydrogen bonding donor is considered a providential avenue for moderating the high basicity and reactivity of the fluoride ion, typically used with large cations. However, the practicality of alcohol-fluoride systems in reactions is hampered by the limited understanding of the pertinent interactions between the OH group and F-. Therefore, this study comparatively investigates the thermal, structural, and physical properties of the CsF-2-propanol and CsF-1,1,1,3,3,3-hexafluoro-2-propanol systems to explicate the effects of the fluoroalkyl group on the interaction of alcohols and F-. The two systems exhibit vastly different phase diagrams despite the similar saturated concentrations. A combination of spectroscopic analyses, alcohol activity coefficient measurements, and theoretical calculations reveal the fluorinated alcohol system harbors the stronger OH···F- interactions between the two systems. The diffusion coefficient and ionic conductivity measurements attribute the present results to disparate states of ion association in the two systems.
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Affiliation(s)
- Nozomi Yoneda
- Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Haruka Iyama
- Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takashi Nagata
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Masato Katahira
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Yoshiki Ishii
- School of Frontier Engineering, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Kohei Tada
- Research Institute of Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka 563-8577, Japan
| | - Kazuhiko Matsumoto
- Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Rika Hagiwara
- Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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26
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Guerzoni MG, van Ingen Y, Babaahmadi R, Wirth T, Richards E, Melen RL. An un-forgotten classic: the nitro-Mannich reaction between nitrones and silyl nitronates catalysed by B(C 6F 5) 3. Chem Sci 2024; 15:2648-2654. [PMID: 38362430 PMCID: PMC10866342 DOI: 10.1039/d3sc05672d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/28/2023] [Indexed: 02/17/2024] Open
Abstract
Herein we report the B(C6F5)3-catalysed nitro-Mannich reaction between nitrones and silyl nitronates, affording silyl-protected α-nitro hydroxylamines with yields up to 99% and diastereoselectivities up to 99 : 1. Crucially, the obtained products can be converted into 1,2-diamines under simple reductive conditions. This work provides a new orthogonal method to the existing routes for the instalment of a nitro moiety under Lewis acid catalysed conditions, and expands the state-of-the-art substrate scope with respect to the silyl nitronates.
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Affiliation(s)
- Michael G Guerzoni
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub Maindy Road, Cathays Cardiff CF24 4HQ Cymru/Wales UK
| | - Yara van Ingen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub Maindy Road, Cathays Cardiff CF24 4HQ Cymru/Wales UK
| | - Rasool Babaahmadi
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub Maindy Road, Cathays Cardiff CF24 4HQ Cymru/Wales UK
| | - Thomas Wirth
- School of Chemistry, Cardiff University, Main Building Park Place Cardiff CF10 3AT Cymru/Wales UK
| | - Emma Richards
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub Maindy Road, Cathays Cardiff CF24 4HQ Cymru/Wales UK
- School of Chemistry, Cardiff University, Main Building Park Place Cardiff CF10 3AT Cymru/Wales UK
| | - Rebecca L Melen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub Maindy Road, Cathays Cardiff CF24 4HQ Cymru/Wales UK
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27
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Timoshkin AY. The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments. Chemistry 2024; 30:e202302457. [PMID: 37752859 DOI: 10.1002/chem.202302457] [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: 07/30/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 09/28/2023]
Abstract
New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.
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Affiliation(s)
- Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, 199034, Universitetskaya emb. 7/9, St. Petersburg, Russia
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28
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Ansmann N, Münch J, Schorpp M, Greb L. Neutral and Anionic Square Planar Palladium(0) Complexes Stabilized by a Silicon Z-Type Ligand. Angew Chem Int Ed Engl 2023; 62:e202313636. [PMID: 37899304 DOI: 10.1002/anie.202313636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/27/2023] [Accepted: 10/29/2023] [Indexed: 10/31/2023]
Abstract
Anionic [Pd(0)-X]- ate complex were proposed as key intermediates in Pd-catalyzed cross-coupling for decades, but their isolation remained elusive. Herein, a chelating Lewis acidic bis(amidophenolato)silane is introduced as a strong Z-type ligand which enables the characterization of the first anionic [Pd(0)-X]- ate complex. Intriguingly, these compounds and the neutral L-Pd(0) analogs exhibit a square planar coordination that is highly unusual for a d10 metal. Theoretical methods scrutinize the interaction between the Lewis acidic Si(IV) center and the late transition metal, while reactivity studies shed light on the potential role of anionic additives in oxidative addition reactions.
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Affiliation(s)
- Nils Ansmann
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Joshua Münch
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Marcel Schorpp
- Institut für Anorganische Chemie, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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29
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Beckmann JL, Krieft J, Vishnevskiy YV, Neumann B, Stammler HG, Mitzel NW. Poly-pnictogen bonding: trapping halide ions by a tetradentate antimony(iii) Lewis acid. Chem Sci 2023; 14:13551-13559. [PMID: 38033898 PMCID: PMC10685332 DOI: 10.1039/d3sc04594c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/05/2023] [Indexed: 12/02/2023] Open
Abstract
A highly halide affine, tetradentate pnictogen-bonding host-system based on the syn-photodimer of 1,8-diethynylanthracene was synthesized by a selective tin-antimony exchange reaction. The host carries four C[triple bond, length as m-dash]C-Sb(C2F5)2 units and has been investigated regarding its ability to act as a Lewis acidic host component for the cooperative trapping of halide ions (F-, Cl-, Br-, I-). The chelating effect makes this host-system superior to its bidentate derivative in competition experiments. It represents a charge-reversed crown-4 and has the ability to dissolve otherwise poorly soluble salts like tetra-methyl-ammonium chloride. Its NMR-spectroscopic properties make it a potential probe for halide ions in solution. Insights into the structural properties of the halide adducts by X-ray diffraction and computational methods (DFT, QTAIM, IQA) reveal a complex interplay of attractive pnictogen bonding interactions and Coulomb repulsion.
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Affiliation(s)
- J Louis Beckmann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
| | - Jonas Krieft
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
| | - Yury V Vishnevskiy
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
| | - Beate Neumann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
| | - Hans-Georg Stammler
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
| | - Norbert W Mitzel
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University Universitätsstrasse 25 Bielefeld 33615 Germany
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30
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Röther A, Farmer JC, Portwich FL, Görls H, Kretschmer R. Anion-Dependent Reactivity of Mono- and Dinuclear Boron Cations. Chemistry 2023; 29:e202302544. [PMID: 37641815 DOI: 10.1002/chem.202302544] [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: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
The dinuclear bis(N-heterocyclic carbene) borane adduct 2 rapidly reacts with tritylium salts at room temperature but the outcome is strongly impacted by the respective counter-ion. Using tritylium tetrakis(perfluoro-tert-butoxy)aluminate affords - depending on the solvent - either the bis(boronium) ion 4 or the hydride-bridged dication 5. In case of tritylium hexafluorophosphate, however, H/F exchange occurs between boron and phosphorus yielding the dinuclear BF3 adduct 3 along with phosphorus dihydride trifluoride. H/F exchange also takes place when using the mononuclear N-heterocyclic carbene BH3 adduct 6 and hence provides a facile route to PH2 F3 , which is usually synthesized in more complex reaction sequences regularly involving toxic hydrogen fluoride. DFT calculations shed light on the H/F exchange between the borenium ion and the [PF6 ]- counter-ion and the computed mechanism features only small barriers in line with the experimental observations.
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Affiliation(s)
- Alexander Röther
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - James C Farmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Flavio L Portwich
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
- Institute of Chemistry, Chemnitz University of Technology, Straße der Nationen 62, 09111, Chemnitz, Germany
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31
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Sokolnicki T, Alharbi MM, van Ingen Y, Rahim S, Pramanik M, Roldan A, Walkowiak J, Melen RL. Reactivity of a series of triaryl borates, B(OAr x) 3, in hydroboration catalysis. Dalton Trans 2023; 52:16118-16122. [PMID: 37901910 DOI: 10.1039/d3dt03333c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
In this paper, we compare the reactivity of a series of triaryl borates B(OArx)3 as catalysts for the hydroboration of alkenes and alkynes. It was observed that commercially available B(OPh)3 performed the poorest, whereas catalysts with o-F atoms appeared to perform much better.
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Affiliation(s)
- Tomasz Sokolnicki
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
- Adam Mickiewicz University, Faculty of Chemistry, Uniwersytetu Poznanskiego 8, 61-614, Poznan, Poland.
- Adam Mickiewicz University, Center for Advanced Technology, Uniwersytetu Poznanskiego 10, 61-614, Poznan, Poland
| | - Mashael M Alharbi
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
- Department of Chemistry, King Faisal University, College of Science, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia
| | - Yara van Ingen
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
| | - Shahnaz Rahim
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
- Department of Chemistry, Abdul Wali Khan University, Mardan, Pakistan
| | - Milan Pramanik
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
| | - Alberto Roldan
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
| | - Jędrzej Walkowiak
- Adam Mickiewicz University, Center for Advanced Technology, Uniwersytetu Poznanskiego 10, 61-614, Poznan, Poland
| | - Rebecca L Melen
- Cardiff Catalysis Institute, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ Wales, UK.
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32
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Beckmann JL, Krieft J, Vishnevskiy YV, Neumann B, Stammler HG, Mitzel NW. A Bidentate Antimony Pnictogen Bonding Host System. Angew Chem Int Ed Engl 2023; 62:e202310439. [PMID: 37773008 DOI: 10.1002/anie.202310439] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023]
Abstract
A bidentate pnictogen bonding host-system based on 1,8-diethynylanthracene was synthesized by a selective tin-antimony exchange reaction and investigated regarding its ability to act as a Lewis acidic host component for the complexation of Lewis basic or anionic guests. In this work, the novel C≡C-Sb(C2 F5 )2 unit was established to study the potential of antimony(III) sites as representatives for the scarcely explored pnictogen bonding donors. The capability of this partly fluorinated host system was investigated towards halide anions (Cl- , Br- , I- ), dimethyl chalcogenides Me2 Y (Y=O, S, Se, Te), and nitrogen heterocycles (pyridine, pyrimidine). Insights into the adduct formation behavior as well as the bonding situation of such E⋅⋅⋅Sb-CF moieties were obtained in solution by means of NMR spectroscopy, in the solid state by X-ray diffraction, by elemental analyses, and by computational methods (DFT, QTAIM, IQA), respectively.
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Affiliation(s)
- J Louis Beckmann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Jonas Krieft
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Yury V Vishnevskiy
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Beate Neumann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Norbert W Mitzel
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2 Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
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33
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Radiush EA, Wang H, Chulanova EA, Ponomareva YA, Li B, Wei QY, Salnikov GE, Petrakova SY, Semenov NA, Zibarev AV. Halide Complexes of 5,6-Dicyano-2,1,3-Benzoselenadiazole with 1 : 4 Stoichiometry: Cooperativity between Chalcogen and Hydrogen Bonding. Chempluschem 2023; 88:e202300523. [PMID: 37750466 DOI: 10.1002/cplu.202300523] [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: 09/19/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 09/27/2023]
Abstract
The [M4 -Hal]- (M=the title compound; Hal=Cl, Br, and I) complexes were isolated in the form of salts of [Et4 N]+ cation and characterized by XRD, NMR, UV-Vis, DFT, QTAIM, EDD, and EDA. Their stoichiometry is caused by a cooperative interplay of σ-hole-driven chalcogen (ChB) and hydrogen (HB) bondings. In the crystal, [M4 -Hal]- are connected by the π-hole-driven ChB; overall, each [Hal]- is six-coordinated. In the ChB, the electrostatic interaction dominates over orbital and dispersion interactions. In UV-Vis spectra of the M+[Hal]- solutions, ChB-typical and [Hal]- -dependent charge-transfer bands are present; they reflect orbital interactions and allow identification of the individual [Hal]- . However, the structural situation in the solutions is not entirely clear. Particularly, the UV-Vis spectra of the solutions are different from the solid-state spectra of the [Et4 N]+ [M4 -Hal]- ; very tentatively, species in the solutions are assigned [M-Hal]- . It is supposed that the formation of the [M4 -Hal]- proceeds during the crystallization of the [Et4 N]+ [M4 -Hal]- . Overall, M can be considered as a chromogenic receptor and prototype sensor of [Hal]- . The findings are also useful for crystal engineering and supramolecular chemistry.
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Affiliation(s)
- Ekaterina A Radiush
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Hui Wang
- School of Physical Science and Technology, Southwest Jiaotong University, 610031, Chengdu, P. R. China
| | - Elena A Chulanova
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Current address: Institute for Applied Physics, University of Tübingen, 72076, Tübingen, Germany
| | - Yana A Ponomareva
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Department of Natural Sciences, National Research University - Novosibirsk State University, 630090, Novosibirsk, Russia
| | - Bin Li
- School of Physical Science and Technology, Southwest Jiaotong University, 610031, Chengdu, P. R. China
| | - Qiao Yu Wei
- School of Physical Science and Technology, Southwest Jiaotong University, 610031, Chengdu, P. R. China
| | - Georgy E Salnikov
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Svetlana Yu Petrakova
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Nikolay A Semenov
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Andrey V Zibarev
- Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
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34
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Werner L, Hagn J, Walpuski J, Radius U. Aluminum(III) Cations [(NHC) ⋅ AlMes 2 ] + : Synthesis, Characterization, and Application in FLP-Chemistry. Angew Chem Int Ed Engl 2023:e202312111. [PMID: 37877231 DOI: 10.1002/anie.202312111] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 10/26/2023]
Abstract
The three-coordinate aluminum cations ligated by N-heterocyclic carbenes (NHCs) [(NHC) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- (NHC=IMeMe 4, IiPrMe 5, IiPr 6, Mes=2,4,6-trimethylphenyl) were prepared via hydride abstraction of the alanes (NHC) ⋅ AlHMes2 (NHC=IMeMe 1, IiPrMe 2, IiPr 3) using [Ph3 C]+ [B(C6 F5 )4 ]- in toluene as hydride acceptor. If this reaction was performed in diethyl ether, the corresponding four-coordinate aluminum etherate cations [(NHC) ⋅ AlMes2 (OEt2 )]+ [B(C6 F5 )4 ]- 7-9 (NHC=IMeMe 7, IiPrMe 8, IiPr 9) were isolated. According to a theoretical and experimental assessment of the Lewis-acidity of the [(IMeMe ) ⋅ AlMes2 ]+ cation is the acidity larger than that of B(C6 F5 )3 and of similar magnitude as reported for Al(C6 F5 )3 . The reaction of [(IMeMe ) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- 4 with the sterically less demanding, basic phosphine PMe3 afforded a mixed NHC/phosphine stabilized cation [(IMeMe ) ⋅ AlMes2 (PMe3 )]+ [B(C6 F5 )4 ]- 10. Equimolar mixtures of 4 and the sterically more demanding PCy3 gave a frustrated Lewis-pair (FLP), i.e., [(IMeMe ) ⋅ AlMes2 ]+ [B(C6 F5 )4 ]- /PCy3 FLP-11, which reacts with small molecules such as CO2 , ethene, and 2-butyne.
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Affiliation(s)
- Luis Werner
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julika Hagn
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Janis Walpuski
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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35
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Bormann N, Ward JS, Bergmann AK, Wenz P, Rissanen K, Gong Y, Hatz WB, Burbaum A, Mulks FF. Diiminium Nucleophile Adducts Are Stable and Convenient Strong Lewis Acids. Chemistry 2023; 29:e202302089. [PMID: 37427889 DOI: 10.1002/chem.202302089] [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: 07/05/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/11/2023]
Abstract
Strong Lewis acids are essential tools for manifold chemical procedures, but their scalable deployment is limited by their costs and safety concerns. We report a scalable, convenient, and inexpensive synthesis of stable diiminium-based reagents with a Lewis acidic carbon centre. Coordination with pyridine donors stabilises these centres; the 2,2'-bipyridine adduct shows a chelation effect at carbon. Due to high fluoride, hydride, and oxide affinities, the diiminium pyridine adducts are promising soft and hard Lewis acids. They effectively produce acylpyridinium salts from carboxylates that can acylate amines to give amides and imides even from electronically intractable coupling partners.
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Affiliation(s)
- Niklas Bormann
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Jas S Ward
- Department of Chemistry, University of Jyvaskyla, P. O. Box. 35, Survontie 9 B, 40014, Jyväskylä, Finland
| | - Ann Kathrin Bergmann
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Paula Wenz
- Department of Chemistry, University of Jyvaskyla, P. O. Box. 35, Survontie 9 B, 40014, Jyväskylä, Finland
| | - Kari Rissanen
- Department of Chemistry, University of Jyvaskyla, P. O. Box. 35, Survontie 9 B, 40014, Jyväskylä, Finland
| | - Yiwei Gong
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Wolf-Benedikt Hatz
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Alexander Burbaum
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Florian F Mulks
- Institute for Organic Chemistry (iOC), RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
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36
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Moon HW, Lavagnino MN, Lim S, Palkowitz MD, Mandler MD, Beutner GL, Drance MJ, Lipshultz JM, Scola PM, Radosevich AT. Deoxyfluorination of 1°, 2°, and 3° Alcohols by Nonbasic O-H Activation and Lewis Acid-Catalyzed Fluoride Shuttling. J Am Chem Soc 2023; 145:22735-22744. [PMID: 37812176 PMCID: PMC11179691 DOI: 10.1021/jacs.3c08373] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
A method for deoxyfluorination of aliphatic primary, secondary, and tertiary alcohols is reported, employing a nontrigonal phosphorus triamide for base-free alcohol activation in conjunction with an organic soluble fluoride donor and a triarylborane fluoride shuttling catalyst. Mechanistic experiments are consistent with a reaction that proceeds by the collapse of an oxyphosphonium fluoroborate ion pair with fluoride transfer. The substrate scope complements existing deoxyfluorination methods and enables the preparation of homochiral secondary and tertiary alkylfluorides by stereoinversion of the substrate alcohol.
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Affiliation(s)
- Hye Won Moon
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Marissa N. Lavagnino
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Soohyun Lim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Maximilian D. Palkowitz
- Small Molecule Drug Discovery, Bristol Myers Squibb, 250 Water Street, Cambridge, Massachusetts 02141, United States
| | - Michael D. Mandler
- Small Molecule Drug Discovery, Bristol Myers Squibb, Princeton, New Jersey 08543, United States
| | - Gregory L. Beutner
- Chemical and Synthetic Development, Bristol Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Myles J. Drance
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeffrey M. Lipshultz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Paul M. Scola
- Small Molecule Drug Discovery, Bristol Myers Squibb, 250 Water Street, Cambridge, Massachusetts 02141, United States
| | - Alexander T. Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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37
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Biskup D, Schnakenburg G, Boeré RT, Espinosa Ferao A, Streubel RK. Challenging an old paradigm by demonstrating transition metal-like chemistry at a neutral nonmetal center. Nat Commun 2023; 14:6456. [PMID: 37833259 PMCID: PMC10575908 DOI: 10.1038/s41467-023-42127-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
We describe nonmetal adducts of the phosphorus center of terminal phosphinidene complexes using classical C- and N-ligands from metal coordination chemistry. The nature of the L-P bond has been analyzed by various theoretical methods including a refined method on the variation of the Laplacian of electron density ∇2ρ along the L-P bond path. Studies on thermal stability reveal stark differences between N-ligands such as N-methyl imidazole and C-ligands such as tert-butyl isocyanide, including ligand exchange reactions and a surprising formation of white phosphorus. A milestone is the transformation of a nonmetal-bound isocyanide into phosphaguanidine or an acyclic bisaminocarbene bound to phosphorus; the latter is analogous to the chemistry of transition metal-bound isocyanides, and the former reveals the differences. This example has been studied via cutting-edge DFT calculations leading to two pathways differently favored depending on variations in steric demand. This study reveals the emergence of organometallic from coordination chemistry of a neutral nonmetal center.
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Affiliation(s)
- David Biskup
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany
| | - René T Boeré
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, T1K3M4, Canada
| | - Arturo Espinosa Ferao
- Departamento de Química Orgánica, Facultad de Química, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain.
| | - Rainer K Streubel
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany.
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38
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Murphy B, Gabbaï FP. Binding, Sensing, And Transporting Anions with Pnictogen Bonds: The Case of Organoantimony Lewis Acids. J Am Chem Soc 2023; 145:19458-19477. [PMID: 37647531 PMCID: PMC10863067 DOI: 10.1021/jacs.3c06991] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Indexed: 09/01/2023]
Abstract
Motivated by the discovery of main group Lewis acids that could compete or possibly outperform the ubiquitous organoboranes, several groups, including ours, have engaged in the chemistry of Lewis acidic organoantimony compounds as new platforms for anion capture, sensing, and transport. Principal to this approach are the intrinsically elevated Lewis acidic properties of antimony, which greatly favor the addition of halide anions to this group 15 element. The introduction of organic substituents to the antimony center and its oxidation from the + III to the + V state provide for tunable Lewis acidity and a breadth of applications in supramolecular chemistry and catalysis. The performances of these antimony-based Lewis acids in the domain of anion sensing in aqueous media illustrate the favorable attributes of antimony as a central element. At the same time, recent advances in anion binding catalysis and anion transport across phospholipid membranes speak to the numerous opportunities that lie ahead in the chemistry of these unique main group compounds.
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Affiliation(s)
- Brendan
L. Murphy
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843-3255, United States
| | - François P. Gabbaï
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843-3255, United States
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39
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Sinha S, Das A, Giri S. Insights into the catalytic activity of boron-doped thiazoles in the Diels-Alder reaction. Phys Chem Chem Phys 2023; 25:23708-23716. [PMID: 37614158 DOI: 10.1039/d3cp02441e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The role of boron-doped thiazoles as a Lewis acid catalyst in [4+2] cycloaddition reaction between 1,3-butadiene and acrolein has been addressed. Three different organic heterocycles were designed to study their catalytic activity. It has been observed that these heterocycles efficiently work as catalysts than the well-known Lewis acid BF3. All the reactions follow the normal electron demand process and are exothermic. Different conceptual DFT-based reactivity descriptors and electronic structure principles such as maximum hardness and minimum electrophilicity lend additional support to the feasibility of the reaction mechanism. The reaction force (RF), reaction electronic flux (REF), and its different components exhibit a detailed electronic activity throughout the reaction.
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Affiliation(s)
- Swapan Sinha
- School of Applied Science and Humanities, Haldia Institute of Technology, Haldia, 721657, India.
- Maulana Abul Kalam Azad University of Technology, Haringhata, 741249, India
| | - Abhishek Das
- School of Applied Science and Humanities, Haldia Institute of Technology, Haldia, 721657, India.
| | - Santanab Giri
- School of Applied Science and Humanities, Haldia Institute of Technology, Haldia, 721657, India.
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40
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Schulz J, Antala J, Rezazgui D, Císařová I, Štěpnička P. Synthesis, Structure, Reactivity, and Intramolecular Donor-Acceptor Interactions in a Phosphinoferrocene Stibine and Its Corresponding Phosphine Chalcogenides and Stiboranes. Inorg Chem 2023; 62:14028-14043. [PMID: 37566394 PMCID: PMC10466383 DOI: 10.1021/acs.inorgchem.3c02075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Indexed: 08/12/2023]
Abstract
Ferrocene-based phosphines equipped with additional functional groups are versatile ligands for coordination chemistry and catalysis. This contribution describes a new compound of this type, combining phosphine and stibine groups at the ferrocene backbone, viz. 1-(diphenylphosphino)-1'-(diphenylstibino)ferrocene (1). Phosphinostibine 1 and the corresponding P-chalcogenide derivatives Ph2P(E)fcSbPh2 (1E, fc = ferrocene-1,1'-diyl, E = O, S, Se) were synthesized and further converted to the corresponding stiboranes Ph2P(E)fcSb(O2C6Cl4)Ph2 (6 and 6E) by oxidation with o-chloranil. All compounds were characterized by spectroscopic methods, X-ray diffraction analysis, cyclic voltammetry, and theoretical methods. Both NMR spectroscopy and DFT calculations confirmed the presence of P → Sb and P═O → Sb donor-acceptor interactions in 6 and 6O, triggered by the oxidation of the stibine moiety into Lewis acidic stiborane. The corresponding interactions in 6S and 6Se were of the same type but significantly weaker. A coordination study with AuCl as the model metal fragment revealed that the phosphine group acts as the "primary" coordination site, in line with its higher basicity. The obtained Au(I) complexes were applied as catalysts in the Au-catalyzed cyclization of N-propargylbenzamide and in the oxidative [2 + 2 + 1] cyclization of ethynylbenzene with acetonitrile and pyridine N-oxides. The catalytic results showed that the stibine complexes had worse catalytic performance than their phosphine counterparts, most likely due to the formation of weaker coordination bonds and hence poorer stabilization of the active metal species. Nevertheless, the stibine moiety could be used to fine-tune the properties of the ligated metal center by changing the oxidation state or substituents at the "remote" Sb atom.
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Affiliation(s)
- Jiří Schulz
- Department
of Inorganic Chemistry,
Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic
| | - Jakub Antala
- Department
of Inorganic Chemistry,
Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic
| | - David Rezazgui
- Department
of Inorganic Chemistry,
Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic
| | - Ivana Císařová
- Department
of Inorganic Chemistry,
Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic
| | - Petr Štěpnička
- Department
of Inorganic Chemistry,
Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic
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41
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Wingering PMR, Hohnstein S, Krämer F, Dilanas MEA, Ruiz-Martínez C, Fernández I, Breher F. Synthesis, Crystal Structures, and Ion Pairing of κ 6 N Complexes with Rare-Earth Elements in the Solid State and in Solution. Chemistry 2023; 29:e202301529. [PMID: 37294063 DOI: 10.1002/chem.202301529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/09/2023] [Accepted: 06/09/2023] [Indexed: 06/10/2023]
Abstract
The rare earth element complexes (Ln=Y, La, Sm, Lu, Ce) of several podant κ6 N-coordinating ligands have been synthetized and thoroughly characterized. The structural properties of the complexes have been investigated by X-ray diffraction in the solid state and by advanced NMR methods in solution. To estimate the donor capabilities of the presented ligands, an experimental comparison study has been conducted by cyclic voltammetry as well as absorption experiments using the cerium complexes and by analyzing 89 Y NMR chemical shifts of the different yttrium complexes. In order to obtain a complete and detailed picture, all experiments were corroborated by state-of-the-art quantum chemical calculations. Finally, coordination competition studies have been carried out by means of 1 H and 31 P NMR spectroscopy to investigate the correlation with donor properties and selectivity.
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Affiliation(s)
- Perrine M R Wingering
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Silvia Hohnstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Felix Krämer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Melina E A Dilanas
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Cristina Ruiz-Martínez
- Laboratory of Organic Chemistry, University of Almería Carretera de Sacramento s/n, 04120, Almería, Spain
| | - Ignacio Fernández
- Laboratory of Organic Chemistry, University of Almería Carretera de Sacramento s/n, 04120, Almería, Spain
| | - Frank Breher
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
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42
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Sakata K, Suzuki S, Sugimoto T, Yoshikawa T. Quantum Chemical Study of the Cycloaddition Reaction of Tropone with 1,1-Diethoxyethene Catalyzed by B(C 6F 5) 3 or BPh 3. ACS OMEGA 2023; 8:30410-30420. [PMID: 37636958 PMCID: PMC10448487 DOI: 10.1021/acsomega.3c03560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/27/2023] [Indexed: 08/29/2023]
Abstract
Cycloaddition reaction of tropone with 1,1-diethoxyethene catalyzed by Lewis acid (LA), B(C6F5)3 or BPh3, was examined by using ωB97X-D-level density functional theory (DFT) calculations. In the absence of LA, the reaction proceeds in a stepwise fashion to form two chemical bonds, first between the C2 atom in tropone and the C2 atom in ethene and then between the C5 atom in the former and the C1 atom in the latter. When B(C6F5)3 is attached to the O atom in tropone, the C5 atom in tropone is attacked preferentially by the C1 atom in ethene in the second stage. The attack of the O atom in tropone is shown to be less likely; thus, the [4 + 2] addition is favored in the B(C6F5)3-catalyzed reaction. In contrast, the attack of the O atom in the BPh3-attached tropone to the C1 atom in ethene is preferred over the attack of the C5 atom, indicating that the [8 + 2] cycloaddition instead of the [4 + 2] cycloaddition proceeds in the BPh3-catalyzed reaction. Whether the C1 atom in ethene is attacked by C5 or by O in the second bond formation step is shown in this study to be governed mainly by the nucleophilicity of σ-lone pair electrons of the carbonyl O atom of tropone in the presence of LA. These results are consistent with the experiments reported by Li and Yamamoto.
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Affiliation(s)
- Ken Sakata
- Faculty of Pharmaceutical
Sciences, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan
| | - Sarina Suzuki
- Faculty of Pharmaceutical
Sciences, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan
| | - Tsubasa Sugimoto
- Faculty of Pharmaceutical
Sciences, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan
| | - Takeshi Yoshikawa
- Faculty of Pharmaceutical
Sciences, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan
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43
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Maltz L, Gabbaï FP. Analyzing Fluoride Binding by Group 15 Lewis Acids: Pnictogen Bonding in the Pentavalent State. Inorg Chem 2023; 62:13566-13572. [PMID: 37551938 PMCID: PMC10862541 DOI: 10.1021/acs.inorgchem.3c01987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Indexed: 08/09/2023]
Abstract
We report the results of a computational investigation into fluoride binding by a series of pentavalent pnictogen Lewis acids: pnictogen pentahalides (PnX5), tetraphenyl pnictogeniums (PnPh4+), and triphenyl pnictogen tetrachlorocatecholates (PnPh3Cat). Activation strain and energy decomposition analyses of the Lewis adducts not only clearly delineate the electrostatic and orbital contributions to these acid-base interactions but also highlight the importance of Pauli repulsion and molecular flexibility in determining relative Lewis acidity among the pnictogens.
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Affiliation(s)
- Logan
T. Maltz
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843, United States
| | - François P. Gabbaï
- Department of Chemistry, Texas A&M University, College
Station, Texas 77843, United States
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44
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Yadav R, Janßen P, Schorpp M, Greb L. Calix[4]pyrrolato-germane-(thf) 2: Unlocking the Anti-van't Hoff-Le Bel Reactivity of Germanium(IV) by Ligand Dissociation. J Am Chem Soc 2023; 145:17746-17754. [PMID: 37549106 PMCID: PMC10436272 DOI: 10.1021/jacs.3c04424] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 08/09/2023]
Abstract
Anti-van't Hoff-Le Bel configured p-block element species possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept to reach anti-van't Hoff-Le Bel reactivity by ligand dissociation from a rigid calix[4]pyrrole germane in its bis(thf) adduct. While the macrocyclic ligand assures square-planar coordination in the uncomplexed form, the labile thf donors provide robustness for isolation on a multigram scale. Unique properties of a low-lying acceptor orbital imparted to germanium(IV) can be verified, e.g., by isolating an elusive anionic hydrido germanate and exploiting it for challenging bond activations. Aldehydes, water, alcohol, and a CN triple bond are activated for the first time by germanium-ligand cooperativity. Unexpected behaviors against fluoride ion donors disclose critical interferences of a putative redox-coupled fluoride ion transfer during the experimental determination of Lewis acidity. Overall, we showcase how ligand lability grants access to the uncharted chemistry of anti-van't Hoff-Le Bel germanium(IV) and line up this element as a member in the emerging class of structurally constrained p-block elements.
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Affiliation(s)
| | | | | | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
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45
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Brinck T, Sahoo SK. Anomalous π-backbonding in complexes between B(SiR 3) 3 and N 2: catalytic activation and breaking of scaling relations. Phys Chem Chem Phys 2023; 25:21006-21019. [PMID: 37519222 DOI: 10.1039/d3cp00248a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Chemical transformations of molecular nitrogen (N2), including the nitrogen reduction reaction (NRR), are difficult to catalyze because of the weak Lewis basicity of N2. In this study, it is shown that Lewis acids of the types B(SiR3)3 and B(GeR3)3 bind N2 and CO with anomalously short and strong B-N or B-C bonds. B(SiH3)3·N2 has a B-N bond length of 1.48 Å and a complexation enthalpy of -15.9 kcal mol-1 at the M06-2X/jun-cc-pVTZ level. The selective binding enhancement of N2 and CO is due to π-backbonding from Lewis acid to Lewis base, as demonstrated by orbital analysis and density difference plots. The π-backbonding is found to be a consequence of constructive orbital interactions between the diffuse and highly polarizable B-Si and B-Ge bond regions and the π and π* orbitals of N2. This interaction is strengthened by electron donating substituents on Si or Ge. The π-backbonding interaction is predicted to activate N2 for chemical transformation and reduction, as it decreases the electron density and increases the length of the N-N bond. The binding of N2 and CO by the B(SiR3)3 and B(GeR3)3 types of Lewis acids also has a strong σ-bonding contribution. The relatively high σ-bond strength is connected to the highly positive surface electrostatic potential [VS(r)] above the B atom in the tetragonal binding conformation, but the σ-bonding also has a significant coordinate covalent (dative) contribution. Electron withdrawing substituents increase the potential and the σ-bond strength, but favor the binding of regular Lewis acids, such as NH3 and F-, more strongly than binding of N2 and CO. Molecules of the types B(SiR3)3 and B(GeR3)3 are chemically labile and difficult to synthesize. Heterogenous catalysts with the wanted B(Si-)3 or B(Ge-)3 bonding motif may be prepared by boron doping of nanostructured silicon or germanium compounds. B-doped and hydrogenated silicene is found to have promising properties as catalyst for the electrochemical NRR.
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Affiliation(s)
- Tore Brinck
- Department of Chemistry, CBH, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Suman Kalyan Sahoo
- Department of Chemistry, CBH, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
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46
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Mancinelli JP, Kong WY, Guo W, Tantillo DJ, Wilkerson-Hill SM. Borane-Catalyzed C-F Bond Functionalization of gem-Difluorocyclopropenes Enables the Synthesis of Orphaned Cyclopropanes. J Am Chem Soc 2023; 145:17389-17397. [PMID: 37494703 DOI: 10.1021/jacs.3c05278] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Herein, we disclose an approach to synthesize tert-alkyl cyclopropanes by leveraging C-F bond functionalization of gem-difluorocyclopropenes using tris(pentafluorophenyl)borane catalysis. The reaction proceeds through the intermediacy of a fluorocyclopropenium ion, which was confirmed by the isolation of [Ph2(C6D5)C3]+[(C6F5)3BF]-. We found that silylketene acetal nucleophiles were optimal reaction partners with fluorocyclopropenium ion intermediates yielding fully substituted cyclopropenes functionalized with two α-tert-alkyl centers (63-93% yield). The regioselectivity of the addition to cyclopropenium ions is controlled by their steric and electronic properties and enables access to 3,3-bis(difluoromethyl)cyclopropenes in short order. The resulting cyclopropene products are readily reduced to the corresponding orphaned cyclopropanes under hydrogenation conditions. Quantum chemical calculations reveal the nature of the C-F bond cleavage steps and provide evidence for catalysis by boron and not silylated oxonium ions, though Si-F bond formation is the enthalpic driving force for the reaction.
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Affiliation(s)
- Joseph P Mancinelli
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Wang-Yeuk Kong
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Wentao Guo
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Sidney M Wilkerson-Hill
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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47
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Adachi Y, Hasegawa T, Ohshita J. Highly luminescent antiaromatic diborinines with fused thiophene rings. Dalton Trans 2023. [PMID: 37357987 DOI: 10.1039/d3dt01841e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Tricoordinate boron-incorporated π-conjugated systems are widely investigated as optoelectronic materials because of their unique p-π* orbital interactions and high Lewis acidity. Among them, thiophene-fused diborinines are characterized by moderate antiaromaticity and extended conjugation. In this work, we have developed two new dithienodiborinines with C2h and C2v symmetries, which exhibited completely different optical properties. The thiophene-fused diborinines synthesized in this study showed excellent fluorescence properties both in solution and in the solid state, with quantum yields of up to 95%. The high antiaromaticity enhanced the Lewis acidity of the boron centers, as proven by the large association constants with fluoride ion estimated from titration experiments. The high Lewis acidity and the superior luminescence property have enabled their application as fluorescent sensor materials for the detection of ammonia vapor.
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Affiliation(s)
- Yohei Adachi
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Takumi Hasegawa
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Joji Ohshita
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
- Digital Monozukuri (Manufacturing) Education and Research Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan.
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48
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Shibutani Y, Kusumoto S, Nozaki K. Synthesis, Characterization, and Trapping of a Cyclic Diborylcarbene, an Electrophilic Carbene. J Am Chem Soc 2023. [PMID: 37354094 DOI: 10.1021/jacs.3c04933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2023]
Abstract
A carbene bearing two geminal boryl substituents, called diborylcarbene (DBC), has been predicted to be highly Lewis acidic in sharp contrast to the well-studied persistent carbenes stabilized by π-donating substituents. Studies on DBC have been limited to either the base-trapping or theoretical calculations. Herein, we developed chemical equivalents for DBC, namely, K/X-diborylcarbenoids 2X (X = F or Cl). Treatment of 2F with Al(C6F5)3 yielded [AlF(C6F5)3]--stabilized DBC 1-FAl, which showed a significant low-field shift of the carbenoid carbon from 169 ppm (doublet, coupling with 19F) to 242 ppm (singlet). The loss of halogen was also detected through electrospray ionization time-of-flight mass spectrometry analysis of 2X only in the presence of Al(C6F5)3. Generated DBC 1 from 1-FAl or 2Cl was successfully trapped with excess amounts of trialkylphosphines (PR3, R = Me or Et), which afforded the corresponding DBC-PR3 adducts. In addition, the Lewis acidity of DBC 1 was evaluated both experimentally and theoretically to reveal that 1 is one of the most Lewis acidic species among neutral molecules.
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Affiliation(s)
- Yuki Shibutani
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shuhei Kusumoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kyoko Nozaki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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49
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McKnight EA, Arora R, Pradhan E, Fujisato YH, Ajayi AJ, Lautens M, Zeng T, Le CM. BF 3-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling. J Am Chem Soc 2023; 145:11012-11018. [PMID: 37172320 DOI: 10.1021/jacs.3c03982] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A BF3-catalyzed atom-economical fluorocarbamoylation reaction of alkyne-tethered carbamoyl fluorides is reported. The catalyst acts as both a fluoride source and Lewis acid activator, thereby enabling the formal insertion of alkynes into strong C-F bonds through a halide recycling mechanism. The developed method provides access to 3-(fluoromethylene) oxindoles and γ-lactams with excellent stereoselectivity, including fluorinated derivatives of known protein kinase inhibitors. Experimental and computational studies support a stepwise mechanism for the fluorocarbamoylation reaction involving a turnover-limiting cyclization step, followed by internal fluoride transfer from a BF3-coordinated carbamoyl adduct. For methylene oxindoles, a thermodynamically driven Z-E isomerization is facilitated by a transition state with aromatic character. In contrast, this aromatic stabilization is not relevant for γ-lactams, which results in a higher barrier for isomerization and the exclusive formation of the Z-isomer.
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Affiliation(s)
- E Ali McKnight
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Ramon Arora
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Ekadashi Pradhan
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Yuriko H Fujisato
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Ayonitemi J Ajayi
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Mark Lautens
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Tao Zeng
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Christine M Le
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
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Hannah TJ, McCarvell WM, Kirsch T, Bedard J, Hynes T, Mayho J, Bamford KL, Vos CW, Kozak CM, George T, Masuda JD, Chitnis SS. Planar bismuth triamides: a tunable platform for main group Lewis acidity and polymerization catalysis. Chem Sci 2023; 14:4549-4563. [PMID: 37152250 PMCID: PMC10155930 DOI: 10.1039/d3sc00917c] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/14/2023] [Indexed: 05/09/2023] Open
Abstract
Geometric deformation in main group compounds can be used to elicit unique properties including strong Lewis acidity. Here we report on a family of planar bismuth(iii) complexes (cf. typically pyramidal structure for such compounds), which show a geometric Lewis acidity that can be further tuned by varying the steric and electronic features of the triamide ligand employed. The structural dynamism of the planar bismuth complexes was probed in both the solid and solution phase, revealing at least three distinct modes of intermolecular association. A modified Gutmann-Beckett method was used to assess their electrophilicity by employing trimethylphosphine sulfide in addition to triethylphosphine oxide as probes, providing insights into the preference for binding hard or soft substrates. Experimental binding studies were complemented by a computational assessment of the affinities and dissection of the latter into their intrinsic bond strength and deformation energy components. The results show comparable Lewis acidity to triarylboranes, with the added ability to bind two bases simultaneously, and reduced discrimination against soft substrates. We also study the catalytic efficacy of these complexes in the ring opening polymerization of cyclic esters ε-caprolactone and rac-lactide. The polymers obtained show excellent dispersity values and high molecular weights with low catalyst loadings used. The complexes retain their performance under industrially relevant conditions, suggesting they may be useful as less toxic alternatives to tin catalysts in the production of medical grade materials. Collectively, these results establish planar bismuth complexes as not only a novel neutral platform for main group Lewis acidity, but also a potentially valuable one for catalysis.
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Affiliation(s)
- Tyler J Hannah
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - W Michael McCarvell
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Tamina Kirsch
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Joseph Bedard
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Toren Hynes
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Jacqueline Mayho
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Karlee L Bamford
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Cyler W Vos
- Department of Chemistry, Memorial University of Newfoundland St. John's NL A1B 3X7 Canada
| | - Christopher M Kozak
- Department of Chemistry, Memorial University of Newfoundland St. John's NL A1B 3X7 Canada
| | - Tanner George
- Department of Chemistry, Saint Mary's University 923 Robie St. Halifax NS B3H 3C3 Canada
| | - Jason D Masuda
- Department of Chemistry, Saint Mary's University 923 Robie St. Halifax NS B3H 3C3 Canada
| | - S S Chitnis
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
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