1
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Boegli MC, Coffinet A, Bijani C, Simonneau A. Seven-Coordinate Group 6 Metal Hydrides Obtained by H 2 Activation at B(C 6F 5) 3 Adducts of N 2 Complexes: Frustrated Lewis Pair-Type Reactivity of The B-N Linkage. Chem Asian J 2024; 19:e202400451. [PMID: 38864406 DOI: 10.1002/asia.202400451] [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: 04/23/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
The adducts 2M,R of general formula trans-[(L)M{R2P(CH2)2PR2}2{N2B(C6F5)3}] (L=ø or N2, M=Mo or W, R=Et or Ph), formed from Lewis acid-base pairing of B(C6F5)3 to a dinitrogen ligand of zero-valent group 6 bis(phosphine) complexes trans-[M{R2P(CH2)2PR2}2(N2)2] are shown to react with dihydrogen to afford hepta-coordinated bis(hydride) complexes [M(H)2{R2P(CH2)2PR2}{N2B(C6F5)3}] 3M,R which feature the rare ability to activate both dinitrogen and dihydrogen at a single metal center, except in the case where M=Mo and R=Ph for which fast precipitation of insoluble [Mo(H)4(dppe)2] (dppe=1,2-bis(diphenylphosphino)ethane) occurs. The frustrated Lewis pair (FLP)-related reactivity of the B-N linkage in compounds 3W,R was explored and led to distal N functionalization without involvement of the hydride ligands. It is shown in one example that the resulting bis(hydride) diazenido compounds may also be obtained through a sequence involving first FLP-type N-functionalization followed by oxidative addition of H2. Those oily compounds were found to have limited stability in solution or in their isolated states. Finally, treatment of 3W,Et with the Lewis base N,N-dimethylaminopyridine (DMAP) affords the simple but unknown bis(hydride)-dinitrogen species [W(H)2(depe)2(N2)] 11Et (depe=1,2-bis(diethylphosphino)ethane) which direct, selective formation from trans-[W(N2)2(depe)2] is not possible.
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Affiliation(s)
- Marie-Christine Boegli
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Anaïs Coffinet
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Christian Bijani
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Antoine Simonneau
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
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2
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Saptal VB, Ranjan P, Zbořil R, Nowicki M, Walkowiak J. Magnetically Recyclable Borane Lewis Acid Catalyst for Hydrosilylation of Imines and Reductive Amination of Carbonyls. CHEMSUSCHEM 2024; 17:e202400058. [PMID: 38630961 DOI: 10.1002/cssc.202400058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/05/2024] [Accepted: 04/15/2024] [Indexed: 04/19/2024]
Abstract
Fluorinated arylborane-based Lewis acid catalysts have shown remarkable activity and serve as ideal examples of transition metal-free catalysts for diverse organic transformations. However, their homogeneous nature poses challenges in terms of recyclability and separation from reaction mixtures. This work presents an efficient technique for the heterogenization of boron Lewis acid catalysts by anchoring Piers' borane to allyl-functionalized iron oxide. This catalyst demonstrates excellent activity in the hydrosilylation of imines and the reductive amination of carbonyls using various silanes as reducing agents under mild reaction conditions. The catalyst exhibits broad tolerance towards a wide range of functional substrates. Furthermore, it exhibits good recyclability and can be easily separated from the products using an external magnetic field. This work represents a significant advance in the development of sustainable heterogenous metal-free catalysts for organic transformations.
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Affiliation(s)
- Vitthal B Saptal
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego Poznań, 10, 61-614, Poznan, Poland
| | - Prabodh Ranjan
- Department of Chemistry, Indian Institute of Technology, Kanpur, India, 208016
| | - Radek Zbořil
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, CATRIN), Palacký University Olomouc, Šlechtitelů 27, 779 00, Olomouc, Czech Republic
- CEET, Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 2172/15, 708 00, Ostrava-Poruba, Czech Republic
| | - Marek Nowicki
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego Poznań, 10, 61-614, Poznan, Poland
- Institute of Physics, Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965, Poznan, Poland
| | - Jędrzej Walkowiak
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego Poznań, 10, 61-614, Poznan, Poland
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3
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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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4
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Pahar S, van Ingen Y, Babaahmadi R, Kariuki BM, Wirth T, Richards E, Melen RL. Diverse Reactivity of Amidinate-Supported Boron Centers with the Hypersilyl Anion and Access to a Monomeric Secondary Boron Hydride. Inorg Chem 2024; 63:8302-8311. [PMID: 38652816 PMCID: PMC11080068 DOI: 10.1021/acs.inorgchem.4c00612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
Diverse reactivity of the bulky tris(trimethylsilyl)silyl substituent [Si(SiMe3)3], also known as the hypersilyl group, was observed for amidinate-supported dichloro- and phenylchloroborane complexes. Treatment of the dichloroborane with potassium tris(trimethylsilyl)silyl led to the activation of the backbone β-carbon center and formation of saturated four-membered heterocyclic chloroboranes R'{Si(SiMe3)3}C(NR)2BCl [R' = Ph, R = Cy (3); R' = Ph, R = iPr (6); R' = tBu, R = Cy (8)], whereas the four-membered amidinate hypersilyl-substituted phenyl borane 4 {PhC(NCy)2B(Ph)[Si(SiMe3)3]} was observed for the case of an amidinate-supported phenylchloroborane. The highly deshielded 11B NMR spectroscopic resonance and the distinct difference in the 29Si NMR spectrum confirmed the presence of a σ-donating hypersilyl effect on compounds 3, 6, and 8. Reaction of 3 with the Lewis acid AlCl3 led to the formation of complex 11 in which an unusual cleavage of one of the C-N bonds of the amidinate backbone is observed. Nucleophilic substitution at the boron center of saturated chloroborane 3 with phenyllithium generated the phenylborane derivative 12, whereas the secondary monomeric boron hydride 13 was observed after treatment with alane (AlH3). All compounds (2-13) have been fully characterized by NMR spectroscopy and single-crystal X-ray structure determination studies.
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Affiliation(s)
- Sanjukta Pahar
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff CF24 4HQ, Cymru/Wales, U.K.
| | - Yara van Ingen
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff CF24 4HQ, Cymru/Wales, U.K.
| | - Rasool Babaahmadi
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff CF24 4HQ, Cymru/Wales, U.K.
| | - Benson M. Kariuki
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, Cymru/Wales, U.K.
| | - Thomas Wirth
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, Cymru/Wales, U.K.
| | - Emma Richards
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff CF24 4HQ, Cymru/Wales, U.K.
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, Cymru/Wales, U.K.
| | - Rebecca L. Melen
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff CF24 4HQ, Cymru/Wales, U.K.
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5
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Kótai B, Laczkó G, Hamza A, Pápai I. Stereocontrol via Propeller Chirality in FLP-Catalyzed Asymmetric Hydrogenation. Chemistry 2024; 30:e202400241. [PMID: 38294415 DOI: 10.1002/chem.202400241] [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: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/01/2024]
Abstract
Utilization of chiral frustrated Lewis pairs as catalysts in enantioselective hydrogenation of unsaturated molecules represents a promising approach in asymmetric synthesis. In our effort to improve our current understanding of the factors governing the stereoselectivity in these catalytic processes, herein we examined the mechanism of direct hydrogenation of aromatic enamines catalyzed by a binaphthyl-based chiral amino-borane. Our computational analysis reveals that only one particular conformer of the key borohydride reaction intermediate can be regarded as a reactive form of this species. This borohydride conformer has a well-defined chiral propeller shape, which induces facial selectivity in the hydride transfer to pro-chiral iminium intermediates. The propeller chirality of the reactive borohydride conformer is generated by the axially chiral binaphthyl scaffold of the amino-borane catalyst through stabilizing π-π stacking interactions. This new computational insight can be readily used to interpret the high degree of stereoinduction observed for these reactions. We expect that the concept of chirality relay could be further exploited in catalyst design endeavors.
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Affiliation(s)
- B Kótai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, H-1117, Budapest, Magyar tudósok körútja 2
- Hevesy György Ph.D. School of Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518, Budapest, Hungary
| | - G Laczkó
- Institute of Organic Chemistry, Research Centre for Natural Sciences, H-1117, Budapest, Magyar tudósok körútja 2
- Hevesy György Ph.D. School of Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518, Budapest, Hungary
| | - A Hamza
- Institute of Organic Chemistry, Research Centre for Natural Sciences, H-1117, Budapest, Magyar tudósok körútja 2
| | - I Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, H-1117, Budapest, Magyar tudósok körútja 2
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6
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Zhang YY, Yang GW, Lu C, Zhu XF, Wang Y, Wu GP. Organoboron-mediated polymerizations. Chem Soc Rev 2024; 53:3384-3456. [PMID: 38411207 DOI: 10.1039/d3cs00115f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The scientific community has witnessed extensive developments and applications of organoboron compounds as synthetic elements and metal-free catalysts for the construction of small molecules, macromolecules, and functional materials over the last two decades. This review highlights the achievements of organoboron-mediated polymerizations in the past several decades alongside the mechanisms underlying these transformations from the standpoint of the polymerization mode. Emphasis is placed on free radical polymerization, Lewis pair polymerization, ionic (cationic and anionic) polymerization, and polyhomologation. Herein, alkylborane/O2 initiating systems mediate the radical polymerization under ambient conditions in a controlled/living manner by careful optimization of the alkylborane structure or additives; when combined with Lewis bases, the selected organoboron compounds can mediate the Lewis pair polymerization of polar monomers; the bicomponent organoboron-based Lewis pairs and bifunctional organoboron-onium catalysts catalyze ring opening (co)polymerization of cyclic monomers (with heteroallenes, such as epoxides, CO2, CO, COS, CS2, episulfides, anhydrides, and isocyanates) with well-defined structures and high reactivities; and organoboranes initiate the polyhomologation of sulfur ylides and arsonium ylides providing functional polyethylene with different topologies. The topological structures of the produced polymers via these organoboron-mediated polymerizations are also presented in this review mainly including linear polymers, block copolymers, cyclic polymers, and graft polymers. We hope the summary and understanding of how organoboron compounds mediate polymerizations can inspire chemists to apply these principles in the design of more advanced organoboron compounds, which may be beneficial for the polymer chemistry community and organometallics/organocatalysis community.
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Affiliation(s)
- Yao-Yao Zhang
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
- National Engineering Laboratory for Textile Fiber Materials and Processing Technology, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China
| | - Guan-Wen Yang
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
| | - Chenjie Lu
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
- College of Material Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, 311121, Zhejiang, China
| | - Xiao-Feng Zhu
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
| | - Yuhui Wang
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
| | - Guang-Peng Wu
- MOE Laboratory of Macromolecular Synthesis and Functionalization, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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7
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Elsherbeni S, Melen RL, Pulis AP, Morrill LC. Accessing Highly Substituted Indoles via B(C 6F 5) 3-Catalyzed Secondary Alkyl Group Transfer. J Org Chem 2024; 89:4244-4248. [PMID: 38389441 PMCID: PMC10949240 DOI: 10.1021/acs.joc.4c00025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/24/2024]
Abstract
Herein, we report a synthetic method to access a range of highly substituted indoles via the B(C6F5)3-catalyzed transfer of 2° alkyl groups from amines. The transition-metal-free catalytic approach has been demonstrated across a broad range of indoles and amine 2° alkyl donors, including various substituents on both reacting components, to access useful C(3)-alkylated indole products. The alkyl transfer process can be performed using Schlenk line techniques in combination with commercially available B(C6F5)3·nH2O and solvents, which obviates the requirement for specialized equipment (e.g., glovebox).
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Affiliation(s)
- Salma
A. Elsherbeni
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K.
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Rebecca L. Melen
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, CF24 4HQ, U.K.
| | | | - Louis C. Morrill
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K.
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8
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Kapp L, Wölper C, Siera H, Haberhauer G, Schulz S. Catalytic hydroboration of aldehydes and ketones with an electron-rich acyclic metallasilylene. Chem Sci 2024; 15:4161-4170. [PMID: 38487240 PMCID: PMC10935726 DOI: 10.1039/d3sc06842k] [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: 12/20/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
The application of main group metal complexes in catalytic reactions is of increasing interest. Here we show that the electron-rich, acyclic metallasilylene L'(Cl)GaSiL C (L' = HC[C(Me)NDipp]2, Dipp = 2,6-iPr2C6H3; L = PhC(NtBu)2) acts as a precatalyst in the hydroboration of aldehydes with HBPin. Mechanistic studies with iso-valeraldehyde show that silylene C first reacts with the aldehyde with [2 + 1] cycloaddition in an oxidative addition to the oxasilirane 1, followed by formation of the alkoxysilylene LSiOCH[Ga(Cl)L']CH2CHMe2 (2), whose formation formally results from a reductive elimination reaction at the Si center. Alkoxysilylene 2 represents the active hydroboration catalyst and shows the highest catalytic activity with n-hexanal (reaction time: 40 min, yield: >99%, TOF = 150 h-1) at room temperature with a catalytic load of only 1 mol%. Furthermore, the hydroboration reaction catalysed by alkoxysilylene 2 is a living reaction with good chemoselectivity. Quantum chemical calculations not only provide mechanistic insights into the formation of alkoxysilylene 2 but also show that two completely different hydroboration mechanisms are possible.
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Affiliation(s)
- Leon Kapp
- Institute for Inorganic Chemistry, University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
| | - Christoph Wölper
- Institute for Inorganic Chemistry, University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
| | - Hannah Siera
- Institute for Organic Chemistry, University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
| | - Gebhard Haberhauer
- Institute for Organic Chemistry, University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
| | - Stephan Schulz
- Institute for Inorganic Chemistry, University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
- Center for Nanointegration Duisburg-Essen (Cenide), University of Duisburg-Essen Carl-Be Germany
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9
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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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10
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Akram MO, Martin CD, Dutton JL. The Effect of Carborane Substituents on the Lewis Acidity of Boranes. Inorg Chem 2023; 62:13495-13504. [PMID: 37560972 DOI: 10.1021/acs.inorgchem.3c01872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
The Lewis acidity of primary, secondary, and tertiary boranes with phenyl, pentafluorophenyl, and all three isomers of the C-substituted icosahedral carboranes (ortho, meta, and para) was investigated by computing their fluoride, hydride, and ammonia affinities as well as their global electrophilicity indices and LUMO energies. From these calculations, it was determined that the substituent effects on the Lewis acidity of these boranes follow the trend of ortho-carborane > meta-carborane > para-carborane > C6F5 > C6H5.
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Affiliation(s)
- Manjur O Akram
- Baylor University, Department of Chemistry and Biochemistry, One Bear Place #97348, Waco, Texas 76798, United States
| | - Caleb D Martin
- Baylor University, Department of Chemistry and Biochemistry, One Bear Place #97348, Waco, Texas 76798, United States
| | - Jason L Dutton
- La Trobe University, Department of Chemistry, La Trobe Institute for Molecular Science, Melbourne, Victoria 3086,Australia
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11
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Akram MO, Tidwell JR, Dutton JL, Martin CD. Bis(1-Methyl-ortho-Carboranyl)Borane. Angew Chem Int Ed Engl 2023; 62:e202307040. [PMID: 37338991 DOI: 10.1002/anie.202307040] [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: 05/18/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/22/2023]
Abstract
The Lewis superacid, bis(1-methyl-ortho-carboranyl)borane, is rapidly accessed in two steps. It is a very effective hydroboration reagent capable of B-H addition to alkenes, alkynes, and cyclopropanes. To date, this is the first identified Lewis superacidic secondary borane and most reactive neutral hydroboration reagent.
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Affiliation(s)
- Manjur O Akram
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX, 76798, USA
| | - John R Tidwell
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX, 76798, USA
| | - 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, One Bear Place #97348, Waco, TX, 76798, USA
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12
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Vashisth K, Dutta S, Akram MO, Martin CD. Examining the reactivity of tris( ortho-carboranyl)borane with Lewis bases and application in frustrated Lewis pair Si-H bond cleavage. Dalton Trans 2023. [PMID: 37377440 DOI: 10.1039/d3dt01557b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Reactions of tris(ortho-carboranyl)borane with Lewis bases reveals only small bases bind. The tremendous bulk and Lewis acidity is leveraged in frustrated Lewis pair Si-H cleavage with a wider range of Lewis bases and greater efficacy than B(C6F5)3.
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Affiliation(s)
- Kanika Vashisth
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, USA.
| | - Sanjay Dutta
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, USA.
| | - Manjur O Akram
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, USA.
| | - Caleb D Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, USA.
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13
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Tan J, Hu C, Yang X, Ju S, Cao LL, Wu Y, Liu LL, Stephan DW. Structure and reactivity studies of the aluminum analogue of Piers' borane [HAl(C 6F 5) 2] 3. Chem Commun (Camb) 2023; 59:282-285. [PMID: 36484802 DOI: 10.1039/d2cc06075b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The aluminum analogue of Piers' borane, [HAl(C6F5)2]31, is prepared on a gram-scale. Density functional theory (DFT) calculations reveal 1 has a higher fluoride ion affinity (FIA) than Piers' borane, while the Al-H moiety proved to be a strong hydride donor, reacting with alcohol and terminal alkyne to give the corresponding dehydrogenative products 3 and 4. Hydroalumination product 5 was prepared via reaction of 1 with aldehyde. In addition, 1 catalyzes the hydrosilylation of alkynes and alkenes.
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Affiliation(s)
- Jingjie Tan
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.
| | - Chaopeng Hu
- Department of Chemistry, Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Xin Yang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.
| | - Shaoying Ju
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.
| | - Levy L Cao
- Department of Chemistry, University of Toronto, Toronto, 80 St. George Street, Ontario M5S 3H6, Canada.
| | - Yile Wu
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.
| | - Liu Leo Liu
- Department of Chemistry, Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Douglas W Stephan
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China. .,Department of Chemistry, University of Toronto, Toronto, 80 St. George Street, Ontario M5S 3H6, Canada.
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14
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Baird SR, Vogels CM, Geier SJ, Watanabe LK, Binder JF, Macdonald CLB, Westcott SA. The phosphinoboration of thiosemicarbazones. CAN J CHEM 2022. [DOI: 10.1139/cjc-2022-0088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study reports on the exploration of the phosphinoboration reaction with several thiosemicarbazones (R5R4NC(S)NR3N=CR1R2). Reactions between either Ph2PBpin (pin = 1,2-O2C2Me4) or Ph2PBcat (cat = 1,2-O2C6H4) with thiosemicarbazones containing a terminal primary or secondary amine afforded boron-containing heterocyclic 1,3,4-thiadiazoline products in excellent yield. The addition of Ph2PBpin to thiosemicarbazones containing an NMe2 group in the terminal position generated novel five-membered heterocycles in moderate yield, which included boron, sulfur, and nitrogen atoms. Heterocyclization of the thiosemicarbazones occurs preferentially in the presence of functional groups such as acetyl and pyridyl groups.
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Affiliation(s)
- Samuel R. Baird
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Christopher M. Vogels
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Stephen J. Geier
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Lara K. Watanabe
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Justin F. Binder
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | | | - Stephen A. Westcott
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
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15
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Saito T, Hill MR, Lennon Luo SX, Ye HZ, Van Voorhis T, Johnson JA. Converting Commodity Polyolefins to Electronic Materials through Borane-Catalyzed Alkene Isomerization. J Am Chem Soc 2022; 144:23010-23018. [DOI: 10.1021/jacs.2c10030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Teruhiko Saito
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Technology Innovation Division, Panasonic Corporation, Kyoto 619-0237, Japan
| | - Megan R. Hill
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Shao-Xiong Lennon Luo
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Hong-Zhou Ye
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Troy Van Voorhis
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeremiah A. Johnson
- Department of Chemistry Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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16
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Kustiana BA, Melen RL, Morrill LC. One-Pot Synthesis of Styrene Derivatives from Allyl Silanes via B(C 6F 5) 3-Catalyzed Isomerization–Hiyama Coupling. Org Lett 2022; 24:8694-8697. [DOI: 10.1021/acs.orglett.2c03584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Betty A. Kustiana
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - Rebecca L. Melen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - Louis C. Morrill
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
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17
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Akram MO, Tidwell JR, Dutton JL, Martin CD. Tris(ortho-carboranyl)borane: An Isolable, Halogen-Free, Lewis Superacid. Angew Chem Int Ed Engl 2022; 61:e202212073. [PMID: 36135949 PMCID: PMC9828388 DOI: 10.1002/anie.202212073] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Indexed: 01/12/2023]
Abstract
The synthesis of tris(ortho-carboranyl)borane (BoCb3 ), a single site neutral Lewis superacid, in one pot from commercially available materials is achieved. The high fluoride ion affinity (FIA) confirms its classification as a Lewis superacid and the Gutmann-Beckett method as well as adducts with Lewis bases indicate stronger Lewis acidity over the widely used fluorinated aryl boranes. The electron withdrawing effect of ortho-carborane and lack of pi-delocalization of the LUMO rationalize the unusually high Lewis acidity. Catalytic studies indicate that BoCb3 is a superior catalyst for promoting C-F bond functionalization reactions than tris(pentafluorophenyl)borane [B(C6 F5 )3 ].
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Affiliation(s)
- Manjur O. Akram
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
| | - John R. Tidwell
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
| | - Jason L. Dutton
- Department of Biochemistry and ChemistryLa Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoria3086Australia
| | - Caleb D. Martin
- Department of Chemistry and BiochemistryBaylor UniversityOne Bear Place #97348WacoTX 76798USA
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18
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Kustiana BA, Elsherbeni SA, Linford‐Wood TG, Melen RL, Grayson MN, Morrill LC. B(C 6 F 5 ) 3 -Catalyzed E-Selective Isomerization of Alkenes. Chemistry 2022; 28:e202202454. [PMID: 35943082 PMCID: PMC9804281 DOI: 10.1002/chem.202202454] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Indexed: 01/05/2023]
Abstract
Herein, we report the B(C6 F5 )3 -catalyzed E-selective isomerization of alkenes. The transition-metal-free method is applicable across a diverse array of readily accessible substrates, giving access to a broad range of synthetically useful products containing versatile stereodefined internal alkenes. The reaction mechanism was investigated by using synthetic and computational methods.
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Affiliation(s)
- Betty A. Kustiana
- Cardiff Catalysis InstituteSchool of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
| | - Salma A. Elsherbeni
- Cardiff Catalysis InstituteSchool of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
| | | | - Rebecca L. Melen
- Cardiff Catalysis InstituteSchool of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
| | | | - Louis C. Morrill
- Cardiff Catalysis InstituteSchool of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
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19
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Clarke J, Seo Y, Gagné MR, Bender TA. Achieving Site-Selective C–O Bond Reduction for High-Value Cellulosic Valorization. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joshua Clarke
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Youngran Seo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michel R. Gagné
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Trandon A. Bender
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, United States
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20
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Phatake RS, Averdunk A, Würtele C, Gellrich U. Piers’ Borane-Catalyzed Dimerization of Arylallenes via Transborylation: A Synthetic and Mechanistic Study. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ravindra S. Phatake
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392Gießen, Germany
| | - Arthur Averdunk
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392Gießen, Germany
| | - Christian Würtele
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392Gießen, Germany
| | - Urs Gellrich
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392Gießen, Germany
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21
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Sun Q, Daniliuc CG, Mück‐Lichtenfeld C, Kehr G, Erker G. Formation of a Hybrid 1‐Bora‐3‐boratabenzene Heteroarene Anion Derivative. Angew Chem Int Ed Engl 2022; 61:e202205565. [DOI: 10.1002/anie.202205565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Qiu Sun
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Christian Mück‐Lichtenfeld
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
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22
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Sun Q, Daniliuc CG, Mück-Lichtenfeld C, Kehr G, Erker G. Formation of a Hybrid 1‐Bora‐3‐boratabenzene Heteroarene Anion Derivative. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Qiu Sun
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemisches Institut GERMANY
| | - Constantin G. Daniliuc
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemsiches Institut GERMANY
| | | | - Gerald Kehr
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemisches Institut GERMANY
| | - Gerhard Erker
- Universität Münster Organisch-Chemisches Institut Corrensstr. 40 48149 Münster GERMANY
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23
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Škoch K, Chen C, Daniliuc CG, Kehr G, Erker G. A deprotonation pathway to reactive [B]CH 2 boraalkenes. Dalton Trans 2022; 51:7695-7704. [PMID: 35521694 DOI: 10.1039/d2dt01193j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The BH compounds IMes(ArF)BH(NTf2) (ArF: C6F5 or FpXyl) were converted to the IMes(ArF)BCH2 boraalkenes in a three step reaction sequence of B-methylation with methyllithium, hydride abstraction and deprotonation. The BCH2 boraalkenes reacted with elemental sulfur to give a thiaborirane product. They underwent [2+2] cycloaddition reactions with carbon dioxide or sulfur dioxide to give four-membered boron containing heterocycles. The boraalkenes added strongly Lewis acidic boranes at their CH2 carbon atoms. The corresponding HB(C6F5)2/boraalkene adduct reduced carbon monoxide to a -OCH(C6F5)- moiety inside a five-membered heterocycle at the B-CH2-B template. The boraalkenes reacted with the [(Me2S)AuCl] reagent to form the corresponding (boraalkene)AuCl complexes.
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Affiliation(s)
- Karel Škoch
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany.
| | - Chaohuang Chen
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany.
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany.
| | - Gerald Kehr
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany.
| | - Gerhard Erker
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany.
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24
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Mahaut D, Champagne B, Berionni G. Frustrated Lewis Pair Catalyzed Hydrogenation of Unactivated Alkenes With Sterically Hindered 9‐Phosphatriptycenes. ChemCatChem 2022. [DOI: 10.1002/cctc.202200294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Damien Mahaut
- University of Namur: Universite de Namur Chemistry BELGIUM
| | | | - Guillaume Berionni
- University of Namur: Universite de Namur Chemistry Department Rue de Bruxelles 61 5000 Namur BELGIUM
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25
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Esarte Palomero O, Jones RA. Ferrocene tethered boramidinate frustrated Lewis pairs: stepwise capture of CO 2 and CO. Dalton Trans 2022; 51:6275-6284. [PMID: 35379999 DOI: 10.1039/d2dt00691j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and reactivity of novel ferrocene tethered boramidinate frustrated Lewis pairs (FLPs), capable of the sequential capture of small molecules, is reported. Reactions of 1,1'-dicarbodiimidoferrocenes with different boranes provides access to metallocene tethered FLPs. The reactivity of the boramidinate moieties can be tuned by the nature of the carbodiimido substituents (alkyl vs. aryl) and the borane used in the reduction (9-borabicyclo[3.3.1]nonane [(C8H14)2BH]2vs. bis-pentafluorophenyl borane [(C6F5)2BH]2). The boramidinate FLP arms do not engage in intramolecular reactions, allowing for independent small molecule capture by each FLP. By careful synthetic control, sequential capture of different gaseous small molecules (CO2 and CO or CO2 and CNtBu) by the same bis(boramidinate)ferrocene molecule has been demonstrated.
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Affiliation(s)
- Orhi Esarte Palomero
- Department of Chemistry - The University of Texas at Austin, 105 E 24th St., Austin, TX 78712, USA.
| | - Richard A Jones
- Department of Chemistry - The University of Texas at Austin, 105 E 24th St., Austin, TX 78712, USA.
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26
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Sun Q, Daniliuc CG, Yu X, Mück-Lichtenfeld C, Kehr G, Erker G. Borole/Borapyramidane Relationship. J Am Chem Soc 2022; 144:7815-7821. [PMID: 35438485 DOI: 10.1021/jacs.2c01727] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Boroles and borapyramidanes are classical and nonclassical constitutional isomers, respectively. It is here shown that they can indeed be interconverted. Treatment of the bis(alkynyl)B(C6F5) SMe2 adduct 3·SMe2 with HB(C6F5)2 gave borole 1·SMe2, featuring trimethylsilyl substituents in both α positions to boron, by means of a 1,1-hydroboration/alkenylboration sequence. Photolysis of the classical borole adduct 1·SMe2 resulted in rearrangement to its nonclassical structural isomer, borapyramidane 2, in high yield, which exhibits a vicinal pair of trimethylsilyl substituents at the square pyramidane base. Neutral borapyramidane 2 is a rare example of an isoster of the (CH)5+ pyramidane cation. Thermolysis of borapyramidane 2 in the presence of SMe2 at 60 °C re-formed borole 1·SMe2, which converted at 100 °C to 2,3-bis-silyl-substituted borole isomer 8·SMe2. Its photolysis also gave borapyramidane 2. Prolonged photolysis of 2 at elevated temperatures converted this to borapyramidane isomer 10 containing a pair of trimethylsilyl groups in 1,3-position at its square C4-pyramidal base. The borole and borapyramidane isomers were characterized by X-ray diffraction, and the system was analyzed by density functional theory (DFT) calculations.
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Affiliation(s)
- Qiu Sun
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Xiaoye Yu
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
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27
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Škoch K, Daniliuc CG, Müller M, Grimme S, Kehr G, Erker G. Stereochemical Behavior of Pairs of P‐stereogenic Phosphanyl Groups at the Dimethylxanthene Backbone. Chemistry 2022; 28:e202200248. [DOI: 10.1002/chem.202200248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Karel Škoch
- Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
- Current address: Institute of Inorganic Chemistry of the Czech Academy of Sciences Husinec 250 68 Husinec-Řež (Czech Republic
| | | | - Marcel Müller
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstraβe 4 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstraβe 4 53115 Bonn Germany
| | - Gerald Kehr
- Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Gerhard Erker
- Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
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28
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Aryldifluoroboranes: Lewis acidity and catalytic activity in the alkylation of phenols. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Hasenbeck M, Müller T, Averdunk A, Becker J, Gellrich U. Piers' Borane-Induced Tetramerization of Arylacetylenes. Chemistry 2022; 28:e202104254. [PMID: 34882876 PMCID: PMC9303334 DOI: 10.1002/chem.202104254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Indexed: 12/22/2022]
Abstract
We herein report that the reaction of Piers' borane, i. e. HB(C6 F5 )2 , with an excess of arylacetylenes at room temperature leads to tetramerization of the acetylene and the diastereoselective formation of boryl-substituted tetra-aryl-tetrahydropentalenes. The reaction mechanism was investigated by isotope labeling experiments and DFT computations. These investigations indicate that a series of 1,2-carboboration reactions form an octatetraene that undergoes an electrocyclization. Two skeletal rearrangements then presumably lead to the formation of the tetrahydropentalene core. Overall, this intricate and unprecedented transformation comprises five carbon-carbon bond formations in a single reaction.
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Affiliation(s)
- Max Hasenbeck
- Institut für Organische ChemieJustus-Liebig-Universität GießenHeinrich-Buff-Ring 1735392GießenGermany
| | - Tizian Müller
- Institut für Organische ChemieJustus-Liebig-Universität GießenHeinrich-Buff-Ring 1735392GießenGermany
| | - Arthur Averdunk
- Institut für Organische ChemieJustus-Liebig-Universität GießenHeinrich-Buff-Ring 1735392GießenGermany
| | - Jonathan Becker
- Institut für Anorganische und Analytische ChemieJustus-Liebig-Universität GießenHeinrich-Buff-Ring 1735392GießenGermany
| | - Urs Gellrich
- Institut für Organische ChemieJustus-Liebig-Universität GießenHeinrich-Buff-Ring 1735392GießenGermany
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30
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Guerzoni MG, van Ingen Y, Melen RL. Recent applications of fluorinated arylborane derivatives. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2022. [DOI: 10.1016/bs.adomc.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Boron compounds for catalytic applications. ADVANCES IN CATALYSIS 2022. [DOI: 10.1016/bs.acat.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Dasgupta A, Pahar S, Babaahmadi R, Gierlichs L, Yates BF, Ariafard A, Melen RL. Borane Catalyzed Selective Diazo Cross‐Coupling Towards Pyrazoles. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202101312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ayan Dasgupta
- Cardiff Catalysis Institute, School of Chemistry Cardiff University Main Building, Park Place Cardiff CF10 3AT Cymru/Wales United Kingdom
| | - Sanjukta Pahar
- Cardiff Catalysis Institute, School of Chemistry Cardiff University Main Building, Park Place Cardiff CF10 3AT Cymru/Wales United Kingdom
| | - Rasool Babaahmadi
- School of Natural Sciences (Chemistry) University of Tasmania Private Bag 75 Hobart Tasmania 7001 Australia
| | - Lukas Gierlichs
- Cardiff Catalysis Institute, School of Chemistry Cardiff University Main Building, Park Place Cardiff CF10 3AT Cymru/Wales United Kingdom
| | - Brian F. Yates
- School of Natural Sciences (Chemistry) University of Tasmania Private Bag 75 Hobart Tasmania 7001 Australia
| | - Alireza Ariafard
- School of Natural Sciences (Chemistry) University of Tasmania Private Bag 75 Hobart Tasmania 7001 Australia
| | - Rebecca L. Melen
- Cardiff Catalysis Institute, School of Chemistry Cardiff University Main Building, Park Place Cardiff CF10 3AT Cymru/Wales United Kingdom
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33
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Schepper JDW, Orthaber A, Pammer F. Preparation of Structurally and Electronically Diverse N → B-Ladder Boranes by [2 + 2 + 2] Cycloaddition. J Org Chem 2021; 86:14767-14776. [PMID: 34613723 DOI: 10.1021/acs.joc.1c01402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the synthesis of a series of eight N → B-ladder boranes through cobalt-mediated cyclotrimerization of (2-cyanophenyl)-dimesitylborane with different dialkynes. The resulting tetracoordinate boranes show variable electrochemical and optical properties depending on the substitution pattern in the backbone of the coordinating pyridine-derivatives. While boranes containing alkyl-substituted pyridines show lower electron affinities than the known parent compound, boranes featuring π-extended pyridine derivatives show higher electron affinities in the range of acceptor substituted triarylboranes. All derivatives show larger Stokes shifts (8790-6920 cm-1) compared to the N → B-ladder borane coordinated by an unsubstituted pyridine.
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Affiliation(s)
- Jonas D W Schepper
- Institute of Organic Chemistry II and Advanced Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Andreas Orthaber
- Department of Chemistry, Ångström Laboratories, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Frank Pammer
- Institute of Organic Chemistry II and Advanced Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.,Helmholtz-Institut Ulm, Helmholtzstrasse 11, D-89081 Ulm, Germany
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34
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Katzman BD, Maar RR, Cappello D, Sattler MO, Boyle PD, Staroverov VN, Gilroy JB. A strongly Lewis-acidic and fluorescent borenium cation supported by a tridentate formazanate ligand. Chem Commun (Camb) 2021; 57:9530-9533. [PMID: 34546239 DOI: 10.1039/d1cc03873g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lewis acids are highly sought after for their applications in sensing, small-molecule activation, and catalysis. When combined with π-conjugated molecular frameworks, Lewis acids with unique optoelectronic properties can be realized. Here, we use a tridentate formazanate ligand to create a planar, redox-active, fluorescent, and strongly Lewis-acidic borenium cation. We also demonstrate that this compound can act as a colourimetric probe for reactivity.
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Affiliation(s)
- Benjamin D Katzman
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Ryan R Maar
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Daniela Cappello
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Madeleine O Sattler
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Paul D Boyle
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Viktor N Staroverov
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Joe B Gilroy
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
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35
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Yolsal U, Horton TAR, Wang M, Shaver MP. Cyclic Ether Triggers for Polymeric Frustrated Lewis Pair Gels. J Am Chem Soc 2021; 143:12980-12984. [PMID: 34387464 PMCID: PMC8397318 DOI: 10.1021/jacs.1c06408] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Sterically hindered
Lewis acid and base centers are unable to form
Lewis adducts, instead forming frustrated Lewis pairs (FLPs), where
latent reactivity can be utilized for the activation of small molecules.
Applying FLP chemistry into polymeric frameworks transforms this chemistry
into responsive and functional materials. Here, we report a versatile
synthesis strategy for the preparation of macromolecular FLPs and
explore its potential with the ring-opening reactions of cyclic ethers.
Addition of the cyclic substrates triggered polymer network formation,
where the extent of cross-linking, strength of network, and reactivity
are tuned by the steric and electronic properties of the ethers. The
resultant networks behave like covalently cross-linked polymers, demonstrating
the versatility of FLPs to simultaneously tune both small-molecule
capture and mechanical properties of materials.
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Affiliation(s)
- Utku Yolsal
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester, M1 3BB, United Kingdom
| | - Thomas A R Horton
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester, M1 3BB, United Kingdom
| | - Meng Wang
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester, M1 3BB, United Kingdom
| | - Michael P Shaver
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester, M1 3BB, United Kingdom.,Sustainable Materials Innovation Hub, Henry Royce Institute, University of Manchester, Oxford Road, Manchester, M13 9BL, United Kingdom
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36
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Škoch K, Daniliuc CG, Kehr G, Ehlert S, Müller M, Grimme S, Erker G. Frustrated Lewis-Pair Neighbors at the Xanthene Framework: Epimerization at Phosphorus and Cooperative Formation of Macrocyclic Adduct Structures. Chemistry 2021; 27:12104-12114. [PMID: 34076908 DOI: 10.1002/chem.202100835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Indexed: 11/07/2022]
Abstract
Attachment of a pair of P-stereogenic mesityl(alkynyl)phosphanyl groups at the 4- and 5-positions of a 9,9-dimethylxanthene framework gave mixtures of the respective rac- and meso-bisphosphanyl diastereoisomers. They slowly epimerized in a thermally induced reaction with Gibbs activation barriers of about 25 kcal mol-1 at room temperature (measured and DFT calculated). The reaction of the meso-mesityl(tert-butylethynyl)phosphanyl derivative with two molar equivalents of Piers' borane [HB(C6 F5 )2 ] led to the formation of the alkylidene-bridged geminal bisphosphane/borane-frustrated Lewis pair system. The compound was obtained enriched (>85 %) in the rac diastereoisomer. With a variety of bifunctional donor substrates, the rac-bis-P/B FLP formed macrocyclic compounds. They were all formally derived from meso-configurated diastereoisomers of the bisphosphanylxanthene backbone.
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Affiliation(s)
- Karel Škoch
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149, Münster, Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149, Münster, Germany
| | - Sebastian Ehlert
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraβe 4, 53115, Bonn, Germany
| | - Marcel Müller
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraβe 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraβe 4, 53115, Bonn, Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149, Münster, Germany
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37
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Fischer M, Hering-Junghans C. On 1,3-phosphaazaallenes and their diverse reactivity. Chem Sci 2021; 12:10279-10289. [PMID: 34377415 PMCID: PMC8336469 DOI: 10.1039/d1sc02947a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/30/2021] [Indexed: 11/21/2022] Open
Abstract
1,3-Phosphaazaallenes are heteroallenes of the type RP
Created by potrace 1.16, written by Peter Selinger 2001-2019
]]>
CNR′ and little is known about their reactivity. In here we describe the straightforward synthesis of ArPCNR (Ar = Mes*, 2,4,6-tBu-C6H2; MesTer, 2.6-(2,4,6-Me3C6H2)–C6H3; DipTer, 2.6-(2,6-iPr2C6H2)–C6H3; R = tBu; Xyl, 2,6-Me2C6H3) starting from phospha-Wittig reagents ArPPMe3 and isonitriles CNR. It is further shown that ArPCNtBu are thermally labile with respect to the loss of iso-butene and it is shown that the cyanophosphines ArP(H)CN are synthetically feasible and form the corresponding phosphanitrilium borates with B(C6F5)3, whereas deprotonation of DipTerP(H)CN was shown to give an isolable cyanidophosphide. Lastly, the reactivity of ArPCNR towards Pier's borane was investigated, showing hydroboration of the CN bond in Mes*PCNtBu to give a hetero-butadiene, while with DipTerPCNXyl the formation of the Lewis acid–base adduct with a B–P linkage was observed. The combination of phospha-Wittig reagents with isonitriles affords 1,3-phosphaazaallenes and their diverse reactivity has been studied in detail.![]()
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Affiliation(s)
- Malte Fischer
- Leibniz Institut für Katalyse e.V. (LIKAT) A.-Einstein-Str. 3a 18059 Rostock Germany [https://www.catalysis.de/forschung/aktivierung-kleiner-molekuele/]
| | - Christian Hering-Junghans
- Leibniz Institut für Katalyse e.V. (LIKAT) A.-Einstein-Str. 3a 18059 Rostock Germany [https://www.catalysis.de/forschung/aktivierung-kleiner-molekuele/]
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38
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Ton NNH, Mai BK, Nguyen TV. Tropylium-Promoted Hydroboration Reactions: Mechanistic Insights Via Experimental and Computational Studies. J Org Chem 2021; 86:9117-9133. [PMID: 34134487 DOI: 10.1021/acs.joc.1c01208] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydroboration reaction of alkynes is one of the most synthetically powerful tools to access organoboron compounds, versatile precursors for cross-coupling chemistry. This type of reaction has traditionally been mediated by transition-metal or main group catalysts. Herein, we report a novel method using tropylium salts, typically known as organic oxidants and Lewis acids, to promote the hydroboration reaction of alkynes. A broad range of vinylboranes can be easily accessed via this metal-free protocol. Similar hydroboration reactions of alkenes and epoxides can also be efficiently catalyzed by the same tropylium catalysts. Experimental studies and DFT calculations suggested that the reaction follows an uncommon mechanistic pathway, which is triggered by the hydride abstraction of pinacolborane with tropylium ion. This is followed by a series of in situ counterion-activated substituent exchanges to generate boron intermediates that promote the hydroboration reaction.
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Affiliation(s)
- Nhan N H Ton
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Thanh Vinh Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
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39
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Hasenbeck M, Wech F, Averdunk A, Becker J, Gellrich U. Indene formation upon borane-induced cyclization of arylallenes, 1,1-carboboration, and retro-hydroboration. Chem Commun (Camb) 2021; 57:5518-5521. [PMID: 33955432 DOI: 10.1039/d1cc01750k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We herein report the reaction of arylallenes with tris(pentafluorophenyl)borane that yields pentafluorophenyl substituted indenes. The tris(pentafluorophenyl)borane induces the cyclization of the allene and transfers a pentafluorophenyl ring in the course of this reaction. A Hammett plot analysis and DFT computations indicate a 1,1-carboboration to be the C-C bond-forming step.
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Affiliation(s)
- Max Hasenbeck
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
| | - Felix Wech
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
| | - Arthur Averdunk
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
| | - Jonathan Becker
- Institut für Analytische und Anorganische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, Gießen 35392, Germany
| | - Urs Gellrich
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
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40
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Rojas RS, Muñoz-Becerra K, Toro-Labbé A, Mesías-Salazar A, Martínez I, Antiñolo A, Carrillo-Hermosilla F, Fernández-Galán R, Ramos A, Daniliuc CG. New guanidine-borane adducts: An experimental and theoretical approach. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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41
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Škoch K, Daniliuc CG, Kehr G, Erker G. Alkyne 1,1‐Hydroboration to a Reactive Frustrated P/B‐H Lewis Pair. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014562] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Karel Škoch
- Westfälische Wilhelms-Universität Münster Corrensstrasse 40 48149 Münster Germany
| | | | - Gerald Kehr
- Westfälische Wilhelms-Universität Münster Corrensstrasse 40 48149 Münster Germany
| | - Gerhard Erker
- Westfälische Wilhelms-Universität Münster Corrensstrasse 40 48149 Münster Germany
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42
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Belli RG, Pantazis DA, McDonald R, Rosenberg L. Reversible Silylium Transfer between P-H and Si-H Donors. Angew Chem Int Ed Engl 2021; 60:2379-2384. [PMID: 33031611 DOI: 10.1002/anie.202011372] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Indexed: 11/11/2022]
Abstract
The Mo=PR2 π* orbital in a Mo phosphenium complex acts as acceptor in a new PIII -based Lewis superacid. This Lewis acid (LA) participates in electrophilic Si-H abstraction from E3 SiH to give a Mo-bound secondary phosphine ligand, Mo-PR2 H. The resulting Et3 Si+ ion remains associated with the Mo complex, stabilized by η1 -P-H donation, yet undergoes rapid exchange with an η1 -Si-H adduct of free silane in solution. The equilibrium between these two adducts presents an opportunity to assess the role of this new LA in catalytic reactions of silanes: is the LA acting as a catalyst or as an initiator? Preliminary results suggest that a cycle including the Mo-bound phosphine-silylium adduct dominates in the catalytic hydrosilylation of acetophenone, relative to a putative cycle involving the silane-silylium adduct or "free" silylium.
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Affiliation(s)
- Roman G Belli
- Department of Chemistry, University of Victoria, P.O. Box 1700 STN CSC, Victoria, British Columbia, V8W 2Y2, Canada
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Robert McDonald
- X-ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Lisa Rosenberg
- Department of Chemistry, University of Victoria, P.O. Box 1700 STN CSC, Victoria, British Columbia, V8W 2Y2, Canada
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43
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Belli RG, Pantazis DA, McDonald R, Rosenberg L. Reversible Silylium Transfer between P‐H and Si‐H Donors. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Roman G. Belli
- Department of Chemistry University of Victoria P.O. Box 1700 STN CSC Victoria British Columbia V8W 2Y2 Canada
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Robert McDonald
- X-ray Crystallography Laboratory Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Lisa Rosenberg
- Department of Chemistry University of Victoria P.O. Box 1700 STN CSC Victoria British Columbia V8W 2Y2 Canada
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44
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Škoch K, Daniliuc CG, Kehr G, Erker G. Alkyne 1,1-Hydroboration to a Reactive Frustrated P/B-H Lewis Pair. Angew Chem Int Ed Engl 2021; 60:6757-6763. [PMID: 33306863 DOI: 10.1002/anie.202014562] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Indexed: 12/18/2022]
Abstract
The Mes2 P-C≡C-SiMe3 alkyne reacts with the borane H2 B-Fmes by means of a rare 1,1-hydroboration reaction to give an unsaturated C2 -bridged frustrated P/B-H Lewis pair. Most of its reactions are determined by the presence of the B-H functionality at the FLP function and the activated connecting carbon-carbon double bond. It reduces carbon monoxide to the formyl stage. With nitriles it reacts in an extraordinary way: it undergoes a reaction sequence that eventually results in the formation of a P-substituted dihydro-1,2-azaborole derivative. Several similar examples were found. In one case a P-ylide was isolated that was related to an intermediate of the reaction sequence. It subsequently opened in an alternative way to give an alkenyl borane product.
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Affiliation(s)
- Karel Škoch
- Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Gerald Kehr
- Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Gerhard Erker
- Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
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45
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Pan Y, Cui J, Wei Y, Xu Z, Wang T. B-H and O-H bonds activation via a single electron transfer of frustrated radical pairs. Dalton Trans 2021; 50:8947-8954. [PMID: 34109966 DOI: 10.1039/d1dt01169c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The rare examples of B-H bond activation in a frustrated radical pair regime have been observed by treatment of TEMPO radicals with Piers' borane HB(C6F5)2 or bis-borane, respectively. The resulting concomitant formation of zwitterionic products and geminal N/B frustrated Lewis pairs implied a one electron process. In addition, the reaction of a TEMPO/B(C6F5)3 pair with H2O·B(C6F5)3 was assumed to involve one-electron reduction of water. Our results provide insights into chemical bond (e.g. B-H and O-H) activation via a single electron transfer.
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Affiliation(s)
- Yanlin Pan
- Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China.
| | - Jie Cui
- Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China.
| | - Yongliang Wei
- Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China.
| | - Zhaochao Xu
- Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China. and CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Tongdao Wang
- Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China.
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46
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Abstract
An overview of the available methods to functionalize dinitrogen with boron reagents using transition metal complexes is given.
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47
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Hasenbeck M, Ahles S, Averdunk A, Becker J, Gellrich U. Die Bildung nukleophiler Allylborane aus molekularem Wasserstoff und Allenen katalysiert durch ein Pyridonatboran, das die Reaktivität eines frustrierten Lewis‐Paares zeigt. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011790] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Max Hasenbeck
- Institut für Organische Chemie Justus-Liebig-Universität Gießen Heinrich-Buff-Ring 17 35392 Gießen Deutschland
| | - Sebastian Ahles
- Institut für Organische Chemie Justus-Liebig-Universität Gießen Heinrich-Buff-Ring 17 35392 Gießen Deutschland
| | - Arthur Averdunk
- Institut für Organische Chemie Justus-Liebig-Universität Gießen Heinrich-Buff-Ring 17 35392 Gießen Deutschland
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie Justus-Liebig-Universität Gießen Heinrich-Buff-Ring 17 35392 Gießen Deutschland
| | - Urs Gellrich
- Institut für Organische Chemie Justus-Liebig-Universität Gießen Heinrich-Buff-Ring 17 35392 Gießen Deutschland
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48
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Hasenbeck M, Ahles S, Averdunk A, Becker J, Gellrich U. Formation of Nucleophilic Allylboranes from Molecular Hydrogen and Allenes Catalyzed by a Pyridonate Borane that Displays Frustrated Lewis Pair Reactivity. Angew Chem Int Ed Engl 2020; 59:23885-23891. [PMID: 32926511 PMCID: PMC7814673 DOI: 10.1002/anie.202011790] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Indexed: 11/05/2022]
Abstract
Here we report the in situ generation of nucleophilic allylboranes from H2 and allenes mediated by a pyridonate borane that displays frustrated‐Lewis‐pair reactivity. Experimental and computational mechanistic investigations reveal that upon H2 activation, the covalently bound pyridonate substituent becomes a datively bound pyridone ligand. Dissociation of the formed pyridone borane complex liberates Piers borane and enables a hydroboration of the allene. The allylboranes generated in this way are reactive towards nitriles. A catalytic protocol for the formation of allylboranes from H2 and allenes and the allylation of nitriles has been devised. This catalytic reaction is a conceptually new way to use molecular H2 in organic synthesis.
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Affiliation(s)
- Max Hasenbeck
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Sebastian Ahles
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Arthur Averdunk
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Urs Gellrich
- Institut für Organische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
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49
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Su B, Li Y, Li ZH, Hou JL, Wang H. Activation of C–C Bonds via σ-Bond Metathesis: Hydroborenium-Catalyzed Hydrogenolysis of Cyclopropanes. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00099] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Bo Su
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Songhu Road 2205, Shanghai 200438, People’s Republic of China
| | - Yawei Li
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Songhu Road 2205, Shanghai 200438, People’s Republic of China
| | - Zhen Hua Li
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Songhu Road 2205, Shanghai 200438, People’s Republic of China
| | - Jun-Li Hou
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Songhu Road 2205, Shanghai 200438, People’s Republic of China
| | - Huadong Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Songhu Road 2205, Shanghai 200438, People’s Republic of China
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50
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Hamza A, Sorochkina K, Kótai B, Chernichenko K, Berta D, Bolte M, Nieger M, Repo T, Pápai I. Origin of Stereoselectivity in FLP-Catalyzed Asymmetric Hydrogenation of Imines. ACS Catal 2020. [DOI: 10.1021/acscatal.0c04263] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea Hamza
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Kristina Sorochkina
- Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, 00014 Helsinki, Finland
| | - Bianka Kótai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Konstantin Chernichenko
- Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, 00014 Helsinki, Finland
| | - Dénes Berta
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Michael Bolte
- Institute of Inorganic Chemistry, Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany
| | - Martin Nieger
- Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, 00014 Helsinki, Finland
| | - Timo Repo
- Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, 00014 Helsinki, Finland
| | - Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
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