1
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Wang X, Yu C, Atodiresei IL, Patureau FW. Phosphine-Catalyzed Dearomative [3 + 2] Cycloaddition of Benzoxazoles with a Cyclopropenone. Org Lett 2022; 24:1127-1131. [PMID: 35085442 PMCID: PMC8845044 DOI: 10.1021/acs.orglett.1c04045] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
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The triphenylphosphine-catalyzed
dearomative [3 + 2] cycloaddition
of benzoxazoles with 1,2-diphenylcyclopropenone is herein described.
The reaction scope, mechanism, and possible future applications of
this rare organocatalyzed cycloaddition are herein discussed.
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Affiliation(s)
- Xingben Wang
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Congjun Yu
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Iuliana L Atodiresei
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Frederic W Patureau
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
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2
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Federmann P, Herwig C, Beckmann F, Cula B, Limberg C. Ring-Opening of THF via an Intramolecular P/Al-Based Frustrated Lewis Pair: Assistance by C6F5 Groups beyond Electronegativity? Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Patrick Federmann
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Christian Herwig
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Fabian Beckmann
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Beatrice Cula
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Christian Limberg
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
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3
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Wübker A, Koppe J, Bradtmüller H, Keweloh L, Pleschka D, Uhl W, Hansen MR, Eckert H. Solid-State Nuclear Magnetic Resonance Techniques for the Structural Characterization of Geminal Alane-Phosphane Frustrated Lewis Pairs and Secondary Adducts. Chemistry 2021; 27:13249-13257. [PMID: 34270155 PMCID: PMC8518393 DOI: 10.1002/chem.202102113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Indexed: 11/17/2022]
Abstract
The first comprehensive solid-state nuclear magnetic resonance (NMR) characterization of geminal alane-phosphane frustrated Lewis pairs (Al/P FLPs) is reported. Their relevant NMR parameters (isotropic chemical shifts, direct and indirect 27 Al-31 P spin-spin coupling constants, and 27 Al nuclear electric quadrupole coupling tensor components) have been determined by numerical analysis of the experimental NMR line shapes and compared with values computed from the known crystal structures by using density functional theory (DFT) methods. Our work demonstrates that the 31 P NMR chemical shifts for the studied Al/P FLPs are very sensitive to slight structural inequivalences. The 27 Al NMR central transition signals are spread out over a broad frequency range (>200 kHz), owing to the presence of strong nuclear electric quadrupolar interactions that can be well-reproduced by the static 27 Al wideband uniform rate smooth truncation (WURST) Carr-Purcell-Meiboom-Gill (WCPMG) NMR experiment. 27 Al chemical shifts and quadrupole tensor components offer a facile and clear distinction between three- and four-coordinate aluminum environments. For measuring internuclear Al⋅⋅⋅P distances a new resonance-echo saturation-pulse double-resonance (RESPDOR) experiment was developed by using efficient saturation via frequency-swept WURST pulses. The successful implementation of this widely applicable technique indicates that internuclear Al⋅⋅⋅P distances in these compounds can be measured within a precision of ±0.1 Å.
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Affiliation(s)
- Anna‐Lena Wübker
- Institut für Physikalische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Jonas Koppe
- Institut für Physikalische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Henrik Bradtmüller
- Institut für Physikalische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
- Department of Materials EngineeringVitreous Materials LaboratoryFederal University of São CarlosCP 67613565-905São CarlosSPBrazil
| | - Lukas Keweloh
- Institut für Anorganische und Analytische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Damian Pleschka
- Institut für Anorganische und Analytische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Michael Ryan Hansen
- Institut für Physikalische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
| | - Hellmut Eckert
- Institut für Physikalische Chemie WWU MünsterCorrensstraße 28/3048149MünsterGermany
- Instituto de Física de São CarlosUniversidade de São PauloSão CarlosSP13566-590Brazil
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4
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Friedrich A, Eyselein J, Elsen H, Langer J, Pahl J, Wiesinger M, Harder S. Cationic Aluminium Complexes as Catalysts for Imine Hydrogenation. Chemistry 2021; 27:7756-7763. [PMID: 33780071 PMCID: PMC8252007 DOI: 10.1002/chem.202100641] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Indexed: 12/14/2022]
Abstract
Strongly Lewis acidic cationic aluminium complexes, stabilized by β–diketiminate (BDI) ligands and free of Lewis bases, have been prepared as their B(C6F5)4− salts and were investigated for catalytic activity in imine hydrogenation. The backbone (R1) and N (R2) substituents on the R1,R2BDI ligand (R1,R2BDI=HC[C(R1)N(R2)]2) influence sterics and Lewis acidity. Ligand bulk increases along the row Me,DIPPBDI<Me,DIPePBDI≈tBu,DIPPBDI<tBu,DIPePBDI; DIPP=2,6‐C(H)Me2‐phenyl, DIPeP=2,6‐C(H)Et2‐phenyl. The Gutmann‐Beckett test showed acceptor numbers of: (tBu,DIPPBDI)AlMe+ 85.6, (tBu,DIPePBDI)AlMe+ 85.9, (Me,DIPPBDI)AlMe+ 89.7, (Me,DIPePBDI)AlMe+ 90.8, (Me,DIPPBDI)AlH+ 95.3. Steric and electronic factors need to be balanced for catalytic activity in imine hydrogenation. Open, highly Lewis acidic, cations strongly coordinate imine rendering it inactive as a Frustrated Lewis Pair (FLP). The bulkiest cations do not coordinate imine but its combination is also not an active catalyst. The cation (tBu,DIPPBDI)AlMe+ shows the best catalytic activity for various imines and is also an active catalyst for the Tishchenko reaction of benzaldehyde to benzylbenzoate. DFT calculations on the mechanism of imine hydrogenation catalysed by cationic Al complexes reveal two interconnected catalytic cycles operating in concert. Hydrogen is activated either by FLP reactivity of an Al⋅⋅⋅imine couple or, after formation of significant quantities of amine, by reaction with an Al⋅⋅⋅amine couple. The latter autocatalytic Al⋅⋅⋅amine cycle is energetically favoured.
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Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jonathan Eyselein
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jürgen Pahl
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Michael Wiesinger
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
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5
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Nakao S, Nishimoto Y, Yasuda M. Tuning of Lewis Acidity of Phebox-Al Complexes by Substituents on the Benzene Backbone and Unexpected Photocatalytic Activity for Hydrodebromination of Aryl Bromide. CHEM LETT 2021. [DOI: 10.1246/cl.200894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Shuichi Nakao
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoshihiro Nishimoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Makoto Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
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6
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Horstmann JS, Klabunde S, Hepp A, Layh M, Hansen MR, Eckert H, Würthwein E, Uhl W. Reactions of Al‐N Based Active Lewis Pairs with Ketones and 1,2‐Diketones: Insertion into Al‐N Bonds, C‐C and C‐N Bond Formation and a Tricyclic Saturated Tetraaza Compound. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Julia Silissa Horstmann
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Sina Klabunde
- Institut für Physikalische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Michael Ryan Hansen
- Institut für Physikalische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Hellmut Eckert
- Institut für Physikalische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Ernst‐Ulrich Würthwein
- Organisch‐chemisches Institut and Center for Multiscale Theory and Computation (CMTC) Universität Münster Corrensstrasse 40 48149 Münster Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
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7
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Simon M, Radius M, Wagner HE, Breher F. Imidazolyl Alanes – Synthesis, Structures, and Reactivity Studies. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Martin Simon
- Institute of Inorganic Chemistry Division Molecular Chemistry Karlsruhe Institute of Technology (KIT) Engesserstr.15 76131 Karlsruhe Germany
| | - Michael Radius
- Institute of Inorganic Chemistry Division Molecular Chemistry Karlsruhe Institute of Technology (KIT) Engesserstr.15 76131 Karlsruhe Germany
| | - Hanna E. Wagner
- Institute of Inorganic Chemistry Division Molecular Chemistry Karlsruhe Institute of Technology (KIT) Engesserstr.15 76131 Karlsruhe Germany
| | - Frank Breher
- Institute of Inorganic Chemistry Division Molecular Chemistry Karlsruhe Institute of Technology (KIT) Engesserstr.15 76131 Karlsruhe Germany
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8
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Brand A, Wegener P, Hepp A, Uhl W. A Geometrically Constrained Tricyclic Phosphine: Coordination, Ring Expansion by Insertion of CO into a P–C Bond, and Lewis Acid Initiated Formation of an Oligocyclic Molecule with a P 2C 22 backbone. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander Brand
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Philipp Wegener
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
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9
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Uhl W, Martinewski K, Bruchhage JS, Hepp A, Layh M, Dielmann F, Mehlmann P. Cooperative activation of azides by an Al/N-based active Lewis pair – unexpected insertion of nitrogen atoms into C–Si bonds and formation of AlCN3 heterocycles. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2019. [DOI: 10.1515/znb-2019-0138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The active Lewis pairs (ALPs) 2,6-Me2H8C5N–C(H) = C(SiMe3)–AlR2 (1a: R =
t
Bu, 1b, R =
i
Bu) have strained AlC2N heterocycles and relatively weak Al–N bonds. They react readily with a series of organic azides R′N3 [R′ = Ph, CH2C6H4(4-
t
Bu),
t
Bu, SiMe3, CH2Ph] by cleavage of the heterocycles and addition of the azides with their α-N atoms to the Al atom. The Al–N interactions result in an activation of the azide groups which insert into the C–Si bonds of the vinyl groups with their terminal γ-N atoms. Compounds with approximately planar five-membered AlCN3 heterocycles and intact N3 groups are formed in highly selective reactions.
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Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Katja Martinewski
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Julia Silissa Bruchhage
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Fabian Dielmann
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
| | - Paul Mehlmann
- Institut für Anorganische und Analytische Chemie der Universität Münster , Corrensstraße 30 , 48149 Münster , Germany
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10
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Uhl W, Hengesbach F, Isermann J, Soleimani M, Schürmann L, Hepp A, Layh M. New Ga/N‐based Active Lewis Pairs, Trifunctional Ga–Ga Compounds, Reactions with Cyanamide and Dual Insertion of Isocyanate. Z Anorg Allg Chem 2019. [DOI: 10.1002/zaac.201900195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Werner Uhl
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Frank Hengesbach
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Jennifer Isermann
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Meisam Soleimani
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Lina Schürmann
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
| | - Marcus Layh
- Institut für Anorganische und Analytische Chemie Universität Münster Corrensstraße 30 48149 Münster Germany
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