1
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Le TMT, Brégent T, Jubault P, Poisson T. Photocatalytic
E
→
Z Contra
‐Thermodynamic Isomerization of Vinyl Silanes with Lewis Base. Chemistry 2022; 28:e202201514. [PMID: 35652371 PMCID: PMC9541780 DOI: 10.1002/chem.202201514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Indexed: 11/22/2022]
Abstract
Herein, we disclosed the contra‐thermodynamic E→Z isomerization of alkenyl silanes, according to the in situ formation of a chromophoric species, in the presence of rac‐BINAP as the catalyst. The reaction carried out in DMSO or CH3CN under irradiation at 405 nm allowed the interconversion of the E‐isomers into the Z‐congeners in good to excellent yields and outstanding Z/E selectivities, on 18 examples. Finally, the mechanism of this E→Z isomerization was studied to get insight into the reaction mechanism.
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Affiliation(s)
- Thi Minh Thi Le
- Normandie Univ. INSA Rouen UNIROUEN CNRS COBRA (UMR 6014) 76000 Rouen France
| | - Thibaud Brégent
- Normandie Univ. INSA Rouen UNIROUEN CNRS COBRA (UMR 6014) 76000 Rouen France
| | - Philippe Jubault
- Normandie Univ. INSA Rouen UNIROUEN CNRS COBRA (UMR 6014) 76000 Rouen France
| | - Thomas Poisson
- Normandie Univ. INSA Rouen UNIROUEN CNRS COBRA (UMR 6014) 76000 Rouen France
- Institut Universitaire de France 1 rue Descartes 75231 Paris France
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2
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Shibatani A, Kataoka Y, Ura Y. Palladium‐Catalyzed Aerobic α,β‐Dehydrogenation of Carboxylic Acids. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Ayaka Shibatani
- Department of Chemistry, Biology, and Environmental Science Faculty of Science Nara Women's University Kitauoyanishi-machi, Nara 630-8506 Japan
| | - Yasutaka Kataoka
- Department of Chemistry, Biology, and Environmental Science Faculty of Science Nara Women's University Kitauoyanishi-machi, Nara 630-8506 Japan
| | - Yasuyuki Ura
- Department of Chemistry, Biology, and Environmental Science Faculty of Science Nara Women's University Kitauoyanishi-machi, Nara 630-8506 Japan
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3
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Brégent T, Bouillon JP, Poisson T. Photocatalyzed E→Z Contra-thermodynamic Isomerization of Vinyl Boronates with Binaphthol. Chemistry 2021; 27:13966-13970. [PMID: 34411357 DOI: 10.1002/chem.202102536] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Indexed: 11/11/2022]
Abstract
The photocatalytic contra-thermodynamic E→Z isomerization of vinyl boronates by using a binaphthol catalyst is disclosed. The reaction, based on the transient formation of a suitable chromophore with a BINOL derivative as the catalyst, allowed geometrical isomerization in good-to-excellent Z/E ratio and excellent-to-quantitative yields. The mechanism of this E→Z contra-thermodynamic isomerization was studied, and the formation of a transient chromophore species is suggested.
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Affiliation(s)
- Thibaud Brégent
- Normandie Université, INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
| | - Jean-Philippe Bouillon
- Normandie Université, INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
| | - Thomas Poisson
- Normandie Université, INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France.,Institut Universitaire de France, 1 rue Descartes, 75231, Paris, France
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4
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Peschel MT, Kabaciński P, Schwinger DP, Thyrhaug E, Cerullo G, Bach T, Hauer J, Vivie‐Riedle R. Activation of 2‐Cyclohexenone by BF
3
Coordination: Mechanistic Insights from Theory and Experiment. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016653] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Martin T. Peschel
- Department Chemie Ludwig-Maximilians-Universität München 81377 München Germany
| | - Piotr Kabaciński
- IFN-CNR and Dipartimento di Fisica Politecnico di Milano 20133 Milano Italy
| | - Daniel P. Schwinger
- Department of Chemistry and Catalysis Research Center (CRC) Technische Universität München 85747 Garching Germany
| | - Erling Thyrhaug
- Department of Chemistry and Catalysis Research Center (CRC) Technische Universität München 85747 Garching Germany
| | - Giulio Cerullo
- IFN-CNR and Dipartimento di Fisica Politecnico di Milano 20133 Milano Italy
| | - Thorsten Bach
- Department of Chemistry and Catalysis Research Center (CRC) Technische Universität München 85747 Garching Germany
| | - Jürgen Hauer
- Department of Chemistry and Catalysis Research Center (CRC) Technische Universität München 85747 Garching Germany
| | - Regina Vivie‐Riedle
- Department Chemie Ludwig-Maximilians-Universität München 81377 München Germany
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5
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Peschel MT, Kabaciński P, Schwinger DP, Thyrhaug E, Cerullo G, Bach T, Hauer J, de Vivie-Riedle R. Activation of 2-Cyclohexenone by BF 3 Coordination: Mechanistic Insights from Theory and Experiment. Angew Chem Int Ed Engl 2021; 60:10155-10163. [PMID: 33595902 PMCID: PMC8252487 DOI: 10.1002/anie.202016653] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/01/2021] [Indexed: 11/22/2022]
Abstract
Lewis acids have recently been recognized as catalysts enabling enantioselective photochemical transformations. Mechanistic studies on these systems are however rare, either due to their absorption at wavelengths shorter than 260 nm, or due to the limitations of theoretical dynamic studies for larger complexes. In this work, we overcome these challenges and employ sub-30-fs transient absorption in the UV, in combination with a highly accurate theoretical treatment on the XMS-CASPT2 level. We investigate 2-cyclohexenone and its complex to boron trifluoride and analyze the observed dynamics based on trajectory calculations including non-adiabatic coupling and intersystem crossing. This approach explains all ultrafast decay pathways observed in the complex. We show that the Lewis acid remains attached to the substrate in the triplet state, which in turn explains why chiral boron-based Lewis acids induce a high enantioselectivity in photocycloaddition reactions.
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Affiliation(s)
- Martin T Peschel
- Department Chemie, Ludwig-Maximilians-Universität München, 81377, München, Germany
| | - Piotr Kabaciński
- IFN-CNR and Dipartimento di Fisica, Politecnico di Milano, 20133, Milano, Italy
| | - Daniel P Schwinger
- Department of Chemistry and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Erling Thyrhaug
- Department of Chemistry and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Giulio Cerullo
- IFN-CNR and Dipartimento di Fisica, Politecnico di Milano, 20133, Milano, Italy
| | - Thorsten Bach
- Department of Chemistry and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Jürgen Hauer
- Department of Chemistry and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
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6
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Li X, Kutta RJ, Jandl C, Bauer A, Nuernberger P, Bach T. Photochemically Induced Ring Opening of Spirocyclopropyl Oxindoles: Evidence for a Triplet 1,3‐Diradical Intermediate and Deracemization by a Chiral Sensitizer. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008384] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xinyao Li
- Department Chemie and Catalysis Research Center (CRC) Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Roger J. Kutta
- Institut für Physikalische und Theoretische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC) Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC) Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC) Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
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7
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Li X, Kutta RJ, Jandl C, Bauer A, Nuernberger P, Bach T. Photochemically Induced Ring Opening of Spirocyclopropyl Oxindoles: Evidence for a Triplet 1,3-Diradical Intermediate and Deracemization by a Chiral Sensitizer. Angew Chem Int Ed Engl 2020; 59:21640-21647. [PMID: 32757341 PMCID: PMC7756555 DOI: 10.1002/anie.202008384] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/23/2020] [Indexed: 12/17/2022]
Abstract
The photochemical deracemization of spiro[cyclopropane‐1,3′‐indolin]‐2′‐ones (spirocyclopropyl oxindoles) was studied. The corresponding 2,2‐dichloro compound is configurationally labile upon direct irradiation at λ=350 nm and upon irradiation at λ=405 nm in the presence of achiral thioxanthen‐9‐one as the sensitizer. The triplet 1,3‐diradical intermediate generated in the latter reaction was detected by transient absorption spectroscopy and its lifetime determined (τ=22 μs). Using a chiral thioxanthone or xanthone, with a lactam hydrogen bonding site as a photosensitizer, allowed the deracemization of differently substituted chiral spirocyclopropyl oxindoles with yields of 65–98 % and in 50–85 % ee (17 examples). Three mechanistic contributions were identified to co‐act favorably for high enantioselectivity: the difference in binding constants to the chiral thioxanthone, the smaller molecular distance in the complex of the minor enantiomer, and the lifetime of the intermediate 1,3‐diradical.
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Affiliation(s)
- Xinyao Li
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Roger J Kutta
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
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8
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Kremsmair A, Skotnitzki J, Knochel P. Diastereo- and Enantioselective Cross-Couplings of Secondary Alkylcopper Reagents with 3-Halogeno-Unsaturated Carbonyl Derivatives. Chemistry 2020; 26:11971-11973. [PMID: 32557902 PMCID: PMC7540566 DOI: 10.1002/chem.202002297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/17/2020] [Indexed: 01/28/2023]
Abstract
Chiral secondary alkylcopper reagents were prepared from the corresponding alkyl iodides with retention of configuration by an I/Li-exchange using tBuLi (-100 °C, 1 min) followed by a transmetalation with CuBr⋅P(OEt)3 (-100 °C, 20 s). These stereodefined secondary alkylcoppers underwent stereoretentive cross-couplings with several 3-iodo or 3-bromo unsaturated carbonyl derivatives leading to the corresponding γ-methylated Michael acceptors in good yields and with high diastereoselectivities (dr up to 96:4). The method was extended to enantiomerically enriched alkylcoppers, providing optically enriched advanced natural product intermediates with up to 90 % ee.
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Affiliation(s)
- Alexander Kremsmair
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
| | - Juri Skotnitzki
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
| | - Paul Knochel
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstraße 5–13, Haus F81377MünchenGermany
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9
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Hörmann FM, Kerzig C, Chung TS, Bauer A, Wenger OS, Bach T. Triplet Energy Transfer from Ruthenium Complexes to Chiral Eniminium Ions: Enantioselective Synthesis of Cyclobutanecarbaldehydes by [2+2] Photocycloaddition. Angew Chem Int Ed Engl 2020; 59:9659-9668. [PMID: 32166853 PMCID: PMC7318320 DOI: 10.1002/anie.202001634] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/12/2020] [Indexed: 12/30/2022]
Abstract
Chiral eniminium salts, prepared from α,β-unsaturated aldehydes and a chiral proline derived secondary amine, underwent, upon irradiation with visible light, a ruthenium-catalyzed (2.5 mol %) intermolecular [2+2] photocycloaddition to olefins, which after hydrolysis led to chiral cyclobutanecarbaldehydes (17 examples, 49-74 % yield), with high diastereo- and enantioselectivities. Ru(bpz)3 (PF6 )2 was utilized as the ruthenium catalyst and laser flash photolysis studies show that the catalyst operates exclusively by triplet-energy transfer (sensitization). A catalytic system was devised with a chiral secondary amine co-catalyst. In the catalytic reactions, Ru(bpy)3 (PF6 )2 was employed, and laser flash photolysis experiments suggest it undergoes both electron and energy transfer. However, experimental evidence supports the hypothesis that energy transfer is the only productive quenching mechanism. Control experiments using Ir(ppy)3 showed no catalysis for the intermolecular [2+2] photocycloaddition of an eniminium ion.
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Affiliation(s)
- Fabian M. Hörmann
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstraße 485747GarchingGermany
| | - Christoph Kerzig
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Tim S. Chung
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstraße 485747GarchingGermany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstraße 485747GarchingGermany
| | - Oliver S. Wenger
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstraße 485747GarchingGermany
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10
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Pecho F, Zou Y, Gramüller J, Mori T, Huber SM, Bauer A, Gschwind RM, Bach T. A Thioxanthone Sensitizer with a Chiral Phosphoric Acid Binding Site: Properties and Applications in Visible Light-Mediated Cycloadditions. Chemistry 2020; 26:5190-5194. [PMID: 32065432 PMCID: PMC7216904 DOI: 10.1002/chem.202000720] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Indexed: 11/06/2022]
Abstract
A chiral phosphoric acid with a 2,2'-binaphthol core was prepared that displays two thioxanthone moieties at the 3,3'-position as light-harvesting antennas. Despite its relatively low triplet energy, the phosphoric acid was found to be an efficient catalyst for the enantioselective intermolecular [2+2] photocycloaddition of β-carboxyl-substituted cyclic enones (e.r. up to 93:7). Binding of the carboxylic acid to the sensitizer is suggested by NMR studies and by DFT calculations to occur by means of two hydrogen bonds. The binding event not only enables an enantioface differentiation but also modulates the triplet energy of the substrates.
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Affiliation(s)
- Franziska Pecho
- Department of Chemistry and Catalysis Research Center (CRC)Technical University MunichLichtenbergstr. 485747GarchingGermany
| | - You‐Quan Zou
- Department of Chemistry and Catalysis Research Center (CRC)Technical University MunichLichtenbergstr. 485747GarchingGermany
| | - Johannes Gramüller
- Faculty of Chemistry and PharmacyInstitute of Organic ChemistryUniversity of RegensburgUniversitätsstraße 3193040RegensburgGermany
| | - Tadashi Mori
- Department of Applied ChemistryGraduate School of EngineeringOsaka University2-1 Yamada-okaSuita, Osaka565-871Japan
| | - Stefan M. Huber
- Faculty for Chemistry and Biochemistry, Organic Chemistry IRuhr-Universität BochumUniversitätsstraße 15044801BochumGermany
| | - Andreas Bauer
- Department of Chemistry and Catalysis Research Center (CRC)Technical University MunichLichtenbergstr. 485747GarchingGermany
| | - Ruth M. Gschwind
- Faculty of Chemistry and PharmacyInstitute of Organic ChemistryUniversity of RegensburgUniversitätsstraße 3193040RegensburgGermany
| | - Thorsten Bach
- Department of Chemistry and Catalysis Research Center (CRC)Technical University MunichLichtenbergstr. 485747GarchingGermany
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11
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Hörmann FM, Kerzig C, Chung TS, Bauer A, Wenger OS, Bach T. Triplet Energy Transfer from Ruthenium Complexes to Chiral Eniminium Ions: Enantioselective Synthesis of Cyclobutanecarbaldehydes by [2+2] Photocycloaddition. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001634] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Fabian M. Hörmann
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Christoph Kerzig
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Tim S. Chung
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
| | - Oliver S. Wenger
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstraße 4 85747 Garching Germany
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12
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Petzold D, Giedyk M, Chatterjee A, König B. A Retrosynthetic Approach for Photocatalysis. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901421] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daniel Petzold
- Department of Organic Chemistry University of Regensburg Universitätsstraße 31 93053 Regensburg Germany
| | - Maciej Giedyk
- Department of Organic Chemistry University of Regensburg Universitätsstraße 31 93053 Regensburg Germany
- Institute of Organic Chemistry Polish Academy of Sciences Kasprzaka 44/52 01‐224 Warsaw Poland
| | - Anamitra Chatterjee
- Department of Organic Chemistry University of Regensburg Universitätsstraße 31 93053 Regensburg Germany
| | - Burkhard König
- Department of Organic Chemistry University of Regensburg Universitätsstraße 31 93053 Regensburg Germany
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13
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Poplata S, Bauer A, Storch G, Bach T. Intramolecular [2+2] Photocycloaddition of Cyclic Enones: Selectivity Control by Lewis Acids and Mechanistic Implications. Chemistry 2019; 25:8135-8148. [PMID: 30983074 PMCID: PMC6618137 DOI: 10.1002/chem.201901304] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Indexed: 11/16/2022]
Abstract
The intramolecular [2+2] photocycloaddition of 3‐alkenyl‐2‐cycloalkenones was performed in an enantioselective fashion (nine representative examples, 54–86 % yield, 76–96 % ee) upon irradiation at λ=366 nm in the presence of an AlBr3‐activated oxazaborolidine as the Lewis acid. An extensive screening of proline‐derived oxazaborolidines showed that the enantioface differentiation depends strongly on the nature of the aryl group at the 3‐position of the heterocycle. DFT calculations of the Lewis acid–substrate complex indicate that attractive dispersion forces may be responsible for a change of the binding mode. The catalytic [2+2] photocycloaddition was shown to proceed on the triplet hypersurface with a quantum yield of 0.05. The positive effect of Lewis acids on the outcome of a given intramolecular [2+2] photocycloaddition was illustrated by optimizing the key step in a concise total synthesis of the sesquiterpene (±)‐italicene.
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Affiliation(s)
- Saner Poplata
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Golo Storch
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, 85747, Garching, Germany
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14
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Ishikawa H, Chung TS, Fukuhara G, Shigemitsu H, Kida T, Bach T, Mori T. Diastereoselective Photocycloaddition Reaction of Vinyl Ether Tethered to 1,4‐Naphthoquinone. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hiroki Ishikawa
- Department of Applied Chemistry Graduate School of EngineeringOsaka University 2-1 Yamada-oka Suita 565-0871 Japan
| | - Tim S. Chung
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstrasse 4 85747 Garching Germany
| | - Gaku Fukuhara
- Department of ChemistryTokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku Tokyo 152-8551 Japan
- JST, PRESTO 4-1-8 Honcho, Kawaguchi Saitama 332-0012 Japan
| | - Hajime Shigemitsu
- Department of Applied Chemistry Graduate School of EngineeringOsaka University 2-1 Yamada-oka Suita 565-0871 Japan
| | - Toshiyuki Kida
- Department of Applied Chemistry Graduate School of EngineeringOsaka University 2-1 Yamada-oka Suita 565-0871 Japan
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC)Technische Universität München Lichtenbergstrasse 4 85747 Garching Germany
| | - Tadashi Mori
- Department of Applied Chemistry Graduate School of EngineeringOsaka University 2-1 Yamada-oka Suita 565-0871 Japan
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15
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Tröster A, Bauer A, Jandl C, Bach T. Enantioselective Visible-Light-Mediated Formation of 3-Cyclopropylquinolones by Triplet-Sensitized Deracemization. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814193] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andreas Tröster
- Department Chemie and Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Germany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Germany
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16
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Tröster A, Bauer A, Jandl C, Bach T. Enantioselective Visible-Light-Mediated Formation of 3-Cyclopropylquinolones by Triplet-Sensitized Deracemization. Angew Chem Int Ed Engl 2019; 58:3538-3541. [PMID: 30644639 DOI: 10.1002/anie.201814193] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Indexed: 11/10/2022]
Abstract
3-Allyl-substituted quinolones undergo a triplet-sensitized di-π-methane rearrangement reaction to the corresponding 3-cyclopropylquinolones upon irradiation with visible light (λ=420 nm). A chiral hydrogen-bonding sensitizer (10 mol %) was shown to promote the reaction enantioselectively (88-96 % yield, 32-55 % ee). Surprisingly, it was found that the enantiodifferentiation does not occur at the state of initial product formation but that it is the result of a deracemization event. The individual parameters that control the distribution of enantiomers in the photostationary state have been identified.
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Affiliation(s)
- Andreas Tröster
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Andreas Bauer
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstr. 4, 85747, Garching, Germany
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Stegbauer S, Jandl C, Bach T. Enantioselective Lewis Acid Catalyzed ortho Photocycloaddition of Olefins to Phenanthrene-9-carboxaldehydes. Angew Chem Int Ed Engl 2018; 57:14593-14596. [PMID: 30225921 PMCID: PMC6220838 DOI: 10.1002/anie.201808919] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/07/2018] [Indexed: 11/21/2022]
Abstract
Visible-light irradiation (λ=457 nm) enabled the enantioselective ortho photocycloaddition of olefins to phenanthrene-9-carboxaldehydes (15 examples, 46-93 % yield, 82-98 % ee). A chiral oxazaborolidine Lewis acid (20 mol %) was employed as the catalyst. It operates by coordination to the aldehyde inducing a bathochromic absorption shift beyond the nπ* absorption of the uncomplexed aldehyde. At long wavelengths the Lewis acid complex is exclusively excited; within the complex, one enantiotopic face of the aromatic aldehyde is efficiently shielded. Lewis acid coordination also alters the type selectivity and the simple diastereoselectivity of the photocycloaddition.
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Affiliation(s)
- Simone Stegbauer
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstr. 485747GarchingGermany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstr. 485747GarchingGermany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC)Technische Universität MünchenLichtenbergstr. 485747GarchingGermany
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Stegbauer S, Jandl C, Bach T. Enantioselektive Lewis-Säure-katalysierte ortho
-Photocycloaddition von Phenanthren-9-carbaldehyden. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808919] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Simone Stegbauer
- Department Chemie und Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Deutschland
| | - Christian Jandl
- Department Chemie und Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Deutschland
| | - Thorsten Bach
- Department Chemie und Catalysis Research Center (CRC); Technische Universität München; Lichtenbergstr. 4 85747 Garching Deutschland
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ORCHEM-Preise: I. Fleischer und F. Beuerle / Emil-Fischer-Medaille: T. Bach / Leonidas Zervas Award: C. P. R. Hackenberger / Hanwha-Total IUPAC Young Scientist Award: A. Walther / Thieme-IUPAC-Preis: S. Herzon / Greifswald Research Award: U. T. Bornscheue. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bonilla P, Rey YP, Holden CM, Melchiorre P. Photo-Organocatalytic Enantioselective Radical Cascade Reactions of Unactivated Olefins. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808183] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Pablo Bonilla
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology; Avenida Països Catalans 16-43007 Tarragona Spain
| | - Yannick P. Rey
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology; Avenida Països Catalans 16-43007 Tarragona Spain
| | - Catherine M. Holden
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology; Avenida Països Catalans 16-43007 Tarragona Spain
| | - Paolo Melchiorre
- ICREA-Catalan Institution for Research and Advanced Studies; Passeig Lluís Companys 23-08010 Barcelona Spain
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology; Avenida Països Catalans 16-43007 Tarragona Spain
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Bonilla P, Rey YP, Holden CM, Melchiorre P. Photo-Organocatalytic Enantioselective Radical Cascade Reactions of Unactivated Olefins. Angew Chem Int Ed Engl 2018; 57:12819-12823. [PMID: 30098097 PMCID: PMC6175195 DOI: 10.1002/anie.201808183] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/09/2018] [Indexed: 11/09/2022]
Abstract
Radical cascade processes are invaluable for their ability to rapidly construct complex chiral molecules from simple substrates. However, implementing catalytic asymmetric variants is difficult. Reported herein is a visible‐light‐mediated organocatalytic strategy that exploits the excited‐state reactivity of chiral iminium ions to trigger radical cascade reactions with high enantioselectivity. By combining two sequential radical‐based bond‐forming events, the method converts unactivated olefins and α,β‐unsaturated aldehydes into chiral adducts in a single step. The implementation of an asymmetric three‐component radical cascade further demonstrates the complexity‐generating power of this photochemical strategy.
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Affiliation(s)
- Pablo Bonilla
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans, 16-43007, Tarragona, Spain
| | - Yannick P Rey
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans, 16-43007, Tarragona, Spain
| | - Catherine M Holden
- ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans, 16-43007, Tarragona, Spain
| | - Paolo Melchiorre
- ICREA-Catalan Institution for Research and Advanced Studies, Passeig Lluís Companys, 23-08010, Barcelona, Spain.,ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans, 16-43007, Tarragona, Spain
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