1
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Nguyen TVT, Bossonnet A, Wodrich MD, Waser J. Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles. J Am Chem Soc 2023; 145:25411-25421. [PMID: 37934629 DOI: 10.1021/jacs.3c09789] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
We report the use of photocatalysis for the homolytic ring-opening of carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or a strong reductant. The carbonyl cyclopropanes can be employed for both [2σ + 2σ] and [2σ + 2π] annulation with either alkenes/alkynes or bicyclo[1.1.0]butanes, yielding cyclopent-anes/-enes and bicyclo[3.1.1]heptanes (BCHs), respectively. BCHs are promising bioisosteres for 1,2,4,5 tetra-substituted aromatic rings. Mechanistic studies, including density functional theory computation and a trapping experiment with DMPO, support a 1,3-biradical generated from cyclopropane as a key intermediate for these transformations.
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Affiliation(s)
- Tin V T Nguyen
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - André Bossonnet
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - Matthew D Wodrich
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - Jerome Waser
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
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2
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Cao W, Mao H, McCallum NC, Zhou X, Sun H, Sharpe C, Korpanty J, Hu Z, Ni QZ, Burkart MD, Shawkey MD, Wasielewski MR, Gianneschi NC. Biomimetic pheomelanin to unravel the electronic, molecular and supramolecular structure of the natural product. Chem Sci 2023; 14:4183-4192. [PMID: 37063797 PMCID: PMC10094096 DOI: 10.1039/d2sc06418a] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/18/2023] [Indexed: 04/03/2023] Open
Abstract
A robust route to synthetic pheomelanin gives insight into the electronic, molecular and supramolecular structure of the natural product, further advancing our understanding of this important subfamily of melanin.
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Affiliation(s)
- Wei Cao
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Biomedical Engineering, Department of Pharmacology, International Institute for Nanotechnology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Lurie Cancer Center, Northwestern University, Evanston, Illinois, 60208, USA
| | - Haochuan Mao
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
- Institute for Sustainability and Energy at Northwestern University, Evanston, Illinois, 60208, USA
| | - Naneki C. McCallum
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
| | - Xuhao Zhou
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
| | - Hao Sun
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Biomedical Engineering, Department of Pharmacology, International Institute for Nanotechnology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Lurie Cancer Center, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Chemistry and Chemical & Biomedical Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, Connecticut, 06516, USA
| | - Christopher Sharpe
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, 60208, USA
| | - Joanna Korpanty
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
| | - Ziying Hu
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
| | - Qing Zhe Ni
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA
| | - Michael D. Burkart
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA
| | - Matthew D. Shawkey
- Evolution and Optics of Nanostructures Group, Department of Biology, The University of Ghent, 9000, Ghent, Belgium
| | - Michael R. Wasielewski
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
- Institute for Sustainability and Energy at Northwestern University, Evanston, Illinois, 60208, USA
| | - Nathan C. Gianneschi
- Department of Chemistry, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Biomedical Engineering, Department of Pharmacology, International Institute for Nanotechnology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Lurie Cancer Center, Northwestern University, Evanston, Illinois, 60208, USA
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA
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3
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Jin P, Rong Y, Liang W, Liang X, Lu R, Wu W, Gou M, Tang Y, Yang C, Inoue Y. Optimizing Photochirogenic Performance by Solvent-Driven Conformational Fixation in Enantiodifferentiating Photoisomerization of ( Z)-Cyclooctene Mediated by Sensitizing β-Cyclodextrin Hosts. J Org Chem 2021; 87:1679-1688. [PMID: 34743518 DOI: 10.1021/acs.joc.1c01748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Catalytic enantiodifferentiating photoisomerization of cyclooctene (1Z) included and sensitized by regioisomeric 6-O-(o-, m-, and p-methoxybenzoyl)-β-cyclodextrins (CDs) was performed under a variety of solvent conditions for higher enantioselectivities. The enantiomeric excess (ee) of chiral (E)-isomer (1E) produced was a critical function of all the internal and external factors examined, in particular, the sensitizer structure and the solvent conditions, to afford (R)-1E in record-high ee's of up to 67% upon sensitization with the meta-substituted β-CD host in water and salt solutions but neither in 50% aqueous ethanol nor with the ortho- and para-substituted hosts. The mechanistic origin of the sudden ee enhancement achieved under the specific conditions is discussed on the basis of the circular dichroism spectral behaviors upon substrate inclusion and the compensatory enthalpy-entropy relationship of the activation parameters for the enantiodifferentiating photoisomerization.
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Affiliation(s)
- Pengyue Jin
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu 610065, Sichuan, China
| | - Yanqin Rong
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, and Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610064, China
| | - Wenting Liang
- Institute of Environmental Science, Department of Chemistry, Shanxi University, Taiyuan 030006, China
| | - Xiaotong Liang
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu 610065, Sichuan, China
| | - Runhua Lu
- Department of Applied Chemistry, College of Sciences, China Agricultural University, Beijing 100094, China
| | - Wuanhua Wu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, and Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610064, China
| | - Min Gou
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu 610065, Sichuan, China
| | - Yueqin Tang
- College of Architecture and Environment, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu 610065, Sichuan, China
| | - Cheng Yang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, and Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610064, China
| | - Yoshihisa Inoue
- Department of Applied Chemistry, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan
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4
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Großkopf J, Kratz T, Rigotti T, Bach T. Enantioselective Photochemical Reactions Enabled by Triplet Energy Transfer. Chem Rev 2021; 122:1626-1653. [PMID: 34227803 DOI: 10.1021/acs.chemrev.1c00272] [Citation(s) in RCA: 160] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For molecules with a singlet ground state, the population of triplet states is mainly possible (a) by direct excitation and subsequent intersystem crossing or (b) by energy transfer from an appropriate sensitizer. The latter scenario enables a catalytic photochemical reaction in which the sensitizer adopts the role of a catalyst undergoing several cycles of photon absorption and subsequent energy transfer to the substrate. If the product molecule of a triplet-sensitized process is chiral, this process can proceed enantioselectively upon judicious choice of a chiral triplet sensitizer. An enantioselective reaction can also occur in a dual catalytic approach in which, apart from an achiral sensitizer, a second chiral catalyst activates the substrate toward sensitization. Although the idea of enantioselective photochemical reactions via triplet intermediates has been pursued for more than 50 years, notable selectivities exceeding 90% enantiomeric excess (ee) have only been realized in the past decade. This review attempts to provide a comprehensive survey on the various photochemical reactions which were rendered enantioselective by triplet sensitization.
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Affiliation(s)
- Johannes Großkopf
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, D-85747 Garching, Germany
| | - Thilo Kratz
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, D-85747 Garching, Germany
| | - Thomas Rigotti
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, D-85747 Garching, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), Technische Universität München, D-85747 Garching, Germany
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5
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Kinoshita T, Imai Y, Fukuhara G. Hydrostatic Pressure-Controllable Chiroptical Properties of Chiral Perylene Bisimide Dyes: A Chiral Aggregation Case. J Phys Chem B 2021; 125:5952-5958. [PMID: 34032446 DOI: 10.1021/acs.jpcb.1c02112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hydrostatically pressurized spectroscopic and lifetime decay analyses of optically active perylene bisimides were demonstrated in the pressure range of 0.1-320 MPa to show a π-stacked aggregation. The hydrostatic pressure-induced excitation and circular dichroism spectral changes of the fluorescence perylene dye enabled us to differentiate the slight pressure-sensitive aggregates. This work will lead to a new strategy for creating a pressure-responsive supramolecular polymerization material.
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Affiliation(s)
- Tomokazu Kinoshita
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Yoshitane Imai
- Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan
| | - Gaku Fukuhara
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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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: 44] [Impact Index Per Article: 11.0] [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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Achiral Zeolites as Reaction Media for Chiral Photochemistry. Molecules 2019; 24:molecules24193570. [PMID: 31581744 PMCID: PMC6804131 DOI: 10.3390/molecules24193570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/17/2022] Open
Abstract
Obtaining enantiomerically-enriched photoproducts from achiral reactants has been a long-sought goal. The various methods developed to achieve chiral induction in photoproducts during the last fifty years still suffer from a lack of predictability, generality, and simplicity. With the current emphasis on green chemistry, obtaining enantiomerically enriched products via photochemistry is a likely viable alternative for the future. Of the various approaches developed during the last three decades, the one pioneered in the author's laboratory involved the use of commercially-available and inexpensive achiral zeolites as the media. This approach does not use any solvent for the reaction. Examples from these studies are highlighted in this article. Since no chiral zeolites were available, when the work was initiated in the author's laboratory, commercially-available zeolites X and Y were modified with chiral inductors so that the reaction space becomes chiral. The results obtained established the value of chirally-modified, commercial zeolites as media for achieving chiral induction in photochemical reactions. A recent report of the synthesis of a chiral zeolite is likely to stimulate zeolite-based chiral photochemistry in synthesizing enantiomerically-pure organic molecules. The availability of chiral zeolites in future is likely to energize research in this area. Our earlier observations on this topic, we believe, would be valuable for progress of the field. Keeping this in mind, I have summarized the work carried out in our laboratory on chiral photochemistry on chirally-modified zeolites. This review does not include examples where high chiral induction has been obtained via a strategy that examines molecules appended with chiral auxiliary within achiral and chirally-modified zeolites. The latter approach yields products with diastereomeric excess >80%.
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9
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Affiliation(s)
- Shinji Yamada
- Department of Chemistry, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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10
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Shailaja J, Sivaguru J, Ramamurthy V. Zeolite matrix assisted decomposition of singlet oxygen sensitizers during photooxidation. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2016.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Matsui Y, Oishi T, Ohta E, Ikeda H. Adiabatic process of higher electronically excited states: luminescence from an excited state biradical generated by irradiation of benzophenone-substituted cyclopropanes. J PHYS ORG CHEM 2016. [DOI: 10.1002/poc.3636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yasunori Matsui
- Department of Applied Chemistry, Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
- The Research Institute for Molecular Electronic Devices (RIMED); Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Toru Oishi
- Department of Applied Chemistry, Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Eisuke Ohta
- Department of Applied Chemistry, Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
- The Research Institute for Molecular Electronic Devices (RIMED); Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Hiroshi Ikeda
- Department of Applied Chemistry, Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
- The Research Institute for Molecular Electronic Devices (RIMED); Osaka Prefecture University; Sakai Osaka 599-8531 Japan
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12
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Ramamurthy V, Mondal B. Supramolecular photochemistry concepts highlighted with select examples. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2015. [DOI: 10.1016/j.jphotochemrev.2015.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Abstract
AbstractSupramolecular photochirogenesis is a new strategy for circumventing the inherent difficulties encountered in conventional photochirogenesis, i.e. the interactions associated with geometrically less-defined, short-lived excited states, by confining a prochiral substrate(s) in a chiral supramolecular environment(s) prior to photoexcitation. This rather simple, but very successful, strategy has been applied to a variety of chiral photoreactions. However, a stoichiometric, or even excess amount of supramolecular host is often needed to ensure full complexation of the substrate, and achieve the optimum stereochemical outcome. This apparent drawback has recently been removed by introducing a sensitizing moiety to the supramolecular host, or by bathochromically shifting the absorption band of substrate through Lewis acid, or charge-transfer complexation. Recent progress in catalytic supramolecular photochirogenesis will be reviewed.
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14
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Ayitou AJL, Clay A, Kumarasamy E, Jockusch S, Sivaguru J. Enantiospecific photochemical 6π-ring closure of α-substituted atropisomeric acrylanilides – role of alkali metal ions. Photochem Photobiol Sci 2014; 13:141-4. [DOI: 10.1039/c3pp50278c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Alonso R, Jiménez MC, Miranda MA. Stereodifferentiation in the Compartmentalized Photooxidation of a Protein-Bound Anthracene. Org Lett 2011; 13:3860-3. [DOI: 10.1021/ol201209h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Rafael Alonso
- Departamento de Química/Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, E-46022 Valencia, Spain
| | - M. Consuelo Jiménez
- Departamento de Química/Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, E-46022 Valencia, Spain
| | - Miguel A. Miranda
- Departamento de Química/Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, E-46022 Valencia, Spain
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16
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Ding J, Cao L, Wang J, Xue W, Zhu Y, Wu A. The Conversion of Aryl and Heteroaryl Methylketones to the Corresponding Secondary or Tertiary Amides. JOURNAL OF CHEMICAL RESEARCH 2011. [DOI: 10.3184/174751911x13053065216840] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Secondary or tertiary amides have been prepared directly from aryl, heteroaryl methyl ketones using an iodine– amine–NaOH system which afforded the expected products in good yields in an aqueous medium. The present method has the advantages of using inexpensive reagents, mild reaction condition and ease of manipulation.
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Affiliation(s)
- Jiaoyang Ding
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
| | - Liping Cao
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
| | - Jungang Wang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
| | - Weijian Xue
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
| | - Yanping Zhu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
| | - Anxin Wu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Central China Normal University, Wuhan 430079, P. R. China
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17
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Kusaka S, Kano N, Kawashima T. Elucidation of the stereochemistry of thiirane formation from a 1λ4,2-dithietane bearing two chiral carbon centers. HETEROATOM CHEMISTRY 2010. [DOI: 10.1002/hc.20630] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Sundaresan AK, Gibb CLD, Gibb BC, Ramamurthy V. Chiral Photochemistry in a Confined Space: Torquoselective Photoelectrocyclization of Pyridones within an Achiral Hydrophobic Capsule. Tetrahedron 2009; 65:7277-7288. [PMID: 21037975 DOI: 10.1016/j.tet.2009.01.110] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Chiral induction during the photoelectrocyclization of pyridones included within octa acid (OA) capsule has been established. Chiral induction is brought about by a chiral auxiliary appended to the reactive pyridone moiety. Importantly, the same chiral auxiliary while ineffective in acetonitrile solution is found to be effective within the confined space of OA capsule. The diastereomeric excess of 92% obtained here is comparable only to that in solid state. OA capsule, we believe, provides restriction to the rotational motions of the reactant pyridone and chiral auxiliary and thus places the chiral auxiliary in a selective conformation with respect to the reactive pyridone part. A correlation between the position of the methyl group on the pyridone ring and diastereoselectivity was noted. Structures of the host-guest complexes were examined by (1)H NMR and the data was used to obtain preliminary information concerning the mechanism of chiral induction within the confined spaces of OA capsule.
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19
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Sini G, Tessier A, Pytkowicz J, Brigaud T. Fluorine... and pi...alkali metal interactions control in the stereoselective amide enolate alkylation with fluorinated oxazolidines (Fox) as a chiral auxiliary: an experimental and theoretical study. Chemistry 2008; 14:3363-70. [PMID: 18283703 DOI: 10.1002/chem.200701604] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The alpha-alkylation of amide enolates by using a pseudo-C(2) symmetry trans 4-phenyl-2-trifluoromethyloxazolidine (trans-Fox) as a chiral auxiliary occurs with an extremely high diastereoselectivity (>99 % de). The origin of this excellent stereocontrol was investigated by an experimental and theoretical (DFT) study. With this trans chiral auxiliary, both F...metal and pi...metal interactions compete to give the same diastereomer through Re face alkylation of the enolate. A 5.5 kcal mol(-1) energy difference found between the Re face and the Si face attack transition states is consistent with the complete diastereoselectivity that has been experimentally achieved. On the other hand, in the case of the cis chiral auxiliary (cis-Fox) the competition between the F...metal and pi...metal interactions is unfavourable to the diastereoselectivity. In this case, the Re face and the Si face attack transition states were found to be nearly isoenergetic (0.3 kcal mol(-1) difference), which is in good agreement with the very low diastereoselectivity observed.
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Affiliation(s)
- Gjergji Sini
- Laboratoire LPPI, Université de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville sur Oise, Cergy-Pontoise cedex, France.
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20
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Affiliation(s)
- Norbert Hoffmann
- Laboratoire des Réactions Sélectives et Applications, UMR 6519 CNRS et Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, F-51687 Reims, Cedex 02, France
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Sivasubramanian K, Kaanumalle LS, Uppili S, Ramamurthy V. Value of zeolites in asymmetric induction during photocyclization of pyridones, cyclohexadienones and naphthalenones. Org Biomol Chem 2007; 5:1569-76. [PMID: 17571186 DOI: 10.1039/b702572f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two strategies, namely chiral inductor and chiral auxiliary approaches, have been examined within zeolites with the aim of achieving asymmetric induction during the photocyclization of cyclohexadienone, naphthalenone and pyridone derivatives. Within zeolites, enantioselectivity as high as 55% and diastereoselectivity as high as 88% have been obtained. The observed stereoselectivities are significant given the fact that these reactions gave very little stereoselectivities in isotropic solution media. The results obtained on the photocyclization of dienones, naphthalenones and N-alkyl pyridones within zeolites compliment our earlier investigations on the photocyclization of tropolone derivatives, the geometric isomerization of 1,2-diphenylcyclopropanes and 2,3-diphenyl-1-benzoyl cyclopropanes, and the Norrish type II reaction of alpha-oxoamides, phenyl adamantyl ketones, phenyl norbornyl ketones and phenyl cyclohexyl ketones. With the help of these examples, we have established the importance of zeolite and its charge compensating cations in effecting asymmetric induction in photochemical reactions.
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Yang C, Mori T, Wada T, Inoue Y. Supramolecular enantiodifferentiating photoisomerization of (Z,Z)-1,3-cyclooctadiene included and sensitized by naphthalene-modified cyclodextrins. NEW J CHEM 2007. [DOI: 10.1039/b615353d] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yang C, Nakamura A, Fukuhara G, Origane Y, Mori T, Wada T, Inoue Y. Pressure and Temperature-Controlled Enantiodifferentiating [4+4] Photocyclodimerization of 2-Anthracenecarboxylate Mediated by Secondary Face- and Skeleton-Modified γ-Cyclodextrins. J Org Chem 2006; 71:3126-36. [PMID: 16599609 DOI: 10.1021/jo0601718] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of secondary-face-substituted and skeleton-modified gamma-cyclodextrins (gamma-CDs) were prepared as chiral hosts for enantiodifferentiating [4+4] photocyclodimerization reactions of 2-anthracenecarboxylic acid (AC). These gamma-CD derivatives form stable ternary complexes with ACs, with altroside-bearing gamma-CDs undergoing induced-fit conformational changes upon complexation, and the photocyclodimerization of AC was, thus, dramatically accelerated. The enantiomeric excess (ee) of anti-head-to-head cyclodimer 3 was greatly enhanced in general with altroside-bearing gamma-CDs 7-9. Although mono-altro-gamma-CD 9 and 3A-azido-3A-deoxy-altro-gamma-CD 7 gave 2 in ee's smaller than those obtained with native gamma-CD, 3A-amino-3A-deoxy-altro-gamma-CD 8 yielded 2 in much higher ee's, which is likely to be ascribed to the combined effects of the less-symmetric cavity and the electrostatic interactions. The influence of temperature and high pressure on the supramolecular photochirogenic reaction has been investigated in depth. An ee as high as 71% was obtained for cyclodimer 2 in the photocyclodimerization of AC mediated by 8 at 210 MPa and -21.5 degrees C.
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Affiliation(s)
- Cheng Yang
- ICORP Entropy Control Project, JST, 4-6-3 Kamishinden, Toyonaka 560-0085, Japan
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Natarajan A, Ramamurthy V. Asymmetric induction during photocyclization of chiral and achiral α-oxoamides within achiral zeolites. Org Biomol Chem 2006; 4:4533-42. [PMID: 17268650 DOI: 10.1039/b611387g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photochemistry of 31 alpha-oxoamides capable of undergoing gamma-hydrogen transfer has been examined within zeolites. These molecules, upon excitation, yield two products--a beta-lactam and oxazolidinone--in solution, both resulting from gamma-hydrogen transfer. While in benzene the major product is oxazolidinone, within an MY zeolite, the main product is a beta-lactam. In this investigation, we have focused our attention on asymmetric induction in the formation of the beta-lactam product. Two approaches--using a chiral inductor and chiral auxiliary--have been employed. While in solution, in the presence of chiral inductors, achiral alpha-oxoamides yield beta-lactams with zero enantioselectivity; within zeolites, an ee of up to 44% has been achieved. Alpha-oxoamides appended with a chiral auxiliary gave beta-lactams with less than 5% diastereoselectivity in solution while within zeolites, the same alpha-oxoamides gave the products with de's of up to 83%. Such a remarkable influence of zeolites is attributed to an alkali ion interaction with the reactant alpha-oxoamides and to the confined environment of the zeolite interior. At this stage, we have not been able to provide a model with predictive power and further work is needed to understand this valuable asymmetric induction strategy.
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Sivaguru J, Saito H, Solomon MR, Kaanumalle LS, Poon T, Jockusch S, Adam W, Ramamurthy V, Inoue Y, Turro NJ. Control of Chirality by Cations in Confined Spaces: Photooxidation of Enecarbamates Inside Zeolite Supercages†. Photochem Photobiol 2006; 82:123-31. [PMID: 16076247 DOI: 10.1562/2005-06-15-ra-573] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
On photooxygenation of the optically active Z/E enecarbamates 1 (X = i-Pr) and 2 (X = Me) equipped with the oxazolidinone chiral auxiliary in methylene-blue (MB)-incorporated, alkali-metal (M = Li, Na, K, Cs, Rb), exchanged Y-type zeolites (MY-MB), oxidative cleavage of the alkenyl functionality releases the enantiomerically enriched methyldesoxybenzoin (MDB) product. The extent (%ee) and/or the sense (R or S) of the stereoselectivity in the formation of the MDB product depends on the choice of the alkyl substiuent (i-Pr or Me) at the C-4 position of the oxazolidinone chiral auxiliary, the Z/E configuration of the alkene functionality in the enecarbamates, and the type of alkali metal in the zeolite. Most significantly-the highlight of this study-is the reversed sense (R or S) in the stereoselection when the photooxygenation is run in CDCl3 solution versus inside the MY-MB zeolite. As a mechanistic rationale for this novel stereochemical behavior, we propose the combined action of spatial confinement and metal-ion coordination (assessed by density-functional calculations) of the substrate within the zeolite supercage, both of which greatly reduce the freedom of the substrate and entropically manipulate the stereochemical outcome.
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Affiliation(s)
- J Sivaguru
- The Department of Chemistry, Columbia University, New York, NY, USA
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Joy A, Kaanumalle LS, Ramamurthy V. Role of cations and confinement in asymmetric photochemistry: enantio- and diastereo-selective photocyclization of tropolone derivatives within zeolites. Org Biomol Chem 2005; 3:3045-53. [PMID: 16186938 DOI: 10.1039/b504865f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Asymmetric induction in photochemical reactions has been explored using the photochemistry of tropolones as a model. Three approaches have been examined: chiral inductor, chiral auxiliary and [chiral inductor + chiral auxiliary]. All three methods gave excellent asymmetric induction in zeolite and very little or zero induction in solution. Results presented on tropolones clearly illustrate the remarkable influence that a confined space studded with cations can have on asymmetric induction. Tropolone derivatives, upon irradiation undergo 4pi-electron electrocyclization to yield a bicyclic product and a rearranged product. Enantiomeric excess up to 68% has been achieved in the cyclized product. In systems where a chiral inductor has been covalently linked, diastereomeric excess as high as 88% has been achieved within a zeolite while the same system in solution gave 10%.
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Affiliation(s)
- Abraham Joy
- Department of Chemistry, University of Miami, Coral Gables, FL 33124, USA
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