1
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Kutta RJ, Großkopf J, van Staalduinen N, Seitz A, Pracht P, Breitenlechner S, Bannwarth C, Nuernberger P, Bach T. Multifaceted View on the Mechanism of a Photochemical Deracemization Reaction. J Am Chem Soc 2023; 145:2354-2363. [PMID: 36660908 DOI: 10.1021/jacs.2c11265] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Upon irradiation in the presence of a chiral benzophenone catalyst (5 mol %), a racemic mixture of a given chiral imidazolidine-2,4-dione (hydantoin) can be converted almost quantitatively into the same compound with high enantiomeric excess (80-99% ee). The mechanism of this photochemical deracemization reaction was elucidated by a suite of mechanistic experiments. It was corroborated by nuclear magnetic resonance titration that the catalyst binds the two enantiomers by two-point hydrogen bonding. In one of the diastereomeric complexes, the hydrogen atom at the stereogenic carbon atom is ideally positioned for hydrogen atom transfer (HAT) to the photoexcited benzophenone. Detection of the protonated ketyl radical by transient absorption revealed hydrogen abstraction to occur from only one but not from the other hydantoin enantiomer. Quantum chemical calculations allowed us to visualize the HAT within this complex and, more importantly, showed that the back HAT does not occur to the carbon atom of the hydantoin radical but to its oxygen atom. The achiral enol formed in this process could be directly monitored by its characteristic transient absorption signal at λ ≅ 330 nm. Subsequent tautomerization leads to both hydantoin enantiomers, but only one of them returns to the catalytic cycle, thus leading to an enrichment of the other enantiomer. The data are fully consistent with deuterium labeling experiments and deliver a detailed picture of a synthetically useful photochemical deracemization reaction.
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Affiliation(s)
- Roger Jan Kutta
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, RegensburgD-93053, Germany
| | - Johannes Großkopf
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, D-85747Garching, Germany
| | - Nils van Staalduinen
- Institut für Physikalische Chemie, RWTH Aachen University, D-52074Aachen, Germany
| | - Antonia Seitz
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, D-85747Garching, Germany
| | - Philipp Pracht
- Institut für Physikalische Chemie, RWTH Aachen University, D-52074Aachen, Germany.,Yusuf Hamied Department of Chemistry, University of Cambridge, CambridgeCB2 1EW, United Kingdom
| | - Stefan Breitenlechner
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, D-85747Garching, Germany
| | - Christoph Bannwarth
- Institut für Physikalische Chemie, RWTH Aachen University, D-52074Aachen, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, RegensburgD-93053, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, D-85747Garching, Germany
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2
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Shrestha R, Khanal HD, Rubio PYM, Mohandoss S, Lee YR. Base-Mediated Denitrogenative Sulfonylation/Benzannulation of Conjugated N-Sulfonylhydrazones with 3-Formylchromones for the Construction of Polyfunctionalized Biaryl Sulfones. Org Lett 2020; 22:7531-7536. [PMID: 32936654 DOI: 10.1021/acs.orglett.0c02724] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Base-promoted benzannulation of conjugated N-sulfonylhydrazones and 3-formylchromones for the synthesis of diverse biaryl sulfones is described. The approach facilitates new C-C and C-S bond formation via the cascade diazo formation/Michael addition/ring opening/denitrogenative sulfonylation/intramolecular cycloaddition/dehydration and introduces diverse functional groups onto biaryl sulfones. The synthesized compounds are converted to aryl sulfones bearing bioactive benzisoxazole and benzofuran frameworks. Moreover, the synthesized biaryl sulfones possess potent turn-on fluorescence sensing and UV absorbance properties.
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Affiliation(s)
- Rajeev Shrestha
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Hari Datta Khanal
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Peter Yuosef M Rubio
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Sonaimuthu Mohandoss
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Yong Rok Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
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3
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Glaser F, Kerzig C, Wenger OS. Multiphotonen‐Anregung in der Photoredoxkatalyse: Konzepte, Anwendungen und Methoden. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201915762] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Felix Glaser
- Departement Chemie Universität Basel St. Johanns-Ring 19 4056 Basel Schweiz
| | - Christoph Kerzig
- Departement Chemie Universität Basel St. Johanns-Ring 19 4056 Basel Schweiz
| | - Oliver S. Wenger
- Departement Chemie Universität Basel St. Johanns-Ring 19 4056 Basel Schweiz
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4
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Glaser F, Kerzig C, Wenger OS. Multi-Photon Excitation in Photoredox Catalysis: Concepts, Applications, Methods. Angew Chem Int Ed Engl 2020; 59:10266-10284. [PMID: 31945241 DOI: 10.1002/anie.201915762] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/16/2020] [Indexed: 01/28/2023]
Abstract
The energy of visible photons and the accessible redox potentials of common photocatalysts set thermodynamic limits to photochemical reactions that can be driven by traditional visible-light irradiation. UV excitation can be damaging and induce side reactions, hence visible or even near-IR light is usually preferable. Thus, photochemistry currently faces two divergent challenges, namely the desire to perform ever more thermodynamically demanding reactions with increasingly lower photon energies. The pooling of two low-energy photons can address both challenges simultaneously, and whilst multi-photon spectroscopy is well established, synthetic photoredox chemistry has only recently started to exploit multi-photon processes on the preparative scale. Herein, we have a critical look at currently developed reactions and mechanistic concepts, discuss pertinent experimental methods, and provide an outlook into possible future developments of this rapidly emerging area.
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Affiliation(s)
- Felix Glaser
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Christoph Kerzig
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
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5
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Alzueta OR, Cadet J, Cuquerella MC, Miranda MA. Photosensitised biphotonic chemistry of pyrimidine derivatives. Org Biomol Chem 2020; 18:2227-2232. [PMID: 32167122 DOI: 10.1039/d0ob00132e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Photosensitised biphotonic irradiation of DNA has been rarely addressed, probably due to the difficulties in the experimental design. This is associated with the selection of nucleobases and sensitisers with appropriate absorption spectra and photochemical reactivity, in combination with a laser source emitting intense UVA light of the adequate wavelength. The present paper presents a new strategy involving absorption of a first UVA photon by an adequate sensitiser followed by triplet energy transfer to a pyrimidine (Pyr) derivative and absorption of a second UVA photon by the resulting Pyr triplet excited state. The feasibility of the proposed strategy has been demonstrated using two model reactions: (i) the Norrish-Yang photocyclisation of a tert-butyluracil and (ii) the photohydration of its uracil analogue, lacking the tert-butyl substituent.
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Affiliation(s)
- Ofelia R Alzueta
- Instituto Universitario Mixto de Tecnología Química, Universitat Politècnica de València (UPV-CSIC), Av. Los Naranjos s/n, 46022, Valencia, Spain.
| | - Jean Cadet
- Prof. J. Cadet Département de Médecine Nucléaire et Radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - M Consuelo Cuquerella
- Instituto Universitario Mixto de Tecnología Química, Universitat Politècnica de València (UPV-CSIC), Av. Los Naranjos s/n, 46022, Valencia, Spain.
| | - Miguel A Miranda
- Instituto Universitario Mixto de Tecnología Química, Universitat Politècnica de València (UPV-CSIC), Av. Los Naranjos s/n, 46022, Valencia, Spain.
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6
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Yang W, Zhao J, Tang G, Li X, Gurzadyan GG. Direct Observation of Long-Lived Upper Excited Triplet States and Intersystem Crossing in Anthracene-Containing Pt II Complexes. J Phys Chem Lett 2019; 10:7767-7773. [PMID: 31765165 DOI: 10.1021/acs.jpclett.9b03088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Exceptionally long-lived T2 states (7 ns) were observed with the N^N PtII bisacetylide complex (Pt-1) and trans-bis(phosphine) PtII bisacetylide complexes (Pt-2, Pt-3) containing anthryl acetylide ligands. For Pt-1, fluorescence of the anthryl moiety (An) was quenched and phosphorescence was observed. Under 350 nm excitation, the upper long-lived triplet state T2 (3An) was populated via ultrafast intersystem crossing (ISC) of S1 (1An) → T2 (3An) (within 0.2 ps). Interestingly, Pt-3, after population of the S1 state, emits strong fluorescence (ΦF = 89%); the poor ISC is due to the high-lying T2 (3An, 3.36 eV) versus S1 (1An, 2.55 eV) state and the large energy gap between S1 (1An, 2.55 eV) and T1 (3An, 1.32 eV) states. The population of the upper excited state S2 (1LLCT, 3.49 eV) turns to an efficient S2 → T2 → T1, and ISC yield increases by 55% compared with S0 → S1 excitation. These results present new in-depth insights into fundamental photochemistry of upper excited states.
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Affiliation(s)
- Wenbo Yang
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering , Dalian University of Technology , E-208 West Campus, 2 Ling Gong Road , Dalian 116024 , People's Republic of China
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering , Dalian University of Technology , E-208 West Campus, 2 Ling Gong Road , Dalian 116024 , People's Republic of China
| | - Geliang Tang
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering , Dalian University of Technology , E-208 West Campus, 2 Ling Gong Road , Dalian 116024 , People's Republic of China
| | - Xiaoxin Li
- Institute of Artificial Photosynthesis, State Key Laboratory of Fine Chemicals , Dalian University of Technology , F-209 West Campus, 2 Ling Gong Road , Dalian 116024 , People's Republic of China
| | - Gagik G Gurzadyan
- Institute of Artificial Photosynthesis, State Key Laboratory of Fine Chemicals , Dalian University of Technology , F-209 West Campus, 2 Ling Gong Road , Dalian 116024 , People's Republic of China
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7
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BF3
⋅OEt2
-Promoted Annulation for Substituted 2-Arylpyridines as Potent UV Filters and Antibacterial Agents. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201701137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Cai H, Xia L, Lee YR. Regioselective construction of diverse and multifunctionalized 2-hydroxybenzophenones for sun protection by indium(iii)-catalyzed benzannulation. Chem Commun (Camb) 2016; 52:7661-4. [DOI: 10.1039/c6cc02381a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Highly regioselective synthesis of 2-hydroxybenzophenones via the In(OTf)3-catalyzed formal [2+2+2] and [4+2] benzannulations has been successfully developed and their application as sun protection materials was also evaluated.
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Affiliation(s)
- Hongyun Cai
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan 712-749
- Republic of Korea
| | - Likai Xia
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan 712-749
- Republic of Korea
| | - Yong Rok Lee
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan 712-749
- Republic of Korea
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9
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Tamargo RJI, Poudel TN, Lee YR. Mild base-promoted benzannulation for the construction of polyfunctionalized m-terphenyl derivatives and their application as potent UV-filters. RSC Adv 2016. [DOI: 10.1039/c6ra15193k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
An efficient and facile transition-metal-free benzannulation was developed for the construction of polyfunctionalized m-terphenyl derivatives.
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Affiliation(s)
| | - Tej Narayan Poudel
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan 712-749
- Republic of Korea
| | - Yong Rok Lee
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan 712-749
- Republic of Korea
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10
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Huang J, Ma J, Li M, Liu M, Zhang X, Phillips DL. How Does the C–Halogen Bond Break in the Photosubstitution Reaction of 3-Fluorobenzophenone in Acidic Aqueous Solutions? J Org Chem 2015; 80:9425-36. [DOI: 10.1021/acs.joc.5b01308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jinqing Huang
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Jiani Ma
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, People’s Republic of China
| | - Mingde Li
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Mingyue Liu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Xiting Zhang
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
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11
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Fujitsuka M, Kim SS, Lu C, Tojo S, Majima T. Intermolecular and Intramolecular Electron Transfer Processes from Excited Naphthalene Diimide Radical Anions. J Phys Chem B 2014; 119:7275-82. [DOI: 10.1021/jp510850z] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Mamoru Fujitsuka
- The
Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Sung Sik Kim
- The
Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
- Department
of Chemistry, Chonbuk National University, Jeonju 561-756, Korea
| | - Chao Lu
- The
Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Sachiko Tojo
- The
Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Tetsuro Majima
- The
Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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12
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Vendrell-Criado V, Rodríguez-Muñiz GM, Yamaji M, Lhiaubet-Vallet V, Cuquerella MC, Miranda MA. Two-Photon Chemistry from Upper Triplet States of Thymine. J Am Chem Soc 2013; 135:16714-9. [DOI: 10.1021/ja408997j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Victoria Vendrell-Criado
- Instituto
de Tecnología Química UPV-CSIC, Universitat Politècnica de València, Av. Los Naranjos s/n, 46022 Valencia, Spain
| | - Gemma M. Rodríguez-Muñiz
- Instituto
de Tecnología Química UPV-CSIC, Universitat Politècnica de València, Av. Los Naranjos s/n, 46022 Valencia, Spain
| | - Minoru Yamaji
- Division
of Molecular Science, Faculty of Science and Technology, Gunma University, Kiryu Gunma 376-8515, Japan
| | - Virginie Lhiaubet-Vallet
- Instituto
de Tecnología Química UPV-CSIC, Universitat Politècnica de València, Av. Los Naranjos s/n, 46022 Valencia, Spain
| | - M. Consuelo Cuquerella
- Instituto
de Tecnología Química UPV-CSIC, Universitat Politècnica de València, Av. Los Naranjos s/n, 46022 Valencia, Spain
| | - Miguel A. Miranda
- Instituto
de Tecnología Química UPV-CSIC, Universitat Politècnica de València, Av. Los Naranjos s/n, 46022 Valencia, Spain
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13
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Hill MP, Freer LH, Vang MC, Carroll EC, Larsen DS. Multiphoton Manipulations of Enzymatic Photoactivity in Aspartate Aminotransferase. J Phys Chem B 2011; 115:4474-83. [DOI: 10.1021/jp112400g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Melissa P. Hill
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Lucy H. Freer
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Mai C. Vang
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Elizabeth C. Carroll
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Delmar S. Larsen
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States
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14
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Iaroshenko VO, Bunescu A, Spannenberg A, Supe L, Milyutina M, Langer P. 3-Methoxalylchromones – versatile reagents for the regioselective synthesis of functionalized 2,4′-dihydroxybenzophenones, potential UV-filters. Org Biomol Chem 2011; 9:7554-8. [DOI: 10.1039/c1ob05931a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Unravelling the Reaction Mechanism for the Fast Photocyclisation of 2-Benzoylpyridine in Aqueous Solvent by Time-Resolved Spectroscopy and Density Functional Theory Calculations. Chemistry 2010; 16:6961-72. [DOI: 10.1002/chem.200903073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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16
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Horvat M, Görner H, Warzecha KD, Neudörfl J, Griesbeck AG, Mlinarić-Majerski K, Basarić N. Photoinitiated domino reactions: N-(adamantyl)phthalimides and N-(adamantylalkyl)phthalimides. J Org Chem 2009; 74:8219-31. [PMID: 19874065 DOI: 10.1021/jo901753z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Phthalimides 1-6 undergo photochemical reactions upon direct irradiation as well as triplet sensitization and give rise to new products. Besides formation of the primary photoproducts, the first photochemical step initiates a subsequent thermal domino reaction or a domino sequence of a thermal and a photochemical reaction. The latter, involving two photochemical intramolecular gamma-H abstractions, was observed with phthalimides 1, 3, and 6 and delivered stereospecifically the hexacyclic benzazepine products 12, 19, and 27, respectively. The lowest triplet states of 1-6 were characterized in several solvents upon direct and acetone-sensitized excitation. The intermolecular electron transfer from triethylamine and DABCO was studied, and the radical anions were observed. Electrochemical measurements showed that intramolecular electron transfer from the adamantyl group of 1-6 to the lowest triplet state of the phthalimides is not feasible. The formation of products can be explained by intramolecular H-abstraction from the (alkyl)adamantane to the excited phthalimide, either from the excited singlet state or a hidden upper excited triplet state.
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Affiliation(s)
- Margareta Horvat
- Department of Organic Chemistry and Biochemistry, Ruder Bosković Institute, Bijenicka cesta 54, 10 000 Zagreb, Croatia
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17
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Terzidis MA, Tsoleridis CA, Stephanidou-Stephanatou J, Terzis A, Raptopoulou CP, Psycharis V. Successive Michael reactions on chromone derivatives with dimethyl 1,3-acetonedicarboxylate: one-pot synthesis of functionalized benzophenones, benzo[c]chromones and hydroxybenzoylfuroates. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.10.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Samori S, Fujitsuka M, Majima T. Properties of Excited Radical Cations of Substituted Oligothiophenes. J Phys Chem A 2008; 112:11312-8. [DOI: 10.1021/jp804369e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Shingo Samori
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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19
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Synthesis of 2-benzoyl-4-(2-hydroxybenzoyl)phenols by catalytic domino ‘Michael–retro-Michael–Mukaiyama-aldol’ reactions of 1-aryl-1,3-bis(silyloxy)buta-1,3-dienes with 3-formylchromones. Tetrahedron 2008. [DOI: 10.1016/j.tet.2007.10.116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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20
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Oseki Y, Fujitsuka M, Sakamoto M, Majima T. Intramolecular triplet energy transfer via higher triplet excited state during stepwise two-color two-laser irradiation. J Phys Chem A 2007; 111:9781-8. [PMID: 17824596 DOI: 10.1021/jp074062o] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We studied the energy transfer processes in the molecular array consisting of pyrene (Py), biphenyl (Ph2), and bisphthalimidethiophene (ImT), (Py-Ph2)2-ImT, during two-color two-laser flash photolysis (2-LFP). The first laser irradiation predominantly generates ImT in the lowest triplet excited state (ImT(T1)) because of the efficient singlet energy transfer from Py in the lowest singlet excited state to ImT and, then, intersystem crossing of ImT. ImT(T1) was excited to the higher triplet excited state (Tn) with the second laser irradiation. Then, the triplet energy was rapidly transferred to Py via a two-step triplet energy transfer (TET) process through Ph2. The efficient generation of Py(T1) was suggested from the nanosecond-picosecond 2-LFP. The back-TET from Py(T1) to ImT was observed for several tens of microseconds after the second laser irradiation. The estimated intramolecular TET rate from Py(T1) to ImT was as slow as 3.1 x 104 s-1. Hence, long-lived Py(T1) was selectively and efficiently produced during the 2-LFP.
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Affiliation(s)
- Yosuke Oseki
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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21
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One-pot reactions of 2,4-(dioxobutylidene)phosphoranes. Efficient synthesis of 4-(2-hydroxybenzoyl)salicylic acid derivatives and buta-1,3-diene-1,4-dicarboxylates. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.02.062] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Yamaji M, Kojima A, Tobita S. Stepwise Laser Photolysis Studies of β-Bond Cleavage in Highly Excited Triplet States of Biphenyl Derivatives Having C−O Bonds. J Phys Chem A 2007; 111:770-6. [PMID: 17266216 DOI: 10.1021/jp065782i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Photochemical profiles of beta-bond dissociation in highly excited triplet states (Tn) of biphenyl derivatives having C-O bonds were investigated in solution, using stepwise laser photolysis techniques. The lowest triplet states (T1) were produced by triplet sensitization of acetone (Ac) upon 308-nm laser photolysis. The molar absorption coefficients of the T1 states were determined using triplet sensitization techniques. Any photochemical reactions were absent in the T1 states. Upon 355-nm laser flash photolysis of the T1 states, they underwent fragmentation, because of homolysis of the C-O bond in the Tn states from the observations of the transient absorption of the corresponding radicals. The quantum yields (Phidec) for the decomposition of the T1 states upon the second 355-nm laser excitation were determined. Based on the Phidec values and the bond dissociation energies (BDEs) for the C-O bond fission, the state energies (ERT) of the reactive highly excited triplet states (TR) were determined. It was revealed that (i) the Phidec was related to the energy difference (DeltaE) between the BDE and the ERT, and (ii) the rate (kdis) of beta-cleavage in the TR state was formulated as being simply proportional to DeltaE. The reaction mechanism for beta-bond cleavage in the TR states was discussed.
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Affiliation(s)
- Minoru Yamaji
- Department of Chemistry, Gunma University, Kiryu 376-8515, Japan.
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Laser literature watch. Photomed Laser Surg 2006; 24:424-53. [PMID: 16875454 DOI: 10.1089/pho.2006.24.424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Appel B, Rotzoll S, Kranich R, Reinke H, Langer P. Domino Michael/Retro-Michael/Mukaiyama-Aldol Reactions of 1,3-Bis-Silyl Enol Ethers with 3-Acyl- and 3-Formylbenzopyrylium Triflates – Synthesis of Functionalised 2,4′-Dihydroxybenzophenones. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600082] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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