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Latrache M, Lefebvre C, Abe M, Hoffmann N. Photochemically Induced Hydrogen Atom Transfer and Intramolecular Radical Cyclization Reactions with Oxazolones. J Org Chem 2023; 88:16435-16455. [PMID: 37983612 DOI: 10.1021/acs.joc.3c01951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Photochemically induced intramolecular hydrogen atom transfer in oxazolones is reported. An acetal or thioacetal function at the side chain acts as a hydrogen donor while the photochemical exited oxazolone is the acceptor. A one-step process─the electron and the proton are simultaneously transferred─is productive, while electron transfer followed by proton transfer is inefficient. Radical combination then takes place, leading to the formation of a C-C or C-N bond. The regioselectivity of the reaction is explained by the diradical/zwitterion dichotomy of radical intermediates at the singlet state. In the present case, the zwitterion structure plays a central role, and intramolecular electron transfer favors spin-orbit coupling and thus the intersystem crossing to the singlet state. The reaction of corresponding thioacetal derivatives is less efficient. In this case, photochemical electron transfer is competitive. The photoproducts resulting from C-C bond formation easily undergo stepwise thermal decarboxylation in which zwitterionic and polar transition states are involved. A computational study of this step has also been performed.
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Affiliation(s)
- Mohammed Latrache
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Corentin Lefebvre
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Manabu Abe
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Hiroshima Research Center for Photo-Drug-Delivery Systems (Hi-P-DDS), 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Norbert Hoffmann
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
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Gómez Fernández MA, Hoffmann N. Photocatalytic Transformation of Biomass and Biomass Derived Compounds-Application to Organic Synthesis. Molecules 2023; 28:4746. [PMID: 37375301 DOI: 10.3390/molecules28124746] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Biomass and biomass-derived compounds have become an important alternative feedstock for chemical industry. They may replace fossil feedstocks such as mineral oil and related platform chemicals. These compounds may also be transformed conveniently into new innovative products for the medicinal or the agrochemical domain. The production of cosmetics or surfactants as well as materials for different applications are examples for other domains where new platform chemicals obtained from biomass can be used. Photochemical and especially photocatalytic reactions have recently been recognized as being important tools of organic chemistry as they make compounds or compound families available that cannot be or are difficultly synthesized with conventional methods of organic synthesis. The present review gives a short overview with selected examples on photocatalytic reactions of biopolymers, carbohydrates, fatty acids and some biomass-derived platform chemicals such as furans or levoglucosenone. In this article, the focus is on application to organic synthesis.
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Affiliation(s)
- Mario Andrés Gómez Fernández
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Norbert Hoffmann
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
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Michelin C, Hoffmann N. Photosensitization and Photocatalysis—Perspectives in Organic Synthesis. ACS Catal 2018. [DOI: 10.1021/acscatal.8b03050] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Clément Michelin
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Groupe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Norbert Hoffmann
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Groupe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
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Lefebvre C, Michelin C, Martzel T, Djou’ou Mvondo V, Bulach V, Abe M, Hoffmann N. Photochemically Induced Intramolecular Radical Cyclization Reactions with Imines. J Org Chem 2018; 83:1867-1875. [DOI: 10.1021/acs.joc.7b02810] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Corentin Lefebvre
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Clément Michelin
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Thomas Martzel
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Vaneck Djou’ou Mvondo
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
| | - Véronique Bulach
- Laboratoire
de Tectonique Moléculaire (UMR 7140), Institut Le Bel, Université de Strasbourg, 4, rue Blaise Pascal, 67000 Strasbourg, France
| | - Manabu Abe
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Hiroshima Research
Center for Photo-Drug-Delivery Systems (Hi-P-DDS), 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Norbert Hoffmann
- CNRS, Université de Reims Champagne-Ardenne, ICMR, Equipe de Photochimie, UFR Sciences, B.P. 1039, 51687 Reims, France
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Oelgemöller M, Hoffmann N. Studies in organic and physical photochemistry - an interdisciplinary approach. Org Biomol Chem 2016; 14:7392-442. [PMID: 27381273 DOI: 10.1039/c6ob00842a] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Traditionally, organic photochemistry when applied to synthesis strongly interacts with physical chemistry. The aim of this review is to illustrate this very fruitful interdisciplinary approach and cooperation. A profound understanding of the photochemical reactivity and reaction mechanisms is particularly helpful for optimization and application of these reactions. Some typical reactions and particular aspects are reported such as the Norrish-Type II reaction and the Yang cyclization and related transformations, the [2 + 2] photocycloadditions, particularly the Paternò-Büchi reaction, photochemical electron transfer induced transformations, different kinds of catalytic reactions such as photoredox catalysis for organic synthesis and photooxygenation are discussed. Particular aspects such as the structure and reactivity of aryl cations, photochemical reactions in the crystalline state, chiral memory, different mechanisms of hydrogen transfer in photochemical reactions or fundamental aspects of stereoselectivity are discussed. Photochemical reactions are also investigated in the context of chemical engineering. Particularly, continuous flow reactors are of interest. Novel reactor systems are developed and modeling of photochemical transformations and different reactors play a key role in such studies. This research domain builds a bridge between fundamental studies of organic photochemical reactions and their industrial application.
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Affiliation(s)
- Michael Oelgemöller
- James Cook University, College of Science and Engineering, Townsville, QLD 4811, Australia.
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