1
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Das A, Justin Thomas KR. Generation and Application of Aryl Radicals Under Photoinduced Conditions. Chemistry 2024; 30:e202400193. [PMID: 38546345 DOI: 10.1002/chem.202400193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Indexed: 04/26/2024]
Abstract
Photoinduced aryl radical generation is a powerful strategy in organic synthesis that facilitates the formation of diverse carbon-carbon and carbon-heteroatom bonds. The synthetic applications of photoinduced aryl radical formation in the synthesis of complex organic compounds, including natural products, physiologically significant molecules, and functional materials, have received immense attention. An overview of current developments in photoinduced aryl radical production methods and their uses in organic synthesis is given in this article. A generalized idea of how to choose the reagents and approach for the generation of aryl radicals is described, along with photoinduced techniques and associated mechanistic insights. Overall, this article offers a critical assessment of the mechanistic results as well as the selection of reaction parameters for specific reagents in the context of radical cascades, cross-coupling reactions, aryl radical functionalization, and selective C-H functionalization of aryl substrates.
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Affiliation(s)
- Anupam Das
- Organic Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - K R Justin Thomas
- Organic Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
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2
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Piedra HF, Plaza M. Advancements in visible-light-induced reactions via alkenyl radical intermediates. Photochem Photobiol Sci 2024; 23:1217-1228. [PMID: 38700648 DOI: 10.1007/s43630-024-00580-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/15/2024] [Indexed: 06/18/2024]
Abstract
In recent years, visible-light-induced organic transformations have taken a central role driving forward the progress of modern organic synthesis. These processes typically involve the transient generation of highly reactive radical intermediates, facilitating a diverse array of chemical reactions. Despite the abundance of synthetic strategies enabling the access of aryl and alkyl-centered radicals, the exploitation of photochemistry to generate highly reactive alkenyl radicals has remained notably underdeveloped. In this review, we present recent advancements in visible-light-induced transformations that proceed through the generation of alkenyl radicals from alkenyl-containing precursors, predominantly alkenyl halides, showcasing their application in various organic transformations.
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Affiliation(s)
- Helena F Piedra
- Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Manuel Plaza
- Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain.
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3
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Yamaguchi E, Murai M, Itoh A. Halogen-Bonding-Enabled Photoinduced Atom Transfer Radical Addition/Cyclization Reaction Leading to Tricyclic Heterocycles. J Org Chem 2024; 89:6555-6563. [PMID: 38657225 DOI: 10.1021/acs.joc.4c00204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Atom transfer radical addition (ATRA) reactions are crucial for the dual functionalization of unsaturated hydrocarbons. Radical generation, pivotal in ATRA, has seen advancements from thermal to photochemical methods. Recent focus on halogen-bonding-based radical generation, including our group's innovative photochemical approach, offers cost-effective alternatives to transition-metal-dependent photocatalysts. This eliminates the need for high-energy UV light, enhancing the efficiency with noncovalent interactions.
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Affiliation(s)
- Eiji Yamaguchi
- Gifu Pharmaceutical University, 1-25-4, Daigaku-Nishi, Gifu 501-1196, Japan
- Center for One Medicine Innovative Translational Research (COMIT), Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan
| | - Masanobu Murai
- Gifu Pharmaceutical University, 1-25-4, Daigaku-Nishi, Gifu 501-1196, Japan
| | - Akichika Itoh
- Gifu Pharmaceutical University, 1-25-4, Daigaku-Nishi, Gifu 501-1196, Japan
- Center for One Medicine Innovative Translational Research (COMIT), Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan
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4
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Guo P, Pu G, Wang G, Zeng LY, Li WP, Li X, Zhou PP, He CY. Halogen-Bond-Promoted Direct Cross-Coupling of Trifluoromethylated Alkyl Bromides with Coumarins/Quinolinones: Unraveling Trifluoromethyl Effects. Org Lett 2024; 26:3097-3102. [PMID: 38574397 DOI: 10.1021/acs.orglett.4c00717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
This study introduces a novel approach involving XB-mediated cross-coupling of α-trifluoromethylated alkyl bromides with coumarins and quinolinones under visible light irradiation. Both density functional theory (DFT) calculations and experimental studies converge to suggest that the noncovalent interaction between alkyl bromides and DMAP, intensified by the α-trifluoromethyl group, plays a pivotal role in facilitating this chemoselective reaction.
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Affiliation(s)
- Peng Guo
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
| | - Guoliang Pu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
| | - Gairong Wang
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
| | - Lin-Yuan Zeng
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
| | - Wei-Piao Li
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
| | - Xuefei Li
- Department of Nuclear Medicine, Affiliated Hospital of Zunyi Medical University, 563002 Zunyi, Guizhou, P. R. China
| | - Pan-Pan Zhou
- Key Laboratory of Advanced Catalysis of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, 730000 Lanzhou, P. R. China
| | - Chun-Yang He
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, 563002 Guizhou, P. R. China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education. School of Pharmacy, Zunyi Medical University, 563002 Zunyi, Guizhou, P. R. China
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5
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Rrapi M, Batsika CS, Nikitas NF, Tappin NDC, Triandafillidi I, Renaud P, Kokotos CG. Photochemical Synthesis of Lactones, Cyclopropanes and ATRA Products: Revealing the Role of Sodium Ascorbate. Chemistry 2024; 30:e202400253. [PMID: 38324672 DOI: 10.1002/chem.202400253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 02/09/2024]
Abstract
Light-mediated processes have received significant attention, since they have re-surfaced unconventional reactivity platforms, complementary to conventional polar chemistry. γ-Lactones and cyclopropanes are prevalent moieties, found in numerous natural products and pharmaceuticals. Among various methods for their synthesis, light-mediated protocols are coming to the spotlight, although these are contingent upon the use of photoorgano- or metal-based catalysts. Herein, we introduce a novel photochemical activation of iodo-reagents via the use of cheap sodium ascorbate or ascorbic acid to enable their homolytic scission and addition onto double bonds. The developed protocol was applied successfully to the formal [3+2] cycloaddition for the synthesis of γ-lactones, traditional atom transfer radical addition (ATRA) reactions and the one-pot two-step conversion of alkenes to cyclopropanes. In all cases, the desired products were obtained in good to high yields, while the reaction mechanism was thoroughly investigated. Depending on the nature of the iodo-reagent, a halogen or a hydrogen-bonded complex is formed, which initiates the process.
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Affiliation(s)
- Marie Rrapi
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, 15771, Greece
| | - Charikleia S Batsika
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, 15771, Greece
| | - Nikolaos F Nikitas
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, 15771, Greece
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, CH-3012, Bern, Switzerland
| | - Nicholas D C Tappin
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, CH-3012, Bern, Switzerland
| | - Ierasia Triandafillidi
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, 15771, Greece
| | - Philippe Renaud
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, CH-3012, Bern, Switzerland
| | - Christoforos G Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, 15771, Greece
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6
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Meng Y, Zare RN, Gnanamani E. Superfast Formation of C(sp 2 )-N, C(sp 2 )-P, and C(sp 2 )-S Vinylic Bonds in Water Microdroplets. Angew Chem Int Ed Engl 2024; 63:e202316131. [PMID: 38116872 DOI: 10.1002/anie.202316131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
We report examples of C(sp2 )-N, C(sp2 )-S, and C(sp2 )-P bond-forming transformations in water microdroplets at room temperature and atmospheric pressure using N2 as a nebulizing gas. When an aqueous solution of vinylic acid and amine is electrosprayed (+3 kV), the corresponding C(sp2 )-N product is formed in a single step, which was characterized using mass spectrometry (MS) and tandem mass spectrometry (MS2 ). The scope of this reaction was extended to other amines and other unsaturated acids, including acrylic (CH2 =CHCOOH) and crotonic (CH3 CH=CHCOOH) acids. We also found that thiols and phosphines are viable nucleophiles, and the corresponding C(sp2 )-S and C(sp2 )-P products are observed in positive ion mode using MS and MS2 .
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Affiliation(s)
- Yifan Meng
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Elumalai Gnanamani
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
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7
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Jiang Z, You K, Wu H, Xu M, Wang T, Luo J. Photochemical Halogen-Bonding Promoted Synthesis of Vinyl Sulfones via Vinyl and Sulfonyl Radicals. Org Lett 2024; 26:636-641. [PMID: 38273796 DOI: 10.1021/acs.orglett.3c03958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
A photochemical halogen-bonding-assisted synthesis of vinyl sulfones via radical-radical cross-coupling of vinyl bromines and sodium sulfinates is developed. This methodology offers a facile and efficient approach to various vinyl sulfones with excellent functional group tolerance under metal-, photocatalyst-, base-, and oxidant-free conditions. The reaction is also applicable for the late-stage functionalization of drug molecules and the hectogram scale. Moreover, instead of sodium sulfites being prepared, these reactions could also be conducted using sulfonyl chlorides in a one-pot method.
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Affiliation(s)
- Zhou Jiang
- Jiangxi Province Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
| | - Ke You
- Jiangxi Province Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
| | - Haibo Wu
- Jiangxi Province Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
| | - Mengyu Xu
- Jiangxi Province Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
| | - Tao Wang
- Jiangxi Province Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
| | - Jin Luo
- Analytical and Testing Center, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China
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8
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Jiang T, Chen L, Wen S, Zhang L, Wang T, Xiong F. Synthesis of 1,1-Diarylvinylsulfides via Visible-Light-Promoted Cascade Reaction of Alkynoates with Phenyl Disulfides. J Org Chem 2024. [PMID: 38175923 DOI: 10.1021/acs.joc.3c01988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Without any additives and photocatalysts, the visible-light-promoted radical cascade reaction between alkynoates and phenyl disulfides has been developed at room temperature. Through S-S bond photolysis and homolytic cleavage, addition of a sulfur radical, aryl migration, decarboxylation, and H atom abstraction, the cascade reaction provides an efficient and practical route to trisubstituted 1,1-diarylvinylsulfides with a wide scope of substrates and good to excellent yields.
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Affiliation(s)
- Tao Jiang
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
| | - Long Chen
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
| | - Shimei Wen
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
| | - Lei Zhang
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
| | - Tao Wang
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
| | - Fei Xiong
- College of Chemistry and Chemical Engineering, National Research Center for Carbohydrate Synthesis and Key Laboratory of Chemical Biology, Jiangxi Normal University, Nanchang, Jiangxi 330022, P.R. China
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9
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Piedra HF, Gebler V, Valdés C, Plaza M. Photochemical halogen-bonding assisted carbothiophosphorylation reactions of alkenyl and 1,3-dienyl bromides. Chem Sci 2023; 14:12767-12773. [PMID: 38020380 PMCID: PMC10646874 DOI: 10.1039/d3sc05263j] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 10/28/2023] [Indexed: 12/01/2023] Open
Abstract
Herein, we present a synthetic procedure for the facile and general preparation of novel S-alkenyl and dienyl phosphoro(di)thioates for the first time. Extensive mechanistic investigations support that the reactions rely on a photochemical excitation of a halogen-bonding complex, formed with a phosphorothioate salt and an alkenyl or dienyl bromide, which light-induced fragmentation leads to the formation of the desired products through a radical-based pathway. The substrate scope is broad and exhibits a wide functional group tolerance in the formation of the final compounds, including molecules derived from natural products, all with unknown and potentially interesting biological properties. Eventually, a very efficient continuous flow protocol was developed for the upscale of these reactions.
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Affiliation(s)
- Helena F Piedra
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles", Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Victoria Gebler
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles", Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Carlos Valdés
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles", Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Manuel Plaza
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles", Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
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10
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Gupta S, Srinivasu V, Sureshkumar D. Metal and catalyst-free strategy to access 1,3-thio-heteroaryl BCP derivatives. Org Biomol Chem 2023; 21:8136-8140. [PMID: 37772462 DOI: 10.1039/d3ob01377d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
The widespread presence of bicyclo[1.1.1]pentane (BCP) and sulfur motifs in pharmaceutical compounds underscores the significance of synthesizing suitably functionalized BCP thioethers. In response, we have developed a metal-free and photocatalyst-free strategy that harnesses visible light-induced radical cascades. This approach culminates in the synthesis of essential thio-BCP derivatives, which serve as crucial precursors for the formation of the corresponding sulfoxides, sulfones, and sulfoximines. Importantly, this methodology exhibits potential for large-scale applications, displaying commendable tolerance towards various functional groups while operating under mild reaction conditions.
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Affiliation(s)
- Surbhi Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia-741246, West Bengal, India.
| | - Vinjamuri Srinivasu
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia-741246, West Bengal, India.
| | - Devarajulu Sureshkumar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia-741246, West Bengal, India.
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11
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Zhu J, Ye Y, Yan Y, Sun J, Huang Y. Highly Regioselective Dichalcogenation of Alkenyl Sulfonium Salts to Access 1,1-Dichalcogenalkenes. Org Lett 2023. [PMID: 37418314 DOI: 10.1021/acs.orglett.3c01886] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
An unprecedented geminal olefinic dichalcogenation of alkenyl sulfonium salts with dichalcogenides ArYYAr (Y = S, Se, Te) is reported, providing various trisubstituted 1,1-dichalcogenalkenes [Ar1CH = C(YAr2)2] in a highly selective manner under mild and catalyst-free conditions. The key process involves the formation of two geminal olefinic C-Y bonds via sequential C-Y cross-coupling and C-H chalcogenation. A mechanistic rationale is further supported by control experiments and density functional theory calculations.
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Affiliation(s)
- Jie Zhu
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yun Ye
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yifei Yan
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Jinghui Sun
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yinhua Huang
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
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12
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Wu Z, Pratt DA. Radical approaches to C-S bonds. Nat Rev Chem 2023:10.1038/s41570-023-00505-x. [PMID: 37344618 DOI: 10.1038/s41570-023-00505-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2023] [Indexed: 06/23/2023]
Abstract
Organosulfur functionalities are ubiquitous in nature, pharmaceuticals, agrochemicals, materials and flavourants. Historically, these moieties were introduced almost exclusively using ionic chemistry; however, radical-based methods for the installation of sulfur-based functional groups have recently come to the fore. These radical methods have enabled their late-stage introduction into complex molecules, avoiding the need to preserve labile organosulfur moieties through multistep synthetic sequences. Here, we discuss homolytic C-S bond-forming processes, with a particular emphasis on radical substitution approaches to sulfide, disulfide and sulfinyl products, and the use of sulfur dioxide and its surrogates to build sulfonyl products. We also highlight the mechanistic considerations that we hope will guide further development of radical-based strategies compatible with the various organosulfur moieties that feature in modern chemistry.
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Affiliation(s)
- Zijun Wu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Derek A Pratt
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada.
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13
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Piedra HF, Valdés C, Plaza M. Shining light on halogen-bonding complexes: a catalyst-free activation mode of carbon-halogen bonds for the generation of carbon-centered radicals. Chem Sci 2023; 14:5545-5568. [PMID: 37265729 PMCID: PMC10231334 DOI: 10.1039/d3sc01724a] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/03/2023] [Indexed: 06/03/2023] Open
Abstract
The discovery of new activation modes for the creation of carbon-centered radicals is a task of great interest in organic chemistry. Classical activation modes for the generation of highly reactive radical carbon-centered intermediates typically relied on thermal activation of radical initiators or irradiation with unsafe energetic UV light of adequate reaction precursors. In recent years, photoredox chemistry has emerged as a leading strategy towards the catalytic generation of C-centered radicals, which enabled their participation in novel synthetic organic transformations which is otherwise very challenging or even impossible to take place. As an alternative to these activation modes for the generation of C-centered radicals, the pursuit of greener, visible-light initiated reactions that do not necessitate a photoredox/metal catalyst has recently caught the attention of chemists. In this review, we covered recent transformations, which rely on photoactivation with low-energy light of a class of EDA complexes, known as halogen-bonding adducts, for the creation of C-centered radicals.
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Affiliation(s)
- Helena F Piedra
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Carlos Valdés
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Manuel Plaza
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
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14
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Duan S, Zi Y, Du Y, Cong J, Sun X, Jing H, Zhao J, Chen W, Yang X. Radical C(sp 3)-S Coupling for the Synthesis of α-Amino Sulfides. Org Lett 2023; 25:3687-3692. [PMID: 37172304 DOI: 10.1021/acs.orglett.3c01121] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A unique transition-metal-free radical thiolation of 2-azaallyl anions has been developed. Easily accessible thiosulfonates and 2-azaallyls undergo the tandem process of single-electron transfer and radical-radical coupling to construct C(sp3)-S bonds. This robust protocol enables a mild and chemoselective coupling between 2-azaallyl anions and thiosulfonates to access α-amino sulfides in 50-92% yields (25 examples). The scalability of this protocol was demonstrated by telescopic gram-scale experiments. Mechanistic studies provide significant evidence for this radical thiolation reaction.
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Affiliation(s)
- Shengzu Duan
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Yujin Zi
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Ya Du
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Jielun Cong
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Xiaotong Sun
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Hong Jing
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Jingfeng Zhao
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Wen Chen
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
| | - Xiaodong Yang
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Pharmacy, Yunnan University, Kunming 650500, P. R. China
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