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Uchikura T, Akutsu F, Tani H, Akiyama T. Photoreduction of Trifluoromethyl Group: Lithium Ion Assisted Fluoride-Coupled Electron Transfer from EDA Complex. Chemistry 2024; 30:e202400658. [PMID: 38600038 DOI: 10.1002/chem.202400658] [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: 02/19/2024] [Revised: 04/07/2024] [Accepted: 04/10/2024] [Indexed: 04/12/2024]
Abstract
Photoinduced single-electron reduction is an efficient method for the mono-selective activation of the C-F bond on a trifluoromethyl group to construct a difluoroalkyl group. We have developed an electron-donor-acceptor (EDA) complex mediated single-electron transfer (EDA-SET) of α,α,α-trifluoromethyl arenes in the presence of lithium salt to give α,α-difluoroalkylarenes. The C-F bond reduction was realized by lithium iodide and triethylamine, two common feedstock reagents. Mechanistic studies revealed the generation of a α,α-difluoromethyl radical by single-electron reduction and defluorination, followed by the radical addition to alkenes. Lithium salt interacted with the fluorine atom to promote the photoinduced reduction mediated by the EDA complex. Computational studies indicated that the lithium-assisted defluorination and the single-electron reduction occurred concertedly. We call this phenomenon fluoride-coupled electron transfer (FCET). FCET is a novel approach to C-F bond activation for the synthesis of organofluorine compounds.
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Affiliation(s)
- Tatsuhiro Uchikura
- Department of Chemistry, Faculty of Science, Gakushuin University, 171-8588, 1-5-1, Mejiro, Toshima-ku, Tokyo, Japan
| | - Fua Akutsu
- Department of Chemistry, Faculty of Science, Gakushuin University, 171-8588, 1-5-1, Mejiro, Toshima-ku, Tokyo, Japan
| | - Haruna Tani
- Department of Chemistry, Faculty of Science, Gakushuin University, 171-8588, 1-5-1, Mejiro, Toshima-ku, Tokyo, Japan
| | - Takahiko Akiyama
- Department of Chemistry, Faculty of Science, Gakushuin University, 171-8588, 1-5-1, Mejiro, Toshima-ku, Tokyo, Japan
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Liu L, Wu Y, Xiang C, Yu JT, Pan C. Photo-induced phosphorylation/cyclization of N-homoallyl and N-allyl aldehyde hydrazones to access phosphorylated tetrahydropyridazines and dihydropyrazoles. Chem Commun (Camb) 2024; 60:4687-4690. [PMID: 38592732 DOI: 10.1039/d4cc00608a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
A photocatalytic radical carbophosphorylation/cyclization of N-homoallyl aldehyde hydrazones with phosphine oxides was developed under metal-free conditions, achieving phosphorylated tetrahydropyridazines in yields up to 95%. Phosphorylated dihydropyrazoles were also constructed, by reacting N-allyl aldehyde hydrazones with phosphine oxides under the same conditions.
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Affiliation(s)
- Lingli Liu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China.
| | - Yechun Wu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China.
| | - Chengli Xiang
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China.
| | - Jin-Tao Yu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China.
| | - Changduo Pan
- School of Chemistry and Chemical Engineering, Jiangsu University of Technology, Changzhou 213001, P. R. China.
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Majhi J, Molander GA. Recent Discovery, Development, and Synthetic Applications of Formic Acid Salts in Photochemistry. Angew Chem Int Ed Engl 2024; 63:e202311853. [PMID: 37812639 DOI: 10.1002/anie.202311853] [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: 08/14/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/11/2023]
Abstract
The advancement of sustainable photoredox catalysis in synthetic organic chemistry has evolved immensely because of the development of versatile and cost-effective reagents. In recent years, a substantial effort has been dedicated to exploring the utility of formic acid salts in various photochemical reactions. In this context, formates have demonstrated diverse capabilities, functioning as reductants, sources of carbonyl groups, and reagents for hydrogen atom transfer. Notably, the CO2 ⋅- radical anion derived from formate exhibits strong reductant properties for cleaving both C-X and C-O bonds. Moreover, these salts play a pivotal role in carboxylation reactions, further highlighting their significance in a variety of photochemical transformations. The ability of formates to serve as reductants, carbonyl sources, and hydrogen atom transfer reagents reveal exciting possibilities in synthetic organic chemistry. This minireview highlights an array of captivating discoveries, underscoring the crucial role of formates in diverse and distinctive photochemical methods, enabling access to a wide range of value-added compounds.
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Affiliation(s)
- Jadab Majhi
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
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Wu Y, Wu X, Liu L, Yu JT, Pan C. Photocatalytic Carbosulfonylation/Cyclization of N-Homoallyl and N-Allyl Aldehyde Hydrazones toward Sulfonylated Tetrahydropyridazines and Dihydropyrazoles. Org Lett 2024; 26:122-126. [PMID: 38160407 DOI: 10.1021/acs.orglett.3c03733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
N'-Benzylidene-N-homoallylacetohydrazides were designed and synthesized as novel skeletons for the construction of functionalized tetrahydropyridazines. A series of aryl- and alkylsulfonylated tetrahydropyridazines were obtained in yields of up to 94% employing sulfonyl chlorides as the sulfonyl radical sources under visible-light irradiation. Besides, sulfonylated dihydropyrazoles were also produced from N-allyl-N'-benzylideneacetohydrazides. Mechanistic investigations indicated that both energy transfer and single electron transfer processes were involved in accomplishing the radical 6/5-endo-trig cyclization to the C═N bond.
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Affiliation(s)
- Yechun Wu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Xian Wu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Lingli Liu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Jin-Tao Yu
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China
| | - Changduo Pan
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, P. R. China
- School of Chemistry and Chemical Engineering, Jiangsu University of Technology, Changzhou 213001, P. R. China
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Fan Y, Huang Z, Lu Y, Zhu S, Chu L. Defluorinative Alkylboration of Alkenes Enabled by Dual Photoredox and Copper Catalysis. Angew Chem Int Ed Engl 2023:e202315974. [PMID: 38065842 DOI: 10.1002/anie.202315974] [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: 10/22/2023] [Indexed: 12/22/2023]
Abstract
A regioselectivity reversed three-component defluorinative alkylboration of alkenes with trifluoromethyls and bis(pinacolato)diboron via dual photoredox/copper catalysis is reported. The mild conditions are compatible with a wide array of nonactivated trifluoromethyl aromatics bearing electron-donating or electron-neutral substituents, trifluoroacetamides, and various nonactivated terminal and internal alkenes, enabling straightforward access to synthetically valuable γ-gem-difluoroalkyl boronates with high efficiency. Furthermore, this protocol is applicable to alkene-tethered trifluoromethyl aromatics to furnish gem-difluoromethylene-containing cyclic compounds. Synthetic applications and preliminary mechanistic studies are also presented.
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Affiliation(s)
- Yanmin Fan
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China
| | - Zhonghou Huang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China
| | - Yi Lu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China
| | - Shengqing Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China
| | - Lingling Chu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai, 201620, China
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Yue WJ, Martin R. α-Difluoroalkylation of Benzyl Amines with Trifluoromethylarenes. Angew Chem Int Ed Engl 2023; 62:e202310304. [PMID: 37596243 DOI: 10.1002/anie.202310304] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/20/2023]
Abstract
An α-difluoroalkylation of benzyl amines with trifluoromethylarenes is disclosed herein. This protocol is characterized by its operational simplicity, excellent chemoselectivity and broad scope-even with advanced synthetic intermediates-, thus offering a new entry point to medicinally-relevant α-difluoroalkylated amines from simple, yet readily accessible, precursors.
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Affiliation(s)
- Wen-Jun Yue
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
- Universitat Rovira i Virgili, Departament de Química Analítica i Química Orgànica, c/Marcel⋅lí Domingo, 1, 43007, Tarragona, Spain
| | - Ruben Martin
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluïs Companys, 23, 08010, Barcelona, Spain
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