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Fernandes AJ, Giri R, Houk KN, Katayev D. Review and Theoretical Analysis of Fluorinated Radicals in Direct C Ar-H Functionalization of (Hetero)arenes. Angew Chem Int Ed Engl 2024; 63:e202318377. [PMID: 38282182 DOI: 10.1002/anie.202318377] [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: 11/30/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 01/30/2024]
Abstract
We highlight key contributions in the field of direct radical CAr- H (hetero)aromatic functionalization involving fluorinated radicals. A compilation of Functional Group Transfer Reagents and their diverse activation mechanisms leading to the release of radicals are discussed. The substrate scope for each radical is analyzed and classified into three categories according to the electronic properties of the substrates. Density functional theory computational analysis provides insights into the chemical reactivity of several fluorinated radicals through their electrophilicity and nucleophilicity parameters. Theoretical analysis of their reduction potentials also highlights the remarkable correlation between electrophilicity and oxidizing ability. It is also established that highly fluorinated radicals (e.g. ⋅OCF3) are capable of engaging in single-electron transfer (SET) processes rather than radical addition, which is in good agreement with experimental literature data. A reactivity scale, based on activation barrier of addition of these radicals to benzene is also elaborated using the high accuracy DLPNO-(U)CCSD(T) method.
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Affiliation(s)
- Anthony J Fernandes
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Rahul Giri
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, 90095, Los Angeles, California, United States
| | - Dmitry Katayev
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
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Moskalik MY. Monofluoromethylation of N-Heterocyclic Compounds. Int J Mol Sci 2023; 24:17593. [PMID: 38139426 PMCID: PMC10744182 DOI: 10.3390/ijms242417593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023] Open
Abstract
The review focuses on recent advances in the methodologies for the formation or introduction of the CH2F moiety in N-heterocyclic substrates over the past 5 years. The monofluoromethyl group is one of the most versatile fluorinated groups used to modify the properties of molecules in synthetic medical chemistry. The review summarizes two strategies for the monofluoromethylation of N-containing heterocycles: direct monofluoromethylation with simple XCH2F sources (for example, ICH2F) and the assembly of N-heterocyclic structures from CH2F-containing substrates. The review describes the monofluoromethylation of pharmaceutically important three-, five- and six-membered N-heterocycles: pyrrolidines, pyrroles, indoles, imidazoles, triazoles, benzothiazoles, carbazoles, indazoles, pyrazoles, oxazoles, piperidines, morpholines, pyridines, quinolines and pyridazines. Assembling of 6-fluoromethylphenanthridine, 5-fluoromethyl-2-oxazolines, C5-monofluorinated isoxazoline N-oxides, and α-fluoromethyl-α-trifluoromethylaziridines is also shown. Fluoriodo-, fluorchloro- and fluorbromomethane, FCH2SO2Cl, monofluoromethyl(aryl)sulfoniummethylides, monofluoromethyl sulfides, (fluoromethyl)triphenylphosphonium iodide and 2-fluoroacetic acid are the main fluoromethylating reagents in recent works. The replacement of atoms and entire functional groups with a fluorine atom(s) leads to a change and often improvement in activity, chemical or biostability, and pharmacokinetic properties. The monofluoromethyl group is a bioisoster of -CH3, -CH2OH, -CH2NH2, -CH2CH3, -CH2NO2 and -CH2SH moieties. Bioisosteric replacement with the CH2F group is both an interesting task for organic synthesis and a pathway to modify drugs, agrochemicals and useful intermediates.
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Affiliation(s)
- Mikhail Yu Moskalik
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences, 1 Favorsky Street, 664033 Irkutsk, Russia
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Tang J, Lu F, Sun Y, Zhang G, Zhang E, Jiang YY. Late-Stage Diversification of Peptides via Pd-Catalyzed Site-Selective δ-C(sp 2)-H Fluorination and Amination. J Org Chem 2023; 88:14165-14171. [PMID: 37751495 DOI: 10.1021/acs.joc.3c01897] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Site-selective C-H fluorination is an attractive strategy for directly transforming inert C-H bonds into C-F bonds, yet it remains a significant challenge. Herein, we have developed an efficient and versatile strategy for site-selective fluorination and amination of phenylalanine-containing peptides via late-stage Pd-catalyzed δ-C(sp2)-H activation, providing a valuable tool for the in situ synthesis of fluorinated indoline scaffolds within peptides.
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Affiliation(s)
- Jian Tang
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210096, China
| | - Fengjie Lu
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Yi Sun
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Guodong Zhang
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Ensheng Zhang
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Yuan-Ye Jiang
- Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
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Ramkumar N, Baumane L, Zacs D, Veliks J. Merging Copper(I) Photoredox Catalysis and Iodine(III) Chemistry for the Oxy-monofluoromethylation of Alkenes. Angew Chem Int Ed Engl 2023; 62:e202219027. [PMID: 36692216 DOI: 10.1002/anie.202219027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/25/2023]
Abstract
A simple process for the oxy-monofluoromethylation of alkenes is described. In combination with visible-light copper(I) photoredox catalysis, an easily accessible iodine(III) reagent containing monofluoroacetoxy ligands serves as a powerful source of a monofluoromethyl (CH2 F) radical, enabling the step economical synthesis of γ-fluoro-acetates from a broad range of olefinic substrates under mild conditions. Applications to late-stage diversification of alkenes derived from complex molecules, amino acids and the synthesis of fluoromethylated heterocycles are also demonstrated.
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Affiliation(s)
- Nagarajan Ramkumar
- Latvian Institute of Organic Synthesis, Aizkraukles iela 21, LV-1006, Riga, Latvia
| | - Larisa Baumane
- Latvian Institute of Organic Synthesis, Aizkraukles iela 21, LV-1006, Riga, Latvia
| | - Dzintars Zacs
- Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, LV-1076, Riga, Latvia
| | - Janis Veliks
- Latvian Institute of Organic Synthesis, Aizkraukles iela 21, LV-1006, Riga, Latvia
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Gutiérrez-Bonet Á, Liu W. Synthesis of Alkyl Fluorides and Fluorinated Unnatural Amino Acids via Photochemical Decarboxylation of α-Fluorinated Carboxylic Acids. Org Lett 2023; 25:483-487. [PMID: 36652608 DOI: 10.1021/acs.orglett.2c04144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Leveraging α-fluoroalkyl or fluorobenzyl radicals to introduce fluorinated motifs allows for the rapid preparation of fluorine-containing building blocks. Herein, we report the generation of α-fluoroalkyl or fluorobenzyl radicals from readily available α-fluorocarboxylic acids under mild reaction conditions and their utilization in the Giese-type addition on Michael acceptors and dehydroamino acids, resulting in the preparation of mono- and difluorinated Michael addition adducts and unnatural fluorinated amino acids.
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Affiliation(s)
- Álvaro Gutiérrez-Bonet
- Process Research & Development, MRL, Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Wenbin Liu
- Process Research & Development, MRL, Merck & Co., Inc., West Point, Pennsylvania 19486, United States
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Guo C, Han X, Feng Y, Liu Z, Li Y, Liu H, Zhang L, Dong Y, Li X. Straightforward Synthesis of Alkyl Fluorides via Visible-Light-Induced Hydromono- and Difluoroalkylations of Alkenes with α-Fluoro Carboxylic Acids. J Org Chem 2022; 87:9232-9241. [PMID: 35748751 DOI: 10.1021/acs.joc.2c00965] [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
We herein report the first visible-light-induced hydromono- and difluoroalkylations of alkenes with inexpensive and easily accessible α-fluoro carboxylic acids. This metal-free protocol exhibits mild conditions, high efficiency, and excellent functional-group tolerance, providing a straightforward approach to mono- and difluoroalkylated alkanes. Moreover, the fluorine effect on the hydrofluoroalkylation reaction is discussed in detail.
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Affiliation(s)
- Chunfang Guo
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China.,Shandong Vocational College of Light Industry, Zhoucun Mishan Road, Zibo 255300, P. R. China
| | - Xuliang Han
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Yu Feng
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Zhaolong Liu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Yueyun Li
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Hui Liu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Lizhi Zhang
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Yunhui Dong
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China
| | - Xinjin Li
- School of Chemistry and Chemical Engineering, Shandong University of Technology, 266 West Xincun Road, Zibo 255000, P. R. China.,Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
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Zhu Y, Xiao T, Xia D, Yang W. Recent Advances in the Decarboxylative Fluoroalkylation of Fluoroalkyl Carboxylic Acids. CHINESE J ORG CHEM 2022. [DOI: 10.6023/cjoc202208017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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