1
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Wang P, Lin L, Huang Y, Zhang H, Liao S. Radical Fluorosulfonamidation: A Facile Access to Sulfamoyl Fluorides. Angew Chem Int Ed Engl 2024:e202405944. [PMID: 38837324 DOI: 10.1002/anie.202405944] [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: 03/27/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 06/07/2024]
Abstract
Recently, the introduction of fluorosulfonyl (-SO2F) groups have attracted considerable research interests, as this moiety could often afford enhanced activities and new functions in the context of chemical biology and drug discovery. Herein, we report the design and synthesis of 1-fluorosulfamoyl-pyridinium (FSAP) salts, which could serve as an effective photoredox-active precursor to fluorosulfamoyl radicals and enable the direct radical C-H fluorosulfonamidation of a variety of (hetero)arenes. This method features mild conditions, visible light, broad substrate scope, good group tolerance, etc., and a metal-free protocol is also viable by using organic photocatalysts. Further, FSAP can also be applied to the radical functionalization of alkenes via 1,2-difunctionalization, radical distal migration, tandem radical-polar crossover reactions, etc. In addition, a formal C-H methylamination of (hetero)arenes by combining this radical C-H fluorosulfonamidation with subsequent hydrolysis as well as product derivatization are also demonstrated.
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Affiliation(s)
- Peng Wang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- Key Laboratory of Green and Precise Synthetic Chemistry and Application, Ministry of Education, College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, Anhui, 235000, China
| | - Lu Lin
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yao Huang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Honghai Zhang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Saihu Liao
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
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2
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Lasky MR, Liu EC, Remy MS, Sanford MS. Visible-Light Photocatalytic C-H Amination of Arenes Utilizing Acridine-Lewis Acid Complexes. J Am Chem Soc 2024; 146:14799-14806. [PMID: 38759094 DOI: 10.1021/jacs.4c02991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024]
Abstract
This report describes the development of a visible-light photocatalytic system for C(sp2)-H amination that leverages in situ-generated photocatalysts. We demonstrate that the combination of acridine derivatives and Lewis acids forms potent photooxidants that promote the C-H amination of electronically diverse arenes upon irradiation with visible-light (440 nm). A first-generation photocatalyst composed of Sc(OTf)3 and acridine effects the C-H amination of substrates with oxidation potentials ≤ +2.5 V vs SCE with pyrazole, triazole, and pyridine nucleophiles. Furthermore, the simplicity and modularity of this system enable variation of both Lewis acid and acridine to tune reactivity. This enabled the rapid identification of two second-generation photocatalysts (derived from (i) Al(OTf)3 and acridine or (ii) Sc(OTf)3 and a pyridinium-substituted acridine) that catalyze a particularly challenging transformation: C(sp2)-H amination with benzene as the limiting reagent.
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Affiliation(s)
- Matthew R Lasky
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - En-Chih Liu
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew S Remy
- Corporate R&D, Dow, 1776 Building, Midland, Michigan 48667, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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3
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Jin C, Ning C, Sui Y, Zhang B, Li X, Pan L, Liu Q, Li Y. Photoredox-Catalyzed Alkene Amination: C(sp 2)-H/N-H Radical-Radical Cross Dehydrogenative Coupling. Org Lett 2024; 26:2326-2331. [PMID: 38451219 DOI: 10.1021/acs.orglett.4c00682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Direct alkene C-H/N-H cross dehydrogenative coupling is an infrequent, highly challenging transformation. Herein, a photoredox radical-radical cross-coupling reaction between ketene dithioacetal as a persistent alkene radical cation and azole nitrogen center radical (NCR) was developed. This direct alkene amination proceeded through a synergistic photoredox and cobalt catalysis, with only H2 evolution. The reaction showed excellent tolerance and highly regio- and stereospecific manner, expanding the scope of C(sp2)-N construction methods and radical cross-coupling modes.
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Affiliation(s)
- Chen Jin
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Cailin Ning
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Yating Sui
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Bingxin Zhang
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Xinxin Li
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Ling Pan
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Qun Liu
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Yifei Li
- Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China
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4
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Pratley C, Fenner S, Murphy JA. Ground State Generation and Cyclization of Aminium Radicals in the Formation of Tetrahydroquinolines. Org Lett 2024; 26:1287-1292. [PMID: 38306472 PMCID: PMC10877599 DOI: 10.1021/acs.orglett.4c00179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 01/23/2024] [Accepted: 01/29/2024] [Indexed: 02/04/2024]
Abstract
This paper reports the first examples of ground state radical-mediated intramolecular C-H amination to afford 1-methyl-1,2,3,4-tetrahydroquinolines from N-2,4-dinitrophenoxy derivatives of arylpropylamines. Whereas the photoactivation of N-2,4-dinitrophenoxyamines for intermolecular reactions has been established, ground state chemistry provides the desired cyclization products in moderate to excellent yields using Ru(bpy)3Cl2 (42-95% yields) under acidic conditions under an air atmosphere.
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Affiliation(s)
- Cassie Pratley
- Department
of Pure and Applied Chemistry, University
of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
- GSK Medicines
Research Centre, Gunnels
Wood Road, Stevenage, Hertfordshire SG1 2NY, United
Kingdom
| | - Sabine Fenner
- GSK Medicines
Research Centre, Gunnels
Wood Road, Stevenage, Hertfordshire SG1 2NY, United
Kingdom
| | - John A. Murphy
- Department
of Pure and Applied Chemistry, University
of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
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5
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Alvarez EM, Stewart G, Ullah M, Lalisse R, Gutierrez O, Malapit CA. Site-Selective Electrochemical Arene C-H Amination. J Am Chem Soc 2024; 146:3591-3597. [PMID: 38295054 PMCID: PMC11071122 DOI: 10.1021/jacs.3c11506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Here we present the discovery and development of a highly selective aromatic C-H amination reaction. This electrochemical strategy involves a cathodic reduction process that generates highly electrophilic dicationic N-centered radicals that can efficiently engage in aromatic C-H functionalization and channel the regioselectivity of the aromatic substitution. The nitrogen-radical cation-pi interaction with arenes used throughout nature leads to a charge transfer mechanism, with subsequent aromatic C-N bond formation. This electrochemical process generates aryl DABCOnium salts in excellent yields and regioselectivities (single regioisomer in most cases). The scope of the reaction on arene is broad where various functionalities such as aryl halides (bromides, chlorides, fluorides), carbonyls (ketones, esters, imides), sulfonamides, and heteroarenes (pyridines, bipyridines, and terpyridines) are well tolerated. Moreover, we disclose the synthetic utility of the aryl DABCOnium salt adducts leading to the direct access of diverse aryl piperazines and the chemoselective cleavage of the exocyclic aryl C(sp2)-N bond over electrophilic C(sp3)-N+ bonds via photoredox catalysis to afford synthetically useful aryl radicals that can engage in aryl C-C and C-P bond formation.
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Affiliation(s)
- Eva Maria Alvarez
- Department of Chemistry, Northwestern University, Technological Institute, Evanston, Illinois 60208, United States
| | - Griffin Stewart
- Department of Chemistry, Northwestern University, Technological Institute, Evanston, Illinois 60208, United States
| | - Mohammed Ullah
- Department of Chemistry, Northwestern University, Technological Institute, Evanston, Illinois 60208, United States
| | - Remy Lalisse
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Osvaldo Gutierrez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Christian A Malapit
- Department of Chemistry, Northwestern University, Technological Institute, Evanston, Illinois 60208, United States
- Center for Catalysis and Surface Science, Northwestern University, Evanston, Illinois 60208, United States
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6
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Lv Q, Hu Z, Zhang Y, Zhang Z, Lei H. Advancing Meta-Selective C-H Amination through Non-Covalent Interactions. J Am Chem Soc 2024; 146:1735-1741. [PMID: 38095630 DOI: 10.1021/jacs.3c09904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Regioselective C-H amination of simple arenes is highly desirable, but accessing meta-sites of ubiquitous arenes has proven challenging due to the lack of both electronic and spatial preference. This study demonstrates the successful use of various privileged nitrogen-containing functionalities found in pharmaceutical compounds to direct meta-C-H amination of arenes, overcoming the long-standing requirement for a redundant directing group. The remarkable advancements in functional group accommodation for precise regiochemical control were achieved through the discovery of an unprecedented organo-initiator and the strategic utilization of non-covalent interactions. This protocol has been successfully applied in the concise synthesis and late-stage derivatization of drug molecules, which would have been otherwise challenging to achieve.
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Affiliation(s)
- Qianqian Lv
- College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China
| | - Zongxing Hu
- College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China
| | - Yousong Zhang
- College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China
| | - Zhihan Zhang
- College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China
- Wuhan Institute of Photochemistry and Technology, Wuhan, Hubei 430083, P. R. China
| | - Honghui Lei
- College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, P. R. China
- Wuhan Institute of Photochemistry and Technology, Wuhan, Hubei 430083, P. R. China
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7
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Rao WH, Li YG, Jiang LL, Li Q, Zou GD, Cao X. Metal-Free Selective Ortho-C-H Amidation of Hypervalent(III) Iodobezenes with N-Methoxy Amides under Mild Conditions. J Org Chem 2023; 88:13825-13837. [PMID: 37737590 DOI: 10.1021/acs.joc.3c01472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
A metal-free selective ortho-C-H amidation of aryl iodines(III) with the use of N-methoxy amides as aminating reagents under mild conditions is described here. In the protocol, excellent chemoselectivity and high regioselectivity were obtained. Notably, the iodine substituent rendered the amidation product suitable to be used for further elaboration.
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Affiliation(s)
- Wei-Hao Rao
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
- Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University, Wuhan 430062, China
| | - Ying-Ge Li
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
| | - Li-Li Jiang
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
| | - Qi Li
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
| | - Guo-Dong Zou
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
| | - Xinhua Cao
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China
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8
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Ju G, Li Y, Zhao Y. Organic photoredox-catalyzed oxidative azolation of unactivated fluoroarenes. Org Biomol Chem 2023; 21:6503-6508. [PMID: 37540014 DOI: 10.1039/d3ob01041d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Inexpensive and commercially available 2,4,6-triphenylpyrrolium tetrafluoroborate (TPT) is used as an organic photocatalyst for the nucleophilic aromatic substitution of unactivated fluoroarenes with pyrazole derivatives (SNAr) to form azole arenes. The use of organic photoredox catalysis enables the easy operation of this method under mild conditions. Various fluorinated aromatic compounds are suitable electrophiles for this transformation.
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Affiliation(s)
- Guodong Ju
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou 215123, PR China.
| | - Yalong Li
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou 215123, PR China.
| | - Yingsheng Zhao
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou 215123, PR China.
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453000, P. R. China
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9
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Nan J, Huang G, Liu S, Wang J, Ma Y, Luan X. In(OTf) 3-catalyzed reorganization/cycloaddition of two imine units and subsequent modular assembly of acridinium photocatalysts. Chem Sci 2023; 14:5160-5166. [PMID: 37206409 PMCID: PMC10189902 DOI: 10.1039/d3sc00163f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/15/2023] [Indexed: 05/21/2023] Open
Abstract
Herein, we disclose a novel reorganization/cycloaddition between two imine units catalyzed by In(OTf)3 Lewis acid that differs from the well-known [4 + 2] cycloaddition version via the Povarov reaction. By means of this unprecedented imine chemistry, a collection of synthetically useful dihydroacridines has been synthesized. Notably, the obtained products give rise to a series of structurally novel and fine-tuneable acridinium photocatalysts, offering a heuristic paradigm for synthesis and efficiently facilitating several encouraging dihydrogen coupling reactions.
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Affiliation(s)
- Jiang Nan
- The Youth Innovation Team of Shaanxi Universities, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology Xi'an 710021 China
| | - Guanjie Huang
- The Youth Innovation Team of Shaanxi Universities, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology Xi'an 710021 China
| | - Shilei Liu
- The Youth Innovation Team of Shaanxi Universities, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology Xi'an 710021 China
| | - Jing Wang
- The Youth Innovation Team of Shaanxi Universities, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology Xi'an 710021 China
| | - Yangmin Ma
- The Youth Innovation Team of Shaanxi Universities, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology Xi'an 710021 China
| | - Xinjun Luan
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University Xi'an 710021 China
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10
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Vincent CA, Chiriac MI, Troian-Gautier L, Tambar UK. Photocatalytic Sulfonyl Fluorination of Alkyl Organoboron Substrates. ACS Catal 2023; 13:3668-3675. [PMID: 37124721 PMCID: PMC10135442 DOI: 10.1021/acscatal.3c00107] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Sulfonyl fluorides are highly versatile molecules for click chemistry that have found applications in many areas of chemistry and biology. Recent chemical approaches have focused on the synthesis of alkyl sulfonyl fluorides from readily available starting materials. Here, we report a photocatalytic synthesis of alkyl sulfonyl fluorides from organotrifluoroborates and boronic acid pinacol esters, which are building blocks commonly employed by medicinal chemists in the synthesis of bioactive molecules. Steady-state and time-resolved spectroscopy have confirmed that the absorption of photons by the acridinium catalysts leads to the oxidation of the organotrifluoroborate substrates. The reaction exhibits broad functional group tolerance, which can be attributed to the mild activation with visible light. Importantly, this general approach provides easy access to primary, secondary, and tertiary alkyl sulfonyl fluorides.
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Affiliation(s)
- Cooper A Vincent
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
| | - Maria Irina Chiriac
- Department of Discovery Chemistry, Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Ludovic Troian-Gautier
- Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Institut de la Matierè Condensée et des Nanosciences (IMCN), 1348 Louvain-la-Neuve, Belgium
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
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11
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Roy S, Panja S, Sahoo SR, Chatterjee S, Maiti D. Enroute sustainability: metal free C-H bond functionalisation. Chem Soc Rev 2023; 52:2391-2479. [PMID: 36924227 DOI: 10.1039/d0cs01466d] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
The term "C-H functionalisation" incorporates C-H activation followed by its transformation. In a single line, this can be defined as the conversion of carbon-hydrogen bonds into carbon-carbon or carbon-heteroatom bonds. The catalytic functionalisation of C-H bonds using transition metals has emerged as an atom-economical technique to engender new bonds without activated precursors which can be considered as a major drawback while attempting large-scale synthesis. Replacing the transition-metal-catalysed approach with a metal-free strategy significantly offers an alternative route that is not only inexpensive but also environmentally benign to functionalize C-H bonds. Recently metal free synthetic approaches have been flourishing to functionalize C-H bonds, motivated by the search for greener, cost-effective, and non-toxic catalysts. In this review, we will highlight the comprehensive and up-to-date discussion on recent examples of ground-breaking research on green and sustainable metal-free C-H bond functionalisation.
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Affiliation(s)
- Sayan Roy
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Subir Panja
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Sumeet Ranjan Sahoo
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Sagnik Chatterjee
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Debabrata Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India. .,Department of Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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12
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Roberts RA, Metze BE, Nilova A, Stuart DR. Synthesis of Arynes via Formal Dehydrogenation of Arenes. J Am Chem Soc 2023; 145:3306-3311. [PMID: 36728842 DOI: 10.1021/jacs.2c13007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Arynes offer immense potential for diversification of benzenoid rings, which occur in pharmaceuticals, agrochemicals, and liquid crystals. However, accessing these high-energy intermediates requires synthetic precursors, which involve either harsh conditions or multistep syntheses. The development of alternative methods to access arynes using simpler substrates and milder conditions is necessary for a more streamlined approach. Here, we describe a two-step formal dehydrogenation of simple arenes to generate arynes at a remote position relative to traditionally reactive groups, e.g., halides. This approach is enabled by regioselective installation and ejection of an "onium" leaving group, and we demonstrate the compatibility of simple arenes (20 examples) and arynophiles (8 examples). Moreover, through direct comparison, we show that our formal dehydrogenation method is both more functional group tolerant and efficient in generating arynes than the current state-of-the-art aryne precursors. Finally, we show that aryne intermediates offer opportunities for regioselective C-H amination that are distinct from other methods.
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Affiliation(s)
- Riley A Roberts
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
| | - Bryan E Metze
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
| | - Aleksandra Nilova
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
| | - David R Stuart
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
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13
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Murugesh V, Reddy PR, Singh SP. Photocatalyst-free visible-light triggered amination of benzo[ c][1,2,5]thiadiazole: direct C-N bond formation from C(sp 2)-H bond. Chem Commun (Camb) 2023; 59:1034-1037. [PMID: 36602122 DOI: 10.1039/d2cc05811a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The photoredox amination of arene protocols mostly comprises photocatalyst-mediated transformations. Herein, we presented the photocatalyst-free, visible-light promoted, direct conversion of C(sp2)-H to C(sp2)-N method. Multipurpose benzothiadiazoles are used as model synthons and secondary amines as aminating agents. Mechanistic study reveals that the radical reaction mechanism proceeds through nitrogen-centered radical generation, followed by the addition of arenes, which was demonstrated for the present amination protocol of benzothiadiazole with secondary amines in an atom economical fashion.
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Affiliation(s)
- V Murugesh
- Polymers & Functional Materials Division, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
| | - Patlolla Ravinder Reddy
- Polymers & Functional Materials Division, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Surya Prakash Singh
- Polymers & Functional Materials Division, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
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14
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Abstract
The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C-H functionalization approaches that make use of low energy photons as a controllable energy source. Compared to traditional late-stage functionalization strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- and chemoselectivities. Merging the compelling benefits of photocatalysis with the late-stage functionalization workflow offers a potentially unmatched arsenal to tackle drug development campaigns and beyond. This Review highlights the photocatalytic late-stage C-H functionalization strategies of small-molecule drugs, agrochemicals, and natural products, classified according to the targeted C-H bond and the newly formed one. Emphasis is devoted to identifying, describing, and comparing the main mechanistic scenarios. The Review draws a critical comparison between established ionic chemistry and photocatalyzed radical-based manifolds. The Review aims to establish the current state-of-the-art and illustrate the key unsolved challenges to be addressed in the future. The authors aim to introduce the general readership to the main approaches toward photocatalytic late-stage C-H functionalization, and specialist practitioners to the critical evaluation of the current methodologies, potential for improvement, and future uncharted directions.
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Affiliation(s)
- Peter Bellotti
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Huan-Ming Huang
- School of Physical Science and Technology, ShanghaiTech University, 201210Shanghai, China
| | - Teresa Faber
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
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15
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Lu YC, West JG. Chemoselective Decarboxylative Protonation Enabled by Cooperative Earth-Abundant Element Catalysis. Angew Chem Int Ed Engl 2023; 62:e202213055. [PMID: 36350328 PMCID: PMC9839625 DOI: 10.1002/anie.202213055] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/11/2022]
Abstract
Decarboxylative protonation is a general deletion tactic to replace polar carboxylic acid groups with hydrogen or its isotope. Current methods rely on the pre-activation of acids, non-sustainable hydrogen sources, and/or expensive/highly oxidizing photocatalysts, presenting challenges to their wide adoption. Here we show that a cooperative iron/thiol catalyst system can readily achieve this transformation, hydrodecarboxylating a wide range of activated and unactivated carboxylic acids and overcoming scope limitations in previous direct methods. The reaction is readily scaled in batch configuration and can be directly performed in deuterated solvent to afford high yields of d-incorporated products with excellent isotope incorporation efficiency; characteristics not attainable in previous photocatalyzed approaches. Preliminary mechanistic studies indicate a radical mechanism and kinetic results of unactivated acids (KIE=1) are consistent with a light-limited reaction.
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Affiliation(s)
- Yen-Chu Lu
- Department of Chemistry, Rice University, 6100 Main St, Houston, TX 77005, USA
| | - Julian G West
- Department of Chemistry, Rice University, 6100 Main St, Houston, TX 77005, USA
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16
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Diversification of pharmaceutical molecules via late-stage C(sp2)–H functionalization. GREEN SYNTHESIS AND CATALYSIS 2023. [DOI: 10.1016/j.gresc.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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17
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Huang XK, Li LP, Zhou HY, Xiong MF, Fan JY, Ye BH. Switching the Photoreactions of Ir(III) Diamine Complexes between C-N Coupling and Dehydrogenation under Visible Light Irradiation. Inorg Chem 2022; 61:20834-20847. [PMID: 36520143 DOI: 10.1021/acs.inorgchem.2c03161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The selective photoreactions under mild conditions play an important role in synthetic chemistry. Herein, efficient and mild protocols for switching the photoreactions of Ir(III)-diamine complexes between the interligand C-N coupling and dehydrogenation are developed in the presence of O2 in EtOH solution. The photoreactions of achiral diamine complexes rac-[Ir(L)2(dm)](PF6) (L is 2-phenylquinoline or 2-(2,4-difluorophenyl)quinoline, dm is 1,2-ethylenediamine, 1,2-diaminopropane, 2-methyl-1,2-diamino-propane, or N,N'-dimethyl-1,2-ethylenediamine) are competitive in the oxidative C-N coupling and dehydrogenation at room temperature, which can be switched into the interligand C-N coupling reaction at 60 °C, affording hexadentate complexes in good to excellent yields, or the dehydrogenative reaction in the presence of a catalytic amount of TEMPO as an additive, affording imine complexes. Mechanism studies reveal that 1O2 is the major reactive oxygen species, and metal aminyl is the key intermediate in the formation of the oxidative C-N coupling and imine products in the photoreaction processes. These will provide a new and practical protocol for the synthesis of multidentate and imine ligands in situ via the postcoordinated strategy under mild conditions.
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Affiliation(s)
- Xiao-Kang Huang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
| | - Li-Ping Li
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
| | - Hai-Yun Zhou
- Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
| | - Ming-Feng Xiong
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
| | - Jing-Yan Fan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
| | - Bao-Hui Ye
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275 Guangdong, China
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18
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Paul A, Sengupta A, Yadav S. Organophotoredox-Catalyzed Cross-Dehydrogenative Sulfonamidation of Indoles and Other Heterocycles. J Org Chem 2022. [DOI: 10.1021/acs.joc.2c02022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Aditya Paul
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand 826004, India
| | - Arunava Sengupta
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand 826004, India
| | - Somnath Yadav
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand 826004, India
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19
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Lasky MR, Salvador TK, Mukhopadhyay S, Remy MS, Vaid TP, Sanford MS. Photochemical C(sp 2 )-H Pyridination via Arene-Pyridinium Electron Donor-Acceptor Complexes. Angew Chem Int Ed Engl 2022; 61:e202208741. [PMID: 36100577 PMCID: PMC9828204 DOI: 10.1002/anie.202208741] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Indexed: 01/12/2023]
Abstract
This report describes the development of a photochemical method for C(sp2 )-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. Experimental and DFT studies show that black light (λmax ≈350 nm) irradiation of solutions of protonated pyridines (acceptors) and aromatic C-H substrates (donors) results in single electron transfer to form aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. With some modification of the reaction conditions, this EDA activation mode is also effective for promoting the oxidatively triggered SN Ar pyridination of aryl halides. Overall, this report represents an inexpensive and atom-economical approach to photochemical pyridination reactions that eliminates the requirement of an exogenous photocatalyst.
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Affiliation(s)
- Matthew R. Lasky
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Tolani K. Salvador
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | | | | | - Thomas P. Vaid
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Melanie S. Sanford
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
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20
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Eckhardt P, Elliot Q, Alabugin IV, Opatz T. Two Paths to Oxidative C-H Amination Under Basic Conditions: A Theoretical Case Study Reveals Hidden Opportunities Provided by Electron Upconversion. Chemistry 2022; 28:e202201637. [PMID: 35880945 PMCID: PMC9804812 DOI: 10.1002/chem.202201637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Indexed: 01/09/2023]
Abstract
Traditionally, cross-dehydrogenative coupling (CDC) leads to C-N bond formation under basic and oxidative conditions and is proposed to proceed via a two-electron bond formation mediated by carbenium ions. However, the formation of such high-energy intermediates is only possible in the presence of strong oxidants, which may lead to undesired side reactions and poor functional group tolerance. In this work we explore if oxidation under basic conditions allows the formation of three-electron bonds (resulting in "upconverted" highly-reducing radical-anions). The benefit of this "upconversion" process is in the ability to use milder oxidants (e. g., O2 ) and to avoid high-energy intermediates. Comparison of the two- and three-electron pathways using quantum mechanical calculations reveals that not only does the absence of a strong oxidant shut down two-electron pathways in favor of a three-electron path but, paradoxically, weaker oxidants react faster with the upconverted reductants by avoiding the inverted Marcus region for electron transfer.
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Affiliation(s)
- Paul Eckhardt
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10–1455128MainzGermany
| | - Quintin Elliot
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida 32306USA
| | - Igor V. Alabugin
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida 32306USA
| | - Till Opatz
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10–1455128MainzGermany
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21
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Ji P, Davies CC, Gao F, Chen J, Meng X, Houk KN, Chen S, Wang W. Selective skeletal editing of polycyclic arenes using organophotoredox dearomative functionalization. Nat Commun 2022; 13:4565. [PMID: 35931700 PMCID: PMC9355940 DOI: 10.1038/s41467-022-32201-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/19/2022] [Indexed: 11/29/2022] Open
Abstract
Reactions that lead to destruction of aromatic ring systems often require harsh conditions and, thus, take place with poor selectivities. Selective partial dearomatization of fused arenes is even more challenging but can be a strategic approach to creating versatile, complex polycyclic frameworks. Herein we describe a general organophotoredox approach for the chemo- and regioselective dearomatization of structurally diverse polycyclic aromatics, including quinolines, isoquinolines, quinoxalines, naphthalenes, anthracenes and phenanthrenes. The success of the method for chemoselective oxidative rupture of aromatic moieties relies on precise manipulation of the electronic nature of the fused polycyclic arenes. Mechanistic studies show that the addition of a hydrogen atom transfer (HAT) agent helps favor the dearomatization pathway over the more thermodynamically downhill aromatization pathway. We show that this strategy can be applied to rapid synthesis of biologically valued targets and late-stage skeletal remodeling en route to complex structures. The synthesis of polycyclic structures bearing partially saturated (hetero)arenes is important as many of these structures have biological relevance. Here the authors develop a one-step method for selective dearomative functionalization of feedstock (hetero)arenes via organophotocatalysis.
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Affiliation(s)
- Peng Ji
- Departments of Pharmacology and Toxicology and Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0207, USA
| | - Cassondra C Davies
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, 44074, USA
| | - Feng Gao
- Departments of Pharmacology and Toxicology and Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0207, USA
| | - Jing Chen
- Departments of Pharmacology and Toxicology and Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0207, USA
| | - Xiang Meng
- Departments of Pharmacology and Toxicology and Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0207, USA
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095-1569, USA.
| | - Shuming Chen
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, 44074, USA.
| | - Wei Wang
- Departments of Pharmacology and Toxicology and Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721-0207, USA.
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22
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Ravindar L, Hasbullah SA, Hassan NI, Qin HL. Cross‐Coupling of C‐H and N‐H Bonds: a Hydrogen Evolution Strategy for the Construction of C‐N Bonds. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lekkala Ravindar
- Universiti Kebangsaan Malaysia Fakulti Teknologi dan Sains Maklumat Chemical Sciences Faculty of Science & Technology 43600 Bandar Baru Bangi MALAYSIA
| | - Siti Aishah Hasbullah
- Universiti Kebangsaan Malaysia Fakulti Sains dan Teknologi Chemical Sciences Faculty of Science & Technology 43600 Bandar Baru Bangi MALAYSIA
| | - Nurul Izzaty Hassan
- Universiti Kebangsaan Malaysia Fakulti Sains dan Teknologi Chemical Sciences Faculty of Science & Technology 43600 Bandar Baru Bangi MALAYSIA
| | - Hua-Li Qin
- Wuhan University of Technology School of Chemistry 430070 Hubei CHINA
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23
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Sun Y, Tan F, Hu R, Hu C, Li Y. Visible‐Light Photoredox‐Catalyzed
Hydrodecarboxylation and Deuterodecarboxylation of Fatty Acids. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202200143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yuan‐Li Sun
- Center for Organic Chemistry Frontier Institute of Science and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710054 P. R. China
| | - Fang‐Fang Tan
- Center for Organic Chemistry Frontier Institute of Science and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710054 P. R. China
| | - Rong‐Gui Hu
- Center for Organic Chemistry Frontier Institute of Science and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710054 P. R. China
| | - Chun‐Hong Hu
- Center for Organic Chemistry Frontier Institute of Science and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710054 P. R. China
| | - Yang Li
- Center for Organic Chemistry Frontier Institute of Science and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710054 P. R. China
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24
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Tao Y, Hu R, Xie Z, Lin P, Su W. Cobalt-Catalyzed Regioselective para-Amination of Azobenzenes via Nucleophilic Aromatic Substitution of Hydrogen. J Org Chem 2022; 87:4724-4731. [PMID: 35290054 DOI: 10.1021/acs.joc.2c00026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The metal-catalyzed nucleophilic aromatic substitution of hydrogen (SNArH) via coordination of the substituent on the aromatic ring to the metal catalyst, in terms of reactivity, substrate type, and reaction selectivity, complements the transition metal-catalyzed C-H functionalization that proceeds via C-H metalation but remains an elusive target. Described herein is the development of an unprecedented cobalt-catalyzed para-selective amination of azobenzenes, which is essentially a metal-promoted SNArH process as revealed by Hammett analysis, thus illustrating the concept that coordination of the substituent on the arene ring to the metal catalyst may result in electrophilic activation of the arene ring toward SNArH. This cobalt-catalyzed protocol allows the use of a variety of both aliphatic amines and anilines as aminating reagents, tolerates electronically diverse substituents of azobenzene, and furnishes the corresponding products in good yields with a regiospecific selectivity for para-amination.
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Affiliation(s)
- Yigao Tao
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Rong Hu
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Zeyu Xie
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ping Lin
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Weiping Su
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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25
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Cao YX, Zhu G, Li Y, Le Breton N, Gourlaouen C, Choua S, Boixel J, Jacquot de Rouville HP, Soulé JF. Photoinduced Arylation of Acridinium Salts: Tunable Photoredox Catalysts for C-O Bond Cleavage. J Am Chem Soc 2022; 144:5902-5909. [PMID: 35316065 DOI: 10.1021/jacs.1c12961] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A photoinduced arylation of N-substituted acridinium salts has been developed and has exhibited a high functional group tolerance (e.g., halogen, nitrile, ketone, ester, and nitro). A broad range of well-decorated C9-arylated acridinium-based catalysts with fine-tuned photophysical and photochemical properties, namely, excited-state lifetimes and redox potentials have been synthetized in a one-step procedure. These functionalized acridinium salts were later evaluated in the photoredox-catalyzed fragmentation of 1,2-diol derivatives (lignin models). Among them, 2-bromophenyl substituted N-methyl acridinium has outperformed all photoredox catalysts, including commercial Fukuzumi's catalyst, for the selective CβO-Ar bond cleavage of diol monoarylethers to afford 1,2-diols in good yields.
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Affiliation(s)
- Yi-Xuan Cao
- Univ Rennes, CNRS, UMR 6226, F-3500 Rennes, France
| | - Gan Zhu
- Univ Rennes, CNRS, UMR 6226, F-3500 Rennes, France.,Department of Chemistry, Jinan University, 511443 Guangzhou, China
| | - Yiqun Li
- Department of Chemistry, Jinan University, 511443 Guangzhou, China
| | - Nolwenn Le Breton
- Institut de Chimie de Strasbourg, CNRS UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - Christophe Gourlaouen
- Institut de Chimie de Strasbourg, CNRS UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - Sylvie Choua
- Institut de Chimie de Strasbourg, CNRS UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
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26
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Pratley C, Fenner S, Murphy JA. Nitrogen-Centered Radicals in Functionalization of sp 2 Systems: Generation, Reactivity, and Applications in Synthesis. Chem Rev 2022; 122:8181-8260. [PMID: 35285636 DOI: 10.1021/acs.chemrev.1c00831] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The chemistry of nitrogen-centered radicals (NCRs) has plentiful applications in organic synthesis, and they continue to expand as our understanding of these reactive species increases. The utility of these reactive intermediates is demonstrated in the recent advances in C-H amination and the (di)amination of alkenes. Synthesis of previously challenging structures can be achieved by efficient functionalization of sp2 moieties without prefunctionalization, allowing for faster and more streamlined synthesis. This Review addresses the generation, reactivity, and application of NCRs, including, but not limited to, iminyl, aminyl, amidyl, and aminium species. Contributions from early discovery up to the most recent examples have been highlighted, covering radical initiation, thermolysis, photolysis, and, more recently, photoredox catalysis. Radical-mediated intermolecular amination of (hetero)arenes can occur with a variety of complex amine precursors, generating aniline derivatives, an important class of structures for drug discovery and development. Functionalization of olefins is achievable in high anti-Markovnikov regioselectivity and allows access to difunctionalized structures when the intermediate carbon radicals are trapped. Additionally, the reactivity of NCRs can be harnessed for the rapid construction of N-heterocycles such as pyrrolidines, phenanthridines, quinoxalines, and quinazolinones.
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Affiliation(s)
- Cassie Pratley
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom.,GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, United Kingdom
| | - Sabine Fenner
- GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, United Kingdom
| | - John A Murphy
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
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27
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Allen AR, Noten EA, Stephenson CRJ. Aryl Transfer Strategies Mediated by Photoinduced Electron Transfer. Chem Rev 2022; 122:2695-2751. [PMID: 34672526 PMCID: PMC9272681 DOI: 10.1021/acs.chemrev.1c00388] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Radical aryl migrations are powerful techniques to forge new bonds in aromatic compounds. The growing popularity of photoredox catalysis has led to an influx of novel strategies to initiate and control aryl migration starting from widely available radical precursors. This review encapsulates progress in radical aryl migration enabled by photochemical methods─particularly photoredox catalysis─since 2015. Special attention is paid to descriptions of scope, mechanism, and synthetic applications of each method.
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Affiliation(s)
- Anthony R. Allen
- Department of Chemistry, Willard Henry Dow Laboratory, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Efrey A. Noten
- Department of Chemistry, Willard Henry Dow Laboratory, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Corey R. J. Stephenson
- Department of Chemistry, Willard Henry Dow Laboratory, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.,
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28
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Tay NES, Lehnherr D, Rovis T. Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis. Chem Rev 2022; 122:2487-2649. [PMID: 34751568 PMCID: PMC10021920 DOI: 10.1021/acs.chemrev.1c00384] [Citation(s) in RCA: 128] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do electrochemistry and photoredox catalysis compare? Both approaches provide access to high energy intermediates (e.g., radicals) that enable bond formations not constrained by the rules of ionic or 2 electron (e) mechanisms. Instead, they enable 1e mechanisms capable of bypassing electronic or steric limitations and protecting group requirements, thus enabling synthetic chemists to disconnect molecules in new and different ways. However, while providing access to similar intermediates, electrochemistry and photoredox catalysis differ in several physical chemistry principles. Understanding those differences can be key to designing new transformations and forging new bond disconnections. This review aims to highlight these differences and similarities between electrochemistry and photoredox catalysis by comparing their underlying physical chemistry principles and describing their impact on electrochemical and photochemical methods.
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Affiliation(s)
- Nicholas E S Tay
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Dan Lehnherr
- Process Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Tomislav Rovis
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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29
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Murray PD, Cox JH, Chiappini ND, Roos CB, McLoughlin EA, Hejna BG, Nguyen ST, Ripberger HH, Ganley JM, Tsui E, Shin NY, Koronkiewicz B, Qiu G, Knowles RR. Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis. Chem Rev 2022; 122:2017-2291. [PMID: 34813277 PMCID: PMC8796287 DOI: 10.1021/acs.chemrev.1c00374] [Citation(s) in RCA: 158] [Impact Index Per Article: 79.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Indexed: 12/16/2022]
Abstract
We present here a review of the photochemical and electrochemical applications of multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms in which both an electron and a proton are exchanged together, often in a concerted elementary step. As such, MS-PCET can function as a non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from a wide variety of common organic functional groups. We present an introduction to MS-PCET and a practitioner's guide to reaction design, with an emphasis on the unique energetic and selectivity features that are characteristic of this reaction class. We then present chapters on oxidative N-H, O-H, S-H, and C-H bond homolysis methods, for the generation of the corresponding neutral radical species. Then, chapters for reductive PCET activations involving carbonyl, imine, other X═Y π-systems, and heteroarenes, where neutral ketyl, α-amino, and heteroarene-derived radicals can be generated. Finally, we present chapters on the applications of MS-PCET in asymmetric catalysis and in materials and device applications. Within each chapter, we subdivide by the functional group undergoing homolysis, and thereafter by the type of transformation being promoted. Methods published prior to the end of December 2020 are presented.
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Affiliation(s)
- Philip
R. D. Murray
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - James H. Cox
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Nicholas D. Chiappini
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Casey B. Roos
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | | | - Benjamin G. Hejna
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Suong T. Nguyen
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Hunter H. Ripberger
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Jacob M. Ganley
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Elaine Tsui
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Nick Y. Shin
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Brian Koronkiewicz
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Guanqi Qiu
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
| | - Robert R. Knowles
- Department of Chemistry, Princeton
University, Princeton, New Jersey 08544, United States
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30
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Sakakibara Y, Murakami K, Itami K. C-H Acyloxylation of Polycyclic Aromatic Hydrocarbons. Org Lett 2022; 24:602-607. [PMID: 34994201 DOI: 10.1021/acs.orglett.1c04030] [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
The C-H acyloxylation of polycyclic aromatic hydrocarbons (PAHs) is described. This reaction constructs aryl acyloxylate scaffolds from PAHs with equimolar hypervalent iodine compounds under mild reaction conditions. Interestingly, the blue light irradiation accelerated this transformation. Additionally, the synthesis of structurally new symmetric and unsymmetric diaroyloxylated fluoranthenes was accomplished with a ruthenium photoredox catalyst.
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Affiliation(s)
- Yota Sakakibara
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Kei Murakami
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.,Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuin, Sanda, Hyogo 669-1337, Japan.,JST-PRESTO, 7 Gobancho, Chiyoda, Tokyo 102-0076, Japan
| | - Kenichiro Itami
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
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31
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Bugaenko DI, Karchava AV, Yurovskaya MA. Transition metal-free cross-coupling reactions with the formation of carbon-heteroatom bonds. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Affiliation(s)
- Lauren G. O'Neil
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
| | - John F. Bower
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD UK
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33
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He M, Yu X, Wang Y, Bao M. Tunable Redox Potential Photocatalyst: Aggregates of 2,3-Dicyanopyrazino Phenanthrene Derivatives for the Visible-Light-Induced α-Allylation of Amines. J Org Chem 2021; 86:14720-14731. [PMID: 34694115 DOI: 10.1021/acs.joc.1c01533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work highlights the tunable redox potential of 6,11-dibromo-2,3-dicyanopyrazinophenanthrene (DCPP3) aggregates, which can be formed through physical π-π stacking interactions with other DCPP3 monomers. Electrochemical and scanning electron microscopy showed that the reduction potential of [DCPP3]n aggregates could be increased by decreasing their size. The size of [DCPP3]n aggregates could be regulated by controlling the concentration of DCPP3 in an organic solvent. As such, a fundamental understanding of this tunable redox potential is essential for developing new materials for photocatalytic applications. The [DCPP3]n aggregates as a visible-light photocatalyst in combination with Pd catalysts in the visible-light-induced α-allylation of amines were used. This [DCPP3]n photocatalyst exhibits excellent photo- and electrochemical properties, including a remarkable visible-light absorption, long excited-state lifetime (16.6 μs), good triplet quantum yield (0.538), and high reduction potential (Ered([DCPP3]n/[DCPP3]n-) > -1.8 V vs SCE).
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Affiliation(s)
- Min He
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116023, China
| | - Xiaoqiang Yu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116023, China
| | - Yi Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116023, China
| | - Ming Bao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116023, China
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34
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Sinha SK, Guin S, Maiti S, Biswas JP, Porey S, Maiti D. Toolbox for Distal C-H Bond Functionalizations in Organic Molecules. Chem Rev 2021; 122:5682-5841. [PMID: 34662117 DOI: 10.1021/acs.chemrev.1c00220] [Citation(s) in RCA: 166] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transition metal catalyzed C-H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted to take the help of this methodology to plan their synthetic discourses. This paradigm shift has helped in the development of industrial units as well, making the synthesis of natural products and pharmaceutical drugs step-economical. In the vast zone of C-H bond activation, the functionalization of proximal C-H bonds has gained utmost popularity. Unlike the activation of proximal C-H bonds, the distal C-H functionalization is more strenuous and requires distinctly specialized techniques. In this review, we have compiled various methods adopted to functionalize distal C-H bonds, mechanistic insights within each of these procedures, and the scope of the methodology. With this review, we give a complete overview of the expeditious progress the distal C-H activation has made in the field of synthetic organic chemistry while also highlighting its pitfalls, thus leaving the field open for further synthetic modifications.
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Affiliation(s)
- Soumya Kumar Sinha
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Srimanta Guin
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sudip Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Jyoti Prasad Biswas
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sandip Porey
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Debabrata Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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35
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Ueda Y. Site-Selective Molecular Transformation: Acylation of Hydroxy Groups and C-H Amination. Chem Pharm Bull (Tokyo) 2021; 69:931-944. [PMID: 34602573 DOI: 10.1248/cpb.c21-00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Control of site selectivity is an exciting direction for synthetic organic chemistry owing to the possibility of selective modification of multifunctionalized molecules, ultimately including biomacromolecules. In this review, our recent research related to site selectivity in two types of transformation, namely, the acylation of hydroxy groups and C-H amination, is summarized. Regarding the acylation of hydroxy groups, catalyst-controlled site selectivity enables unconventional retrosynthetic analysis, leading to efficient syntheses of sugar-related natural and unnatural products. Regarding C-H amination, the discovery of unprecedented reaction sites in intermolecular amination mediated by dirhodium nitrenes is described. The findings of this research demonstrate the power of site-selective transformation in the synthesis of a particular class of compounds.
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36
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Abstract
The fields of C-H functionalization and photoredox catalysis have garnered enormous interest and utility in the past several decades. Many different scientific disciplines have relied on C-H functionalization and photoredox strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, and fine chemical synthesis. In this Review, we highlight the use of photoredox catalysis in C-H functionalization reactions. We separate the review into inorganic/organometallic photoredox catalysts and organic-based photoredox catalytic systems. Further subdivision by reaction class-either sp2 or sp3 C-H functionalization-lends perspective and tactical strategies for use of these methods in synthetic applications.
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Affiliation(s)
- Natalie Holmberg-Douglas
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - David A Nicewicz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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37
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Huang R, Zhao W, Xu S, Xu J, Li C, Lu C, Yan H. Photoredox B-H functionalization to selective B-N(sp 3) coupling of nido-carborane with primary and secondary amines. Chem Commun (Camb) 2021; 57:8580-8583. [PMID: 34369517 DOI: 10.1039/d1cc03326c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Access to nido-carborane site-selective B-N(sp3) coupling by photoredox catalysed B-H activation has been achieved for the first time, which leads to the synthesis of a series of nitrogen-containing nido-carboranes with moderate to good yields. This protocol is applicable to primary and secondary amines containing alkyl, or heteroaryl groups as well as sulfonamides. Furthermore, the open to air and metal-free conditions with excellent site-selectivity represent a significant improvement for B-H functionalization of nido-carboranes with organic functionalities.
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Affiliation(s)
- Ronghui Huang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
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38
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Tlili A, Lakhdar S. Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102262] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Anis Tlili
- Institute of Chemistry and Biochemistry (ICBMS-UMR CNRS 5246) Univ Lyon, Université Lyon 1 CNRS CPE-Lyon INSA 43 Bd du 11 Novembre 1918 69622 Villeurbanne France
| | - Sami Lakhdar
- CNRS/Université Toulouse III—Paul Sabatier Laboratoire Hétérochimie Fondamentale et Appliquée LHFA UMR 5069 118 Route de Narbonne 31062 Toulouse Cedex 09 France
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39
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Tlili A, Lakhdar S. Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis. Angew Chem Int Ed Engl 2021; 60:19526-19549. [PMID: 33881207 DOI: 10.1002/anie.202102262] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 04/16/2021] [Indexed: 01/18/2023]
Abstract
The use of organic photocatalysts has revolutionized the field of photoredox catalysis, as it allows access to reactivities that were traditionally restricted to transition-metal photocatalysts. This Minireview reports recent developments in the use of acridinium ions and cyanoarene derivatives in organic synthesis. The activation of inert chemical bonds as well as the late-stage functionalization of biorelevant molecules are discussed, with a special focus on their mechanistic aspects.
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Affiliation(s)
- Anis Tlili
- Institute of Chemistry and Biochemistry (ICBMS-UMR CNRS 5246), Univ Lyon, Université Lyon 1, CNRS, CPE-Lyon, INSA, 43 Bd du 11 Novembre 1918, 69622, Villeurbanne, France
| | - Sami Lakhdar
- CNRS/Université Toulouse III-Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 118 Route de Narbonne, 31062, Toulouse Cedex 09, France
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40
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Gillespie JE, Morrill C, Phipps RJ. Regioselective Radical Arene Amination for the Concise Synthesis of ortho-Phenylenediamines. J Am Chem Soc 2021; 143:9355-9360. [PMID: 34128670 PMCID: PMC8251697 DOI: 10.1021/jacs.1c05531] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
The
formation of arene C–N bonds directly from C–H
bonds is of great importance and there has been rapid recent development
of methods for achieving this through radical mechanisms, often involving
reactive N-centered radicals. A major challenge associated
with these advances is that of regiocontrol, with mixtures of regioisomeric
products obtained in most protocols, limiting broader utility. We
have designed a system that utilizes attractive noncovalent interactions
between an anionic substrate and an incoming radical cation in order
to guide the latter to the arene ortho position.
The anionic substrate takes the form of a sulfamate-protected aniline
and telescoped cleavage of the sulfamate group after amination leads
directly to ortho-phenylenediamines, key building
blocks for a range of medicinally relevant diazoles. Our method can
deliver both free amines and monoalkyl amines allowing access to unsymmetrical,
selectively monoalkylated benzimidazoles and benzotriazoles. As well
as providing concise access to valuable ortho-phenylenediamines,
this work demonstrates the potential for utilizing noncovalent interactions
to control positional selectivity in radical reactions.
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Affiliation(s)
- James E Gillespie
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Charlotte Morrill
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Robert J Phipps
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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41
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Radical philicity and its role in selective organic transformations. Nat Rev Chem 2021; 5:486-499. [PMID: 37118440 DOI: 10.1038/s41570-021-00284-3] [Citation(s) in RCA: 137] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2021] [Indexed: 12/11/2022]
Abstract
Radical intermediates in organic chemistry lack a full octet of electrons and, thus, are commonly said to be electron deficient. By denotation, such a statement is technically correct; however, in modern literature, the term 'electron deficient' carries a connotation of electrophilicity. This lexical quirk leads one to predict that all radicals should behave as electrophiles, when this is not the case. Indeed, practitioners of radical chemistry have known for decades that many radicals behave as nucleophiles, sometimes strongly so. This Review aims to establish guidelines for understanding radical philicity by highlighting examples from recent literature as a demonstration of general reactivity paradigms across a series of different carbon-based and heteroatom-based radicals. We present strategies for predicting the philicity of a given radical on the basis of qualitative features of the radical's structure. Finally, we discuss the implications of radical philicity to selective hydrogen atom transfer.
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42
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O'Neil LG, Bower JF. Electrophilic Aminating Agents in Total Synthesis. Angew Chem Int Ed Engl 2021; 60:25640-25666. [PMID: 33942955 PMCID: PMC9291613 DOI: 10.1002/anie.202102864] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Indexed: 12/12/2022]
Abstract
Classical amination methods involve the reaction of a nitrogen nucleophile with an electrophilic carbon center; however, in recent years, umpoled strategies have gained traction where the nitrogen source acts as an electrophile. A wide range of electrophilic aminating agents are now available, and these underpin a range of powerful C−N bond‐forming processes. In this Review, we highlight the strategic use of electrophilic aminating agents in total synthesis.
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Affiliation(s)
- Lauren G O'Neil
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.,Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
| | - John F Bower
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
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43
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Taeufer T, Hauptmann R, El-Hage F, Mayer TS, Jiao H, Rabeah J, Pospech J. Pyrimidopteridine-Catalyzed Hydroamination of Stilbenes with Primary Amines: A Dual Photoredox and Hydrogen Atom Transfer Catalyst. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tobias Taeufer
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Richy Hauptmann
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Firas El-Hage
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Thea S. Mayer
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Haijun Jiao
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Jabor Rabeah
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Jola Pospech
- Leibniz Institute for Catalysis, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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44
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Abstract
The nature of the terminal oxidant in oxidation reactions is an important reaction variable that can profoundly impact the mechanism, efficiency, and practicality of a synthetic protocol. One might reasonably categorize catalytic oxidation reactions into either "oxygenase" type reactions, in which the oxidant serves as an atom- or group-transfer reagent, or "oxidase" type reactions, where the oxidant is involved in catalyst turnover but does not become structurally incorporated into the product. As the field of photoredox catalysis has matured over the past decade, many successful oxygenase-type photoreactions have been reported. The development of photocatalytic oxidase reactions, on the other hand, has been somewhat slower. This tutorial review presents selected examples of some of the key classes of terminal oxidants that have been used in the design of photoredox oxidase transformations, along with the mechanistic features and benefits of each.
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Affiliation(s)
- Nicholas L Reed
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
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45
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Falk E, Gasser VCM, Morandi B. Synthesis of N-Alkyl Anilines from Arenes via Iron-Promoted Aromatic C-H Amination. Org Lett 2021; 23:1422-1426. [PMID: 33544600 DOI: 10.1021/acs.orglett.1c00099] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report both an intermolecular C-H amination of arenes to access N-methylanilines and an intramolecular variant for the synthesis of tetrahydroquinolines. A newly developed, highly electrophilic aminating reagent was key for the direct synthesis of unprotected N-methylanilines from simple arenes. The reactions display a broad functional group tolerance and employ catalytic amounts of a benign iron salt under mild reaction conditions.
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Affiliation(s)
- Eric Falk
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland
| | | | - Bill Morandi
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland
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46
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Peng HL, Li Y, Chen XY, Li LP, Ke Z, Ye BH. Visible-Light-Induced Amination of Quinoline at the C8 Position via a Postcoordinated Interligand-Coupling Strategy under Mild Conditions. Inorg Chem 2021; 60:908-918. [PMID: 33393292 DOI: 10.1021/acs.inorgchem.0c03026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The postcoordinated interligand-coupling strategy provides a useful and complementary protocol for synthesizing polydentate ligands. Herein, diastereoselective photoreactions of Λ-[Ir(pq)2(d-AA)] (Λ-d) and Λ-[Ir(pq)2(l-AA)] (Λ-l, where pq is 2-phenylquinoline and AA is an amino acid) are reported in the presence of O2 under mild conditions. Diastereomer Λ-d is dehydrogenatively oxidized into an imino acid complex, while diastereomer Λ-l mainly occurs via interligand C-N cross-dehydrogenative coupling between quinoline at the C8 position and AA ligands at room temperature, affording Λ-[Ir(pq)(l-pq-AA)]. Furthermore, the photoreaction of diastereomer Λ-l is temperature-dependent. Mechanistic experiments reveal the ligand-radical intermediates may be involved in the reaction. Density functional theory calculations were used to eluciate the origin of diastereoselectivity and temperature dependence. This will provide a new protocol for the amination of quinoline at the C8 position via the postcoordinated interligand C-N cross-coupling strategy under mild conditions.
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Affiliation(s)
- He-Long Peng
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Yinwu Li
- School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Xing-Yang Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Li-Ping Li
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Zhuofeng Ke
- School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Bao-Hui Ye
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
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47
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Ni Y, Wan X, Zuo H, Bashir MA, Liu Y, Yu H, Liao RZ, Wu G, Zhong F. Iron-catalyzed cross-dehydrogenative C–H amidation of benzofurans and benzothiophenes with anilines. Org Chem Front 2021. [DOI: 10.1039/d0qo01651a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An efficient iron-catalyzed radical cross-dehydrogenative aromatic C–H amidation provides a straightforward access to structurally diverse diarylamine derivatives incorporating benzofuran/benzothiophene motifs.
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Affiliation(s)
- Yang Ni
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Xiang Wan
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Honghua Zuo
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Muhammad Adnan Bashir
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Yu Liu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Huaibin Yu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Guojiao Wu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
| | - Fangrui Zhong
- Key Laboratory of Material Chemistry for Energy Conversion and Storage
- Ministry of Education
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology (HUST)
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48
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Cannalire R, Pelliccia S, Sancineto L, Novellino E, Tron GC, Giustiniano M. Visible light photocatalysis in the late-stage functionalization of pharmaceutically relevant compounds. Chem Soc Rev 2020; 50:766-897. [PMID: 33350402 DOI: 10.1039/d0cs00493f] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The late stage functionalization (LSF) of complex biorelevant compounds is a powerful tool to speed up the identification of structure-activity relationships (SARs) and to optimize ADME profiles. To this end, visible-light photocatalysis offers unique opportunities to achieve smooth and clean functionalization of drugs by unlocking site-specific reactivities under generally mild reaction conditions. This review offers a critical assessment of current literature, pointing out the recent developments in the field while emphasizing the expected future progress and potential applications. Along with paragraphs discussing the visible-light photocatalytic synthetic protocols so far available for LSF of drugs and drug candidates, useful and readily accessible synoptic tables of such transformations, divided by functional groups, will be provided, thus enabling a useful, fast, and easy reference to them.
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Affiliation(s)
- Rolando Cannalire
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy.
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49
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Lim Y, Kuang Y, Wu J, Yao SQ. Late‐Stage C(sp
2
)−H Functionalization: A Powerful Toolkit To Arm Natural Products for In Situ Proteome Profiling? Chemistry 2020; 27:3575-3580. [DOI: 10.1002/chem.202004373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/04/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Ying‐Jie Lim
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Yulong Kuang
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Jie Wu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Shao Q. Yao
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
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Varun BV, Vaithegi K, Yi S, Park SB. Nature-inspired remodeling of (aza)indoles to meta-aminoaryl nicotinates for late-stage conjugation of vitamin B 3 to (hetero)arylamines. Nat Commun 2020; 11:6308. [PMID: 33298909 PMCID: PMC7726565 DOI: 10.1038/s41467-020-19610-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/14/2020] [Indexed: 12/16/2022] Open
Abstract
Despite the availability of numerous routes to substituted nicotinates based on the Bohlmann–Rahtz pyridine synthesis, the existing methods have several limitations, such as the inevitable ortho-substitutions and the inability to conjugate vitamin B3 to other pharmaceutical agents. Inspired by the biosynthesis of nicotinic acid (a form of vitamin B3) from tryptophan, we herein report the development of a strategy for the synthesis of meta-aminoaryl nicotinates from 3-formyl(aza)indoles. Our strategy is mechanistically different from the reported routes and involves the transformation of (aza)indole scaffolds into substituted meta-aminobiaryl scaffolds via Aldol-type addition and intramolecular cyclization followed by C–N bond cleavage and re-aromatization. Unlike previous synthetic routes, this biomimetic method utilizes propiolates as enamine precursors and thus allows access to ortho-unsubstituted nicotinates. In addition, the synthetic feasibility toward the halo-/boronic ester-substituted aminobiaryls clearly differentiates the present strategy from other cross-coupling strategies. Most importantly, our method enables the late-stage conjugation of bioactive (hetero)arylamines with nicotinates and nicotinamides and allows access to the previously unexplored chemical space for biomedical research. Vitamin B3 derivatives display a range of biological activities. Here, the authors report the synthesis of meta-aminoaryl nicotinates, derivatives of vitamin B3, and their late-stage conjugation with (hetero)arylamines, ultimately expanding the chemical space for biomedical research.
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Affiliation(s)
- Begur Vasanthkumar Varun
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kannan Vaithegi
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sihyeong Yi
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seung Bum Park
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
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