1
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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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2
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Liu Y, Li X, Pu Q, Fu R, Wang Z, Li Y, Li X. Innovative screening for functional improved aromatic amine derivatives: Toxicokinetics, free radical oxidation pathway and carcinogenic adverse outcome pathway. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131541. [PMID: 37146326 DOI: 10.1016/j.jhazmat.2023.131541] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/08/2023] [Accepted: 04/28/2023] [Indexed: 05/07/2023]
Abstract
Aromatic amines, one of the most widely used low-cost antioxidants in rubbers, have been regarded as pollutants with human health concerns. To overcome this problem, this study developed a systematic molecular design, screening, and performance evaluation method to design functionally improved, environmentally friendly and synthesizable aromatic amine alternatives for the first time. Nine of 33 designed aromatic amine derivatives have improved antioxidant property (lower bond dissociation energy of N-H), and their environmental and bladder carcinogenicity impacts were evaluated through toxicokinetic model and molecular dynamics simulation. The environmental fate of the designed AAs-11-8, AAs-11-16, and AAs-12-2 after antioxidation (i.e., peroxyl radicals (ROO·), hydroxyl radicals (HO·), superoxide anion radicals (O2·-) and ozonation reaction) was also analyzed. Results showed that the by-products of AAs-11-8 and AAs-12-2 have less toxicity after antioxidation. In addition, human bladder carcinogenicity of the screened alternatives was also evaluated through adverse outcome pathway. The carcinogenic mechanisms were analyzed and verified through amino acid residue distribution characteristics, 3D-QSAR and 2D-QSAR models. AAs-12-2, with high antioxidation property, low environmental impacts and carcinogenicity, was screened as the optimum alternative for 3,5-Dimethylbenzenamine. This study provided theoretical support for designing environmentally friendly and functionally improved aromatic amine alternatives from toxicity evaluation and mechanism analysis.
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Affiliation(s)
- Yajing Liu
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Xinao Li
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Qikun Pu
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Rui Fu
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Zhonghe Wang
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Yu Li
- MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing 102206, China
| | - Xixi Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL A1B 3X5, Canada.
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3
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Zhou J, Zhao Z, Shibata N. Transition-metal-free silylboronate-mediated cross-couplings of organic fluorides with amines. Nat Commun 2023; 14:1847. [PMID: 37012229 PMCID: PMC10070422 DOI: 10.1038/s41467-023-37466-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
C-N bond cross-couplings are fundamental in the field of organic chemistry. Herein, silylboronate-mediated selective defluorinative cross-coupling of organic fluorides with secondary amines via a transition-metal-free strategy is disclosed. The cooperation of silylboronate and potassium tert-butoxide enables the room-temperature cross-coupling of C-F and N-H bonds, effectively avoiding the high barriers associated with thermally induced SN2 or SN1 amination. The significant advantage of this transformation is the selective activation of the C-F bond of the organic fluoride by silylboronate without affecting potentially cleavable C-O, C-Cl, heteroaryl C-H, or C-N bonds and CF3 groups. Tertiary amines with aromatic, heteroaromatic, and/or aliphatic groups were efficiently synthesized in a single step using electronically and sterically varying organic fluorides and N-alkylanilines or secondary amines. The protocol is extended to the late-stage syntheses of drug candidates, including their deuterium-labeled analogs.
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Affiliation(s)
- Jun Zhou
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan
| | - Zhengyu Zhao
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan
| | - Norio Shibata
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
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4
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Sen PP, Roy SR. Introducing Phenalenyl-Based Organic Lewis Acid as a Photocatalyst to Facilitate Oxidative Azolation of Unactivated Arenes. Org Lett 2023; 25:1895-1900. [PMID: 36892632 DOI: 10.1021/acs.orglett.3c00409] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
By revealing the robust photooxidant properties of phenalenyl-based organic Lewis acid, we have introduced this moiety as an effective organophotocatalyst for the oxidative azolation of unactivated and feedstock arenes. In addition to its tolerance for various functional groups and scalability, this photocatalyst was shown to be promising for the defluorinative azolation of fluoroarenes.
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Affiliation(s)
- Partha Pratim Sen
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Sudipta Raha Roy
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
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5
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Previti S, Ettari R, Di Chio C, Ravichandran R, Bogacz M, Hellmich UA, Schirmeister T, Cosconati S, Zappalà M. Development of Reduced Peptide Bond Pseudopeptide Michael Acceptors for the Treatment of Human African Trypanosomiasis. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123765. [PMID: 35744891 PMCID: PMC9229991 DOI: 10.3390/molecules27123765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/27/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022]
Abstract
Human African Trypanosomiasis (HAT) is an endemic protozoan disease widespread in the sub-Saharan region that is caused by T. b. gambiense and T. b. rhodesiense. The development of molecules targeting rhodesain, the main cysteine protease of T. b. rhodesiense, has led to a panel of inhibitors endowed with micro/sub-micromolar activity towards the protozoa. However, whilst impressive binding affinity against rhodesain has been observed, the limited selectivity towards the target still remains a hard challenge for the development of antitrypanosomal agents. In this paper, we report the synthesis, biological evaluation, as well as docking studies of a series of reduced peptide bond pseudopeptide Michael acceptors (SPR10–SPR19) as potential anti-HAT agents. The new molecules show Ki values in the low-micro/sub-micromolar range against rhodesain, coupled with k2nd values between 1314 and 6950 M−1 min−1. With a few exceptions, an appreciable selectivity over human cathepsin L was observed. In in vitro assays against T. b. brucei cultures, SPR16 and SPR18 exhibited single-digit micromolar activity against the protozoa, comparable to those reported for very potent rhodesain inhibitors, while no significant cytotoxicity up to 70 µM towards mammalian cells was observed. The discrepancy between rhodesain inhibition and the antitrypanosomal effect could suggest additional mechanisms of action. The biological characterization of peptide inhibitor SPR34 highlights the essential role played by the reduced bond for the antitrypanosomal effect. Overall, this series of molecules could represent the starting point for further investigations of reduced peptide bond-containing analogs as potential anti-HAT agents
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Affiliation(s)
- Santo Previti
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Stagno d’Alcontres 31, 98166 Messina, Italy; (R.E.); (C.D.C.)
- Correspondence: (S.P.); (M.Z.); Tel.: +39-090-676-6411 (M.Z.)
| | - Roberta Ettari
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Stagno d’Alcontres 31, 98166 Messina, Italy; (R.E.); (C.D.C.)
| | - Carla Di Chio
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Stagno d’Alcontres 31, 98166 Messina, Italy; (R.E.); (C.D.C.)
- Department of Clinical and Experimental Medicine, University of Messina, Via C. Valeria, 98125 Messina, Italy
| | - Rahul Ravichandran
- DiSTABiF, University of Campania Luigi Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy; (R.R.); (S.C.)
| | - Marta Bogacz
- Institute of Organic Chemistry & Macromolecular Chemistry, Friedrich-Schiller-University of Jena, Humboldtstraße 10, 07743 Jena, Germany; (M.B.); (U.A.H.)
| | - Ute A. Hellmich
- Institute of Organic Chemistry & Macromolecular Chemistry, Friedrich-Schiller-University of Jena, Humboldtstraße 10, 07743 Jena, Germany; (M.B.); (U.A.H.)
- Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Tanja Schirmeister
- Institute of Pharmaceutical and Biomedical Sciences, University of Mainz, Staudingerweg 5, 55128 Mainz, Germany;
| | - Sandro Cosconati
- DiSTABiF, University of Campania Luigi Vanvitelli, Via Vivaldi 43, 81100 Caserta, Italy; (R.R.); (S.C.)
| | - Maria Zappalà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Stagno d’Alcontres 31, 98166 Messina, Italy; (R.E.); (C.D.C.)
- Correspondence: (S.P.); (M.Z.); Tel.: +39-090-676-6411 (M.Z.)
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6
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Jati A, Dey K, Nurhuda M, Addicoat MA, Banerjee R, Maji B. Dual Metalation in a Two-Dimensional Covalent Organic Framework for Photocatalytic C-N Cross-Coupling Reactions. J Am Chem Soc 2022; 144:7822-7833. [PMID: 35446576 DOI: 10.1021/jacs.2c01814] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Covalent organic frameworks (COFs) are promising hosts in heterogeneous catalysis. Herein, we report a dual metalation strategy in a single two-dimensional-COF TpBpy for performing a variety of C-N cross-coupling reactions. [Ir(ppy)2(CH3CN)2]PF6 [ppy = 2-phenylpyridine], containing two labile CH3CN groups, and NiCl2 are used as iridium and nickel-metal precursors, respectively, for postsynthetic decoration of the TpBpy COF. Moving from the traditional approach, we focus on the COF-backbone host for visible-light-mediated nickel-catalyzed C-N coupling reactions. The controlled metalation and recyclability without deactivation of both catalytic centers are unique with respect to previously reported coupling strategies. We performed various photoluminescence, electrochemical, kinetic, and Hammett correlation studies to understand the salient features of the catalyst and reaction mechanism. Furthermore, theoretical calculations delineated the feasibility of electron transfer from the Ir center to the Ni center inside the confined pore of the TpBpy COF. The dual metal anchoring within the COF backbone prevented nickel-black formation. The developed protocol enables selective and reproducible coupling of a diverse range of amines (aryl, heteroaryl, and alkyl), carbamides, and sulfonamides with electron-rich, neutral, and poor (hetero) aryl iodides up to 94% isolated yield. The reaction can also be performed on a gram scale. Furthermore, to establish the practical implementation of this approach, we have applied the synthetic strategy for the late-stage diversification of the derivatives of ibuprofen, naproxen, gemfibrozil, helional, and amino acids. The methodology could also be applied to synthesize pharmacophore N,5-diphenyloxazol-2-amine and Food and Drug Administration-approved drugs, including flufenamic acid, flibanserin, and tripelennamine.
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Affiliation(s)
- Ayan Jati
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Kaushik Dey
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India.,Centre for Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Maryam Nurhuda
- School of Science and Technology, Nottingham Trent University, Clifton Lane, NG11 8NS Nottingham, U.K
| | - Matthew A Addicoat
- School of Science and Technology, Nottingham Trent University, Clifton Lane, NG11 8NS Nottingham, U.K
| | - Rahul Banerjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India.,Centre for Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Biplab Maji
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
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7
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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: 123] [Impact Index Per Article: 61.5] [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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8
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Dou Q, Wang T, Cheng B, Li CJ, Zeng H. Recent advances in photochemical construction of aromatic C–P bonds via C–hetero bond cleavage. Org Biomol Chem 2022; 20:8818-8832. [DOI: 10.1039/d2ob01524b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photochemical C–P bond cross-coupling in aromatics via C–X (X = F, Cl, Br, I), C–N bond and C–O bond cleavages with/without photosensitizer were summarized in this review.
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Affiliation(s)
- Qian Dou
- Institute of Marine Biomedicine/Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, Shenzhen 518055, China
- The State Key Laboratory of Applied Organic Chemistry, and College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Road, Lanzhou, 730000, China
| | - Taimin Wang
- Institute of Marine Biomedicine/Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Bin Cheng
- Institute of Marine Biomedicine/Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Chao-Jun Li
- Department of Chemistry, and FQRNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke St West, Montreal, Quebec H3A 0B8, Canada
| | - Huiying Zeng
- The State Key Laboratory of Applied Organic Chemistry, and College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Road, Lanzhou, 730000, China
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9
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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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10
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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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11
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Lasso JD, Castillo-Pazos DJ, Li CJ. Green chemistry meets medicinal chemistry: a perspective on modern metal-free late-stage functionalization reactions. Chem Soc Rev 2021; 50:10955-10982. [PMID: 34382989 DOI: 10.1039/d1cs00380a] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The progress of drug discovery and development is paced by milestones reached in organic synthesis. In the last decade, the advent of late-stage functionalization (LSF) reactions has represented a valuable breakthrough. Recent literature has defined these reactions as the chemoselective modification of complex molecules by means of C-H functionalization or the manipulation of endogenous functional groups. Traditionally, these diversifications have been accomplished by organometallic means. However, the presence of metals carries disadvantages related to their cost, environmental hazard and health risks. Fundamentally, green chemistry directives can help minimize such hazards through the development of metal-free LSF methodologies. In this review, we expand the current discussion on metal-free LSF reactions by providing an overview of C(sp2)-H, and C(sp3)-H functionalizations, as well as the utilization of heteroatom-containing functional groups as chemical handles. Selected topics such as metal-free cross-dehydrogenative coupling (CDC) reactions, organocatalysis, electrochemistry and photochemistry are also discussed. By writing the first review on metal-free LSF methodologies, we aim to highlight current advances in the field with examples that reveal specific challenges and solutions, as well as future research opportunities.
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Affiliation(s)
- Juan D Lasso
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke St. W., Montreal, Quebec H3A 0B8, Canada.
| | - Durbis J Castillo-Pazos
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke St. W., Montreal, Quebec H3A 0B8, Canada.
| | - Chao-Jun Li
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke St. W., Montreal, Quebec H3A 0B8, Canada.
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12
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Mantell MA, Lasky MR, Lee M, Remy M, Sanford MS. S NAr and C-H Amination of Electron Rich Arenes with Pyridine as a Nucleophile Using Photoredox Catalysis. Org Lett 2021; 23:5213-5217. [PMID: 34161730 DOI: 10.1021/acs.orglett.1c01749] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This report describes the development of two photocatalytic methods for the pyridination of electron rich arenes. First, an SNAr-type reaction between aryl halides and pyridine is developed and optimized. This transformation affords selective substitution of C(sp2)-halogen over C(sp2)-OR bonds to afford arylpyridinium products under anaerobic conditions. Under complementary aerobic conditions, analogous substrates are shown to undergo oxidative C(sp2)-H pyridination.
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Affiliation(s)
- Mark A Mantell
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew R Lasky
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melissa Lee
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew Remy
- Corporate R&D, Dow, 1710 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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13
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Pistritto VA, Schutzbach-Horton ME, Nicewicz DA. Nucleophilic Aromatic Substitution of Unactivated Fluoroarenes Enabled by Organic Photoredox Catalysis. J Am Chem Soc 2020; 142:17187-17194. [PMID: 32986412 PMCID: PMC7720250 DOI: 10.1021/jacs.0c09296] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Nucleophilic aromatic substitution (SNAr) is a classical reaction with well-known reactivity toward electron-poor fluoroarenes. However, electron-neutral and electron-rich fluoro(hetero)arenes are considerably underrepresented. Herein, we present a method for the nucleophilic defluorination of unactivated fluoroarenes enabled by cation radical-accelerated nucleophilic aromatic substitution. The use of organic photoredox catalysis renders this method operationally simple under mild conditions and is amenable to various nucleophile classes, including azoles, amines, and carboxylic acids. Select fluorinated heterocycles can be functionalized using this method. In addition, the late-stage functionalization of pharmaceuticals is also presented. Computational studies demonstrate that the site selectivity of the reaction is dictated by arene electronics.
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Affiliation(s)
- Vincent A Pistritto
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Megan E Schutzbach-Horton
- 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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