1
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Danopoulou M, Zorba LP, Karantoni AP, Tzeli D, Vougioukalakis GC. Copper-Catalyzed α-Alkylation of Aryl Acetonitriles with Benzyl Alcohols. J Org Chem 2024; 89:14242-14254. [PMID: 39292689 PMCID: PMC11459520 DOI: 10.1021/acs.joc.4c01662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 08/26/2024] [Accepted: 09/11/2024] [Indexed: 09/20/2024]
Abstract
A highly efficient, in situ formed CuCl2/TMEDA catalytic system (TMEDA = N,N,N',N'-tetramethylethylene-diamine) for the cross-coupling reaction of aryl acetonitriles with benzyl alcohols is reported. This user-friendly protocol, employing a low catalyst loading and a catalytic amount of base, leads to the synthesis of α-alkylated nitriles in up to 99% yield. Experimental mechanistic investigations reveal that the key step of this transformation is the C(sp3)-H functionalization of the alcohol, taking place via a hydrogen atom abstraction, with the simultaneous formation of copper-hydride species. Detailed density functional theory studies shed light on all reaction steps, confirming the catalytic pathway proposed on the basis of the experimental findings.
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Affiliation(s)
- Marianna Danopoulou
- Laboratory
of Organic Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Leandros P. Zorba
- Laboratory
of Organic Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Athanasia P. Karantoni
- Laboratory
of Physical Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Demeter Tzeli
- Laboratory
of Physical Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis, 15771 Athens, Greece
- Theoretical
and Physical Chemistry Institute, National
Hellenic Research Foundation, Vas. Constantinou, 48, 11635 Athens, Greece
| | - Georgios C. Vougioukalakis
- Laboratory
of Organic Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis, 15771 Athens, Greece
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2
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Khan J, Taneja N, Yadav N, Hazra CK. Silane-mediated, facile C-H and N-H methylation using formaldehyde. Chem Commun (Camb) 2024; 60:11367-11370. [PMID: 39308363 DOI: 10.1039/d4cc03976a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2024]
Abstract
The use of (para)-formaldehyde for the methylation/alkylation of C(sp2)-H and N-H bonds, utilizing a combination of silane and hexafluoroisopropanol (HFIP) as activators, is reported. Overcoming the complexity of C(sp2)-H methylation on aryl and indole substrates, the process utilizes a Friedel-Crafts alkylation, followed by silane as a hydride donor, under a mild acidic medium. The method has been employed for the synthesis of the antifungal drug butenafine and a derivative of the non-steroidal anti-inflammatory drug (NSAID) flurbiprofen.
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Affiliation(s)
- Jabir Khan
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - Neha Taneja
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - Naveen Yadav
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - Chinmoy Kumar Hazra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
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3
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Romano C, Martin R. Ni-catalysed remote C(sp 3)-H functionalization using chain-walking strategies. Nat Rev Chem 2024:10.1038/s41570-024-00649-4. [PMID: 39354168 DOI: 10.1038/s41570-024-00649-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2024] [Indexed: 10/03/2024]
Abstract
The dynamic translocation of a metal catalyst along an alkyl side chain - often coined as 'chain-walking' - has opened new retrosynthetic possibilities that enable functionalization at unactivated C(sp3)-H sites. The use of nickel complexes in chain-walking strategies has recently gained considerable momentum owing to their versatility for forging sp3 architectures and their redox promiscuity that facilitates both one-electron or two-electron reaction manifolds. This Review discusses the relevance and impact that these processes might have in synthetic endeavours, including mechanistic considerations when appropriate. Particular emphasis is given to the latest discoveries that leverage the potential of Ni-catalysed chain-walking scenarios for tackling transformations that would otherwise be difficult to accomplish, including the merger of chain-walking with other new approaches such as photoredox catalysis or electrochemical activation.
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Affiliation(s)
- Ciro Romano
- Department of Chemistry, University of Manchester, Manchester, UK.
- Institute of Chemical Research of Catalonia (ICIQ), Tarragona, Spain.
| | - Ruben Martin
- Institute of Chemical Research of Catalonia (ICIQ), Tarragona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
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4
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Wright BA, Sarpong R. Molecular complexity as a driving force for the advancement of organic synthesis. Nat Rev Chem 2024; 8:776-792. [PMID: 39251714 DOI: 10.1038/s41570-024-00645-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2024] [Indexed: 09/11/2024]
Abstract
The generation of molecular complexity is a primary goal in the field of synthetic chemistry. In the context of retrosynthetic analysis, the concept of molecular complexity is central to identifying productive disconnections and the development of efficient total syntheses. However, this field-defining concept is frequently invoked on an intuitive basis without precise definition or appreciation of its subtleties. Methods for quantifying molecular complexity could prove useful for characterizing the state of synthesis in a more rigorous, reliable and reproducible fashion. As a first step to evaluating the importance of these methods to the state of the field, here we present our perspective on the development of molecular complexity quantification and its implications for chemical synthesis. The extension and application of these methods beyond computer-aided synthesis planning and medicinal chemistry to the traditional practice of 'complex molecule' synthesis could have the potential to unearth new opportunities and more efficient approaches for synthesis.
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Affiliation(s)
- Brandon A Wright
- Department of Chemistry, University of California, Berkeley, USA
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, USA.
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5
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Zhan YF, Chen JM, Sheng XX, Qiu CY, Jiang Y, Yang S, Chen M. Photoinduced copper catalyzed nitrogen-to-alkyl radical relay Sonogashira-type coupling of o-alkylbenzamides with alkynes. Chem Commun (Camb) 2024; 60:7906-7909. [PMID: 38979947 DOI: 10.1039/d4cc02861a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
This report describes a copper-catalyzed, photoinduced N-to-alkyl radical relay Sonogashira-type reactions at benzylic sites in o-alkylbenzamides with alkynes. The process employs an N-to-alkyl radical mechanism, initiated through the copper-catalyzed reductive generation of nitrogen radicals. Radical translocation is facilitated by a 1,5-hydrogen atom transfer (1,5-HAT), leading to the formation of translocated carbon radicals. These radicals are then subjected to copper-catalyzed alkynylation. The methodology exhibits broad sub-strate scope and applicability to the synthesis of complex natural products.
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Affiliation(s)
- Yan-Fang Zhan
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Jia-Ming Chen
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Xia-Xin Sheng
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Chao-Ying Qiu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Yan Jiang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Sen Yang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
| | - Ming Chen
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Chang-zhou University, Changzhou, 213164, China.
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6
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Mondal M, Ghosh S, Lai D, Hajra A. C-H Functionalization of Heteroarenes via Electron Donor-Acceptor Complex Photoactivation. CHEMSUSCHEM 2024:e202401114. [PMID: 38975970 DOI: 10.1002/cssc.202401114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/09/2024]
Abstract
C-H Functionalization of heteroarenes stands as a potent instrument in organic synthesis, and with the incorporation of visible light, it emerged as a transformative game-changer. In this domain, electron donor-acceptor (EDA) complex, formed through the pairing of an electron-rich substrate with an electron-accepting molecule, has garnered substantial consideration in recent years due to the related avoidance of the requirement of photocatalyst as well as oxidant. EDA complexes can undergo photoactivation under mild conditions and exhibit high functional group tolerance, making them potentially suitable for the functionalization of biologically relevant heteroarenes. This review article provides an overview of recent advancements in the field of C-H functionalization of heteroarenes via EDA complex photoactivation with literature coverage up to April, 2024.
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Affiliation(s)
- Madhusudan Mondal
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, India
| | - Sumit Ghosh
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, India
| | - Dipti Lai
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, India
| | - Alakananda Hajra
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, India
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7
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Sakai D, Kojima T, Kawasaki-Takasuka T, Mori K. Stereoselective synthesis of 6/7/6-fused heterocycles with multiple stereocenters via an internal redox reaction/inverse electron-demand hetero-Diels-Alder reaction sequence. Chem Commun (Camb) 2024; 60:6797-6800. [PMID: 38869043 DOI: 10.1039/d4cc02351j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
A highly stereoselective synthesis of fused heterocycles with multiple stereocenters via an internal redox reaction/inverse electron-demand hetero-Diels-Alder (IEDHDA) reaction sequence is described. The present reaction sequence has three interesting features: (1) complete control of two potentially competitive processes, i.e., hetero-Diels-Alder reaction and [1,5]-hydride shift; (2) one-shot construction of the complicated 6/7/6-fused heterocyclic structure having multiple stereocenters; and (3) high control of its stereoselectivity. When alkenylidene barbiturates with an allyl benzyl ether moiety were treated with a catalytic amount of Sc(OTf)3 and 2,2'-bipyridine, the internal redox reaction/IEDHDA reaction proceeded successively to afford 6/7/6-fused heterocycles in good chemical yields with good to excellent diastereoselectivities.
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Affiliation(s)
- Dan Sakai
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
| | - Tatsuhiro Kojima
- Department of Applied Chemistry, Kobe City College of Technology (KCCT), 8-3 Gakuen-Higashimachi, Nishi-ku, Kobe, Hyogo 651-2194, Japan
| | - Tomoko Kawasaki-Takasuka
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
| | - Keiji Mori
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
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8
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Dastari S, Murugappan S, John SE, Shankaraiah N. Microwave-Assisted Ru(II)-Catalyzed Regioselective Methyl Acylation of 2-Arylbenzoazoles: Synthesis of Benzofuran Conjugates via C-H Activation/Annulation. J Org Chem 2024; 89:7027-7035. [PMID: 38688712 DOI: 10.1021/acs.joc.4c00402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
An efficient Ru(II)-catalyzed C-H functionalization protocol for 2-arylbenzoazoles as the directing group and sulfoxonium ylide has been developed. Gratifyingly, concomitant annulation was observed when 3-(benzo[d]azol-2-yl) phenol was used, enabling the construction of benzofuran conjugates. Notably, the utilization of water as the solvent and an energy efficient approach makes the reaction greener, contributing to overall sustainability. This protocol exhibits excellent scalability up to the gram scale with a diverse array of substitutions. Furthermore, the mechanism was examined by ESI-MS, and photophysical studies were also performed.
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Affiliation(s)
- Sowmya Dastari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India
| | - Solai Murugappan
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India
| | - Stephy Elza John
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India
| | - Nagula Shankaraiah
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India
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9
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Pati TK, Molla SA, Ghosh NN, Kundu M, Ajarul S, Maity P, Khamrai U, Maiti DK. 2-Pyridone-Directed Cu II-Catalyzed General Method of C(sp 2)-H Activation for C-S, C-Se, and C-N Cross-Coupling: Easy Access to Aryl Thioethers, Selenide Ethers, and Sulfonamides and DFT Study. J Org Chem 2024; 89:6798-6812. [PMID: 38662434 DOI: 10.1021/acs.joc.4c00120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
We have demonstrated N-substituted 2-pyridones as an N,O-directing group for selective C(sp2)-H-activated thiolation, selenylation, and sulfonamidation of ortho C-H bonds of benzamides. This method utilizes a cost-effective Cu(II)-salt catalyst instead of precious metal catalysts, achieving high yields, including gram-scale synthesis and excellent functional group tolerance. We applied this protocol to access 30 different compounds with high yields, demonstrating thiolation of fluorine-substituted benzamides as well. Density functional theory (DFT) calculations support the mechanism, including acetate-supported concerted metalation deprotonation (CMD) steps and the unique role of dimethyl sulfoxide (DMSO) solvent. The facile synthesis of pharmaceutically important sulfonamides and other compounds highlights the method's potential in chemistry and medicinal chemistry.
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Affiliation(s)
- Tanmay K Pati
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata700009, India
- Department of Chemistry, Rensselaer Polytechnic Institute, 110 eighth St, Troy, New York 12180, United States
- TCG Lifesciences Private Limited, Sector V, Salt Lake City, Kolkata 700091, India
| | - Sabir Ali Molla
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata700009, India
| | | | - Mrinalkanti Kundu
- TCG Lifesciences Private Limited, Sector V, Salt Lake City, Kolkata 700091, India
| | - Sk Ajarul
- Government General Degree College at Salboni, Bhimpur, Paschim Medinipur 721516, India
| | - Pradip Maity
- Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Uttam Khamrai
- TCG Lifesciences Private Limited, Sector V, Salt Lake City, Kolkata 700091, India
| | - Dilip K Maiti
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata700009, India
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10
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Kunz S, Barnå F, Urrutia MP, Ingner FJL, Martínez-Topete A, Orthaber A, Gates PJ, Pilarski LT, Dyrager C. Derivatization of 2,1,3-Benzothiadiazole via Regioselective C-H Functionalization and Aryne Reactivity. J Org Chem 2024; 89:6138-6148. [PMID: 38648018 PMCID: PMC11077497 DOI: 10.1021/acs.joc.4c00122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/29/2024] [Accepted: 03/15/2024] [Indexed: 04/25/2024]
Abstract
Despite growing interest in 2,1,3-benzothiadiazole (BTD) as an integral component of many functional molecules, methods for the functionalization of its benzenoid ring have remained limited, and many even simply decorated BTDs have required de novo synthesis. We show that regioselective Ir-catalyzed C-H borylation allows access to versatile 5-boryl or 4,6-diboryl BTD building blocks, which undergo functionalization at the C4, C5, C6, and C7 positions. The optimization and regioselectivity of C-H borylation are discussed. A broad reaction scope is presented, encompassing ipso substitution at the C-B bond, the first examples of ortho-directed C-H functionalization of BTD, ring closing reactions to generate fused ring systems, as well as the generation and capture reactions of novel BTD-based heteroarynes. The regioselectivity of the latter is discussed with reference to the Aryne Distortion Model.
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Affiliation(s)
- Susanna Kunz
- Department
of Chemistry—BMC, Uppsala University, Box 576, Uppsala 75123, Sweden
| | - Fredrik Barnå
- Department
of Chemistry—BMC, Uppsala University, Box 576, Uppsala 75123, Sweden
| | | | | | | | - Andreas Orthaber
- Department
of Chemistry—Ångström, Uppsala University, Box 523, Uppsala 75120, Sweden
| | - Paul J. Gates
- School
of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K.
| | - Lukasz T. Pilarski
- Department
of Chemistry—BMC, Uppsala University, Box 576, Uppsala 75123, Sweden
| | - Christine Dyrager
- Department
of Chemistry—BMC, Uppsala University, Box 576, Uppsala 75123, Sweden
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11
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Decembrino D, Cannella D. The thin line between monooxygenases and peroxygenases. P450s, UPOs, MMOs, and LPMOs: A brick to bridge fields of expertise. Biotechnol Adv 2024; 72:108321. [PMID: 38336187 DOI: 10.1016/j.biotechadv.2024.108321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/04/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Many scientific fields, although driven by similar purposes and dealing with similar technologies, often appear so isolated and far from each other that even the vocabularies to describe the very same phenomenon might differ. Concerning the vast field of biocatalysis, a special role is played by those redox enzymes that employ oxygen-based chemistry to unlock transformations otherwise possible only with metal-based catalysts. As such, greener chemical synthesis methods and environmentally-driven biotechnological approaches were enabled over the last decades by the use of several enzymes and ultimately resulted in the first industrial applications. Among what can be called today the environmental biorefinery sector, biomass transformation, greenhouse gas reduction, bio-gas/fuels production, bioremediation, as well as bulk or fine chemicals and even pharmaceuticals manufacturing are all examples of fields in which successful prototypes have been demonstrated employing redox enzymes. In this review we decided to focus on the most prominent enzymes (MMOs, LPMO, P450 and UPO) capable of overcoming the ∼100 kcal mol-1 barrier of inactivated CH bonds for the oxyfunctionalization of organic compounds. Harnessing the enormous potential that lies within these enzymes is of extreme value to develop sustainable industrial schemes and it is still deeply coveted by many within the aforementioned fields of application. Hence, the ambitious scope of this account is to bridge the current cutting-edge knowledge gathered upon each enzyme. By creating a broad comparison, scientists belonging to the different fields may find inspiration and might overcome obstacles already solved by the others. This work is organised in three major parts: a first section will be serving as an introduction to each one of the enzymes regarding their structural and activity diversity, whereas a second one will be encompassing the mechanistic aspects of their catalysis. In this regard, the machineries that lead to analogous catalytic outcomes are depicted, highlighting the major differences and similarities. Finally, a third section will be focusing on the elements that allow the oxyfunctionalization chemistry to occur by delivering redox equivalents to the enzyme by the action of diverse redox partners. Redox partners are often overlooked in comparison to the catalytic counterparts, yet they represent fundamental elements to better understand and further develop practical applications based on mono- and peroxygenases.
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Affiliation(s)
- Davide Decembrino
- Photobiocatalysis Unit - Crop Production and Biostimulation Lab (CPBL), and Biomass Transformation Lab (BTL), École Interfacultaire de Bioingénieurs, Université Libre de Bruxelles, Belgium.
| | - David Cannella
- Photobiocatalysis Unit - Crop Production and Biostimulation Lab (CPBL), and Biomass Transformation Lab (BTL), École Interfacultaire de Bioingénieurs, Université Libre de Bruxelles, Belgium.
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12
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Pilli R, Selvam K, Balamurugan BSS, Jose V, Rasappan R. C(sp 3)-C(sp 3) Coupling of Cycloalkanes and Alkyl Halides via Dual Photocatalytic Hydrogen Atom Transfer and Nickel Catalysis. Org Lett 2024; 26:2993-2998. [PMID: 38592728 DOI: 10.1021/acs.orglett.4c00567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Functionalization of C(sp3)-H bonds represents the most straightforward and atom-economical transformation in organic synthesis. An innovative approach integrating photocatalytic hydrogen atom transfer (HAT) and transition metal catalysis has made significant progress in the coupling of α-heterosubstituted C-H bonds with alkyl halides. However, unactivated alkanes were ineffective as a result of the preponderance of byproduct formation. Herein, we demonstrate direct HAT and nickel catalysis in the coupling of cycloalkanes and benzyl bromides/primary alkyl iodides. Additionally, tetrabutylammonium decatungstate (TBADT) was recovered and recycled.
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Affiliation(s)
- Ramadevi Pilli
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Keerthika Selvam
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Bala S S Balamurugan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Vidya Jose
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Ramesh Rasappan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
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13
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Rani P, Chahal S, Singh R, Sindhu J. Pushing Boundaries: What's Next in Metal-Free C-H Functionalization for Sulfenylation? Top Curr Chem (Cham) 2024; 382:13. [PMID: 38607428 DOI: 10.1007/s41061-024-00460-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/15/2024] [Indexed: 04/13/2024]
Abstract
The synthesis of thioether derivatives has been explored widely due to the potential application of these derivatives in medicinal chemistry, pharmaceutical industry and material chemistry. Within this context, there has been an increasing demand for the environmentally benign construction of C-S bonds via C-H functionalization under metal-free conditions. In the present article, we highlight recent developments in metal-free sulfenylation that have occurred in the past three years. The synthesis of organosulfur compounds via a metal-free approach using a variety of sulfur sources, including thiophenols, disulfides, sulfonyl hydrazides, sulfonyl chlorides, elemental sulfur and sulfinates, is discussed. Non-conventional strategies, which refer to the development of thioether derivatives under visible light and electrochemically mediated conditions, are also discussed. The key advantages of the reviewed methodologies include broad substrate scope and high reaction yields under environmentally benign conditions. This comprehensive review will provide chemists with a synthetic tool that will facilitate further development in this field.
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Affiliation(s)
- Payal Rani
- Department of Chemistry, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar, Haryana, 125004, India
| | - Sandhya Chahal
- Department of Chemistry, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar, Haryana, 125004, India
| | - Rajvir Singh
- Department of Chemistry, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar, Haryana, 125004, India
| | - Jayant Sindhu
- Department of Chemistry, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar, Haryana, 125004, India.
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14
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Babu SA, A A, Mohan M, Paul N, Mathew J, John J. Tandem Reactions of Electrophilic Indoles toward Indolizines and Their Subsequent Transformations through Pd(II)-Mediated C-H Functionalization to Access Polyring-Fused N-Heterocycles. ACS OMEGA 2024; 9:16196-16206. [PMID: 38617644 PMCID: PMC11007710 DOI: 10.1021/acsomega.3c10194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/15/2024] [Accepted: 03/20/2024] [Indexed: 04/16/2024]
Abstract
A simple and efficient synthetic approach for generating a library of structurally novel indolizines has been developed via sequential 1,3-dipolar cycloaddition-ring opening processes. Using this methodology, a series of indolizines bearing different substituents were made in moderate to good yields. The presence of two functionalizable C-H bonds in these indolizine motifs makes them attractive for accessing fused indolizine scaffolds. In this line, we have introduced palladium-mediated site-selective C-H functionalizations, where the N-center and the two C-H centers of the indolizine moiety can be readily functionalized to generate fused N-heterocycles. Utilizing a Pd-mediated dual C-H activation of 5-benzoyl-substituted indolizine afforded 6H-indeno-indolizine, and a tetracene, viz., indolizino[2,1-b]indoles, was produced in the same substrate by the Pd-catalyzed selective C-H amination in the presence of oxygen.
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Affiliation(s)
- Sheba Ann Babu
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Aparna A
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Malavika Mohan
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Namitha Paul
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Jomon Mathew
- Research
and Post-Graduate Department of Chemistry, St. Joseph’s College, Devagiri, Calicut 673008, India
| | - Jubi John
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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15
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Koyama R, Anada M, Sueki S, Makino K, Kojima T, Kawasaki-Takasuka T, Mori K. Divergent synthesis of multi-substituted phenanthrenes via an internal redox reaction/ring expansion sequence. Chem Commun (Camb) 2024; 60:3822-3825. [PMID: 38497170 DOI: 10.1039/d4cc00797b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
We report an effective synthetic route to multi-substituted phenanthrenes via an internal redox reaction/ring expansion sequence. The interesting feature of the present system is that it allows for the divergent synthesis of the target skeleton depending on the selected Lewis acid catalyst. When benzylidene malonates with a cyclic structure at the ortho-position were treated with BF3·OEt2, three sequential processes (internal redox reaction/elimination of the alkoxy group/ring expansion) proceeded to give phenanthrene derivatives in which the alkoxycarbonyl (CO2R) group and the alkyl (R) group were in close proximity to each other, in good chemical yields. In sharp contrast, treatment with Bi(OTf)3 exclusively led to the formation of another type of phenanthrene, whose R group was positioned distal to the CO2R group.
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Affiliation(s)
- Ryosei Koyama
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
| | - Masahiro Anada
- Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
- Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Shunsuke Sueki
- Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
- Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Kosho Makino
- Faculty of Pharmacy, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
- Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Tatsuhiro Kojima
- Department of Applied Chemistry, Kobe City College of Technology (KCCT), 8-3 Gakuen-Higashimachi, Nishi-ku, Kobe, 651-2194, Japan
| | - Tomoko Kawasaki-Takasuka
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
| | - Keiji Mori
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
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16
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Nguyen TT, Bosse AT, Ly D, Suarez CA, Fu J, Shimabukuro K, Musaev DG, Davies HML. Diaryldiazoketones as Effective Carbene Sources for Highly Selective Rh(II)-Catalyzed Intermolecular C-H Functionalization. J Am Chem Soc 2024; 146:8447-8455. [PMID: 38478893 PMCID: PMC10979447 DOI: 10.1021/jacs.3c14552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 03/28/2024]
Abstract
A novel donor/acceptor carbene intermediate has been developed using diaryldiazoketones as carbene precursors. In the presence of the chiral dirhodium catalyst, Rh2(S-TPPTTL)4, diaryldiazoketones undergo highly regio-, stereo-, and diastereoselective C-H functionalization of activated and unactivated secondary and tertiary C-H bonds. Computational studies revealed that the arylketo group behaves differently than the carboxylate acceptor group because the orientation of the arylketo group predetermines which face of the carbene will be attacked.
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Affiliation(s)
| | | | - Duc Ly
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
| | - Camila A. Suarez
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
| | - Jiantao Fu
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
| | - Kristin Shimabukuro
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
| | | | - Huw M. L. Davies
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
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17
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Cheung-Lee WL, Kolev JN, McIntosh JA, Gil AA, Pan W, Xiao L, Velásquez JE, Gangam R, Winston MS, Li S, Abe K, Alwedi E, Dance ZEX, Fan H, Hiraga K, Kim J, Kosjek B, Le DN, Marzijarani NS, Mattern K, McMullen JP, Narsimhan K, Vikram A, Wang W, Yan JX, Yang RS, Zhang V, Zhong W, DiRocco DA, Morris WJ, Murphy GS, Maloney KM. Engineering Hydroxylase Activity, Selectivity, and Stability for a Scalable Concise Synthesis of a Key Intermediate to Belzutifan. Angew Chem Int Ed Engl 2024; 63:e202316133. [PMID: 38279624 DOI: 10.1002/anie.202316133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 01/28/2024]
Abstract
Biocatalytic oxidations are an emerging technology for selective C-H bond activation. While promising for a range of selective oxidations, practical use of enzymes catalyzing aerobic hydroxylation is presently limited by their substrate scope and stability under industrially relevant conditions. Here, we report the engineering and practical application of a non-heme iron and α-ketoglutarate-dependent dioxygenase for the direct stereo- and regio-selective hydroxylation of a non-native fluoroindanone en route to the oncology treatment belzutifan, replacing a five-step chemical synthesis with a direct enantioselective hydroxylation. Mechanistic studies indicated that formation of the desired product was limited by enzyme stability and product overoxidation, with these properties subsequently improved by directed evolution, yielding a biocatalyst capable of >15,000 total turnovers. Highlighting the industrial utility of this biocatalyst, the high-yielding, green, and efficient oxidation was demonstrated at kilogram scale for the synthesis of belzutifan.
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Affiliation(s)
| | - Joshua N Kolev
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - John A McIntosh
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Agnieszka A Gil
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Weilan Pan
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Li Xiao
- Modeling & Informatics, Discovery Chemistry, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Juan E Velásquez
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Rekha Gangam
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Matthew S Winston
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Shasha Li
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Kotoe Abe
- Chemical Commercialization Technologies, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Embarek Alwedi
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Zachary E X Dance
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Haiyang Fan
- API Process Research & Development (Biocatalysis), Shanghai STA Pharmaceutical Co., Ltd., Shanghai, 201507, China
| | - Kaori Hiraga
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Jungchul Kim
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Birgit Kosjek
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Diane N Le
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | | | - Keith Mattern
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | | | - Karthik Narsimhan
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Ajit Vikram
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Wei Wang
- API Process Research & Development (Biocatalysis), Shanghai STA Pharmaceutical Co., Ltd., Shanghai, 201507, China
| | - Jia-Xuan Yan
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Rong-Sheng Yang
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Victoria Zhang
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Wendy Zhong
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Daniel A DiRocco
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - William J Morris
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Grant S Murphy
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Kevin M Maloney
- Process Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
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18
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Amano K, Kawasaki-Takasuka T, Mori K. Synthesis of Polysubstituted Naphthalenes by a Hydride Shift Mediated C-H Bond Functionalization/Aromatization Sequence. Org Lett 2024; 26:1824-1827. [PMID: 38416568 DOI: 10.1021/acs.orglett.3c04355] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
A synthetic strategy for forming multisubstituted naphthalenes based on hydride shift mediated C(sp3)-H bond functionalization was developed. This strategy consists of three successive transformations: (1) an intramolecular hydride shift mediated C(sp3)-H bond functionalization; (2) a decarboxylative fragmentation; and (3) an oxidation reaction. When benzylidene malonates having a 2-alkoxyethyl group at the ortho position were treated with a catalytic amount of Al(OTf)3, the hydride shift/cyclization reaction proceeded smoothly to afford tetralin derivatives in good chemical yields. The resulting tetralins were easily converted into naphthalenes by exposing them to modified Krapcho decarboxylation reaction conditions (LiCl, DMSO, and heating under an O2 atmosphere). The one-pot operation of these two reactions was also realized.
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Affiliation(s)
- Koutarou Amano
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Tomoko Kawasaki-Takasuka
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Keiji Mori
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
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19
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Okawa H, Kawasaki-Takasuka T, Mori K. Silyl-Group Boosted Internal Redox Reaction: Hydride Shift from an Aliphatic Secondary Position for the Formation of Six- and Seven-Membered Carbocycles. Org Lett 2024; 26:1662-1666. [PMID: 38382544 DOI: 10.1021/acs.orglett.4c00140] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
We report a hydride shift/cyclization reaction at the aliphatic secondary position (methylene group). The key to accomplishing this reaction was the employment of benzylidene malonate having a silyl group β to the hydride donor carbon. When the corresponding malonates were treated with a catalytic amount of Al(OTf)3, the [1,5]-hydride shift from the simple aliphatic secondary position proceeded smoothly to afford silyl-group substituted tetralin derivatives in excellent chemical yields (up to 98%). This reaction system was applied to the formation of seven-membered carbocycles via the [1,6]-hydride shift mediated process.
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Affiliation(s)
- Hiroto Okawa
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Tomoko Kawasaki-Takasuka
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Keiji Mori
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
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20
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Nolasco-Hernández Á, Quintero L, Cruz-Gregorio S, Sartillo-Piscil F. β-Alkenylation of Saturated N-Heterocycles via a C(sp 3)-O Bond Wittig-like Olefination. J Org Chem 2024; 89:1762-1768. [PMID: 38215398 PMCID: PMC10845111 DOI: 10.1021/acs.joc.3c02466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/17/2023] [Accepted: 12/29/2023] [Indexed: 01/14/2024]
Abstract
Although the C-Hα functionalization of N-heterocycles is, in fact, an easy chemical transformation, the C-Hβ functionalization is, on the contrary, a quite difficult chemical process. Here, we present a two-step protocol that allows the ready conversion of pyrrolidines, piperidines, and an azepane into their corresponding 3-exo-alkenyl lactams via the transient formation of 3-alkoxyamino lactams followed by a Wittig-like C(sp3)-O bond olefination with stabilized ylides from phosphonium salts mediated by t-BuOK. Additionally, as a proof of the synthetic effectiveness of this novel methodology, the first synthesis of the natural product callylactam A was achieved through a TiCl4-catalyzed double bond isomerization of a 3-exo-alkenyl 2-piperidone to its endo-isomer.
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Affiliation(s)
- Ángel
A. Nolasco-Hernández
- Centro de Investigación
de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla (BUAP), 14 Sur Esq. San Claudio, Col. San
Manuel, 72570 Puebla, México
| | - Leticia Quintero
- Centro de Investigación
de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla (BUAP), 14 Sur Esq. San Claudio, Col. San
Manuel, 72570 Puebla, México
| | - Silvano Cruz-Gregorio
- Centro de Investigación
de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla (BUAP), 14 Sur Esq. San Claudio, Col. San
Manuel, 72570 Puebla, México
| | - Fernando Sartillo-Piscil
- Centro de Investigación
de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla (BUAP), 14 Sur Esq. San Claudio, Col. San
Manuel, 72570 Puebla, México
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21
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Pipaón Fernández N, Cruise O, Easton SEF, Kaplan JM, Woodard JL, Hruszkewycz DP, Leitch DC. Direct Heterocycle C-H Alkenylation via Dual Catalysis Using a Palladacycle Precatalyst: Multifactor Optimization and Scope Exploration Enabled by High-Throughput Experimentation. J Org Chem 2024. [PMID: 38206166 DOI: 10.1021/acs.joc.3c02311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
One of the major challenges in developing catalytic methods for C-C bond formation is the identification of generally applicable reaction conditions, particularly if multiple substrate structural classes are involved. Pd-catalyzed direct arylation reactions are powerful transformations that enable direct functionalization of C-H bonds; however, the corresponding direct alkenylation reactions, using vinyl (pseudo) halide electrophiles, are less well developed. Inspired by process development efforts toward GSK3368715, an investigational active pharmaceutical ingredient, we report that a Pd(II) palladacycle derived from tri-tert-butylphosphine and Pd(OAc)2 is an effective single-component precatalyst for a variety of direct alkenylation reactions. High-throughput experimentation identified optimal solvent/base combinations for a variety of HetAr-H substrate classes undergoing C-H activation without the need for cocatalysts or stoichiometric silver bases (e.g., Ag2CO3). We propose this reaction proceeds via a dual cooperative catalytic mechanism, where in situ-generated Pd(0) supports a canonical Pd(0)/(II) cross-coupling cycle and the palladacycle effects C-H activation via CMD in a redox-neutral cycle. In all, 192 substrate combinations were tested with a hit rate of approximately 40% and 24 isolated examples. Importantly, this method was applied to prepare a key intermediate in the synthesis of GSK3368715 on multigram scale.
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Affiliation(s)
- Nahiane Pipaón Fernández
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Odhran Cruise
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Sarah E F Easton
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
| | - Justin M Kaplan
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - John L Woodard
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Damian P Hruszkewycz
- Chemical Development, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - David C Leitch
- Department of Chemistry, University of Victoria, 3800 Finnerty Road., Victoria, Briish Columbia V8P 5C2, Canada
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22
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Odena C, Gómez-Bengoa E, Martin R. Ring Walking Mediated by Ni-Ni Species as a Vehicle for Enabling Distal C(sp 2)-H Functionalization of Aryl Pivalates. J Am Chem Soc 2024; 146:112-117. [PMID: 38153272 DOI: 10.1021/jacs.3c12497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Herein, we report the utilization of Ni-Ni species as a manifold for enabling a "ring-walking" event by dynamic translocation of the metal center over the arene backbone. Experimental and computational studies support a translocation occurring via a 1,2-hydride shift. The synthetic applicability of the method is illustrated in a series of C-C bond formations that occur at distal C(sp2)-H sites of simple aryl pivalates.
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Affiliation(s)
- Carlota Odena
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007 Tarragona, Spain
- Universitat Rovira i Virgili, Departament de Química Orgànica, c/Marcel·lí Domingo, 1, 43007 Tarragona, Spain
| | - Enrique Gómez-Bengoa
- Department of Organic Chemistry I, Universidad País Vasco, UPV/EHU, Apdo. 1072, 20080 San Sebastian, Spain
| | - Ruben Martin
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007 Tarragona, Spain
- ICREA, Passeig Lluís Companys, 23, 08010 Barcelona, Spain
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23
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Oh H, Kim I. Catalyst-free assembly of a polyfunctionalized 1,2,4-triazole-fused N-heterocycle, 6-acylated pyrrolo[1,2- a][1,2,4]triazolo[5,1- c]pyrazine. Org Biomol Chem 2024; 22:320-336. [PMID: 38063086 DOI: 10.1039/d3ob01747h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
A catalyst-free synthetic route to a new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was realized upon sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide through which acylated pyrazine and 1,2,4-triazole rings were consecutively formed with the formation of multiple bonds (one C-C bond and three C-N bonds). This annulative functionalization approach towards N-fused polycycles enabled us to install various substituents at specific positions on the core skeleton.
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Affiliation(s)
- Hyunjin Oh
- College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea.
| | - Ikyon Kim
- College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea.
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24
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Morozkov GV, Abel AS, Lyssenko KA, Roznyatovsky VA, Averin AD, Beletskaya IP, Bessmertnykh-Lemeune A. Ruthenium(II) complexes with phosphonate-substituted phenanthroline ligands as reusable photoredox catalysts. Dalton Trans 2024; 53:535-551. [PMID: 38053435 DOI: 10.1039/d3dt02936k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Ru(II) complexes with polypyridyl ligands (2,2'-bipyridine = bpy, 1,10-phenanthroline = phen) play a central role in the development of photocatalytic organic reactions. In this work, we synthesized four mixed-ligand [Ru(phen)(bpy)2]2+-type complexes (Ru-Pcat-A) bearing two phosphonate substituents P(O)(OH)(OR) (R = H, Et) attached to the phen core at positions 3,8 (Ru-3,8PH and Ru-3,8PHEt) and 4,7 (Ru-4,7PH and Ru-4,7PHEt) of the heterocycle in high yields (87-99%) and characterized them using spectral methods. Single crystal X-ray diffraction was employed to determine the coordination mode of the ditopic phen ligand in Ru-4,7PH. This complex exists as the neutral species and forms a 1D hydrogen-bonded framework in the crystals. The light absorption characteristics were found to be similar for all complexes prepared in this work. However, the emission maxima in aqueous solutions were significantly affected by the substitution of the heterocycle, ranging from 629 nm for Ru-4,7PH to 661 nm for Ru-3,8PHEt. The emission quantum yields in Ar-saturated deionized water showed a strong dependence on the substitution pattern of the phen ligand, with maximal values reaching approximately 0.11 for Ru-4,7PHEt and Ru-4,7PH, which is twice as high as that of the classical [Ru(bpy)3]2+ complex (Ru-bpy). The photocatalytic performance of Ru-Pcat-A was investigated using visible light photoredox catalytic transformations of tertiary amines. With Ru-Pcat-A, we achieved the phosphonylation of N-aryl-1,2,3,4-tetrahydroisoquinolines (THIQs) and cyanation of THIQs and N,N-dimethylaniline in methanol, while a mixture of nitromethane/methanol (1 : 1 v/v) proved to be the optimal solvent for conducting the nitromethylation of THIQs. In the majority of the studied reactions, Ru-4,7PHEt exhibited greater efficiency compared to Ru-bpy, and it could be easily separated from the products using water extraction and reused in the next catalytic cycle. We successfully performed seven consecutive nitromethylation and phosphonylation of N-phenyl-1,2,3,4-tetrahydroisoquinoline using the recycled homogeneous photoredox catalyst.
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Affiliation(s)
- Gleb V Morozkov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
| | - Anton S Abel
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
| | - Konstantin A Lyssenko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
- National Research University Higher School of Economics, Miasnitskaya Str. 20, 101000, Moscow, Russian Federation.
| | - Vitaly A Roznyatovsky
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
| | - Alexei D Averin
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
| | - Irina P Beletskaya
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, Moscow 119991, Russian Federation.
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Pr. 31, Moscow 119071, Russian Federation
| | - Alla Bessmertnykh-Lemeune
- ENS de Lyon, UMR 5182, CNRS, Université Claude Bernard Lyon 1, Laboratoire de Chimie, 69342 Lyon, France.
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25
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Bhavyesh D, Soliya S, Konakanchi R, Begari E, Ashalu KC, Naveen T. The Recent Advances in Iron-Catalyzed C(sp 3 )-H Functionalization. Chem Asian J 2023:e202301056. [PMID: 38149480 DOI: 10.1002/asia.202301056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 12/28/2023]
Abstract
The use of iron as a core metal in catalysis has become a research topic of interest over the last few decades. The reasons are clear. Iron is the most abundant transition metal on Earth's crust and it is widely distributed across the world. It has been extracted and processed since the dawn of civilization. All these features render iron a noncontaminant, biocompatible, nontoxic, and inexpensive metal and therefore it constitutes the perfect candidate to replace noble metals (rhodium, palladium, platinum, iridium, etc.). Moreover, direct C-H functionalization is one of the most efficient strategies by which to introduce new functional groups into small organic molecules. The majority of organic compounds contain C(sp3 )-H bonds. Given the enormous importance of organic molecules in so many aspects of existence, the utilization and bioactivity of C(sp3 )-H bonds are of the utmost importance. This review sheds light on the substrate scope, selectivity, benefits, and limitations of iron catalysts for direct C(sp3 )-H bond activations. An overview of the use of iron catalysis in C(sp3 )-H activation protocols is summarized herein up to 2022.
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Affiliation(s)
- Desai Bhavyesh
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
| | - Sudha Soliya
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
| | - Ramaiah Konakanchi
- Department of Chemistry, VNR Vignana Jyoti Institute of Engineering and Technology, Hyderabad, 500090, India
| | - Eeshwaraiah Begari
- School of Applied Material Sciences, Central University of Gujarat, Gandhinagar, 382030, India
| | - Kashamalla Chinna Ashalu
- Department of Chemistry, School of Science, Indrashil University, Rajpur, Kadi, Gujarat, 382715, India
| | - Togati Naveen
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
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26
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Rodrigalvarez J, Haut FL, Martin R. Regiodivergent sp3 C-H Functionalization via Ni-Catalyzed Chain-Walking Reactions. JACS AU 2023; 3:3270-3282. [PMID: 38155646 PMCID: PMC10751781 DOI: 10.1021/jacsau.3c00617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/02/2023] [Accepted: 11/07/2023] [Indexed: 12/30/2023]
Abstract
The catalytic translocation of a metal catalyst along a saturated hydrocarbon side chain constitutes a powerful strategy for enabling bond-forming reactions at remote, yet previously unfunctionalized, sp3 C-H sites. In recent years, Ni-catalyzed chain-walking reactions have offered counterintuitive strategies for forging sp3 architectures that would be difficult to accomplish otherwise. Although these strategies have evolved into mature tools for advanced organic synthesis, it was only recently that chemists showed the ability to control the motion at which the catalyst "walks" throughout the alkyl chain. Specialized ligand backbones, additives and a judicious choice of noninnocent functional groups on the side chain have allowed the design of "a la carte" protocols that enable regiodivergent bond-forming scenarios at different sp3 C-H sites with distinct topological surface areas. Given the inherent interest in increasing the fraction of sp3 hybridized carbons in medicinal chemistry, Ni-catalyzed regiodivergent chain-walking reactions might expedite the access to target leads in drug discovery campaigns.
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Affiliation(s)
- Jesus Rodrigalvarez
- The
Barcelona Institute of Science and Technology, Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Spain
| | - Franz-Lucas Haut
- The
Barcelona Institute of Science and Technology, Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Spain
| | - Ruben Martin
- The
Barcelona Institute of Science and Technology, Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Spain
- ICREA, Passeig Lluís Companys, 23, 08010 Barcelona, Spain
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27
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Binnani C, Arora S, Priya B, Gupta P, Singh SK. 2-Hydroxypyridine-based Ligands as Promoter in Ruthenium(II) Catalyzed C-H Bond Activation/Arylation Reactions. Chem Asian J 2023; 18:e202300569. [PMID: 37811781 DOI: 10.1002/asia.202300569] [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: 06/30/2023] [Revised: 09/14/2023] [Accepted: 10/09/2023] [Indexed: 10/10/2023]
Abstract
A class of 2-hydroxypyridine based ligands are explored to achieve enhanced catalytic activity for ortho-C-H bond activation/arylation reaction over [(η6 -p-cymene)RuCl2 ]2 catalyst in water. Extensive studies using a series of substituted 2-hydroxypyridine based ligands (L1-L6) inferred that 5-trifluoromethyl-2-hydroxypyridine (L6) exhibited favorable effects to enhance the catalytic activity of Ru(II) catalyst for ortho C-H bond arylation of 2-phenylpyridine by 8 folds compared to those performed without ligands. The (η6 -p-cymene)Ru - L6 system also exhibited enhanced catalytic activity for ortho C-H bond arylation of 2-phenylpyridine using a variety of aryl halides. NMR and mass investigations inferred the presence of several ligand coordinated Ru(II) species, suggesting the involvement of these species in C-H bond activation reaction. Further in concurrence with the experimental findings, the density functional theory (DFT) calculations also evidenced the prominent role of 2-hydroxypyridine based ligands in Ru(II) catalyzed C-H bond arylation of 2-phenylpyridine with lower energy barrier for the C-H activation step.
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Affiliation(s)
- Chinky Binnani
- Catalysis Group, Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, Madhya Pradesh, India
| | - Sumangla Arora
- Computational Catalysis Center, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Bhanu Priya
- Catalysis Group, Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, Madhya Pradesh, India
| | - Puneet Gupta
- Computational Catalysis Center, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Sanjay K Singh
- Catalysis Group, Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, Madhya Pradesh, India
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28
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Krishna Rao MV, Kareem S, Vali SR, Subba Reddy BV. Recent advances in metal directed C-H amidation/amination using sulfonyl azides and phosphoryl azides. Org Biomol Chem 2023; 21:8426-8462. [PMID: 37831479 DOI: 10.1039/d3ob01160g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Transition metal-catalyzed C-N bond formation reactions have gained popularity as a method for selectively transforming common C-H bonds into N-functionalized molecules. This approach is particularly useful for synthesizing aminated molecules, which require aminating reagents and amidated building blocks. Over the past two decades, significant advancements have been achieved in transition-metal-catalyzed C-H functionalization, with organic azides emerging as promising amino sources and internal oxidants. This review focuses on recent developments in utilizing sulfonyl and phosphoryl azides as building blocks for directed intra- and intermolecular C-H functionalization reactions. Specifically, it discusses methods for synthesizing sulfonamidates and phosphoramidates using sulfonyl and phosphoryl azides, respectively. The article highlights the potential of C-H functionalization reactions with organic azides for efficiently and sustainably synthesizing N-functionalized molecules, providing valuable insights into the latest advancements in this field.
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Affiliation(s)
- M V Krishna Rao
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India.
| | - Shaik Kareem
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India.
| | - Shaik Ramjan Vali
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India.
| | - B V Subba Reddy
- Department of Fluoro & Agrochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India.
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29
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Das J, Ali W, Ghosh A, Pal T, Mandal A, Teja C, Dutta S, Pothikumar R, Ge H, Zhang X, Maiti D. Access to unsaturated bicyclic lactones by overriding conventional C(sp 3)-H site selectivity. Nat Chem 2023; 15:1626-1635. [PMID: 37563324 PMCID: PMC10624629 DOI: 10.1038/s41557-023-01295-x] [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: 07/07/2022] [Accepted: 07/17/2023] [Indexed: 08/12/2023]
Abstract
Transition metal catalysis plays a pivotal role in transforming unreactive C-H bonds. However, regioselective activation of distal aliphatic C-H bonds poses a tremendous challenge, particularly in the absence of directing templates. Activation of a methylene C-H bond in the presence of methyl C-H is underexplored. Here we show activation of a methylene C-H bond in the presence of methyl C-H bonds to form unsaturated bicyclic lactones. The protocol allows the reversal of the general selectivity in aliphatic C-H bond activation. Computational studies suggest that reversible C-H activation is followed by β-hydride elimination to generate the Pd-coordinated cycloalkene that undergoes stereoselective C-O cyclization, and subsequent β-hydride elimination to provide bicyclic unsaturated lactones. The broad generality of this reaction has been highlighted via dehydrogenative lactonization of mid to macro ring containing acids along with the C-H olefination reaction with olefin and allyl alcohol. The method substantially simplifies the synthesis of important bicyclic lactones that are important features of natural products as well as pharmacoactive molecules.
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Affiliation(s)
- Jayabrata Das
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Wajid Ali
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Animesh Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Tanay Pal
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Astam Mandal
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Chitrala Teja
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Suparna Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | | | - Haibo Ge
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA.
| | - Xinglong Zhang
- Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Debabrata Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India.
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30
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Bakanas I, Lusi RF, Wiesler S, Hayward Cooke J, Sarpong R. Strategic application of C-H oxidation in natural product total synthesis. Nat Rev Chem 2023; 7:783-799. [PMID: 37730908 DOI: 10.1038/s41570-023-00534-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2023] [Indexed: 09/22/2023]
Abstract
The oxidation of unactivated C-H bonds has emerged as an effective tactic in natural product synthesis and has altered how chemists approach the synthesis of complex molecules. The use of C-H oxidation methods has simplified the process of synthesis planning by expanding the choice of starting materials, limiting functional group interconversion and protecting group manipulations, and enabling late-stage diversification. In this Review, we propose classifications for C-H oxidations on the basis of their strategic purpose: type 1, which installs functionality that is used to establish the carbon skeleton of the target; type 2, which is used to construct a heterocyclic ring; and type 3, which installs peripheral functional groups. The reactions are further divided based on whether they are directed or undirected. For each classification, examples from recent literature are analysed. Finally, we provide two case studies of syntheses from our laboratory that were streamlined by the judicious use of C-H oxidation reactions.
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Affiliation(s)
- Ian Bakanas
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Robert F Lusi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Stefan Wiesler
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Jack Hayward Cooke
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
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31
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Intelli AJ, Pal M, Selvaraju M, Altman RA. Palladium-Catalyzed Dearomatization of Benzothiophenes: Isolation and Functionalization of a Discrete Dearomatized Intermediate. SYNTHESIS-STUTTGART 2023; 55:3568-3574. [PMID: 37915377 PMCID: PMC10617892 DOI: 10.1055/a-2092-9012] [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] [Indexed: 11/03/2023]
Abstract
A Pd-catalyzed decarboxylative dearomatization reaction of a heterocyclic substrate enables access to an uncommon reaction intermediate that rearomatizes in the presence of amine bases in a net C-H functionalization sequence. The dearomatized benzo[b]thiophene intermediate bears an exocyclic alkene that can be functionalized through cycloaddition and halogenation reactions to deliver complex heterocyclic products.
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Affiliation(s)
- Andrew John Intelli
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
| | - Mohan Pal
- NuChem Sciences Inc.; 2350 Rue Cohen Suite 201, Saint-Laurent, Quebec, Canada H4R 2N6
| | | | - Ryan A Altman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
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32
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Wang H, Liu R, Sun Q, Xu K. Direct alkylation of quinoxalinones with electron-deficient alkenes enabled by a sequential paired electrolysis. Chem Commun (Camb) 2023; 59:12763-12766. [PMID: 37812023 DOI: 10.1039/d3cc04356h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The metal-free alkylation of N-heterocycles with alkenes has remained a synthetic challenge. We report here the successful implementation of metal-free alkylation of quinoxalinones with electron-deficient alkenes enabled by a sequential paired electrolysis. This protocol provides a mechanistically distinct approach to prepare a variety of C-3 alkylated quinoxalinones that are otherwise quite difficult to synthesize by other means.
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Affiliation(s)
- Huiqiao Wang
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Ruoyu Liu
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Qi Sun
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China.
| | - Kun Xu
- Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
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33
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Il'in MV, Polonnikov DA, Novikov AS, Sysoeva AA, Safinskaya YV, Bolotin DS. Influence of Coordination to Silver(I) Centers on the Activity of Heterocyclic Iodonium Salts Serving as Halogen-Bond-Donating Catalysts. Chempluschem 2023; 88:e202300304. [PMID: 37675949 DOI: 10.1002/cplu.202300304] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/08/2023]
Abstract
Kinetic data based on 1 H NMR monitoring and computational studies indicate that in solution, pyrazole-containing iodonium triflates and silver(I) triflate bind to each other, and such an interplay results in the decrease of the total catalytic activity of the mixture of these Lewis acids compared to the separate catalysis of the Schiff condensation, the imine-isocyanide coupling, or the nucleophilic attack on a triple carbon-carbon bond. Moreover, the kinetic data indicate that such a cooperation with the silver(I) triflate results in prevention of decomposition of the iodonium salts during the reaction progress. XRD study confirms that the pyrazole-containing iodonium triflate coordinates to the silver(I) center via the pyrazole N atom to produce a rare example of a pentacoordinated trigonal bipyramidal dinuclear silver(I) complex featuring cationic ligands.
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Affiliation(s)
- Mikhail V Il'in
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
| | - Denis A Polonnikov
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
| | - Alexander S Novikov
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
- Research Institute of Chemistry, Рeoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya St. 6, Moscow, 117198, Russia
| | - Alexandra A Sysoeva
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
| | - Yana V Safinskaya
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
| | - Dmitrii S Bolotin
- Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, Saint Petersburg, 199034, Russia
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34
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Murtaza A, Ulhaq Z, Shirinfar B, Rani S, Aslam S, Martins GM, Ahmed N. Arenes and Heteroarenes C-H Functionalization Under Enabling Conditions: Electrochemistry, Photoelectrochemistry & Flow Technology. CHEM REC 2023; 23:e202300119. [PMID: 37255348 DOI: 10.1002/tcr.202300119] [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: 04/04/2023] [Revised: 05/18/2023] [Indexed: 06/01/2023]
Abstract
C-H bond functionalization generates molecular complexity in single-step transformation. However, the activation of C-H bonds requires expensive metals or stoichiometric amounts of oxidizing/reducing species. In many cases, they often require pre-functionalization of starting molecules. Such pre-activating measures cause waste generation and their separation from the final product is also troublesome. In such a scenario, reactions activating elements generating from renewable energy resources such as electricity and light would be more efficient, green, and cost-effective. Further, incorporation of growing flow technology in chemical transformation processes will accelerate the safer accesses of valuable products. Arenes & heteroarenes are ubiquitous in pharmaceuticals, natural products, medicinal compounds, and other biologically important molecules. Herein, we discussed enabling tools and technologies used for the recent C-H bonds functionalization of arenes and heteroarenes.
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Affiliation(s)
- Ayesha Murtaza
- Department of Chemistry, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Zia Ulhaq
- Chemical Engineering Department, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Bahareh Shirinfar
- Department of Chemistry, University of Bath, BA2 7AY, Bath, United Kingdom
- West Herts College, Hertfordshire, Watford, WD17 3EZ, London, United Kingdom
| | - Sadia Rani
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Samina Aslam
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Guilherme M Martins
- Department of Chemistry, Federal University of Sao Carlos - UFS Car, 13565-905, São Carlos -SP, Brazil
- School of Chemistry, Cardiff University, Main Building Park Place, Cardiff, CF10 3AT, United Kingdom
| | - Nisar Ahmed
- School of Chemistry, Cardiff University, Main Building Park Place, Cardiff, CF10 3AT, United Kingdom
- Centre for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, University of Karachi, Karachi, 75270, Pakistan
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35
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Romero AH. C-H Bond Functionalization of N-Heteroarenes Mediated by Selectfluor. Top Curr Chem (Cham) 2023; 381:29. [PMID: 37736818 DOI: 10.1007/s41061-023-00437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 08/21/2023] [Indexed: 09/23/2023]
Abstract
Herein, recent developments for Selectfluor-mediated C-H functionalization of N-heteroarenes are described. This type of C-H bond activation is an attractive and competitive alternative to traditional methodologies, allowing the functionalization of a variety of chemical functions. In addition, Selectfluor is a more sustainable and economically accessible oxidant compared with expensive/toxic metals or hazardous peroxides. For a practical understanding, the current review classified systematically the reported strategies in four subsections as follows: (1) carbon-carbon formation, (2) carbon-nitrogen bond formation, (3) carbon-chalcogen bond, and (4) carbon-halogen bond formation. Mechanistic aspects and reaction conditions are fully discussed to provide an understanding of the aspects that govern C-H functionalization in N-heteroarenes mediated by Selectfluor.
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Affiliation(s)
- Angel H Romero
- Grupo de Química Orgánica Medicinal, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400, Montevideo, Uruguay.
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36
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Tali JA, Kumar G, Sharma BK, Rasool Y, Sharma Y, Shankar R. Synthesis and site selective C-H functionalization of imidazo-[1,2- a]pyridines. Org Biomol Chem 2023; 21:7267-7289. [PMID: 37655687 DOI: 10.1039/d3ob00849e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Imidazo[1,2-a]pyridine has attracted much interest in drug development because of its potent medicinal properties, therefore the discovery of novel methods for its synthesis and functionalization continues to be an exciting area of research. Although transition metal catalysis has fuelled the most significant developments, extremely beneficial metal-free approaches have also been identified. Even though pertinent reviews focused on imidazo[1,2-a]pyridine synthesis, properties (physicochemical and medicinal), and functionalization at the C3 position have been published, none of these reviews has focused on the outcomes obtained in the field of global ring functionalization. We wish here to describe a brief synthesis and an overview of all the functionalization reactions at each carbon atom, viz, C2, C3, C5, C6, C7 and C8 of this scaffold, divided into sections based on site-selectivity and the type of functionalization methods used.
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Affiliation(s)
- Javeed Ahmad Tali
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Gulshan Kumar
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Bhupesh Kumar Sharma
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Younis Rasool
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Yashika Sharma
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
| | - Ravi Shankar
- Natural Product and Medicinal Chemistry Division (NPMC), CSIR-Indian Institute of Integrative Medicine, Jammu-180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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37
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Chen M, Ventura AM, Das S, Ibrahim AF, Zimmerman PM, Montgomery J. Oxidative Cross Dehydrogenative Coupling of N-Heterocycles with Aldehydes through C( sp3)-H Functionalization. J Am Chem Soc 2023; 145:20176-20181. [PMID: 37672664 PMCID: PMC10915535 DOI: 10.1021/jacs.3c06532] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Existing methodologies for metal-catalyzed cross-couplings typically rely on preinstallation of reactive functional groups on both reaction partners. In contrast, C-H functionalization approaches offer promise in simplification of the requisite substrates; however, challenges from low reactivity and similar reactivity of various C-H bonds introduce considerable complexity. Herein, the oxidative cross dehydrogenative coupling of α-amino C(sp3)-H bonds and aldehydes to produce ketone derivatives is described using an unusual reaction medium that incorporates the simultaneous use of di-tert-butyl peroxide as an oxidant and zinc metal as a reductant. The method proceeds with a broad substrate scope, representing an attractive approach for accessing α-amino ketones through the formal acylation of C-H bonds α to nitrogen in N-heterocycles. A combination of experimental investigation and computational modeling provides evidence for a mechanistic pathway involving cross-selective nickel-mediated cross-coupling of α-amino radicals and acyl radicals.
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Affiliation(s)
- Mo Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Austin M Ventura
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Soumik Das
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Ammar F Ibrahim
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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38
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Verma N, Tyagi R, Khanna A, Malviya M, Sagar R. Electro-organic synthesis of isatins and hydrazones through C-N cross-coupling and C(sp 2)-H/C(sp 3)-H functionalization. Org Biomol Chem 2023; 21:6707-6714. [PMID: 37563999 DOI: 10.1039/d3ob01128c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
An efficient and unique approach to synthesize isatin (indole-2,3-dione) from 2-aminoacetophenone under electrochemical conditions supported by I2-DMSO through C-N cross-coupling and C(sp2)-H/C(sp3)-H functionalization is presented. This synthetic method spans a wide range of substituted 2-aminoacetophenone substrates. The use of iodine as a promoter and shorter reaction times produced good to very good yields of isatin derivatives, which is a significant improvement over the reaction in a batch process. Further, hydrazones of isatin were synthesized by using hydrazine hydrate which produces electrochemically active molecules, namely isatin-hydrazones. The hydrazones of acetophenone were also obtained using the same reaction protocol. Additionally, the effect of increasing scan rate studied using cyclic voltammetry shows that the process followed a diffusion-controlled mechanism.
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Affiliation(s)
- Neetu Verma
- Department of Chemistry, IIT (Banaras Hindu University), Varanasi-221005, India.
| | - Rajdeep Tyagi
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India.
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Manisha Malviya
- Department of Chemistry, IIT (Banaras Hindu University), Varanasi-221005, India.
| | - Ram Sagar
- Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India.
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
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39
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Maity B, Dutta S, Cavallo L. The mechanism of visible light-induced C-C cross-coupling by C sp3-H bond activation. Chem Soc Rev 2023; 52:5373-5387. [PMID: 37464786 DOI: 10.1039/d2cs00960a] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Csp3-C cross-coupling by activating Csp3-H bonds is a dream reaction for the chemical community, and visible light-induced transition metal-catalysis under mild reaction conditions is considered a powerful tool to achieve it. Advancement of this research area is still in its infancy because of the chemical and technical complexity of this catalysis. Mechanistic studies illuminating the operative reaction pathways can rationalize the increasing amount of experimental catalysis data and provide the knowledge allowing faster and rational advances in the field. This goal requires complementary experimental and theoretical mechanistic studies, as each of them is unfit to clarify the operative mechanisms alone. In this tutorial review we summarize representative experimental and computational mechanistic studies, highlighting weaknesses, strengths, and synergies between the two approaches.
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Affiliation(s)
- Bholanath Maity
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Sayan Dutta
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
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40
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Biswas A. Aromatic C-H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel-Crafts reaction: a recent update. Beilstein J Org Chem 2023; 19:956-981. [PMID: 37404800 PMCID: PMC10315893 DOI: 10.3762/bjoc.19.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/15/2023] [Indexed: 07/06/2023] Open
Abstract
The aza-Friedel-Crafts reaction allows an efficient coupling of electron-rich aromatic systems with imines for the facile incorporation of aminoalkyl groups into the aromatic ring. This reaction has a great scope of forming aza-stereocenters which can be tuned by different asymmetric catalysts. This review assembles recent advances in asymmetric aza-Friedel-Crafts reactions mediated by organocatalysts. The mechanistic interpretation with the origin of stereoselectivity is also explained.
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Affiliation(s)
- Anup Biswas
- Department of Chemistry, Hooghly Women’s College, Vivekananda Road, Pipulpati, Hooghly - 712103, WB, India
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41
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van den Heuvel N, Mason SM, Mercado BQ, Miller SJ. Aspartyl β-Turn-Based Dirhodium(II) Metallopeptides for Benzylic C(sp 3)-H Amination: Enantioselectivity and X-ray Structural Analysis. J Am Chem Soc 2023; 145:12377-12385. [PMID: 37216431 PMCID: PMC10330621 DOI: 10.1021/jacs.3c03587] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Amination of C(sp3)-H bonds is a powerful tool to introduce nitrogen into complex organic frameworks in a direct manner. Despite significant advances in catalyst design, full site- and enantiocontrol in complex molecular regimes remain elusive using established catalyst systems. To address these challenges, we herein describe a new class of peptide-based dirhodium(II) complexes derived from aspartic acid-containing β-turn-forming tetramers. This highly modular system can serve as a platform for the rapid generation of new chiral dirhodium(II) catalyst libraries, as illustrated by the facile synthesis of a series of 38 catalysts. Critically, we present the first crystal structure of a dirhodium(II) tetra-aspartate complex, which unveils retention of the β-turn conformation of the peptidyl ligand; a well-defined hydrogen-bonding network is evident, along with a near-C4 symmetry that renders the rhodium centers inequivalent. The utility of this catalyst platform is illustrated by the enantioselective amination of benzylic C(sp3)-H bonds, in which state-of-the-art levels of enantioselectivity up to 95.5:4.5 er are obtained, even for substrates that present challenges with previously reported catalyst systems. Additionally, we found these complexes to be competent catalysts for the intermolecular amination of N-alkylamides via insertion into the C(sp3)-H bond α to the amide nitrogen, yielding differentially protected 1,1-diamines. Of note, this type of insertion was also observed to occur on the amide functionalities of the catalyst itself in the absence of the substrate but did not appear to be detrimental to reaction outcomes when the substrate was present.
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Affiliation(s)
- Naudin van den Heuvel
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Savannah M. Mason
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Brandon Q. Mercado
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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42
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Docherty JH, Lister TM, Mcarthur G, Findlay MT, Domingo-Legarda P, Kenyon J, Choudhary S, Larrosa I. Transition-Metal-Catalyzed C-H Bond Activation for the Formation of C-C Bonds in Complex Molecules. Chem Rev 2023. [PMID: 37163671 DOI: 10.1021/acs.chemrev.2c00888] [Citation(s) in RCA: 62] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Site-predictable and chemoselective C-H bond functionalization reactions offer synthetically powerful strategies for the step-economic diversification of both feedstock and fine chemicals. Many transition-metal-catalyzed methods have emerged for the selective activation and functionalization of C-H bonds. However, challenges of regio- and chemoselectivity have emerged with application to highly complex molecules bearing significant functional group density and diversity. As molecular complexity increases within molecular structures the risks of catalyst intolerance and limited applicability grow with the number of functional groups and potentially Lewis basic heteroatoms. Given the abundance of C-H bonds within highly complex and already diversified molecules such as pharmaceuticals, natural products, and materials, design and selection of reaction conditions and tolerant catalysts has proved critical for successful direct functionalization. As such, innovations within transition-metal-catalyzed C-H bond functionalization for the direct formation of carbon-carbon bonds have been discovered and developed to overcome these challenges and limitations. This review highlights progress made for the direct metal-catalyzed C-C bond forming reactions including alkylation, methylation, arylation, and olefination of C-H bonds within complex targets.
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Affiliation(s)
- Jamie H Docherty
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Thomas M Lister
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Gillian Mcarthur
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Michael T Findlay
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Pablo Domingo-Legarda
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Jacob Kenyon
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Shweta Choudhary
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Igor Larrosa
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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43
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Wang J, Üner NB, Dubowsky SE, Confer MP, Bhargava R, Sun Y, Zhou Y, Sankaran RM, Moore JS. Plasma Electrochemistry for Carbon-Carbon Bond Formation via Pinacol Coupling. J Am Chem Soc 2023; 145:10470-10474. [PMID: 37146270 DOI: 10.1021/jacs.3c01779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The formation of carbon-carbon bonds by pinacol coupling of aldehydes and ketones requires a large negative reduction potential, often realized with a stoichiometric reducing reagent. Here, we use solvated electrons generated via a plasma-liquid process. Parametric studies with methyl-4-formylbenzoate reveal that selectivity over the competing reduction to the alcohol requires careful control over mass transport. The generality is demonstrated with benzaldehydes, benzyl ketones, and furfural. A reaction-diffusion model explains the observed kinetics, and ab initio calculations provide insight into the mechanism. This study opens the possibility of a metal-free, electrically-powered, sustainable method for reductive organic reactions.
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Affiliation(s)
- Jian Wang
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Necip B Üner
- Nuclear, Plasma and Radiological Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Chemical Engineering Department, Middle East Technical University, Ankara 06800, Turkey
| | - Scott Edwin Dubowsky
- Nuclear, Plasma and Radiological Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Matthew P Confer
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rohit Bhargava
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Departments of Bioengineering, Chemical and Biomolecular Engineering, Electrical and Computer Engineering, Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yunyan Sun
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yuting Zhou
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - R Mohan Sankaran
- Nuclear, Plasma and Radiological Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jeffrey S Moore
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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44
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Rahman I, Baruah B, Rajbongshi BK, Deb ML, Baruah PK. Catalyst‐/Additive‐Free One‐Pot Synthesis of Oxazolidines in Water via Regioselective and Stereoselective C−H Functionalization Approach. ChemistrySelect 2023. [DOI: 10.1002/slct.202300093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Affiliation(s)
- Iftakur Rahman
- Department of Applied Sciences GUIST Gauhati University Guwahati 781014 Assam India
| | - Biswajita Baruah
- Department of Chemistry Pandu College Guwahati-781012 Assam India
| | | | - Mohit L. Deb
- Department of Applied Sciences GUIST Gauhati University Guwahati 781014 Assam India
| | - Pranjal K. Baruah
- Department of Applied Sciences GUIST Gauhati University Guwahati 781014 Assam India
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45
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Tachikawa H. C-C Bond Formation Reaction Catalyzed by a Lithium Atom: Benzene-to-Biphenyl Coupling. ACS OMEGA 2023; 8:10600-10606. [PMID: 36969438 PMCID: PMC10034993 DOI: 10.1021/acsomega.3c00520] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Transition-metal-catalyzed carbon-carbon (C-C) bond formation is an important reaction in pharmaceutical and organic chemistry. However, the reaction process is composed of multiple steps and is expensive owing to the presence of transition metals. This study proposes a lithium-catalyzed C-C coupling reaction of two benzene molecules (Bz) to form a biphenyl molecule, which is a transition-metal-free reaction, based on ab initio and direct ab initio molecular dynamics (AIMD) calculations. The static ab initio calculations indicate that the reaction of two Bz molecules with Li- ions (reactant state, RC) can form a stable sandwiched complex (precomplex), where the Li- ion is sandwiched by two Bz molecules. The complex formation reaction can be expressed as 2Bz + Li - → Bz(Li -)Bz, where the C-C distance between the Bz rings is 2.449 Å. This complex moves to the transition state (TS) via the structural deformation of Bz(Li-)Bz, where the C-C distance is shortened to 2.118 Å. The barrier height was calculated to be -9.9 kcal/mol (relative to RC) at the MP2/6-311++G(d,p) level. After TS, the C(sp3)-C(sp3) single bond was completely formed between the Bz rings (the C-C bond distance was 1.635 Å) (late complex). After the dissociation of H2 from the late complex, a biphenyl molecule was formed: the C(sp2)-C(sp2) bond. The calculations suggest that the C-C bond coupling of Bz occurred spontaneously from 2Bz + Li-, and biphenyl molecules were directly formed without an activation barrier. Direct AIMD calculations show that the C-C coupling reaction also takes place under electron attachment to Li(Bz)2: Li(Bz)2 + e- → [Li-(Bz)2]ver → precomplex → TS → late complex, where [Li-(Bz)2]ver is the vertical electron capture species of Li(Bz)2. Namely, the C-C coupling reaction spontaneously occurred in Li(Bz)2 owing to electron attachment. Similar C-C coupling reactions were also observed for halogen-substituted benzene molecules (Bz-X, X = F and Cl). Furthermore, this study discusses the mechanism of C-C bond formation in electron capture based on the theoretical results.
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46
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Srinivas B, Shakeena K, Kota DL, Abhinav V, Eswar P, Geetha Sravani R, Sampath Pavan Kumar A, Indukuri K, Dhanaraju KA, Murali Krishna Kumar M, Alla SK. Iron(III)-Catalyzed Regioselective Synthesis of Electron-Rich Benzothiazoles from Aryl Isothiocyanates via C-H Functionalization. J Org Chem 2023; 88:4458-4471. [PMID: 36912001 DOI: 10.1021/acs.joc.2c03078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
We report herein a direct synthetic route for the preparation of 2-arylbenzothiazoles using aryl isothiocyanates and electron-rich arenes. The synthetic route involves triflic acid promoted addition of the arenes to aryl isothiocyanates followed by FeCl3-catalyzed C-S bond formation via C-H functionalization. The approach provides the advantage of synthesis of benzothiazoles without the conventional use of aryl aldehyde/carboxylic acid precursors employing the less expensive iron(III) catalyst.
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Affiliation(s)
- Bokka Srinivas
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Kotari Shakeena
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Durgeswari Lakkavarapu Kota
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Valeti Abhinav
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Pyla Eswar
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Rongali Geetha Sravani
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Anandam Sampath Pavan Kumar
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
| | - Kiran Indukuri
- Chemistry-Discovery Research Lab, Dextro Synthesis Private Limited, Hyderabad, Telangana 500090, India
| | | | | | - Santhosh Kumar Alla
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh 530045, India
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47
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Rana G, Kar A, Kundal S, Musib D, Jana U. DDQ/Fe(NO 3) 3-Catalyzed Aerobic Synthesis of 3-Acyl Indoles and an In Silico Study for the Binding Affinity of N-Tosyl-3-acyl Indoles toward RdRp against SARS-CoV-2. J Org Chem 2023; 88:838-851. [PMID: 36622749 DOI: 10.1021/acs.joc.2c02009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the present study, we herein report a DDQ-catalyzed new protocol for the synthesis of substituted 3-acylindoles. Being a potential system for virtual hydrogen storage, introduction of catalytic DDQ in combination with Fe(NO3)3·9H2O and molecular oxygen as co-catalysts offers a regioselective oxo-functionalization of C-3 alkyl-/aryllidine indolines even with scale-up investigations. Intermediate isolation, their spectroscopic characterization, and the density functional theory calculations indicate that the method involves dehydrogenative allylic hydroxylation and 1,3-functional group isomerization/aromatization followed by terminal oxidation to afford 3-acylindoles quantitatively with very high regioselectivity. This method is very general for a large number of substrates with varieties of functional groups tolerance emerging high-yield outcome. Moreover, molecular docking studies were performed for some selected ligands with an RNA-dependent RNA polymerase complex (RdRp complex) of SARS-CoV-2 to illustrate the binding potential of those ligands. The docking results revealed that few of the ligands possess the potential to inhibit the RdRp of SARS-Cov-2 with binding energies (-6.7 to -8.19 kcal/mol), which are comparably higher with respect to the reported binding energies of the conventional re-purposed drugs such as Remdesivir, Ribavirin, and so forth (-4 to -7 kcal/mol).
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Affiliation(s)
- Gopal Rana
- Department of Chemistry, Jadavpur University, Kolkata 700 032, West Bengal, India
| | - Abhishek Kar
- Department of Chemistry, Jadavpur University, Kolkata 700 032, West Bengal, India
| | - Sandip Kundal
- Department of Chemistry, Jadavpur University, Kolkata 700 032, West Bengal, India
| | - Dulal Musib
- Department of Chemistry, National Institute of Technology Manipur, Langol, Imphal 795004, Manipur, India
| | - Umasish Jana
- Department of Chemistry, Jadavpur University, Kolkata 700 032, West Bengal, India
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48
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Greiner LC, Arichi N, Inuki S, Ohno H. Gold(I)-Catalyzed Benzylic C(sp 3 )-H Functionalizations: Divergent Synthesis of Indole[a]- and [b]-Fused Polycycles. Angew Chem Int Ed Engl 2023; 62:e202213653. [PMID: 36255174 DOI: 10.1002/anie.202213653] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/17/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Phenyl azides substituted by an (alkylphenyl)ethynyl group facilitate benzylic sp3 (C-H) functionalization in the presence of a JohnPhosAu catalyst, resulting in indole-fused tetra- and pentacycles via divergent N- or C-cyclization. The chemoselectivity is influenced depending on the counter-anion, the electron density of the α-imino gold(I) carbene, and the alkyl groups stabilizing the benzylic carbocation originating from a 1,5-hydride shift. An isotopic labeling experiment demonstrates the involvement of an indolylgold(I) species resulting from a tautomerization that is much faster than the deauration. The formation of a benzylic sp3 (C-H) functionalization leading to an indole-fused seven-membered ring is also demonstrated.
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Affiliation(s)
- Luca C Greiner
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Norihito Arichi
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
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49
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Reimann CE, Kim KE, Rand AW, Moghadam FA, Stoltz BM. What is a Cross-Coupling? An Argument for a Universal Definition. Tetrahedron 2023; 130:133176. [PMID: 36710952 PMCID: PMC9878734 DOI: 10.1016/j.tet.2022.133176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Despite amazing advances in cross-coupling technologies over the past several decades, there is not a consistent definition of what a cross-coupling reaction is. Often, definitions rely on comparison to "traditional" palladium-catalyzed cross-couplings pioneered in the 1970s by chemists such as Suzuki, Negishi, and Heck. While these reactions provide a basis for a cross-coupling definition, they do not define this type of transformation, originally described by Linstead almost 20 years prior. Rather than modify and compartmentalize modern transformations to categorize them into either a synthetic or mechanistic definition, we make an argument for broadening the cross-coupling definition to the union of two distinct molecular entities in a covalent-bond-forming process, to encourage discussion around exploring novel reactivity and disconnections. In addition to making a case for a universal cross-coupling definition, we cite specific examples of reactions that break the mold of prior cross-coupling definitions. We believe this perspective will stimulate dialog around what it means to be a cross-coupling and in turn inspire future developments within this field.
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Affiliation(s)
| | - Kelly E Kim
- California Institute of Technology, Pasadena, CA 91125
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50
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Weliwatte NS, Chen H, Tang T, Minteer SD. Three-Stage Conversion of Chemically Inert n-Heptane to α-Hydrazino Aldehyde Based on Bioelectrocatalytic C-H Bond Oxyfunctionalization. ACS Catal 2023; 13:563-572. [PMID: 36644649 PMCID: PMC9830989 DOI: 10.1021/acscatal.2c04003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/12/2022] [Indexed: 12/24/2022]
Abstract
Simple petrochemical feedstocks are often the starting material for the synthesis of complex commodity and fine and specialty chemicals. Designing synthetic pathways for these complex and specific molecular structures with sufficient chemo-, regio-, enantio-, and diastereo-selectivity can expand the existing petrochemicals landscape. The two overarching challenges in designing such pathways are selective activation of chemically inert C-H bonds in hydrocarbons and systematic functionalization to synthesize complex structures. Multienzyme cascades are becoming a growing means of overcoming the first challenge. However, extending multienzyme cascade designs is restricted by the arsenal of enzymes currently at our disposal and the compatibility between specific enzymes. Here, we couple a bioelectrocatalytic multienzyme cascade to organocatalysis, which are two distinctly different classes of catalysis, in a single system to address both challenges. Based on the development and utilization of an anthraquinone (AQ)-based redox polymer, the bioelectrocatalytic step achieves regioselective terminal C-H bond oxyfunctionalization of chemically inert n-heptane. A second biocatalytic step selectively oxidizes the resulting 1-heptanol to heptanal. The succeeding inherently simple and durable l-proline-based organocatalysis step is a complementary partner to the multienzyme steps to further functionalize heptanal to the corresponding α-hydrazino aldehyde. The "three-stage" streamlined design exerts much control over the chemical conversion, which renders the collective system a versatile and adaptable model for a broader substrate scope and more complex C-H functionalization.
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