1
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Roy M, Sardar B, Mallick I, Srimani D. Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C-O bonds in organic transformations. Beilstein J Org Chem 2024; 20:1348-1375. [PMID: 38887583 PMCID: PMC11181251 DOI: 10.3762/bjoc.20.119] [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: 01/30/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024] Open
Abstract
Alkyl and acyl radicals play a critical role in the advancement of chemical synthesis. The generation of acyl and alkyl radicals by activation of C-O bonds using visible-light photoredox catalysis offers a mild and environmentally benign approach to useful chemical transformations. Alcohols, carboxylic acids, anhydrides, xanthates, oxalates, N-phthalimides, and thiocarbonates are some examples of alkyl and acyl precursors that can produce reactive radicals by homolysis of the C-O bond. These radicals can then go through a variety of transformations that are beneficial for the construction of synthetic materials that are otherwise difficult to access. This study summarizes current developments in the use of organic photocatalysts, transition-metal photoredox catalysts, and metallaphotocatalysts to produce acyl and alkyl radicals driven by visible light.
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Affiliation(s)
- Mithu Roy
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Bitan Sardar
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Itu Mallick
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Dipankar Srimani
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
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2
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Durin G, Romero RM, Godou T, Chauvier C, Thuéry P, Nicolas E, Cantat T. Formoxyboranes as hydroborane surrogates for the catalytic reduction of carbonyls through transfer hydroboration. Catal Sci Technol 2024; 14:1848-1853. [PMID: 38571548 PMCID: PMC10987016 DOI: 10.1039/d3cy01702h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/13/2024] [Indexed: 04/05/2024]
Abstract
A new class of Lewis base stabilized formoxyboranes demonstrates the feasibility of catalytic transfer hydroboration. In the presence of a ruthenium catalyst, they have shown broad applicability for reducing carbonyl compounds. Various borylated alcohols are obtained in high selectivity and yields up to 99%, tolerating several functional groups. Computational studies enabled to propose a mechanism for this transformation, revealing the role of the ruthenium catalyst and the absence of hydroborane intermediates.
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Affiliation(s)
- Gabriel Durin
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - R Martin Romero
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - Timothé Godou
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - Clément Chauvier
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - Pierre Thuéry
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - Emmanuel Nicolas
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
| | - Thibault Cantat
- NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France
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3
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Biremond T, Riomet M, Jubault P, Poisson T. Photocatalytic and Electrochemical Borylation and Silylation Reactions. CHEM REC 2023; 23:e202300172. [PMID: 37358334 DOI: 10.1002/tcr.202300172] [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: 05/10/2023] [Revised: 06/05/2023] [Indexed: 06/27/2023]
Abstract
Due to their high versatility borylated and silylated compounds are inevitable synthons for organic chemists. To escape the classical hydroboration/hydrosilylation paradigm, chemists turned their attention to more modern and green methods such as photoredox chemistry and electrosynthesis. This account focuses on novel methods for the generation of boryl and silyl radicals to forge C-B and C-Si bonds from our group.
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Affiliation(s)
- Tony Biremond
- Normandie Univ., INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
| | - Margaux Riomet
- Normandie Univ., INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
| | - Philippe Jubault
- Normandie Univ., INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
| | - Thomas Poisson
- Normandie Univ., INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014), 76000, Rouen, France
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4
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Ratnam S, Unone S, Janssen-Müller D. 2,2'-Biquinoline-Based Recyclable Electroauxiliaries for the Generation of Alkyl Radicals via C-C Bond Cleavage. Chemistry 2023; 29:e202301685. [PMID: 37265104 DOI: 10.1002/chem.202301685] [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: 05/26/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/03/2023]
Abstract
Alkyl radical precursors are essential for a wide variety of photocatalytic and 3d-metal-catalyzed C-C bond forming reactions. Neutral organic heterocycles as electroauxiliaries such as 4-alkyl Hantzsch esters have become reliable tools for alkyl radical formation. Here we show that 2,2'-biquinoline-derived alkyl-substituted dihydroquinolines act as competent radical precursors with the ability to form primary, secondary and tertiary alkyl radicals. Hydroalkylation of benzalmalononitriles and N-Boc protected diazenes has been achieved through copper catalysis under mild conditions of 50 °C with good to very good yields of up to 85 %. Furthermore, the dihydroquinolines' reactivity towards a denitrative alkylation of nitroolefins such as β-nitrostyrene was discovered. Most importantly, the released biquinoline can be recycled, which greatly improves the overall atom-economy of these alkyl radical precursors in comparison to previous N-heterocyclic electroauxiliaries.
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Affiliation(s)
- Shahilan Ratnam
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Shreya Unone
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Daniel Janssen-Müller
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
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5
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Abstract
Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N-O•. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R1 and R2 prevents nitroxide radical dimerization, ensuring their kinetic stability. Despite their reactivity toward various transient C radicals, some nitroxides can be easily stored under air at room temperature. Furthermore, nitroxides can be oxidized to oxoammonium salts (R1R2N═O+) or reduced to anions (R1R2N-O-), enabling them to act as valuable oxidants or reductants depending on their oxidation state. Therefore, they exhibit interesting reactivity across all three oxidation states. Due to these fascinating properties, nitroxides find extensive applications in diverse fields such as biochemistry, medicinal chemistry, materials science, and organic synthesis. This review focuses on the versatile applications of nitroxides in organic synthesis. For their use in other important fields, we will refer to several review articles. The introductory part provides a brief overview of the history of nitroxide chemistry. Subsequently, the key methods for preparing nitroxides are discussed, followed by an examination of their structural diversity and physical properties. The main portion of this review is dedicated to oxidation reactions, wherein parent nitroxides or their corresponding oxoammonium salts serve as active species. It will be demonstrated that various functional groups (such as alcohols, amines, enolates, and alkanes among others) can be efficiently oxidized. These oxidations can be carried out using nitroxides as catalysts in combination with various stoichiometric terminal oxidants. By reducing nitroxides to their corresponding anions, they become effective reducing reagents with intriguing applications in organic synthesis. Nitroxides possess the ability to selectively react with transient radicals, making them useful for terminating radical cascade reactions by forming alkoxyamines. Depending on their structure, alkoxyamines exhibit weak C-O bonds, allowing for the thermal generation of C radicals through reversible C-O bond cleavage. Such thermally generated C radicals can participate in various radical transformations, as discussed toward the end of this review. Furthermore, the application of this strategy in natural product synthesis will be presented.
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Affiliation(s)
- Dirk Leifert
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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6
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Uchikura T, Nakamura H, Sakai H, Akiyama T. 2-Silylated Dihydroquinazolinone as a Photocatalytic Energy Transfer Enabled Radical Hydrosilylation Reagent. Chemistry 2023; 29:e202301090. [PMID: 37269182 DOI: 10.1002/chem.202301090] [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: 06/10/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/04/2023]
Abstract
The hydrosilylation of alkenes is one of the most important methods for the synthesis of organosilicon compounds. In addition to the platinum-catalyzed hydrosilylation, silyl radical addition reactions are notable as economic reactions. An efficient and widely applicable silyl radical addition reaction was developed by using 2-silylated dihydroquinazolinone derivatives under photocatalytic conditions. Electron-deficient alkenes and styrene derivatives underwent hydrosilylation to give addition products in good to high yields. Mechanistic studies indicated that the photocatalyst functioned not as a photoredox catalyst but as an energy transfer catalyst. DFT calculations clarified that the triplet excited state of 2-silylated dihydroquinazolinone derivatives released a silyl radical through the homolytic cleavage of a carbon-silicon bond, and this was followed by the hydrogen atom transfer pathway, not the redox pathway.
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Affiliation(s)
- Tatsuhiro Uchikura
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, 171-8588, Toshima-ku, Tokyo, Japan
| | - Haruka Nakamura
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, 171-8588, Toshima-ku, Tokyo, Japan
| | - Hinata Sakai
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, 171-8588, Toshima-ku, Tokyo, Japan
| | - Takahiko Akiyama
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1, Mejiro, 171-8588, Toshima-ku, Tokyo, Japan
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7
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Singha T, Kadam GA, Hari DP. Photocatalyzed Dowd-Beckwith radical-polar crossover reaction for the synthesis of medium-sized carbocyclic compounds. Chem Sci 2023; 14:6930-6935. [PMID: 37389258 PMCID: PMC10306080 DOI: 10.1039/d3sc01908j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/24/2023] [Indexed: 07/01/2023] Open
Abstract
The Dowd-Beckwith reaction, a ring-expansion of carbonyl compounds via alkoxy radicals, is a powerful approach for synthesizing medium to large-sized carbocyclic scaffolds, which takes advantage of existing ring structures and avoids entropic and enthalpic factors that arise from the end-to-end cyclization strategies. However, the Dowd-Beckwith ring-expansion followed by H-atom abstraction is still the dominating pathway, which hampers its synthetic applications, and there currently exist no reports on the functionalization of ring-expanded radicals using non-carbon based nucleophilic reagents. Herein, we report a redox-neutral decarboxylative Dowd-Beckwith/radical-polar crossover (RPC) sequence that delivers functionalized medium-sized carbocyclic compounds with broad functional group tolerance. The reaction allows one-carbon ring-expansion of 4-, 5-, 6-, 7-, and 8-membered ring substrates and can also be applied to three-carbon chain incorporation, enabling remote functionalization in medium-sized rings.
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Affiliation(s)
- Tushar Singha
- Department of Organic Chemistry, Indian Institute of Science Bangalore 560012 India
| | - Ganesh Arjun Kadam
- Department of Organic Chemistry, Indian Institute of Science Bangalore 560012 India
| | - Durga Prasad Hari
- Department of Organic Chemistry, Indian Institute of Science Bangalore 560012 India
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8
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Zhang W, Guan W, Martinez Alvarado JI, Novaes LFT, Lin S. Deep Electroreductive Chemistry: Harnessing Carbon- and Silicon-based Reactive Intermediates in Organic Synthesis. ACS Catal 2023; 13:8038-8048. [PMID: 38707967 PMCID: PMC11067979 DOI: 10.1021/acscatal.3c01174] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
This Viewpoint outlines our recent contribution in electroreductive synthesis. Specifically, we leveraged deeply reducing potentials provided by electrochemistry to generate radical and anionic intermediates from readily available alkyl halides and chlorosilanes. Harnessing the distinct reactivities of radicals and anions, we have achieved several challenging transformations to construct C-C, C-Si, and Si-Si bonds. We highlight the mechanistic design principle that underpinned the development of each transformation and provide a view forward on future opportunities in growing area of reductive electrosynthesis.
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Affiliation(s)
| | | | | | - Luiz F. T. Novaes
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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9
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Li BX, Ishida H, Wang C, Uchiyama M. Visible-Light-Driven Silyl or Germyl Radical Generation via Si-C or Ge-C Bond Homolysis. Org Lett 2023; 25:1765-1770. [PMID: 36883960 DOI: 10.1021/acs.orglett.3c00503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
We report a simple, rapid, and selective protocol for visible-light-driven generation of silyl radicals through photoredox-induced Si-C bond homolysis. Irradiating 3-silyl-1,4-cyclohexadienes with blue light in the presence of a commercially available photocatalyst smoothly generated silyl radicals bearing various substituents within 1 h, and these radicals were trapped by a broad range of alkenes to afford products in good yields. This process is also available for efficient generation of germyl radicals.
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Affiliation(s)
- Bi-Xiao Li
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Ishida
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Chao Wang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanobu Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Research Initiative for Supra-Materials, Shinshu University, 4-17-1 Wakasato, Nagano-shi, Nagano 380-8553, Japan
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10
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Zhang G, Tian Y, Zhang C, Li X, Chen F. Decarboxylative C-H silylation of N-heteroarenes with silanecarboxylic acids. Chem Commun (Camb) 2023; 59:2449-2452. [PMID: 36752089 DOI: 10.1039/d2cc06380h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Established decarboxylative Minisci reactions are limited to aliphatic carboxylic acids, as their analogs, silanecarboxylic acids, have been rarely investigated. Herein, we present a new decarboxylative Minisci-type reaction of N-heteroarenes with silanecarboxylic acids under photo- or silver-mediated conditions. This C-H silylation strategy provides efficient access to diverse N-heteroarylsilanes in moderate to excellent yields with high regioselectivity, among which Ag-catalysed decarboxylation of silanecarboxylic acids furnishes an unprecedented method for silyl radical generation.
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Affiliation(s)
- Guodong Zhang
- School of Chemistry and Chemical Engineering, Yangzhou University, Siwangting Road 180, 225002, Yangzhou, China.
| | - Ye Tian
- School of Chemistry and Chemical Engineering, Yangzhou University, Siwangting Road 180, 225002, Yangzhou, China.
| | - Chengyu Zhang
- School of Chemistry and Chemical Engineering, Yangzhou University, Siwangting Road 180, 225002, Yangzhou, China.
| | - Xiang Li
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, 710021, Shaanxi, China.
| | - Feng Chen
- School of Chemistry and Chemical Engineering, Yangzhou University, Siwangting Road 180, 225002, Yangzhou, China.
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11
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Photoredox/Nickel Cooperatively Catalyzed Radical Allylic Silylation of Allyl Acetates – Scope and Mechanism. J Catal 2023. [DOI: 10.1016/j.jcat.2023.01.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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12
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Constantin T, Górski B, Tilby MJ, Chelli S, Juliá F, Llaveria J, Gillen KJ, Zipse H, Lakhdar S, Leonori D. Halogen-atom and group transfer reactivity enabled by hydrogen tunneling. Science 2022; 377:1323-1328. [DOI: 10.1126/science.abq8663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin and silicon reagents that maximize the interplay of enthalpic (thermodynamic) and polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled by quantum mechanical tunneling that uses the cyclohexadiene derivative γ-terpinene as the abstractor under mild photochemical conditions. This protocol activates alkyl and aryl halides as well as several alcohol and thiol derivatives. Experimental and computational studies unveiled a noncanonical pathway whereby a cyclohexadienyl radical undergoes concerted aromatization and halogen-atom or group abstraction through the reactivity of an effective H atom. This activation mechanism is seemingly thermodynamically and kinetically unfavorable but is rendered feasible through quantum tunneling.
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Affiliation(s)
| | - Bartosz Górski
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Michael J. Tilby
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Saloua Chelli
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Fabio Juliá
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Josep Llaveria
- Global Discovery Chemistry, Therapeutics Discovery, Janssen Research & Development, Janssen-Cilag S.A., 45007 Toledo, Spain
| | - Kevin J. Gillen
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Hendrik Zipse
- Department Chemie, LMU München, D-81377 München, Germany
| | - Sami Lakhdar
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Daniele Leonori
- Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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13
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Singha T, Rouf Samim Mondal A, Midya S, Prasad Hari D. The Dowd–Beckwith Reaction: History, Strategies, and Synthetic Potential. Chemistry 2022; 28:e202202025. [DOI: 10.1002/chem.202202025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Tushar Singha
- Department of Organic Chemistry Indian Institute of Scienece Bangalore 560012 India
| | | | - Suparnak Midya
- Department of Organic Chemistry Indian Institute of Scienece Bangalore 560012 India
| | - Durga Prasad Hari
- Department of Organic Chemistry Indian Institute of Scienece Bangalore 560012 India
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14
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Romero RM, Thyagarajan N, Hellou N, Chauvier C, Godou T, Anthore-Dalion L, Cantat T. Silyl formates as hydrosilane surrogates for the transfer hydrosilylation of ketones. Chem Commun (Camb) 2022; 58:6308-6311. [PMID: 35522145 PMCID: PMC9476892 DOI: 10.1039/d2cc00666a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A transfer hydrosilylation of ketones employing silyl formates as hydrosilane surrogates under mild conditions is presented. A total of 24 examples of ketones have been successfully converted to their corresponding silyl ethers with 61-99% yields in the presence of a PNHP-based ruthenium catalyst and silyl formate reagent. The crucial role of the ligand for the transformation is demonstrated.
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Affiliation(s)
- R Martin Romero
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
| | - Neethu Thyagarajan
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
| | - Nora Hellou
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
| | - Clément Chauvier
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
| | - Timothé Godou
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
| | | | - Thibault Cantat
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.
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15
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Ding L, Niu K, Liu Y, Wang Q. Visible Light-Induced Hydrosilylation of Electron-Deficient Alkenes by Iron Catalysis. CHEMSUSCHEM 2022; 15:e202200367. [PMID: 35302291 DOI: 10.1002/cssc.202200367] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Herein, we reported a method for iron-catalyzed, visible-light-induced hydrosilylation reactions of electron-deficient alkenes to produce value-added silicon compounds. Alkenes bearing functional groups with different steric properties were suitable substrates, as were derivatives of structurally complex natural products. Mechanistic studies showed that chlorine radicals generated by iron-catalyzed ligand-to-metal charge transfer in the presence of lithium chloride promoted the formation of silyl radicals.
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Affiliation(s)
- Ling Ding
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, P. R. China
| | - Kaikai Niu
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, P. R. China
| | - Yuxiu Liu
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, P. R. China
| | - Qingmin Wang
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, P. R. China
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16
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17
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Singh B, Ahmed J, Biswas A, Paira R, Mandal SK. Reduced Phenalenyl in Catalytic Dehalogenative Deuteration and Hydrodehalogenation of Aryl Halides. J Org Chem 2021; 86:7242-7255. [PMID: 33949861 DOI: 10.1021/acs.joc.1c00573] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehalogenative deuteration reactions are generally performed through metal-mediated processes. This report demonstrates a mild protocol for hydrodehalogenation and dehalogenative deuteration of aryl/heteroaryl halides (39 examples) using a reduced odd alternant hydrocarbon phenalenyl under transition metal-free conditions and has been employed successfully for the incorporation of deuterium in various biologically active compounds. The combined approach of experimental and theoretical studies revealed a single electron transfer-based mechanism.
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Affiliation(s)
- Bhagat Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
| | - Jasimuddin Ahmed
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
| | - Amit Biswas
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
| | - Rupankar Paira
- Department of Chemistry, Maharaja Manindra Chandra College, 20 Ramkanto Bose Street, Kolkata 700003, India
| | - Swadhin K Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
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18
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Lu L, Siu JC, Lai Y, Lin S. An Electroreductive Approach to Radical Silylation via the Activation of Strong Si-Cl Bond. J Am Chem Soc 2020; 142:21272-21278. [PMID: 33290654 DOI: 10.1021/jacs.0c10899] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The construction of C(sp3)-Si bonds is important in synthetic, medicinal, and materials chemistry. In this context, reactions mediated by silyl radicals have become increasingly attractive but methods for accessing these intermediates remain limited. We present a new strategy for silyl radical generation via electroreduction of readily available chlorosilanes. At highly biased potentials, electrochemistry grants access to silyl radicals through energetically uphill reductive cleavage of strong Si-Cl bonds. This strategy proved to be general in various alkene silylation reactions including disilylation, hydrosilylation, and allylic silylation under simple and transition-metal-free conditions.
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Affiliation(s)
- Lingxiang Lu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Juno C Siu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Yihuan Lai
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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19
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Yu X, Lübbesmeyer M, Studer A. Oligosilanes as Silyl Radical Precursors through Oxidative Si−Si Bond Cleavage Using Redox Catalysis. Angew Chem Int Ed Engl 2020; 60:675-679. [DOI: 10.1002/anie.202011738] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/14/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Xiaoye Yu
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
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20
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Yu X, Lübbesmeyer M, Studer A. Oligosilanes as Silyl Radical Precursors through Oxidative Si−Si Bond Cleavage Using Redox Catalysis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Xiaoye Yu
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Corrensstrasse 40 48149 Münster Germany
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21
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Uchikura T, Toda M, Mouri T, Fujii T, Moriyama K, Ibáñez I, Akiyama T. Radical Hydroalkylation and Hydroacylation of Alkenes by the Use of Benzothiazoline under Thermal Conditions. J Org Chem 2020; 85:12715-12723. [PMID: 32900192 DOI: 10.1021/acs.joc.0c01872] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hydroalkylation and hydroacylation of electron-deficient alkenes proceeded smoothly by using benzothiazoline derivatives as radical-transfer reagents under thermal conditions without light irradiation or any additive. Both benzyl and benzoyl moieties were transferred efficiently.
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Affiliation(s)
- Tatsuhiro Uchikura
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Mitsuhiro Toda
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Toshiki Mouri
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Tatsuya Fujii
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Kaworuko Moriyama
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Ignacio Ibáñez
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Takahiko Akiyama
- Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
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22
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Crespi S, Fagnoni M. Generation of Alkyl Radicals: From the Tyranny of Tin to the Photon Democracy. Chem Rev 2020; 120:9790-9833. [PMID: 32786419 PMCID: PMC8009483 DOI: 10.1021/acs.chemrev.0c00278] [Citation(s) in RCA: 173] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Indexed: 01/09/2023]
Abstract
Alkyl radicals are key intermediates in organic synthesis. Their classic generation from alkyl halides has a severe drawback due to the employment of toxic tin hydrides to the point that "flight from the tyranny of tin" in radical processes was considered for a long time an unavoidable issue. This review summarizes the main alternative approaches for the generation of unstabilized alkyl radicals, using photons as traceless promoters. The recent development in photochemical and photocatalyzed processes enabled the discovery of a plethora of new alkyl radical precursors, opening the world of radical chemistry to a broader community, thus allowing a new era of photon democracy.
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Affiliation(s)
- Stefano Crespi
- Stratingh
Institute for Chemistry, Center for Systems
Chemistry University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Maurizio Fagnoni
- PhotoGreen
Lab, Department of Chemistry, V. Le Taramelli 10, 27100 Pavia, Italy
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23
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Santos MS, Betim HLI, Kisukuri CM, Campos Delgado JA, Corrêa AG, Paixão MW. Photoredox Catalysis toward 2-Sulfenylindole Synthesis through a Radical Cascade Process. Org Lett 2020; 22:4266-4271. [DOI: 10.1021/acs.orglett.0c01297] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Marilia S. Santos
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
| | - Hugo L. I. Betim
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
| | - Camila M. Kisukuri
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
| | - Jose Antonio Campos Delgado
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
| | - Arlene G. Corrêa
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
| | - Márcio W. Paixão
- Center of Excellence for Research in Sustainable Chemistry (CERSusChem), Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP 13565-905, Brazil
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24
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Zhang J, Yang JD, Cheng JP. Exploiting the radical reactivity of diazaphosphinanes in hydrodehalogenations and cascade cyclizations. Chem Sci 2020; 11:4786-4790. [PMID: 34122935 PMCID: PMC8159257 DOI: 10.1039/d0sc01352h] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/22/2020] [Indexed: 12/19/2022] Open
Abstract
The remarkable reducibility of diazaphosphinanes has been extensively applied in various hydrogenations, based on and yet limited by their well-known hydridic reactivity. Here we exploited their unprecedented radical reactivity to implement hydrodehalogenations and cascade cyclizations originally inaccessible by hydride transfer. These reactions feature a broad substrate scope, high efficiency and simplicity of manipulation. Mechanistic studies suggested a radical chain process in which a phosphinyl radical is generated in a catalytic cycle via hydrogen-atom transfer from diazaphosphinanes. The radical reactivity of diazaphosphinanes disclosed here differs from their well-established hydridic reactivity, and hence, opens a new avenue for diazaphosphinane applications in organic syntheses.
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Affiliation(s)
- Jingjing Zhang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Jin-Dong Yang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University Beijing 100084 China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University Beijing 100084 China
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University Tianjin 300071 China
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25
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Deng W, Ye C, Li Y, Li D, Bao H. Iron-Catalyzed Oxyalkylation of Terminal Alkynes with Alkyl Iodides. Org Lett 2018; 21:261-265. [PMID: 30582704 DOI: 10.1021/acs.orglett.8b03689] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A general oxyalkylation of terminal alkynes enabled by iron catalysis has been developed. Primary and secondary alkyl iodides acted as the alkylating reagents and afforded a range of α-alkylated ketones under mild reaction conditions. Acetyl tert-butyl peroxide (TBPA) was used as the radical relay precursor, providing the initiated methyl radical to start the radical relay process. Preliminary mechanistic studies were conducted, and late-stage functionalizations of natural product derivatives were performed.
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Affiliation(s)
- Weili Deng
- Key Laboratory of Innate Immune Biology of Fujian Province, Biomedical Research Center of South China, College of Life Sciences , Fujian Normal University , 1 Keji Road , Fuzhou 350117 , P. R. China
| | - Changqing Ye
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis , Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , 155 Yangqiao Road West , Fuzhou , Fujian 350002 , P. R. of China
| | - Yajun Li
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis , Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , 155 Yangqiao Road West , Fuzhou , Fujian 350002 , P. R. of China
| | - Daliang Li
- Key Laboratory of Innate Immune Biology of Fujian Province, Biomedical Research Center of South China, College of Life Sciences , Fujian Normal University , 1 Keji Road , Fuzhou 350117 , P. R. China
| | - Hongli Bao
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis , Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , 155 Yangqiao Road West , Fuzhou , Fujian 350002 , P. R. of China
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26
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Bhunia A, Bergander K, Studer A. Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation of Alkenes and Alkynes Using 1-Methylcyclohexa-2,5-diene-1-carbonitrile. J Am Chem Soc 2018; 140:16353-16359. [PMID: 30392374 DOI: 10.1021/jacs.8b10651] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Catalytic transfer hydrocyanation represents a clean and safe alternative to hydrocyanation processes using toxic HCN gas. Such reactions provide access to pharmaceutically important nitrile derivatives starting with alkenes and alkynes. Herein, an efficient and practical cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation of alkenes and alkynes is presented using 1-methylcyclohexa-2,5-diene-1-carbonitrile as a benign and readily available HCN source. A large set of nitrile derivatives (>50 examples) are prepared from both aliphatic and aromatic alkenes with good to excellent anti-Markovnikov selectivity. A range of aliphatic alkenes engage in selective hydrocyanation to provide the corresponding nitriles. The introduced method is useful for chain walking hydrocyanation of internal alkenes to afford terminal nitriles in good regioselectivities. This protocol is also applicable to late-stage modification of bioactive molecules.
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Affiliation(s)
- Anup Bhunia
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
| | - Klaus Bergander
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
| | - Armido Studer
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
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27
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Huang MH, Hao WJ, Jiang B. Recent Advances in Radical-Enabled Bicyclization and Annulation/1,n
-Bifunctionalization Reactions. Chem Asian J 2018; 13:2958-2977. [DOI: 10.1002/asia.201801119] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Min-Hua Huang
- School of Chemistry & Materials Science; Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials; Jiangsu Normal University; Xuzhou 221116 P. R. China
- Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; Nanjing 210009, Jiangsu P. R. China
| | - Wen-Juan Hao
- School of Chemistry & Materials Science; Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials; Jiangsu Normal University; Xuzhou 221116 P. R. China
| | - Bo Jiang
- School of Chemistry & Materials Science; Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials; Jiangsu Normal University; Xuzhou 221116 P. R. China
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28
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Li G, Noguchi M, Nakamura K, Hayasaka R, Tanaka Y, Shoda SI. First protection-free protocol for synthesis of 1-deoxy sugars through glycosyl dithiocarbamate intermediates. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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29
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Wiesenfeldt MP, Knecht T, Schlepphorst C, Glorius F. Silylarenhydrierung – ein strategischer Ansatz für einen direkten Zugang zu silylierten gesättigten Carbo‐ und Heterocyclen. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804124] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mario P. Wiesenfeldt
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Tobias Knecht
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Christoph Schlepphorst
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
| | - Frank Glorius
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Deutschland
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30
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Wiesenfeldt MP, Knecht T, Schlepphorst C, Glorius F. Silylarene Hydrogenation: A Strategic Approach that Enables Direct Access to Versatile Silylated Saturated Carbo‐ and Heterocycles. Angew Chem Int Ed Engl 2018; 57:8297-8300. [DOI: 10.1002/anie.201804124] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Mario P. Wiesenfeldt
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Tobias Knecht
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Christoph Schlepphorst
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Frank Glorius
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
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31
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Hokamp T, Dewanji A, Lübbesmeyer M, Mück‐Lichtenfeld C, Würthwein E, Studer A. Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane. Angew Chem Int Ed Engl 2017; 56:13275-13278. [PMID: 28841248 PMCID: PMC5698765 DOI: 10.1002/anie.201706534] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Indexed: 11/24/2022]
Abstract
A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
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Affiliation(s)
- Tobias Hokamp
- Organisch-Chemisches InstitutWestfälische Wilhelms-UniversitätCorrensstraße 4048149MünsterGermany
| | - Abhishek Dewanji
- Organisch-Chemisches InstitutWestfälische Wilhelms-UniversitätCorrensstraße 4048149MünsterGermany
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches InstitutWestfälische Wilhelms-UniversitätCorrensstraße 4048149MünsterGermany
| | | | - Ernst‐Ulrich Würthwein
- Organisch-Chemisches InstitutWestfälische Wilhelms-UniversitätCorrensstraße 4048149MünsterGermany
| | - Armido Studer
- Organisch-Chemisches InstitutWestfälische Wilhelms-UniversitätCorrensstraße 4048149MünsterGermany
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32
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Hokamp T, Dewanji A, Lübbesmeyer M, Mück-Lichtenfeld C, Würthwein EU, Studer A. Radikalische Hydrodehalogenierung von Arylbromiden und -chloriden mit Natriumhydrid und 1,4-Dioxan. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tobias Hokamp
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Abhishek Dewanji
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Maximilian Lübbesmeyer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Ernst-Ulrich Würthwein
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
| | - Armido Studer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Deutschland
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33
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Xuan J, Studer A. Radical cascade cyclization of 1,n-enynes and diynes for the synthesis of carbocycles and heterocycles. Chem Soc Rev 2017; 46:4329-4346. [DOI: 10.1039/c6cs00912c] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review highlights recent advances in radical cascade cyclization of 1,n-enynes and diynes for the construction of carbo- and heterocycles.
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Affiliation(s)
- Jun Xuan
- Department of Chemistry
- Anhui University
- Hefei
- People's Republic of China
| | - Armido Studer
- Institute of Organic Chemistry
- Westfälische Wilhems-University
- 48149 Münster
- Germany
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34
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Methoxycarbonyl migration in 3-methylene-1,4-cyclohexadienes. An extension of the von Auwers rearrangement. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Dewanji A, Mück-Lichtenfeld C, Studer A. Radical Hydrodeiodination of Aryl, Alkenyl, Alkynyl, and Alkyl Iodides with an Alcoholate as Organic Chain Reductant through Electron Catalysis. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601930] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Abhishek Dewanji
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
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36
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Dewanji A, Mück-Lichtenfeld C, Studer A. Radical Hydrodeiodination of Aryl, Alkenyl, Alkynyl, and Alkyl Iodides with an Alcoholate as Organic Chain Reductant through Electron Catalysis. Angew Chem Int Ed Engl 2016; 55:6749-52. [DOI: 10.1002/anie.201601930] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/31/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Abhishek Dewanji
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches Institut; Westfälische Wilhelms-Universität; Corrensstraße 40 48149 Münster Germany
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37
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38
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39
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Tang RJ, He Q, Yang L. Metal-free oxidative decarbonylative coupling of aromatic aldehydes with arenes: direct access to biaryls. Chem Commun (Camb) 2015; 51:5925-8. [PMID: 25731601 DOI: 10.1039/c4cc10155c] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A metal-free oxidative decarbonylative coupling of aromatic aldehydes with electron-rich or electron-deficient arenes to produce biaryl compounds was developed. This novel coupling was proposed to proceed via a non-chain radical homolytic aromatic substitution (HAS) type mechanism, based on the substrate scope, ortho-regioselectivity, radical trapping experiments and DFT calculation studies. With the ready availability of aromatic aldehydes and arenes, metal-free conditions should make this coupling attractive for the biaryl synthesis.
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Affiliation(s)
- Ren-Jin Tang
- Key Laboratory for Environmentally Friendly Chemistry and Application of the Ministry of Education, College of Chemistry, Xiangtan University, Hunan, 411105, China.
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40
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Leifert D, Studer A. 9-Silafluorenes via base-promoted homolytic aromatic substitution (BHAS)--the electron as a catalyst. Org Lett 2014; 17:386-9. [PMID: 25536028 DOI: 10.1021/ol503574k] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Transition-metal-free intramolecular radical silylation of 2-diphenylsilylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenylsilylbiaryls are readily prepared, and cross dehydrogenative silylation occurs with tert-butylhydroperoxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetrabutylammonium iodide (TBAI) as an initiator. These cyclizations are catalyzed by the electron.
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Affiliation(s)
- Dirk Leifert
- Institute of Organic Chemistry, Westfälische Wilhelms-Universität , Corrensstraße 40, 48149 Münster, Germany
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41
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Rousseau G, Lebeuf R, Schenk K, Castet F, Robert F, Landais Y. Base-catalyzed intramolecular hydroamination of cyclohexa-2,5-dienes: insights into the mechanism through DFT calculations and application to the total synthesis of epi-elwesine. Chemistry 2014; 20:14771-82. [PMID: 25223607 DOI: 10.1002/chem.201403662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/10/2014] [Indexed: 11/08/2022]
Abstract
The base-catalyzed intramolecular hydroamination of 1-ethylaminocyclohexa-2,5-dienes is described. The transformation proceeds through isomerization of the cyclohexa-1,4-dienyl fragment into the corresponding conjugated 1,3-diene prior to the hydroamination step. Attaching a chiral glycinol ether auxiliary on the amino group allows the protonation to occur with complete diastereocontrol. The resulting lithium amide then adds onto the 1,3-dienyl moiety, affording the desired fused pyrrolidine ring along with the corresponding lithium allylic anion. Protonation of the latter then proceeds with high regiocontrol to favor the resulting allylic amines. In contrast, when the reaction was performed on primary amines, fused pyrrolidines bearing a homoallylic amino group were obtained. The stereochemical course of the process and determination of the reaction pathways were established based on calculations performed at the DFT level. Finally, application of the methodology to the enantioselective synthesis of (+)-epi-elwesine, a crinane alkaloid, is described.
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Affiliation(s)
- Géraldine Rousseau
- ISM, UMR 5255, University of Bordeaux and CNRS, 351, Cours de la liberation, 33400 Talence Cedex (France)
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Yi H, Zhang X, Qin C, Liao Z, Liu J, Lei A. Visible Light-Induced γ-Alkoxynitrile SynthesisviaThree- Component Alkoxycyanomethylation of Alkenes. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400548] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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43
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Chenneberg L, Baralle A, Daniel M, Fensterbank L, Goddard JP, Ollivier C. Visible Light Photocatalytic Reduction ofO-Thiocarbamates: Development of a Tin-Free Barton-McCombie Deoxygenation Reaction. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400729] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Rackl D, Kais V, Kreitmeier P, Reiser O. Visible light photoredox-catalyzed deoxygenation of alcohols. Beilstein J Org Chem 2014; 10:2157-65. [PMID: 25246974 PMCID: PMC4168922 DOI: 10.3762/bjoc.10.223] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/27/2014] [Indexed: 11/23/2022] Open
Abstract
Carbon–oxygen single bonds are ubiquitous in natural products whereas efficient methods for their reductive defunctionalization are rare. In this work an environmentally benign protocol for the activation of carbon–oxygen single bonds of alcohols towards a reductive bond cleavage under visible light photocatalysis was developed. Alcohols were activated as 3,5-bis(trifluoromethyl)-substituted benzoates and irradiation with blue light in the presence of [Ir(ppy)2(dtb-bpy)](PF6) as visible light photocatalyst and Hünig’s base as sacrificial electron donor in an acetonitrile/water mixture generally gave good to excellent yields of the desired defunctionalized compounds. Functional group tolerance is high but the protocol developed is limited to benzylic, α-carbonyl, and α-cyanoalcohols; with other alcohols a slow partial C–F bond reduction in the 3,5-bis(trifluoromethyl)benzoate moiety occurs.
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Affiliation(s)
- Daniel Rackl
- Institute of Organic Chemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Viktor Kais
- Institute of Organic Chemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Peter Kreitmeier
- Institute of Organic Chemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Oliver Reiser
- Institute of Organic Chemistry, University of Regensburg, 93053 Regensburg, Germany
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45
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Chaudhari DA, Kattanguru P, Fernandes RA. A practical and improved process for the synthesis of Hagen’s gland lactones by catalytic hydro-deiodination. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.tetasy.2014.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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46
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Li G, Wu L, Lv G, Liu H, Fu Q, Zhang X, Tang Z. Alkyl transfer from C–C cleavage: replacing the nitro group of nitro-olefins. Chem Commun (Camb) 2014; 50:6246-8. [DOI: 10.1039/c4cc01119h] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogenation is only the beginning: alkyl groups are mildly transferred from alkyl substituted Hantzsch esters to replace the nitro groups of nitro olefins to providetrans-olefins in moderate to excellent yields.
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Affiliation(s)
- Guangxun Li
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Lei Wu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Gang Lv
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Hongxin Liu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Qingquan Fu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Xiaomei Zhang
- Chengdu Institute of Organic Chemistry
- Chinese Academy of Sciences
- Chengdu, China
| | - Zhuo Tang
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
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47
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Abstract
This review article focuses on state-of-the-art borohydride based radical reactions, also covering earlier work, kinetics and some DFT calculations with respect to the hydrogen transfer mechanism.
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Affiliation(s)
- Takuji Kawamoto
- Department of Chemistry
- Graduate School of Science
- Osaka Prefecture University
- Sakai, Japan
| | - Ilhyong Ryu
- Department of Chemistry
- Graduate School of Science
- Osaka Prefecture University
- Sakai, Japan
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48
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Mitsudo K, Nakagawa Y, Mizukawa JI, Tanaka H, Akaba R, Okada T, Suga S. Electro-reductive cyclization of aryl halides promoted by fluorene derivatives. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.03.130] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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Hierold J, Lupton DW. Synthesis of Spirocyclic γ-Lactones by Cascade Beckwith–Dowd Ring Expansion/Cyclization. Org Lett 2012; 14:3412-5. [DOI: 10.1021/ol301386k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Judith Hierold
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | - David W. Lupton
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
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Rouquet G, Robert F, Méreau R, Castet F, Renaud P, Landais Y. Silylboranes as new sources of silyl radicals for chain-transfer reactions. Chemistry 2012; 18:940-50. [PMID: 22180016 DOI: 10.1002/chem.201102318] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Indexed: 11/05/2022]
Abstract
Various silylboranes, which were outfitted with a catecholborane moiety at one end and a (Me(3)Si)(3)Si moiety at the other end of a carbon chain, were prepared through the hydroboration of the corresponding unsaturated silanes. The C-centered radical species generated from these silylboranes efficiently cyclized to provide, through a 5-exo intramolecular homolytic substitution at the silicon center, the corresponding silacycle and a Me(3)Si radical that was subsequently trapped by sulfonyl acceptors. These cyclizations proceeded at unprecedented rates, due, in part, to a strong gem-dialkyl effect that was attributable to the presence of bulky substituents on a quaternary center located on the chain. In parallel, we designed arylsilylboranes that produced silyl radicals through a 1,5-hydrogen transfer. Such silyl radicals may be valuable radical chain carriers, for instance, in oximation reactions of alkyl halides. Finally, computational studies allowed calculation of activation barriers of the homolytic substitution step and additionally illustrated that the overall reaction mechanism involved a transition state in which the attacking carbon center, the central silicon atom, and the Me(3)Si leaving group were collinear.
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Affiliation(s)
- Guy Rouquet
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR-CNRS 5255, 351, Cours de la libération 33405 Talence Cedex, France
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