101
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Saicic RN. Protecting group-free syntheses of natural products and biologically active compounds. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.06.025] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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102
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Nagatomo M, Yoshioka S, Inoue M. Enantioselective Radical Alkynylation of C(sp3)-H Bonds Using Sulfoximine as a Traceless Chiral Auxiliary. Chem Asian J 2014; 10:120-3. [DOI: 10.1002/asia.201402983] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Indexed: 01/22/2023]
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103
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Moteki SA, Usui A, Selvakumar S, Zhang T, Maruoka K. Metal-free C-H bond activation of branched aldehydes with a hypervalent iodine(III) catalyst under visible-light photolysis: successful trapping with electron-deficient olefins. Angew Chem Int Ed Engl 2014; 53:11060-4. [PMID: 25155904 DOI: 10.1002/anie.201406513] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Indexed: 11/08/2022]
Abstract
Direct acyl radical formation of linear aldehydes (RCH2-CHO) and subsequent hydroacylation with electron-deficient olefins can be effected with various types of metal and nonmetal catalysts/reagents. In marked contrast, however, no successful reports on the use of branched aldehydes have been made thus far because of their strong tendency of generating alkyl radicals through the facile decarbonylation of acyl radicals. Here, use of a hypervalent iodine(III) catalyst under visible light photolysis allows a mild way of generating acyl radicals from various branched aldehydes, thereby giving the corresponding hydroacylated products almost exclusively. Another characteristic feature of this approach is the catalytic use of hypervalent iodine(III) reagent, which is a rare example on the generation of radicals in hypervalent iodine chemistry.
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Affiliation(s)
- Shin A Moteki
- Laboratory of Synthetic Organic Chemistry and Special Laboratory of Organocatalytic Chemistry, Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
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104
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Moteki SA, Usui A, Selvakumar S, Zhang T, Maruoka K. Metal-Free CH Bond Activation of Branched Aldehydes with a Hypervalent Iodine(III) Catalyst under Visible-Light Photolysis: Successful Trapping with Electron-Deficient Olefins. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406513] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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105
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Logan AWJ, Sprague SJ, Foster RW, Marx LB, Garzya V, Hallside MS, Thompson AL, Burton JW. Diastereoselective Synthesis of Fused Lactone-Pyrrolidinones; Application to a Formal Synthesis of (−)-Salinosporamide A. Org Lett 2014; 16:4078-81. [DOI: 10.1021/ol501662t] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Angus W. J. Logan
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Simon J. Sprague
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Robert W. Foster
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Léo B. Marx
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | | | - Michal S. Hallside
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Amber L. Thompson
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Jonathan W. Burton
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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106
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Fernández-Salas JA, Rodríguez-Fernández MM, Maestro MC, García-Ruano JL. Synthesis of Enantiomerically Pure (α-Phenylalkyl)amines with Substituents at theorthoPosition through Diastereoselective Radical Alkylation Reaction of Sulfinimines. European J Org Chem 2014. [DOI: 10.1002/ejoc.201402355] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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107
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Zhang N, Samanta SR, Rosen BM, Percec V. Single Electron Transfer in Radical Ion and Radical-Mediated Organic, Materials and Polymer Synthesis. Chem Rev 2014; 114:5848-958. [DOI: 10.1021/cr400689s] [Citation(s) in RCA: 320] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Na Zhang
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Shampa R. Samanta
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Brad M. Rosen
- DuPont Titanium Technologies, Chestnut Run Plaza, Wilmington, Delaware 19805, United States
| | - Virgil Percec
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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108
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Roncaglia F, Ghelfi F, Felluga F, Poppi V. Simultaneous deprotection–oxidation of cyclic hemiacetals: a fine ending for a Ueno–Stork ATRC to dichloro-γ-lactones. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.03.090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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109
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Lewis acid-catalyzed cascade radical addition/cyclization for the synthesis of 3-substituted isoindolin-1-one derivatives. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.03.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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110
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Yoshimitsu T. Endeavors to access molecular complexity: strategic use of free radicals in natural product synthesis. CHEM REC 2014; 14:268-79. [PMID: 24677484 DOI: 10.1002/tcr.201300024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Indexed: 01/16/2023]
Abstract
Free radicals, which in the past were considered unruly chemical species, have become manageable and indispensable for synthetic organic chemistry. The unique nature of free radicals has allowed practitioners in organic synthesis to design flexible approaches to produce various materials ranging from small molecules to polymers. The present Personal Account describes the author's endeavors to create molecular complexity by the strategic use of free radicals, with an emphasis on the synthesis of bioactive natural products.
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Affiliation(s)
- Takehiko Yoshimitsu
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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111
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Huang H, Zhang G, Gong L, Zhang S, Chen Y. Visible-Light-Induced Chemoselective Deboronative Alkynylation under Biomolecule-Compatible Conditions. J Am Chem Soc 2014; 136:2280-3. [DOI: 10.1021/ja413208y] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Hanchu Huang
- State Key Laboratory of Bioorganic
and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 People’s Republic of China
| | - Guojin Zhang
- State Key Laboratory of Bioorganic
and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 People’s Republic of China
| | - Li Gong
- State Key Laboratory of Bioorganic
and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 People’s Republic of China
| | - Shuaiyan Zhang
- State Key Laboratory of Bioorganic
and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 People’s Republic of China
| | - Yiyun Chen
- State Key Laboratory of Bioorganic
and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 People’s Republic of China
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112
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Friestad GK. Control of asymmetry in the radical addition approach to chiral amine synthesis. Top Curr Chem (Cham) 2014; 343:1-32. [PMID: 24085561 PMCID: PMC4114248 DOI: 10.1007/128_2013_481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The state-of-the-science in asymmetric free radical additions to imino compounds is presented, beginning with an overview of methods involving stereocontrol by various chiral auxiliary approaches. Chiral N-acylhydrazones are discussed with respect to their use as radical acceptors for Mn-mediated intermolecular additions, from design to scope surveys to applications to biologically active targets. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and a variety of alkyl iodides may be employed as radical precursors, as discussed in a critical review of the functional group compatibility of the reaction. Applications to amino acid and alkaloid synthesis are presented to illustrate the synthetic potential of these versatile stereocontrolled carbon-carbon bond construction reactions. Asymmetric catalysis is discussed, from seminal work on the stereocontrol of radical addition to imino compounds by non-covalent interactions with stoichiometric amounts of catalysts, to more recent examples demonstrating catalyst turnover.
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113
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Kang YW, Jang HY. NHC-catalyzed one-pot oxidation and oxidative esterification of allylic alcohols using TEMPO: the effect of alcohol additives. RSC Adv 2014. [DOI: 10.1039/c4ra08133a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A combination of N-heterocyclic carbene (NHC) catalysts and 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) was proposed for the synthesis of allylic esters from allylic alcohols.
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Affiliation(s)
- Ye-Won Kang
- Department of Energy Systems Research
- Ajou University
- Suwon 443-749, Korea
| | - Hye-Young Jang
- Department of Energy Systems Research
- Ajou University
- Suwon 443-749, Korea
- Korea Carbon Capture & Sequestration R&D Center
- Deajeon 305-343, Korea
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114
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Broggi J, Terme T, Vanelle P. Organic Electron Donors as Powerful Single-Electron Reducing Agents in Organic Synthesis. Angew Chem Int Ed Engl 2013; 53:384-413. [DOI: 10.1002/anie.201209060] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 05/16/2013] [Indexed: 11/07/2022]
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115
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Broggi J, Terme T, Vanelle P. Organische Elektronendonoren als leistungsfähige Ein-Elektronen-Reduktionsmittel in der organischen Synthese. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201209060] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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116
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Pati K, Hughes AM, Phan H, Alabugin IV. Exo-DigRadical Cascades of Skipped Enediynes: Building a Naphthalene Moiety within a Polycyclic Framework. Chemistry 2013; 20:390-3. [DOI: 10.1002/chem.201304092] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Indexed: 01/23/2023]
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117
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Chudasama V, Akhbar AR, Bahou KA, Fitzmaurice RJ, Caddick S. Metal-free, hydroacylation of C=C and N=N bonds via aerobic C-H activation of aldehydes, and reaction of the products thereof. Org Biomol Chem 2013; 11:7301-17. [PMID: 24068290 DOI: 10.1039/c3ob41632a] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this report, a thorough evaluation of the use of aerobically initiated, metal-free hydroacylation of various C=C and N=N acceptor molecules with a wide range of aldehydes is presented. The aerobic-activation conditions that have been developed are in sharp contrast to previous conditions for hydroacylation, which tend to use transition metals, peroxides that require thermal or photochemical degradation, or N-heterocyclic carbenes. The mildness of the conditions enables a number of reactions involving sensitive reaction partners and, perhaps most significantly, allows for α-functionalised chiral aldehydes to undergo radical-based hydroacylation with complete retention of optical purity. We also demonstrate how the resulting hydroacylation products can be transformed into other useful intermediates, such as γ-keto-sulfonamides, sultams, sultones, cyclic N-sulfonyl imines and amides.
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Affiliation(s)
- Vijay Chudasama
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ, UK.
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118
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Cangönül A, Behlendorf M, Gansäuer A, van Gastel M. Radical-Based Epoxide Opening by Titanocenes. Inorg Chem 2013; 52:11859-66. [DOI: 10.1021/ic401403a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Asli Cangönül
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse
34-36, D-45470 Mülheim
an der Ruhr, Germany
| | - Maike Behlendorf
- Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard Domagk
Str. 1, 53121 Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard Domagk
Str. 1, 53121 Bonn, Germany
| | - Maurice van Gastel
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse
34-36, D-45470 Mülheim
an der Ruhr, Germany
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119
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Lackner GL, Quasdorf KW, Overman LE. Direct construction of quaternary carbons from tertiary alcohols via photoredox-catalyzed fragmentation of tert-alkyl N-phthalimidoyl oxalates. J Am Chem Soc 2013; 135:15342-5. [PMID: 24074152 DOI: 10.1021/ja408971t] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A convenient method for the direct construction of quaternary carbons from tertiary alcohols by visible-light photoredox coupling of tert-alkyl N-phthalimidoyl oxalate intermediates with electron-deficient alkenes is reported.
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Affiliation(s)
- Gregory L Lackner
- Department of Chemistry, University of California , Irvine, California 92697-2025, United States
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120
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Shirakawa S, Usui A, Kan SBJ, Maruoka K. Chiral Organotin Hydride Catalyzed Enantioselective Radical Cyclization of Aldehydes. ASIAN J ORG CHEM 2013. [DOI: 10.1002/ajoc.201300138] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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121
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Fukuyama T, Kawamoto T, Kobayashi M, Ryu I. Flow Giese reaction using cyanoborohydride as a radical mediator. Beilstein J Org Chem 2013; 9:1791-6. [PMID: 24062844 PMCID: PMC3778382 DOI: 10.3762/bjoc.9.208] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/14/2013] [Indexed: 11/23/2022] Open
Abstract
Tin-free Giese reactions, employing primary, secondary, and tertiary alkyl iodides as radical precursors, ethyl acrylate as a radical trap, and sodium cyanoborohydride as a radical mediator, were examined in a continuous flow system. With the use of an automated flow microreactor, flow reaction conditions for the Giese reaction were quickly optimized, and it was found that a reaction temperature of 70 °C in combination with a residence time of 10-15 minutes gave good yields of the desired addition products.
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Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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122
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Stoltz B, Motherwell W. Tetrahedron reports on organic chemistry. Tetrahedron 2013. [DOI: 10.1016/s0040-4020(13)01252-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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123
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Stankiewicz A, Szczygieł I, Szczygieł B. Summary of Existing Models of the Ni-P Coating Electroless Deposition Process. INT J CHEM KINET 2013. [DOI: 10.1002/kin.20810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- A. Stankiewicz
- Department of Inorganic Chemistry; Wrocław University of Economics; 53-345; Wrocław; Poland
| | - I. Szczygieł
- Department of Inorganic Chemistry; Wrocław University of Economics; 53-345; Wrocław; Poland
| | - B. Szczygieł
- Faculty of Chemistry; Wrocław University of Technology; 50-370; Wrocław; Poland
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124
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Gu X, Li X, Qu Y, Yang Q, Li P, Yao Y. Intermolecular Visible-Light Photoredox Atom-Transfer Radical [3+2]-Cyclization of 2-(Iodomethyl)cyclopropane-1,1-dicarboxylate with Alkenes and Alkynes. Chemistry 2013; 19:11878-82. [DOI: 10.1002/chem.201301943] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Indexed: 11/05/2022]
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125
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Miyabe H, Asada R, Takemoto Y. Cascade radical reaction of substrates with a carbon-carbon triple bond as a radical acceptor. Beilstein J Org Chem 2013; 9:1148-55. [PMID: 23843907 PMCID: PMC3701377 DOI: 10.3762/bjoc.9.128] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 05/22/2013] [Indexed: 11/24/2022] Open
Abstract
The limitation of hydroxamate ester as a chiral Lewis acid coordination moiety was first shown in an intermolecular reaction involving a radical addition and sequential allylation processes. Next, the effect of hydroxamate ester was studied in the cascade addition–cyclization–trapping reaction of substrates with a carbon–carbon triple bond as a radical acceptor. When substrates with a methacryloyl moiety and a carbon–carbon triple bond as two polarity-different radical acceptors were employed, the cascade reaction proceeded effectively. A high level of enantioselectivity was also obtained by a proper combination of chiral Lewis acid and these substrates.
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Affiliation(s)
- Hideto Miyabe
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan ; Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
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126
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Bellesia F, Clark AJ, Felluga F, Gennaro A, Isse AA, Roncaglia F, Ghelfi F. Efficient and Green Route to γ-Lactams by Copper-Catalysed Reversed Atom Transfer Radical Cyclisation of α-Polychloro-N-allylamides, using a Low Load of Metal (0.5 mol%). Adv Synth Catal 2013. [DOI: 10.1002/adsc.201300132] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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127
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Kawamoto T, Okada T, Curran DP, Ryu I. Efficient hydroxymethylation reactions of iodoarenes using CO and 1,3-dimethylimidazol-2-ylidene borane. Org Lett 2013; 15:2144-7. [PMID: 23590524 DOI: 10.1021/ol4006294] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A hydroxymethylation reaction of a variety of iodoarenes proceeded effectively in the presence of CO, NHC-borane, diMeImd-BH3 (2) as a radical mediator, and a catalytic amount of AIBN. The reaction took place chemoselectively at the aryl-iodine bond but not at the aryl-bromine and aryl-chlorine bonds. A three-component coupling reaction comprising aryl iodides, CO, and electron-deficient alkenes also proceeded well to give unsymmetrical ketones in good yields. Control experiments show that 2 would act as a hydrogen donor to acyl radicals and iodinated NHC-borane as a reducing agent of aldehydes.
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Affiliation(s)
- Takuji Kawamoto
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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128
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Fernández-Salas JA, Maestro MC, Rodríguez-Fernández MM, García-Ruano JL, Alonso I. Intermolecular alkyl radical additions to enantiopure N-tert-butanesulfinyl aldimines. Org Lett 2013; 15:1658-61. [PMID: 23484734 DOI: 10.1021/ol400439g] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The sulfinyl group in (R)-N-tert-butanesulfinyl aldimines provides efficient control of the stereoselectivity in the intermolecular reactions with alkyl radicals. The methodology is applicable to aryl, heteroaryl, benzyl, and alkynyl imines, even those containing CN, CO2Me, COR, and OH groups. The best results are attained with hindered radicals (tertiary and secondary ones) without C═N bond reduction. This reaction complements the well-established organometallic additions to N-sulfinyl aldimines to obtain enantiomerically pure functionalized α-branched primary amines.
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Affiliation(s)
- José A Fernández-Salas
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049-Cantoblanco, Madrid, Spain
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129
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Quinn RK, Schmidt VA, Alexanian EJ. Radical carbooxygenations of alkenes using hydroxamic acids. Chem Sci 2013. [DOI: 10.1039/c3sc51466h] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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130
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Murai T, Maekawa Y, Monzaki M, Ando T, Maruyama T. Anti-Markovnikov hydrophosphoroselenoylation of alkenes using phosphorodiselenoic acid esters leading to the formation of phosphonoselenoic acid esters. Chem Commun (Camb) 2013; 49:9675-7. [DOI: 10.1039/c3cc45912h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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131
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Clark JS, Berger R, Hayes ST, Senn HM, Farrugia LJ, Thomas LH, Morrison AJ, Gobbi L. Total Syntheses of Multiple Cladiellin Natural Products by Use of a Completely General Strategy. J Org Chem 2012; 78:673-96. [DOI: 10.1021/jo302542h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Stephen Clark
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Raphaëlle Berger
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Stewart T. Hayes
- School of Chemistry, University of Nottingham, University Park, Nottingham
NG7 2RD, United Kingdom
| | - Hans Martin Senn
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Louis J. Farrugia
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Lynne H. Thomas
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | | | - Luca Gobbi
- Discovery Chemistry (PRCB), F. Hoffmann-La Roche Ltd. Pharmaceuticals Division,
CH-4070 Basel, Switzerland
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132
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Rossi B, Prosperini S, Pastori N, Clerici A, Punta C. New advances in titanium-mediated free radical reactions. Molecules 2012; 17:14700-32. [PMID: 23519248 PMCID: PMC6268425 DOI: 10.3390/molecules171214700] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 11/28/2012] [Accepted: 12/06/2012] [Indexed: 01/11/2023] Open
Abstract
Titanium complexes have been widely used as catalysts for C‑C bond-forming processes via free-radical routes. Herein we provide an overview of some of the most significant contributions in the field, that covers the last decade, emphasizing the key role played by titanium salts in the promotion of selective reactions aimed at the synthesis of multifunctional organic compounds, including nucleophilic radical additions to imines, pinacol and coupling reactions, ring opening of epoxides and living polymerization.
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Affiliation(s)
- Bianca Rossi
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy; E-Mails: (B.R.); (S.P.); (N.P.); (A.C.)
| | - Simona Prosperini
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy; E-Mails: (B.R.); (S.P.); (N.P.); (A.C.)
- INSTM (National Consortium for Materials Science and Technology) Local Unit, Politecnico di Milano, 20133 Milan, Italy
| | - Nadia Pastori
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy; E-Mails: (B.R.); (S.P.); (N.P.); (A.C.)
| | - Angelo Clerici
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy; E-Mails: (B.R.); (S.P.); (N.P.); (A.C.)
| | - Carlo Punta
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy; E-Mails: (B.R.); (S.P.); (N.P.); (A.C.)
- INSTM (National Consortium for Materials Science and Technology) Local Unit, Politecnico di Milano, 20133 Milan, Italy
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133
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Yoshioka E, Kohtani S, Sawai K, Kentefu, Tanaka E, Miyabe H. Polarity-mismatched addition of electrophilic carbon radicals to an electron-deficient acceptor: cascade radical addition-cyclization-trapping reaction. J Org Chem 2012; 77:8588-604. [PMID: 22963515 DOI: 10.1021/jo3015227] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The polarity-mismatched perfluoroalkyl radical addition to electron-deficient alkenes was studied. For this study, several substrates having two polarity-different radical acceptors were employed to investigate the regiochemical courses of cascade reaction. In the case of substrate 1 having a methacryloyl moiety, we found polarity-mismatched perfluoroalkylation giving 15a-e as a major course over the polarity-matched perfluoroalkylation giving 16a-e. Moreover, in the case of substrates 2-7, perfluoroalkyl radicals selectively added to an electron-deficient alkene moiety of 2-7, to give polarity-mismatched perfluoroalkylation products without the formation of regioisomers. Next, the control of enantioselectivity was studied. In the case of substrates 1 and 3, the reaction proceeded with good enantioselectivities by employing a chiral Lewis acid, prepared from chiral box ligand 24 and Zn(OTf)(2). For direct comparison, we also studied the reaction with other carbon radicals, derived from ICH(2)CO(2)Et, ICH(2)CN, BrC(CO(2)Et)(2)Me, and CCl(3)Br, which have electrophilic character.
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Affiliation(s)
- Eito Yoshioka
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
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134
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Radical induced fragmentation in a benzoxocane ring system: application to the synthesis of elvirol and a formal synthesis of 7,8-dihydroxycalamenene. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.05.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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135
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Gansäuer A, Klatte M, Brändle GM, Friedrich J. Nachhaltige stereoselektive Radikalreduktion durch katalytischen H-Atom-Transfer (HAT). Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201202818] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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136
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Gansäuer A, Klatte M, Brändle GM, Friedrich J. Catalytic Hydrogen Atom Transfer (HAT) for Sustainable and Diastereoselective Radical Reduction. Angew Chem Int Ed Engl 2012; 51:8891-4. [DOI: 10.1002/anie.201202818] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Indexed: 11/07/2022]
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137
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Asandei AD, Adebolu OI, Simpson CP. Mild-temperature Mn2(CO)10-photomediated controlled radical polymerization of vinylidene fluoride and synthesis of well-defined poly(vinylidene fluoride) block copolymers. J Am Chem Soc 2012; 134:6080-3. [PMID: 22458593 DOI: 10.1021/ja300178r] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
By contrast to typical high-temperature (100-250 °C) telo-/polymerizations of gaseous fluorinated monomers, carried out in high-pressure metal reactors, the visible light, Mn(2)(CO)(10)-photomediated initiation of vinylidene fluoride (bp = -83 °C) polymerization occurs readily from a variety of alkyl, semifluorinated, and perfluorinated halides at 40 °C, in low-pressure glass tubes and in a variety of solvents, including water and alkyl carbonates. Perfluorinated alkyl iodide initiators also induce a controlled radical polymerization via iodine degenerative transfer (IDT). While IDT proceeds with accumulation of the less reactive P(m)-CF(2)-CH(2)-I vs the P(n)-CH(2)-CF(2)-I chain ends, Mn(2)(CO)(10) enables their subsequent quantitative activation toward the synthesis of well-defined poly(vinylidene fluoride) block copolymers with a variety of other monomers.
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Affiliation(s)
- Alexandru D Asandei
- Institute of Materials Science and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06069-3136, USA.
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138
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Miyabe H, Asada R, Takemoto Y. Lewis acid-mediated radical cyclization: stereocontrol in cascade radical addition-cyclization-trapping reactions. Org Biomol Chem 2012; 10:3519-30. [PMID: 22434240 DOI: 10.1039/c2ob25073j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient approach for achieving radical cyclizations by using hydroxamate ester as a coordination tether with Lewis acid was studied. The chiral Lewis acid-mediated cascade radical addition-cyclization-trapping reaction proceeded smoothly with good enantio- and diastereoselectivities, providing various chiral γ-lactams.
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Affiliation(s)
- Hideto Miyabe
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
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139
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Pan X, Lacôte E, Lalevée J, Curran DP. Polarity reversal catalysis in radical reductions of halides by N-heterocyclic carbene boranes. J Am Chem Soc 2012; 134:5669-74. [PMID: 22394128 DOI: 10.1021/ja300416f] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Otherwise sluggish or completely ineffective radical reductions of alkyl and aryl halides by N-heterocyclic carbene boranes (NHC-boranes) are catalyzed by thiols. Reductions and reductive cyclizations with readily available 1,3-dimethylimidazol-2-ylidene borane and a water-soluble triazole relative are catalyzed by thiophenol and tert-dodecanethiol [C(9)H(19)C(CH(3))(2)SH]. Rate constants for reaction of the phenylthiyl (PhS•) radical with two NHC-boranes have been measured to be ~10(8) M(-1) s(-1) by laser flash photolysis experiments. An analysis of the available evidence suggests the operation of polarity reversal catalysis.
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Affiliation(s)
- Xiangcheng Pan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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140
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Gansäuer A, Behlendorf M, Cangönül A, Kube C, Cuerva JM, Friedrich J, van Gastel M. H2O-Aktivierung für den Wasserstoffatom-Transfer: korrekte Strukturen, revidierte Mechanismen. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201107556] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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141
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Gansäuer A, Behlendorf M, Cangönül A, Kube C, Cuerva JM, Friedrich J, van Gastel M. H2O activation for hydrogen-atom transfer: correct structures and revised mechanisms. Angew Chem Int Ed Engl 2012; 51:3266-70. [PMID: 22337565 DOI: 10.1002/anie.201107556] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Indexed: 11/09/2022]
Affiliation(s)
- Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
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142
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Donner CD, Casana MI. Synthesis of novel pyranoquinones using an acyl radical cyclization strategy. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2011.12.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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143
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Gansäuer A, Knebel K, Kube C, van Gastel M, Cangönül A, Daasbjerg K, Hangele T, Hülsen M, Dolg M, Friedrich J. Radical 4-exo Cyclizations via Template Catalysis. Chemistry 2012; 18:2591-9. [DOI: 10.1002/chem.201102959] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Indexed: 11/06/2022]
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144
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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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145
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Ju X, Liang Y, Jia P, Li W, Yu W. Synthesis of oxindolesvia visible light photoredox catalysis. Org Biomol Chem 2012; 10:498-501. [DOI: 10.1039/c1ob06652h] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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146
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El Qacemi M, Petit L, Quiclet-Sire B, Zard SZ. A unified access to diverse heteroaromatic scaffolds using the radical chemistry of xanthates. Org Biomol Chem 2012; 10:5707-19. [DOI: 10.1039/c2ob25169h] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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147
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Pimpalpalle TM, Yin J, Linker T. Barton radical reactions of 2-C-branched carbohydrates. Org Biomol Chem 2011; 10:103-9. [PMID: 22027808 DOI: 10.1039/c1ob06370g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Barton esters have been introduced into the side chain of carbohydrates with high yields in only a few steps from easily available glycals. Their radical reactions afford 2-C-methyl and 2-C-bromomethyl hexoses, pentoses and disaccharides in good yields in analytically pure form. Since the Barton esters have been synthesized by an oxidative radical addition and their transformations by reductive radical processes, our results demonstrate the power of such reactions in carbohydrate chemistry.
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Affiliation(s)
- Tukaram M Pimpalpalle
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
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148
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Summerscales OT, Fettinger JC, Power PP. C–H Activation of Cycloalkenes by Dimetallynes (M = Ge, Sn) under Ambient Conditions. J Am Chem Soc 2011; 133:11960-3. [DOI: 10.1021/ja205816d] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Owen T. Summerscales
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - James C. Fettinger
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Philip P. Power
- Department of Chemistry, University of California, Davis, California 95616, United States
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149
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Beemelmanns C, Lentz D, Reissig HU. Samarium Diiodide Induced Cyclizations of γ-, δ- and ε-Indolyl Ketones: Reductive Coupling, Intermolecular Trapping, and Subsequent Transformations of Indolines. Chemistry 2011; 17:9720-30. [DOI: 10.1002/chem.201100981] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Indexed: 11/11/2022]
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150
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Song L, Liu K, Li C. Efficient and Regioselective 9-Endo Cyclization of α-Carbamoyl Radicals. Org Lett 2011; 13:3434-7. [DOI: 10.1021/ol201180g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Liyan Song
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Kun Liu
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Chaozhong Li
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
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