251
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Walton JC. Synthetic Strategies for 5- and 6-Membered Ring Azaheterocycles Facilitated by Iminyl Radicals. Molecules 2016; 21:molecules21050660. [PMID: 27213311 PMCID: PMC6273063 DOI: 10.3390/molecules21050660] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/11/2016] [Accepted: 05/16/2016] [Indexed: 01/09/2023] Open
Abstract
The totality of chemical space is so immense that only a small fraction can ever be explored. Computational searching has indicated that bioactivity is associated with a comparatively small number of ring-containing structures. Pyrrole, indole, pyridine, quinoline, quinazoline and related 6-membered ring-containing aza-arenes figure prominently. This review focuses on the search for fast, efficient and environmentally friendly preparative methods for these rings with specific emphasis on iminyl radical-mediated procedures. Oxime derivatives, particularly oxime esters and oxime ethers, are attractive precursors for these radicals. Their use is described in conventional thermolytic, microwave-assisted and UV-vis based preparative procedures. Photoredox-catalyzed protocols involving designer oxime ethers are also covered. Choice can be made amongst these synthetic strategies for a wide variety of 5- and 6-membered ring heterocycles including phenanthridine and related aza-arenes. Applications to selected natural products and bioactive molecules, including trispheridine, vasconine, luotonin A and rutaecarpine, are included.
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Affiliation(s)
- John C Walton
- University of St. Andrews, EaStCHEM School of Chemistry, St. Andrews, Fife KY16 9ST, UK.
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252
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Xiong T, Zhang Q. New amination strategies based on nitrogen-centered radical chemistry. Chem Soc Rev 2016; 45:3069-87. [PMID: 27116936 DOI: 10.1039/c5cs00852b] [Citation(s) in RCA: 462] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The interesting and diverse biological activities of nitrogen-containing compounds make the construction of the C-N bond of great importance. Despite the tremendous advances that have been made in this research field, C-N bond formation based on nitrogen-centered radicals remains a significant challenge due to the harsh conditions required for the generation of nitrogen-centered radicals and their propensity for hydrogen abstraction or engaging in other degradation pathways. In the past several years, novel methodologies for C-N bond constructions based on nitrogen centered-radical intermediates, coordinated with metal or generated in the presence of visible-light and a photocatalyst, have attracted considerable attention. This tutorial review will summarize the significant progress of these efficient and mild radical amination reactions, with an emphasis on approaches for the generation of nitrogen-centered radicals and their reaction patterns, related mechanisms and synthetic applications, as well as unmet challenges in this emerging and promising field.
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Affiliation(s)
- Tao Xiong
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
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253
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Gurry M, Aldabbagh F. A new era for homolytic aromatic substitution: replacing Bu3SnH with efficient light-induced chain reactions. Org Biomol Chem 2016; 14:3849-62. [PMID: 27056571 DOI: 10.1039/c6ob00370b] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein is a pertinent review of recent photochemical homolytic aromatic substitution (HAS) literature. Issues with using the reductant Bu3SnH in an oxidative process where the net loss of a hydrogen atom occurs is discussed. Nowadays more efficient light-induced chain reactions are used resulting in HAS becoming a synthetic mechanism of choice rivaling organometallic, transition-metal and electrophilic aromatic substitution protocols. The review includes aromatic substitution as part of a tandem or cascade reaction, Pschorr reaction, as well as HAS facilitated by ipso-substitution, and Smiles rearrangement. Recently visible-light photoredox catalysis, which is carried out at room temperature has become one of the most important means of aromatic substitution. The main photoredox catalysts used are polypyridine complexes of Ru(ii) and Ir(iii), although eosin Y is an alternative allowing metal-free HAS. Other radical initiator-free aromatic substitutions have used 9-mesityl-10-methylacridinium ion and N,N-bis(2,6-diisopropylphenyl)perylene-3,4,9,10-bis(dicarboximide) as the photoredox catalyst, UV-light, photoinduced electron-transfer, zwitterionic semiquinone radical anions, and Barton ester intermediates.
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Affiliation(s)
- Michael Gurry
- School of Chemistry, National University of Ireland Galway, University Road, Galway, SW4 NUI, Ireland.
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254
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Borah A, Gogoi P. Cascade C-C and C-N Bond Formation: A Straightforward Synthesis of Phenanthridines and Fused Quinolines. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600220] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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255
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Catalytic N-radical cascade reaction of hydrazones by oxidative deprotonation electron transfer and TEMPO mediation. Nat Commun 2016; 7:11188. [PMID: 27048886 PMCID: PMC4823831 DOI: 10.1038/ncomms11188] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/25/2016] [Indexed: 12/22/2022] Open
Abstract
Compared with the popularity of various C-centred radicals, the N-centred radicals remain largely unexplored in catalytic radical cascade reactions because of a lack of convenient methods for their generation. Known methods for their generation typically require the use of N-functionalized precursors or various toxic, potentially explosive or unstable radical initiators. Recently, visible-light photocatalysis has emerged as an attractive tool for the catalytic formation of N-centred radicals, but the pre-incorporation of a photolabile groups at the nitrogen atom largely limited the reaction scope. Here, we present a visible-light photocatalytic oxidative deprotonation electron transfer/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediation strategy for catalytic N-radical cascade reaction of unsaturated hydrazones. This mild protocol provides a broadly applicable synthesis of 1,6-dihydropyradazines with complete regioselectivity and good yields. The 1,6-dihydropyradazines can be easily transformed into diazinium salts that showed promising in vitro antifungal activities against fungal pathogens. DFT calculations are conducted to explain the mechanism. The use of N-centred radicals is limited by the difficulties in their preparation. Here, the authors report a photoredox method for the formation of N-centred radicals on hydrazones and their use for the synthesis of heterocyclic compounds through a radical cascade reaction.
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256
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Yang W, Wang J, Wei Z, Zhang Q, Xu X. Kinetic Control of Rh(III)-Catalyzed Annulation of C–H Bonds with Quinones: Chemoselective Synthesis of Hydrophenanthridinones and Phenanthridinones. J Org Chem 2016; 81:1675-80. [DOI: 10.1021/acs.joc.5b02903] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wei Yang
- Department
of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Jingyi Wang
- Department
of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Zhonglin Wei
- College
of Chemistry, Jilin University, Changchun 130012, China
| | - Qian Zhang
- Department
of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Xianxiu Xu
- Department
of Chemistry, Northeast Normal University, Changchun 130024, China
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257
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Chen JR, Hu XQ, Lu LQ, Xiao WJ. Visible light photoredox-controlled reactions of N-radicals and radical ions. Chem Soc Rev 2016; 45:2044-56. [PMID: 26839142 DOI: 10.1039/c5cs00655d] [Citation(s) in RCA: 836] [Impact Index Per Article: 104.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Radicals are an important class of versatile and highly reactive species. Compared with the wide applications of various C-centred radicals, however, the N-radical species including N-centred radicals and radical ions remain largely unexplored due to the lack of convenient methods for their generation. In recent years, visible light photoredox catalysis has emerged as a powerful platform for the generation of various N-radical species and methodology development towards the synthesis of diverse N-containing compounds. In this tutorial review, we highlight recent advances in this rapidly developing area with particular emphases put on the working models and new reaction design.
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Affiliation(s)
- Jia-Rong Chen
- CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China.
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258
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Huang H, Cai J, Tang L, Wang Z, Li F, Deng GJ. Metal-Free Assembly of Polysubstituted Pyridines from Oximes and Acroleins. J Org Chem 2016; 81:1499-505. [DOI: 10.1021/acs.joc.5b02624] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Huawen Huang
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Jinhui Cai
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Lichang Tang
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Zilong Wang
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Feifei Li
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Guo-Jun Deng
- Key Laboratory
of Environmentally
Friendly Chemistry and Application of Ministry of Education, College
of Chemistry, Xiangtan University, Xiangtan 411105, China
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259
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Luo K, Chen YZ, Yang WC, Zhu J, Wu L. Cross-Coupling Hydrogen Evolution by Visible Light Photocatalysis Toward C(sp2)–P Formation: Metal-Free C–H Functionalization of Thiazole Derivatives with Diarylphosphine Oxides. Org Lett 2016; 18:452-5. [DOI: 10.1021/acs.orglett.5b03497] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Kai Luo
- Jiangsu Key Laboratory
of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Yao-Zhong Chen
- Jiangsu Key Laboratory
of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Wen-Chao Yang
- Jiangsu Key Laboratory
of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jie Zhu
- Jiangsu Key Laboratory
of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lei Wu
- Jiangsu Key Laboratory
of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
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260
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Zhou L, Lokman Hossain M, Xiao T. Synthesis ofN-Containing Heterocyclic Compounds Using Visible-light Photoredox Catalysis. CHEM REC 2016; 16:319-34. [PMID: 26751828 DOI: 10.1002/tcr.201500228] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 12/24/2022]
Affiliation(s)
- Lei Zhou
- School of Chemistry and Chemical Engineering; Sun Yat-Sen University; 135 Xingang West Road Guangzhou 510275 P. R. China
| | | | - Tiebo Xiao
- School of Chemistry and Chemical Engineering; Sun Yat-Sen University; 135 Xingang West Road Guangzhou 510275 P. R. China
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261
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Walton JC. Functionalised Oximes: Emergent Precursors for Carbon-, Nitrogen- and Oxygen-Centred Radicals. Molecules 2016; 21:63. [PMID: 26751437 PMCID: PMC6273297 DOI: 10.3390/molecules21010063] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 11/16/2022] Open
Abstract
Oxime derivatives are easily made, are non-hazardous and have long shelf lives. They contain weak N-O bonds that undergo homolytic scission, on appropriate thermal or photochemical stimulus, to initially release a pair of N- and O-centred radicals. This article reviews the use of these precursors for studying the structures, reactions and kinetics of the released radicals. Two classes have been exploited for radical generation; one comprises carbonyl oximes, principally oxime esters and amides, and the second comprises oxime ethers. Both classes release an iminyl radical together with an equal amount of a second oxygen-centred radical. The O-centred radicals derived from carbonyl oximes decarboxylate giving access to a variety of carbon-centred and nitrogen-centred species. Methods developed for homolytically dissociating the oxime derivatives include UV irradiation, conventional thermal and microwave heating. Photoredox catalytic methods succeed well with specially functionalised oximes and this aspect is also reviewed. Attention is also drawn to the key contributions made by EPR spectroscopy, aided by DFT computations, in elucidating the structures and dynamics of the transient intermediates.
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Affiliation(s)
- John C Walton
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
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262
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Brueckner AC, Hancock EN, Anders EJ, Tierney MM, Morgan HR, Scott KA, Lamar AA. Visible-light-mediated, nitrogen-centered radical amination of tertiary alkyl halides under metal-free conditions to form α-tertiary amines. Org Biomol Chem 2016; 14:4387-92. [DOI: 10.1039/c6ob00616g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mild and operationally convenient amino-functionalization of a range of tertiary alkyl halides that involves a N,N-diiodosulfonamide reactive species has been developed.
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Affiliation(s)
| | | | | | | | - Heather R. Morgan
- Department of Chemistry and Biochemistry
- The University of Tulsa
- Tulsa
- USA
| | - Kristina A. Scott
- Department of Chemistry and Biochemistry
- The University of Tulsa
- Tulsa
- USA
| | - Angus A. Lamar
- Department of Chemistry and Biochemistry
- The University of Tulsa
- Tulsa
- USA
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263
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Yang JC, Zhang JJ, Guo LN. Copper-catalyzed oxidative cyclization of vinyl azides with benzylic Csp3–H bonds for the synthesis of substituted phenanthridines. Org Biomol Chem 2016; 14:9806-9813. [DOI: 10.1039/c6ob02012g] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A copper-catalyzed oxidative cyclization of vinyl azides with benzylic Csp3–H bondsviaa tandem dual C–H functionalization process has been developed. This reaction allows access to substituted phenanthridines containing a variety of functional groups.
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Affiliation(s)
- Jun-Cheng Yang
- Department of Chemistry
- School of Science and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Jin-Jiang Zhang
- Department of Chemistry
- School of Science and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Li-Na Guo
- Department of Chemistry
- School of Science and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter
- Xi'an Jiaotong University
- Xi'an 710049
- China
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264
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Nicholls TP, Leonori D, Bissember AC. Applications of visible light photoredox catalysis to the synthesis of natural products and related compounds. Nat Prod Rep 2016; 33:1248-1254. [DOI: 10.1039/c6np00070c] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The total synthesis of natural products and their derivatives continues to inspire organic chemists to identify and test new synthetic strategies and develop and explore novel methodology.
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Affiliation(s)
- Thomas P. Nicholls
- School of Physical Sciences – Chemistry
- University of Tasmania
- Hobart
- Australia
| | | | - Alex C. Bissember
- School of Physical Sciences – Chemistry
- University of Tasmania
- Hobart
- Australia
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265
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Hu B, Li Y, Dong W, Xie X, Wan J, Zhang Z. Visible light-induced aerobic C–N bond activation: a photocatalytic strategy for the preparation of 2-arylpyridines and 2-arylquinolines. RSC Adv 2016. [DOI: 10.1039/c6ra07962h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An efficient method for accessing arylpyridines and arylquinolines via visible light-induced aerobic C–N bond activation is described.
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Affiliation(s)
- Bei Hu
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- China
| | - Yuyuan Li
- College of Chemistry and Molecular Engineering and College of Environment and Safety Engineering
- Qingdao University of Science and Technology
- Qingdao 266042
- China
| | - Wuheng Dong
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- China
| | - Xiaomin Xie
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- China
| | - Jun Wan
- College of Chemistry and Molecular Engineering and College of Environment and Safety Engineering
- Qingdao University of Science and Technology
- Qingdao 266042
- China
| | - Zhaoguo Zhang
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- China
- Shanghai Institute of Organic Chemistry
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266
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Huang H, Cai J, Deng GJ. O-Acyl oximes: versatile building blocks for N-heterocycle formation in recent transition metal catalysis. Org Biomol Chem 2016; 14:1519-30. [DOI: 10.1039/c5ob02417j] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review is dedicated to showcase and discuss recent progress on N-heterocycle formation by transition-metal catalyzed annulation from O-acyl oximes.
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Affiliation(s)
- Huawen Huang
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education
- College of Chemistry
- Xiangtan University
- Xiangtan 411105
- China
| | - Jinhui Cai
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education
- College of Chemistry
- Xiangtan University
- Xiangtan 411105
- China
| | - Guo-Jun Deng
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education
- College of Chemistry
- Xiangtan University
- Xiangtan 411105
- China
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267
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Zhao QQ, Hu XQ, Yang MN, Chen JR, Xiao WJ. A visible-light photocatalytic N-radical cascade of hydrazones for the synthesis of dihydropyrazole-fused benzosultams. Chem Commun (Camb) 2016; 52:12749-12752. [DOI: 10.1039/c6cc05897c] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
An efficient N-centred radical 5-exo cyclization/addition/aromatization cascade by cooperative visible light photoredox and cobalt catalysis is described, giving dihydropyrazole-fused benzosultams in satisfactory yields.
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Affiliation(s)
- Quan-Qing Zhao
- CCNU-uOttawa Joint Research Centre
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
| | - Xiao-Qiang Hu
- CCNU-uOttawa Joint Research Centre
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
| | - Meng-Nan Yang
- CCNU-uOttawa Joint Research Centre
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
| | - Jia-Rong Chen
- CCNU-uOttawa Joint Research Centre
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
| | - Wen-Jing Xiao
- CCNU-uOttawa Joint Research Centre
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
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268
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Ge J, Wang X, Liu T, Shi Z, Xiao Q, Yin D. Assembly of substituted phenanthridines via a cascade palladium-catalyzed coupling reaction, deprotection and intramolecular cyclization. RSC Adv 2016. [DOI: 10.1039/c6ra00249h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A practical method for one-pot synthesis of substituted phenanthridines is described. Via this method, a series of substituted phenanthridines are obtained in good yields with remarkable functional groups compatibility.
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Affiliation(s)
- Jun Ge
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica
- Peking Union Medical College
- Chinese Academy of Medical Sciences
- Beijing 100050
| | - Xiaojian Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica
- Peking Union Medical College
- Chinese Academy of Medical Sciences
- Beijing 100050
| | - Tianqi Liu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica
- Peking Union Medical College
- Chinese Academy of Medical Sciences
- Beijing 100050
| | - Zeyu Shi
- Department of Medicinal Chemistry
- Beijing Key Laboratory of Active Substances
- Discovery and Drugability Evaluation
- Institute of Materia Medica
- Peking Union Medical College
| | - Qiong Xiao
- Department of Medicinal Chemistry
- Beijing Key Laboratory of Active Substances
- Discovery and Drugability Evaluation
- Institute of Materia Medica
- Peking Union Medical College
| | - Dali Yin
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica
- Peking Union Medical College
- Chinese Academy of Medical Sciences
- Beijing 100050
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269
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Yu JT, Pan C. Radical C–H functionalization to construct heterocyclic compounds. Chem Commun (Camb) 2016; 52:2220-36. [DOI: 10.1039/c5cc08872k] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Radical C–H functionalization is a promising and dramatic approach to synthesize heterocyclic compounds with high efficiency and environmental sustainability.
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Affiliation(s)
- Jin-Tao Yu
- School of Petrochemical Engineering
- Advanced Catalysis and Green Manufacturing Collaborative Innovation Center
- Changzhou University
- Changzhou 213164
- P. R. China
| | - Changduo Pan
- School of Chemistry & Environmental Engineering
- Jiangsu University of Technology
- Changzhou 213001
- P. R. China
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270
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Tnay YL, Ang GY, Chiba S. Copper-catalyzed aerobic radical C-C bond cleavage of N-H ketimines. Beilstein J Org Chem 2015; 11:1933-43. [PMID: 26664613 PMCID: PMC4661020 DOI: 10.3762/bjoc.11.209] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/23/2015] [Indexed: 01/11/2023] Open
Abstract
We report herein studies on copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines. Treatment of N–H ketimines having an α-sp3 hybridized carbon under Cu-catalyzed aerobic reaction conditions resulted in a radical fragmentation with C–C bond cleavage to give the corresponding carbonitrile and carbon radical intermediate. This radical process has been applied for the construction of oxaspirocyclohexadienones as well as in the electrophilic cyanation of Grignard reagents with pivalonitrile as a CN source.
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Affiliation(s)
- Ya Lin Tnay
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Gim Yean Ang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Shunsuke Chiba
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
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271
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KOt-Bu promoted homocoupling and decomposition of N′-aryl acylhydrazines: synthesis of unsymmetric N′,N′-diaryl acylhydrazines. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.10.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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272
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Battula S, Kumar A, Gupta AP, Ahmed QN. 2-Oxo-Driven N2 Elimination Induced Decarbonylative Cyclization Reaction in Benzotriazoles to 6-Aminophenanthridines. Org Lett 2015; 17:5562-5. [DOI: 10.1021/acs.orglett.5b02699] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Satyanarayana Battula
- Medicinal
Chemistry Division, Indian Institute of Integrative Medicine (IIIM), Jammu 180001, India
- Academy of Scientific and Innovative Research (AcSIR), Jammu, India
| | - Atul Kumar
- Medicinal
Chemistry Division, Indian Institute of Integrative Medicine (IIIM), Jammu 180001, India
- Academy of Scientific and Innovative Research (AcSIR), Jammu, India
| | | | - Qazi Naveed Ahmed
- Medicinal
Chemistry Division, Indian Institute of Integrative Medicine (IIIM), Jammu 180001, India
- Academy of Scientific and Innovative Research (AcSIR), Jammu, India
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273
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Li D, Ma H, Yu W. Visible Light-Induced Radical Cyclization of Ethyl 2-(N-Arylcarbamoyl)-2-Chloroiminoacetates: Synthesis of Quinoxalin-2(1H)-ones. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500774] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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274
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Li J, Wang DZ. Visible-Light-Promoted Photoredox Syntheses of α,β-Epoxy Ketones from Styrenes and Benzaldehydes under Alkaline Conditions. Org Lett 2015; 17:5260-3. [DOI: 10.1021/acs.orglett.5b02629] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jing Li
- Laboratory of Chemical Genomics,
School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen 518055, China
| | - David Zhigang Wang
- Laboratory of Chemical Genomics,
School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen 518055, China
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275
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An XD, Yu S. Direct Synthesis of Nitriles from Aldehydes Using an O-Benzoyl Hydroxylamine (BHA) as the Nitrogen Source. Org Lett 2015; 17:5064-7. [DOI: 10.1021/acs.orglett.5b02547] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xiao-De An
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Shouyun Yu
- State Key Laboratory of Analytical
Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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276
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Davies J, Booth SG, Essafi S, Dryfe RAW, Leonori D. Visible-Light-Mediated Generation of Nitrogen-Centered Radicals: Metal-Free Hydroimination and Iminohydroxylation Cyclization Reactions. Angew Chem Int Ed Engl 2015; 54:14017-21. [PMID: 26412046 PMCID: PMC4648045 DOI: 10.1002/anie.201507641] [Citation(s) in RCA: 311] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Indexed: 11/09/2022]
Abstract
The formation and use of iminyl radicals in novel and divergent hydroimination and iminohydroxylation cyclization reactions has been accomplished through the design of a new class of reactive O-aryl oximes. Owing to their low reduction potentials, the inexpensive organic dye eosin Y could be used as the photocatalyst of the organocatalytic hydroimination reaction. Furthermore, reaction conditions for a unique iminohydroxylation were identified; visible-light-mediated electron transfer from novel electron donor-acceptor complexes of the oximes and Et3N was proposed as a key step of this process.
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Affiliation(s)
- Jacob Davies
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Samuel G Booth
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Stephanie Essafi
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK)
| | - Robert A W Dryfe
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Daniele Leonori
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
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277
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Davies J, Booth SG, Essafi S, Dryfe RAW, Leonori D. Visible‐Light‐Mediated Generation of Nitrogen‐Centered Radicals: Metal‐Free Hydroimination and Iminohydroxylation Cyclization Reactions. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507641] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jacob Davies
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Samuel G. Booth
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Stephanie Essafi
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK)
| | - Robert A. W. Dryfe
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
| | - Daniele Leonori
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
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278
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Manley DW, Walton JC. Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis. Beilstein J Org Chem 2015; 11:1570-82. [PMID: 26664577 PMCID: PMC4660884 DOI: 10.3762/bjoc.11.173] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/19/2015] [Indexed: 11/23/2022] Open
Abstract
Heterogeneous semiconductor photoredox catalysis (SCPC), particularly with TiO2, is evolving to provide radically new synthetic applications. In this review we describe how photoactivated SCPCs can either (i) interact with a precursor that donates an electron to the semiconductor thus generating a radical cation; or (ii) interact with an acceptor precursor that picks up an electron with production of a radical anion. The radical cations of appropriate donors convert to neutral radicals usually by loss of a proton. The most efficient donors for synthetic purposes contain adjacent functional groups such that the neutral radicals are resonance stabilized. Thus, ET from allylic alkenes and enol ethers generated allyl type radicals that reacted with 1,2-diazine or imine co-reactants to yield functionalized hydrazones or benzylanilines. SCPC with tertiary amines enabled electron-deficient alkenes to be alkylated and furoquinolinones to be accessed. Primary amines on their own led to self-reactions involving C-N coupling and, with terminal diamines, cyclic amines were produced. Carboxylic acids were particularly fruitful affording C-centered radicals that alkylated alkenes and took part in tandem addition cyclizations producing chromenopyrroles; decarboxylative homo-dimerizations were also observed. Acceptors initially yielding radical anions included nitroaromatics and aromatic iodides. The latter led to hydrodehalogenations and cyclizations with suitable precursors. Reductive SCPC also enabled electron-deficient alkenes and aromatic aldehydes to be hydrogenated without the need for hydrogen gas.
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Affiliation(s)
- David W Manley
- University of St. Andrews, EaStCHEM School of Chemistry, St. Andrews, Fife, KY16 9ST, UK
| | - John C Walton
- University of St. Andrews, EaStCHEM School of Chemistry, St. Andrews, Fife, KY16 9ST, UK
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279
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Angnes RA, Li Z, Correia CRD, Hammond GB. Recent synthetic additions to the visible light photoredox catalysis toolbox. Org Biomol Chem 2015; 13:9152-67. [PMID: 26242759 DOI: 10.1039/c5ob01349f] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The boom in visible light photoredox catalysis (VLPC) research has demonstrated that this novel synthetic approach is here to stay. VLPC enables reactive radical intermediates to be catalytically generated at ambient temperature, a feat not generally allowed through traditional pyrolysis- or radical initiator-based methodologies. VLPC has vastly extended the range of substrates and reaction schemes that have been traditionally the domain of radical reactions. In this review the photophysics background of VLPC will be briefly discussed, followed by a report on recent inroads of VLPC into decarboxylative couplings and radical C-H functionalization of aromatic compounds. The bulk of the review will be dedicated to advances in synergistic catalysis involving VLPC, namely the combination of photoredox catalysis with organocatalysis, including β-functionalization of carbonyl groups, functionalization of weak aliphatic C-H bonds, and anti-Markovnikov hydrofunctionalization of alkenes; dual catalysis with gold or with nickel, photoredox catalysis as an oxidation promoter in transition metal catalysis, and acid-catalyzed enantioselective radical addition to π systems.
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Affiliation(s)
- Ricardo A Angnes
- Chemistry Institute, State University of Campinas - Unicamp C.P. 6154, CEP. 13083-970, Campinas, São Paulo, Brazil
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280
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Wang Q, Huang J, Zhou L. Synthesis of Quinolines by Visible-Light Induced Radical Reaction of Vinyl Azides and α-Carbonyl Benzyl Bromides. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500141] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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281
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Miyazawa K, Koike T, Akita M. Regiospecific Intermolecular Aminohydroxylation of Olefins by Photoredox Catalysis. Chemistry 2015; 21:11677-80. [DOI: 10.1002/chem.201501590] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Indexed: 01/07/2023]
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282
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Skonieczny K, Gryko DT. Photochemical Conversion of Phenanthro[9,10-d]imidazoles into π-Expanded Heterocycles. J Org Chem 2015; 80:5753-63. [DOI: 10.1021/acs.joc.5b00714] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kamil Skonieczny
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Daniel T. Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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283
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An XD, Yu S. Visible-Light-Promoted and One-Pot Synthesis of Phenanthridines and Quinolines from Aldehydes and O-Acyl Hydroxylamine. Org Lett 2015; 17:2692-5. [DOI: 10.1021/acs.orglett.5b01096] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiao-De An
- State Key
Laboratory of Analytical Chemistry for Life Science, School of Chemistry
and Chemical Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093, China
| | - Shouyun Yu
- State Key
Laboratory of Analytical Chemistry for Life Science, School of Chemistry
and Chemical Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093, China
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284
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Qin Q, Ren D, Yu S. Visible-light-promoted chloramination of olefins with N-chlorosulfonamide as both nitrogen and chlorine sources. Org Biomol Chem 2015; 13:10295-8. [DOI: 10.1039/c5ob01725d] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A visible-light-promoted chloramination of olefins is reported.
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Affiliation(s)
- Qixue Qin
- State Key Laboratory of Analytical Chemistry for Life Science
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
- China
| | - Daan Ren
- State Key Laboratory of Analytical Chemistry for Life Science
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
- China
| | - Shouyun Yu
- State Key Laboratory of Analytical Chemistry for Life Science
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
- China
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