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Search for "photoredox" in Full Text gives 162 result(s) in Beilstein Journal of Organic Chemistry.

Visible light mediated intermolecular [3 + 2] annulation of cyclopropylanilines with alkynes

  • Theresa H. Nguyen,
  • Soumitra Maity and
  • Nan Zheng

Beilstein J. Org. Chem. 2014, 10, 975–980, doi:10.3762/bjoc.10.96

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  • Theresa H. Nguyen Soumitra Maity Nan Zheng Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, USA 10.3762/bjoc.10.96 Abstract Intermolecular [3 + 2] annulation of cyclopropylanilines with alkynes is realized using visible light photoredox catalysis
  • , yielding a variety of cyclic allylic amines in fair to good yields. This method exhibits significant group tolerance particularly with heterocycles. It can also be used to prepare complex heterocycles such as fused indolines. Keywords: [3 + 2]; alkyne; annulation; cyclopropylaniline; photoredox catalysis
  • parent amine. This oxidation step can be realized enzymatically [6][7][8], chemically [9][10][11][12][13][14], electrochemically [15][16], and photochemically [17][18][19][20]. Recently, visible light photoredox catalysis has emerged as a powerful method to manipulate the redox chemistry of organic
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Published 29 Apr 2014

Tailoring of organic dyes with oxidoreductive compounds to obtain photocyclic radical generator systems exhibiting photocatalytic behavior

  • Christian Ley,
  • Julien Christmann,
  • Ahmad Ibrahim,
  • Luciano H. Di Stefano and
  • Xavier Allonas

Beilstein J. Org. Chem. 2014, 10, 936–947, doi:10.3762/bjoc.10.92

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  • transfer; kinetic; photocatalysis; photochemistry; photocyclic initiating system; photopolymerization; photoredox catalysis; radical generator; Introduction Among the possible usage of light, the conversion of photons into chemical energy, as stored into radicals or ions, is of great interest. As a part
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Published 25 Apr 2014

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

  • Dominik Lenhart and
  • Thorsten Bach

Beilstein J. Org. Chem. 2014, 10, 890–896, doi:10.3762/bjoc.10.86

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  • lactone and lactam substrates, the latter products were the only products isolated. For the six-membered lactones and lactams and for cyclopentenone the simple addition products prevailed. Keywords: cyclization; electron transfer; iridium; photochemistry; photoredox catalysis; radical reactions
  • with the aniline as the limiting agent. To our surprise, however, the relative product ratio remained unchanged when the substrate ratio 5/12 = 1.5/1 was decreased to 1/1.5. Mechanistically, it is likely that the well-established photoredox cascade between aniline 5 and the photoexcited iridium complex
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Published 17 Apr 2014

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

  • Jacques Lalevée,
  • Sofia Telitel,
  • Pu Xiao,
  • Marc Lepeltier,
  • Frédéric Dumur,
  • Fabrice Morlet-Savary,
  • Didier Gigmes and
  • Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

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  • formerly: University of Haute Alsace/ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France 10.3762/bjoc.10.83 Abstract In the present paper, the photoredox catalysis is presented as a unique approach in the field of photoinitiators of polymerization. The principal photocatalysts already reported as
  • -trapping, laser flash photolysis, steady state photolysis, cyclic voltammetry and luminescence experiments. Keywords: LEDs; photoinitiators; photopolymerization; photoredox catalysis; Introduction Photoredox catalysis is now well-known and largely used in organic synthesis, especially in the development
  • , potential toxicity and limited availability of these structures, metal-free organic dye compounds (e.g., Eosin-Y, Nile Red, Alizarine Red S, perylene derivative or Rhodamine B etc.) were recently proposed for cooperative asymmetric organophotoredox catalysis [13][14]. Photoredox catalysis was then
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Published 15 Apr 2014

Visible-light photoredox catalysis enabled bromination of phenols and alkenes

  • Yating Zhao,
  • Zhe Li,
  • Chao Yang,
  • Run Lin and
  • Wujiong Xia

Beilstein J. Org. Chem. 2014, 10, 622–627, doi:10.3762/bjoc.10.53

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  • of phenols and alkenes has been developed utilizing visible light-induced photoredox catalysis. The bromine was generated in situ from the oxidation of Br− by Ru(bpy)33+, both of which resulted from the oxidative quenching process. Keywords: alkenes; bromination; phenols; photoredox catalyst
  • . Recently, an intriguing and promising strategy for the application of photoredox catalysts to initiate single electron transfer processes have been developed [16][17][18][19][20][21][22]. Since the pioneering work from the groups of MacMillan [23][24][25], Stephenson [26][27][28], Yoon [29][30][31] and
  • others [32][33][34][35][36][37][38][39][40][41][42][43][44] demonstrated the usefulness of Ru(bpy)3Cl2 and its application to various visible-light-induced synthetic transformations, visible-light-photoredox catalysis has emerged as a growing field in organic chemistry and has been successfully applied
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Published 07 Mar 2014

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

  • Sebastian Krüger and
  • Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

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  • coworker [200] found an intriguing example of a light mediated radical cyclization/arylvinylcyclopropane rearrangement. Subjecting cyclopropyl bromide 237 to an Ir-polypyridyl catalyst and visible light initiated the desired photoredox cascade forming a cyclopropylradical, which readily cyclized in an 5
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Published 16 Jan 2014

The renaissance of organic radical chemistry – deja vu all over again

  • Corey R. J. Stephenson,
  • Armido Studer and
  • Dennis P. Curran

Beilstein J. Org. Chem. 2013, 9, 2778–2780, doi:10.3762/bjoc.9.312

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  • homolytic aromatic substitution (BHAS) [3], b) photoredox catalysis [4][5][6][7][8], c) redox chemistry using Bu4NI in combination with t-BuOOH [9], d) transition metal catalyzed processes where radicals are suggested to interact directly with copper, nickel, zinc, palladium, gold and so on [10][11][12][13
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Published 04 Dec 2013

New developments in gold-catalyzed manipulation of inactivated alkenes

  • Michel Chiarucci and
  • Marco Bandini

Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294

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  • , (i.e. styrene and gem-disubstituted olefins) to be efficiently employed (Scheme 39b) [85]. An innovative approach to the double functionalization of olefins was developed by Glorius and co-workers, very recently. The authors reported on the use of visible light-mediated photoredox catalysis to access
  • , the initial anti oxy-auration of the double bond led to the alkylgold intermediate 159, that was oxidized to [Au(II)] 160 via a SET process by the aryl radical formed in the photoredox catalytic cycle. The highly reactive species 160 was promptly oxidized by [Ru(III)(bpy)3]3+ affording the [Au(III
  • aryltrimethylsilanes. b) Oxyarylation of alkenes catalyzed by gold in presence of iodine-(III) compound IBA as an external oxidant. Oxy- and amino-arylation of alkenes by [Au(I)]/[Au(III)] photoredox catalysis. Comparison of the catalytic activity of TfOH and PPh3AuOTf in the addition of phenols to alkenes
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Published 21 Nov 2013

Recent advances in transition metal-catalyzed Csp2-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

  • Grégory Landelle,
  • Armen Panossian,
  • Sergiy Pazenok,
  • Jean-Pierre Vors and
  • Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

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  • of N. Kamigata et al. is that the reaction takes place under photoredox catalysis, allowing much milder reaction conditions (23 °C for D. W. C. MacMillan et al. vs 120 °C for N. Kamigata et al.). Higher yields were obtained, especially in the case of pyrroles (2-Rf-pyrrole: 88% yield for D. W. C
  • (Figure 16). The mechanism of the reaction was similar to that proposed by N. Kamigata et al. (Figure 15). A complementary study was published by E. J. Cho et al. in 2012 [106]. Here, terminal and internal alkene C–H bonds were trifluoromethylated under photoredox Ru-catalysis, using trifluoromethyl
  • analogues in the photoredox catalytic reactions discussed in section 3.3.1. Although also active, the iridium catalysts showed lower selectivity and are more expensive [105][106][107]. A different strategy was simultaneously reported by the groups of J. F. Hartwig and Q. Shen [35][37]. The approach consists
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Published 15 Nov 2013

Regioselective 1,4-trifluoromethylation of α,β-unsaturated ketones via a S-(trifluoromethyl)diphenylsulfonium salts/copper system

  • Satoshi Okusu,
  • Yutaka Sugita,
  • Etsuko Tokunaga and
  • Norio Shibata

Beilstein J. Org. Chem. 2013, 9, 2189–2193, doi:10.3762/bjoc.9.257

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  • chalcones. During the preparation of this article, the Nicewicz group showed a single example of conjugate trifluoromethylation of chalcone with sodium trifluoromethanesulfinate salt in the presence of N-methyl-9-mesitylacridinium as a photoredox catalyst resulting in a low product yield of 31% as a mixture
  • detected like in the photoredox trifluoromethylation reaction [22]. Conclusion We developed for the first time the copper-mediated conjugate trifluoromethylation of simple α,β-unsaturated ketones through the use of shelf-stable electrophilic trifluoromethylating reagent 3a under mild conditions. Although
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Published 23 Oct 2013

The chemistry of amine radical cations produced by visible light photoredox catalysis

  • Jie Hu,
  • Jiang Wang,
  • Theresa H. Nguyen and
  • Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

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  • highly sought-after synthetic intermediates including iminium ions, α-amino radicals, and distonic ions. One appealing method to access amine radical cations is through one-electron oxidation of the corresponding amines under visible light photoredox conditions. This approach and subsequent chemistries
  • are emerging as a powerful tool in amine synthesis. This article reviews synthetic applications of amine radical cations produced by visible light photocatalysis. Keywords: α-amino radical; amine radical cation; catalysis; distonic ion; free radical; iminium ion; photoredox; visible light
  • reduction [33][34]. Since 2008, seminal works from MacMillan, Yoon, and Stephenson have reinvigorated the field of visible light photoredox catalysis [35][36][37][38][39][40][41][42]. The use of amines as both the electron donor and the substrate, rather than just the electron donor, has become a major
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Published 01 Oct 2013

Flow photochemistry: Old light through new windows

  • Jonathan P. Knowles,
  • Luke D. Elliott and
  • Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

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  • entirely unsuccessful under batch conditions to be conducted [54]. Eosin Y (36) catalysis was also applied to an organocatalytic (42) photoredox α-alkylation of octanal (40, Scheme 15) to aldehyde 43. The reaction proved to be high yielding under both batch and microflow conditions, and a reduced
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Published 21 Nov 2012
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