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Search for "photoredox" in Full Text gives 177 result(s) in Beilstein Journal of Organic Chemistry.
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
- 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
Graphical Abstract
Scheme 1: Amine radical cations’ mode of reactivity.
Scheme 2: Reductive quenching of photoexcited Ru complexes by Et3N.
Scheme 3: Photoredox aza-Henry reaction.
Scheme 4: Formation of iminium ions using BrCCl3 as stoichiometric oxidant.
Scheme 5: Oxidative functionalization of N-aryltetrahydroisoquinolines using Eosin Y.
Scheme 6: Synthetic and mechanistic studies of Eosin Y-catalyzed aza-Henry reaction.
Scheme 7: Oxidative functionalization of N-aryltetrahydroisoquinolines using RB and GO.
Scheme 8: Merging Ru-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 9: Merging Au-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 10: Merging Ru-based photoredox catalysis and Cu-catalyzed alkynylation reaction.
Scheme 11: Merging Ru-based photoredox catalysis and NHC catalysis.
Scheme 12: 1,3-Dipolar cycloaddition of photogenically formed azomethine ylides.
Scheme 13: Plausible mechanism for photoredox 1,3-dipolar cycloaddition.
Scheme 14: Photoredox-catalyzed cascade reaction for the synthesis of fused isoxazolidines.
Scheme 15: Plausible mechanism for the photoredox-catalyzed cascade reaction.
Scheme 16: Photoredox-catalyzed α-arylation of glycine derivatives.
Scheme 17: Photoredox-catalyzed α-arylation of amides.
Scheme 18: Intramolecular interception of iminium ions by sulfonamides.
Scheme 19: Intramolecular interception of iminium ions by alcohols and sulfonamides.
Scheme 20: Intermolecular interception of iminium ions by phosphites.
Scheme 21: Photoredox-catalyzed oxidative phosphonylation by Eosin Y.
Scheme 22: Conjugated addition of α-amino radicals to Michael acceptors.
Scheme 23: Conjugated addition of α-amino radicals to Michael acceptors assisted by a Brønsted acid.
Scheme 24: Conjugated addition of α-amino radicals derived from anilines to Michael acceptors.
Scheme 25: Oxygen switch between two pathways involving α-amino radicals.
Scheme 26: Interception of α-amino radicals by azodicarboxylates.
Scheme 27: α-Arylation of amines.
Scheme 28: Plausible mechanism for α-arylation of amines.
Scheme 29: Photoinduced C–C bond cleavage of tertiary amines.
Scheme 30: Photoredox cleavage of C–C bonds of 1,2-diamines.
Scheme 31: Proposed mechanism photoredox cleavage of C–C bonds.
Scheme 32: Intermolecular [3 + 2] annulation of cyclopropylamines with olefins.
Scheme 33: Proposed mechanism for intermolecular [3 + 2] annulation.
Scheme 34: Photoinduced clevage of N–N bonds of aromatic hydrazines and hydrazides.
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
- 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
Graphical Abstract
Figure 1: An immersion-well batch reactor with 125 W medium pressure Hg lamp.
Figure 2: Transmission profile of a 0.05 M solution, ε = 200 M−1 cm−1.
Figure 3: Schematic of a typical microflow photochemical reactor (above) and detail of a triple-channel micro...
Figure 4: Schematic of a typical macroflow photochemical reactor (above) and images of the FEP photochemical ...
Scheme 1: [2 + 2] photocycloadditions of enones with enol derivatives.
Scheme 2: Competing reactions in an intramolecular [2 + 2] photocycloaddition.
Scheme 3: Diastereocontrolled cycloaddition of a cyclic enone with cyclopentene.
Scheme 4: Comparison of yields and reaction times for a batch reactor with a microflow system.
Scheme 5: Intramolecular [2 + 2] photocycloaddition.
Scheme 6: Paterno–Büchi reaction of benzophenone with an allylic alcohol.
Scheme 7: Photooxygenation of cyclopentadiene.
Scheme 8: Preparation of the anthelmintic ascaridole 23.
Scheme 9: Production of rose oxide 27 from (−)-β-citronellol (24).
Scheme 10: Photocatalytic alkylation of benzylamine.
Scheme 11: Photocatalytic reduction of 4-nitroacetophenone.
Scheme 12: Conversion of L-lysine to L-pipecolinic acid.
Scheme 13: Photocatalytic hydrodehalogenation.
Scheme 14: Photocatalytic aza-Henry reactions.
Scheme 15: Photocatalytic α-alkylation of aliphatic ketones.
Scheme 16: Decarboxylative photochemical additions.
Scheme 17: Photochemical addition of isopropanol to furanones.
Scheme 18: Photochemical addition of methanol to limonene.
Scheme 19: Light-promoted reduction of flavone.
Scheme 20: Photoreduction of benzophenone with benzhydrol.
Scheme 21: Barton reaction in a microflow system.
Scheme 22: Microflow synthesis of vitamin D3.
Scheme 23: photochemical chlorination of cyclohexane.
Scheme 24: photochemical cyanation of pyrene.
Scheme 25: Intermolecular [2 + 2] cycloaddition of maleimide (76) and intramolecular [2 + 2] cycloaddition of ...
Scheme 26: Intramolecular [5 + 2] cycloaddition of maleimide under flow conditions.
Scheme 27: Intramolecular [5 + 2] cycloaddition as a key step in the synthesis of (±)-neostenine.
Scheme 28: In situ generation of a thioaldehyde by photolysis of a phenacyl sulfide.
Scheme 29: Photodimerisation of maleic anhydride.
Scheme 30: [2 + 2] cycloaddition of a chiral enone with ethylene.
Scheme 31: Intramolecular [2 + 2] cycloaddition of a cyclopentenone.
Scheme 32: Photochemical Wolff rearrangement and cyclisation to β-lactams.
Scheme 33: Photochemical rearrangement of aryl azides.
Scheme 34: Rearrangement of quinoline N-oxides to quinolones.
Scheme 35: Photochemical rearrangement of cyclobutenones.
Scheme 36: Photoisomerisation en route to a vitamin-D derivative.
Scheme 37: Schematic of the Seeberger photooxygenation apparatus and sensitised photooxygenation of citronello...
Scheme 38: Sensitised photooxygenation of dihydroartemisinic acid.
Scheme 39: Photochemical preparation of CpRu(MeCN)3PF6.
Scheme 40: In situ photochemical generation and reaction of a [CpRu]+ catalyst.
Scheme 41: Intermolecular alkene–alkyne coupling with photogenerated catalyst.
Scheme 42: PET deoxygenation of nucleosides.
Scheme 43: Photochemical defluorination of DABFT.
Scheme 44: Aromatic azide reduction by visible-light-mediated photocatalysis.
Scheme 45: Examples of visible-light-mediated reactions.
Scheme 46: Visible-light-mediated formation of iminium ions.
Scheme 47: Examples of visible-light-mediated photocatalytic reactions.
Scheme 48: Anhydride formation from a visible-light-mediated process.
Scheme 49: Light-mediated conjugate addition of glycosyl bromide 141 to acrolein.
Scheme 50: Visible-light-mediated photocyclisation to [5]helicene.
