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Search for "photoinduced electron transfer (PET)" in Full Text gives 29 result(s) in Beilstein Journal of Organic Chemistry.
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
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.
Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates
- Wang-Yong Yang,
- Samantha A. Marrone,
- Nalisha Minors,
- Diego A. R. Zorio and
- Igor V. Alabugin
Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93
- the kinetics of photoinduced electron transfer (PET). The three analogous isomeric lysine conjugates cleaved DNA with different efficiencies (34, 15, and 0% of ds DNA cleavage for p-, m-, and o-substituted lysine conjugates, respectively) consistent with the alkylating ability of the respective
Graphical Abstract
Figure 1: Structure of C-lysine conjugates.
Figure 2: Alternative pathways of enediyne photoreactivity: photo-Bergman cyclization (left), C1–C5 cyclizati...
Figure 3: Summary of possible mechanistic alternatives for the observed DNA cleavage by monoacetylene conjuga...
Scheme 1: Proposed mechanism of photocycloaddition of acetylene with 1,4-CHD.
Figure 4: p-, m-, and o-amidyl acetylenes and respective lysine conjugates.
Scheme 2: Synthesis of amido-substituted monoacetylenes and lysine conjugates. Reagents and conditions: a. Pd...
Scheme 3: Photochemical reactions of TFP-substituted aryl alkynes with selected π-systems. In short, the reac...
Scheme 4: Photocycloaddition of amido acetylenes with 1,4-CHD.
Scheme 5: Possible mechanism for photochemical hydration of diaryl acetylene moiety catalyzed by the ortho-am...
Figure 5: Stern–Volmer plots of three regioisomers, 3 (blue diamond), 4 (red square), and 5 (green triangle),...
Figure 6: Absorption spectra of three isomers, 3, 4, 5, and Ph-TFP in acetonitrile (10 μM).
Figure 7: Quantified DNA cleavage data for 1 (a), 6 (b) and 7 (c). Blue: Form I (supercoiled) DNA; red: Form ...
Figure 8: Effect of hydroxyl radical/singlet oxygen scavengers (20 mM) on the efficiency of DNA cleavage at p...
Figure 9: Cell proliferation assay using A375 cells (human melanoma) and compound 1 (green square), 6 (red up...
Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan
- Axel G. Griesbeck,
- Jörg Neudörfl and
- Alan de Kiff
Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60
- and tryptophan 8–10 was studied with respect to photoinduced electron-transfer (PET) induced decarboxylation and Norrish II bond cleavage. Whereas exclusive photodecarboxylation of the tyrosine substrate 8 was observed, the histidine compound 9 resulted in a mixture of histamine and preferential
- photoinduced electron-transfer (PET) reactions. N-Alkylated phthalimides typically absorb in the 295 nm region with extinction coefficients around 103. The quantum yields for intersystem crossing ФISC significantly change with the substitution on the imide nitrogen, e.g., ФISC = 0.5 for N-isobutylphthalimide
Graphical Abstract
Scheme 1: Three phthalimide/amino acid model reactions: Norrish II process of 1, PET decarboxylation of 3, PE...
Figure 1: Phthalimides from tyrosine 8, histidine 9 and tryptophan 10.
Scheme 2: PET decarboxylation/photocleavage of 8 and 9.
Figure 2: Structure of the tryptophan derivative 10 in the crystal.
Figure 3: UV–vis absorption spectra of compounds 8–10 (c = 2 × 10−4 in CH3OH).
Scheme 3: Direct, triplet-sensitized and ET-sensitized photochemistry of 10.
Figure 4: Fluorescence spectra of compounds 8–10 (c = 6 × 10−5 in CH3OH).
Scheme 4: Mechanistic scenario.
Molecular recognition of organic ammonium ions in solution using synthetic receptors
- Andreas Späth and
- Burkhard König
Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32
- electron transfer (PET) is inhibited and the system shows an enhanced fluorescence. The binding was dependent on the chain length between the two cations, displaying a maximum stability in the case of the protonated 1,3-diaminopropane. for the bis(aza-15-crown-5) chemosensor 48a the following binding
- alkyldiammonium ions in ethanol or in a chloroform/methanol mixture (9:1) based on the PET principle [191]. The fluorescence of the anthracene function is quenched by the free electron pairs of the nitrogen atoms. When hydrogen bonds are formed by both nitrogen atoms to the bis-ammonium guests, the photoinduced
Graphical Abstract
Figure 1: Biologically important amines and quaternary ammonium salts: histamine (1), dopamine (2) and acetyl...
Figure 2: Crown ether 18-crown-6.
Figure 3: Conformations of 18-crown-6 (4) in solvents of different polarity.
Figure 4: Binding topologies of the ammonium ion depending on the crown ring size.
Figure 5: A “pseudorotaxane” structure consisting of 24-crown-8 and a secondary ammonium ion (5); R = Ph.
Figure 6: Typical examples of azacrown ethers, cryptands and related aza macrocycles.
Figure 7: Binding of ammonium to azacrown ethers and cryptands [111-113].
Figure 8: A 19-crown-6-ether with decalino blocking groups (11) and a thiazole-dibenzo-18-crown-6-ether (12).
Figure 9: 1,3-Bis(6-oxopyridazin-1-yl)propane derivatives 13 and 14 by Campayo et al.
Figure 10: Fluorescent azacrown-PET-sensors based on coumarin.
Figure 11: Two different pyridino-cryptands (17 and 18) compared to a pyridino-crown (19); chiral ammonium ion...
Figure 12: Pyridino-18-crown-6 ligand (21), a similar acridino-18-crown-6 ligand (22) and a structurally relat...
Figure 13: Ciral pyridine-azacrown ether receptors 24.
Figure 14: Chiral 15-crown-5 receptors 26 and an analogue 18-crown-6 ligand 27 derived from amino alcohols.
Figure 15: C2-symmetric chiral 18-crown-6 amino alcohol derivatives 28 and related macrocycles.
Figure 16: Macrocycles with diamide-diester groups (30).
Figure 17: C2-symmetric chiral aza-18-crown-6 ethers (31) with phenethylamine residues.
Figure 18: Chiral C-pivot p-methoxy-phenoxy-lariat ethers.
Figure 19: Chiral lariat crown ether 34.
Figure 20: Sucrose-based chiral crown ether receptors 36.
Figure 21: Permethylated fructooligosaccharide 37 showing induced-fit chiral recognition.
Figure 22: Biphenanthryl-18-crown-6 derivative 38.
Figure 23: Chiral lariat crown ethers derived from binol by Fuji et al.
Figure 24: Chiral phenolic crown ether 41 with “aryl chiral barriers” and guest amines.
Figure 25: Chiral bis-crown receptor 43 with a meso-ternaphthalene backbone.
Figure 26: Chromogenic pH-dependent bis-crown chemosensor 44 for diamines.
Figure 27: Triamine guests for binding to receptor 44.
Figure 28: Chiral bis-crown phenolphthalein chemosensors 46.
Figure 29: Crown ether amino acid 47.
Figure 30: Luminescent receptor 48 for bis-alkylammonium guests.
Figure 31: Luminescent CEAA (49a), a bis-CEAA receptor for amino acids (49b) and the structure of lysine bindi...
Figure 32: Luminescent CEAA tripeptide for binding small peptides.
Figure 33: Bis crown ether 51a self assembles co-operatively with C60-ammonium ion 51b.
Figure 34: Triptycene-based macrotricyclic dibenzo-[24]-crown-8 ether host 52 and guests.
Figure 35: Copper imido diacetic acid azacrown receptor 53a and the suggested His-Lys binding motif; a copper ...
Figure 36: Urea (54) and thiourea (55) benzo crown receptor for transport and extraction of amino acids.
Figure 37: Crown pyryliums ion receptors 56 for amino acids.
Figure 38: Ditopic sulfonamide bridged crown ether receptor 57.
Figure 39: Luminescent peptide receptor 58.
Figure 40: Luminescent receptor 59 for the detection of D-glucosamine hydrochloride in water/ethanol and lumin...
Figure 41: Guanidinium azacrown receptor 61 for simple amino acids and ditopic receptor 62 with crown ether an...
Figure 42: Chiral bicyclic guanidinium azacrown receptor 63 and similar receptor 64 for the enantioselective t...
Figure 43: Receptors for zwitterionic species based on luminescent CEAAs.
Figure 44: 1,10-Azacrown ethers with sugar podand arms and the anticancer agent busulfan.
Figure 45: Benzo-18-crown-6 modified β-cyclodextrin 69 and β-cyclodextrin functionalized with diaza-18-crown-6...
Figure 46: Receptors for colorimetric detection of primary and secondary ammonium ions.
Figure 47: Porphyrine-crown-receptors 72.
Figure 48: Porphyrin-crown ether conjugate 73 and fullerene-ammonium ion guest 74.
Figure 49: Calix[4]arene (75a), homooxocalix[4]arene (75b) and resorcin[4]arene (75c) compared (R = H, alkyl c...
Figure 50: Calix[4]arene and ammonium ion guest (R = H, alkyl, OAcyl etc.), possible binding sites; A: co-ordi...
Figure 51: Typical guests for studies with calixarenes and related molecules.
Figure 52: Lower rim modified p-tert-butylcalix[5]arenes 82.
Figure 53: The first example of a water soluble calixarene.
Figure 54: Sulfonated water soluble calix[n]arenes that bind ammonium ions.
Figure 55: Displacement assay for acetylcholine (3) with a sulfonato-calix[6]arene (84b).
Figure 56: Amino acid inclusion in p-sulfonatocalix[4]arene (84a).
Figure 57: Calixarene receptor family 86 with upper and lower rim functionalization.
Figure 58: Calix[6]arenes 87 with one carboxylic acid functionality.
Figure 59: Sulfonated calix[n]arenes with mono-substitution at the lower rim systematically studied on their r...
Figure 60: Cyclotetrachromotropylene host (91) and its binding to lysine (81c).
Figure 61: Calixarenes 92 and 93 with phosphonic acids groups.
Figure 62: Calix[4]arene tetraphosphonic acid (94a) and a double bridged analogue (94b).
Figure 63: Calix[4]arene tetraphosphonic acid ester (92c) for surface recognition experiments.
Figure 64: Calixarene receptors 95 with α-aminophosphonate groups.
Figure 65: A bridged homocalix[3]arene 95 and a distally bridged homocalix[4]crown 96.
Figure 66: Homocalix[3]arene ammonium ion receptor 97a and the Reichardt’s dye (97b) for colorimetric assays.
Figure 67: Chromogenic diazo-bridged calix[4]arene 98.
Figure 68: Calixarene receptor 99 by Huang et al.
Figure 69: Calixarenes 100 reported by Parisi et al.
Figure 70: Guest molecules for inclusion in calixarenes 100: DAP × 2 HCl (101a), APA (101b) and Lys-OMe × 2 HC...
Figure 71: Different N-linked peptido-calixarenes open and with glycol chain bridges.
Figure 72: (S)-1,1′-Bi-2-naphthol calixarene derivative 104 published by Kubo et al.
Figure 73: A chiral ammonium-ion receptor 105 based on the calix[4]arene skeleton.
Figure 74: R-/S-phenylalaninol functionalized calix[6]arenes 106a and 106b.
Figure 75: Capped homocalix[3]arene ammonium ion receptor 107.
Figure 76: Two C3 symmetric capped calix[6]arenes 108 and 109.
Figure 77: Phosphorous-containing rigidified calix[6]arene 110.
Figure 78: Calix[6]azacryptand 111.
Figure 79: Further substituted calix[6]azacryptands 112.
Figure 80: Resorcin[4]arene (75c) and the cavitands (113).
Figure 81: Tetrasulfonatomethylcalix[4]resorcinarene (114).
Figure 82: Resorcin[4]arenes (115a/b) and pyrogallo[4]arenes (115c, 116).
Figure 83: Displacement assay for acetylcholine (3) with tetracyanoresorcin[4]arene (117).
Figure 84: Tetramethoxy resorcinarene mono-crown-5 (118).
Figure 85: Components of a resorcinarene based displacement assay for ammonium ions.
Figure 86: Chiral basket resorcin[4]arenas 121.
Figure 87: Resorcinarenes with deeper cavitand structure (122).
Figure 88: Resorcinarene with partially open deeper cavitand structure (123).
Figure 89: Water-stabilized deep cavitands with partially structure (124, 125).
Figure 90: Charged cavitands 126 for tetralkylammonium ions.
Figure 91: Ditopic calix[4]arene receptor 127 capped with glycol chains.
Figure 92: A calix[5]arene dimer for diammonium salt recognition.
Figure 93: Calixarene parts 92c and 129 for the formation molecular capsules.
Figure 94: Encapsulation of a quaternary ammonium cation by two resorcin[4]arene molecules (NMe4+@[75c]2 × Cl−...
Figure 95: Encapsulation of a quaternary ammonium cation by six resorcin[4]arene molecules (NMe3D+@[130]6 × Cl−...
Figure 96: Structure and schematic of cucurbit[6]uril (CB[6], 131a).
Figure 97: Cyclohexanocucurbit[6]uril (CB′[6], 132) and the guest molecule spermine (133).
Figure 98: α,α,δ,δ-Tetramethylcucurbit[6]uril (134).
Figure 99: Structure of the cucurbituril-phthalhydrazide analogue 135.
Figure 100: Organic cavities for the displacement assay for amine differentiation.
Figure 101: Displacement assay methodology for diammonium- and related guests involving cucurbiturils and some ...
Figure 102: Nor-seco-Cucurbituril (±)-bis-ns-CB[6] (140) and guest molecules.
Figure 103: The cucurbit[6]uril based complexes 141 for chiral discrimination.
Figure 104: Cucurbit[7]uril (131c) and its ferrocene guests (142) opposed.
Figure 105: Cucurbit[7]uril (131c) guest inclusion and representative guests.
Figure 106: Cucurbit[7]uril (131c) binding to succinylcholine (145) and different bis-ammonium and bis-phosphon...
Figure 107: Paraquat-cucurbit[8]uril complex 149.
Figure 108: Gluconuril-based ammonium receptors 150.
Figure 109: Examples of clefts (151a), tweezers (151b, 151c, 151d) and clips (151e).
Figure 110: Kemp’s triacid (152a), on example of Rebek’s receptors (152b) and guests.
Figure 111: Amino acid receptor (154) by Rebek et al.
Figure 112: Hexagonal lattice designed hosts by Bell et al.
Figure 113: Bell’s amidinium receptor (156) and the amidinium ion (157).
Figure 114: Aromatic phosphonic acids.
Figure 115: Xylene phosphonates 159 and 160a/b for recognition of amines and amino alcohols.
Figure 116: Bisphosphonate recognition motif 161 for a colorimetric assay with alizarin complexone (163) for ca...
Figure 117: Bisphosphonate/phosphate clip 164 and bisphosphonate cleft 165.
Figure 118: N-Methylpyrazine 166a, N-methylnicotinamide iodide (166b) and NAD+ (166c).
Figure 119: Bisphosphate cavitands.
Figure 120: Bisphosphonate 167 of Schrader and Finocchiaro.
Figure 121: Tweezer 168 for noradrenaline (80b).
Figure 122: Different tripods and heparin (170).
Figure 123: Squaramide based receptors 172.
Figure 124: Cage like NH4+ receptor 173 of Kim et al.
Figure 125: Ammonium receptors 174 of Chin et al.
Figure 126: 2-Oxazolin-based ammonium receptors 175a–d and 176 by Ahn et al.
Figure 127: Racemic guest molecules 177.
Figure 128: Tripods based on a imidazole containing macrocycle (178) and the guest molecules employed in the st...
Figure 129: Ammonium ion receptor 180.
Figure 130: Tetraoxa[3.3.3.3]paracyclophanes 181 and a cyclophanic tetraester (182).
Figure 131: Peptidic bridged paraquat-cyclophane.
Figure 132: Shape-selective noradrenaline host.
Figure 133: Receptor 185 for binding of noradrenaline on surface layers from Schrader et al.
Figure 134: Tetraphosphonate receptor for binding of noradrenaline.
Figure 135: Tetraphosphonate 187 of Schrader and Finocchiaro.
Figure 136: Zinc-Porphyrin ammonium-ion receptors 188 and 189 of Mizutani et al.
Figure 137: Zinc porphyrin receptor 190.
Figure 138: Zinc porphyrin receptors 191 capable of amino acid binding.
Figure 139: Zinc-porphyrins with amino acid side chains for stereoinduction.
Figure 140: Bis-zinc-bis-porphyrin based on Tröger’s base 193.
Figure 141: BINAP-zinc-prophyrin derivative 194 and it’s guests.
Figure 142: Bisaryl-linked-zinc-porphyrin receptors.
Figure 143: Bis-zinc-porphyrin 199 for diamine recognition and guests.
Figure 144: Bis-zinc-porphyrin crown ether 201.
Figure 145: Bis-zinc-porphyrin 202 for stereodiscrimination (L = large substituent; S = small substituent).
Figure 146: Bis-zinc-porphyrin[3]rotaxane and its copper complex and guests.
Figure 147: Dien-bipyridyl ligand 206 for co-ordination of two metal atoms.
Figure 148: The ligand and corresponding tetradentate co-complex 207 serving as enantioselective receptor for a...
Figure 149: Bis(oxazoline)–copper(II) complex 208 for the recognition of amino acids in aqueous solution.
Figure 150: Zinc-salen-complexes 209 for the recognition tertiary amines.
Figure 151: Bis(oxazoline)–copper(II) 211 for the recognition of amino acids in aqueous solution.
Figure 152: Zn(II)-complex of a C2 terpyridine crown ether.
Figure 153: Displacement assay and receptor for aspartate over glutamate.
Figure 154: Chiral complex 214 for a colorimetric displacement assay for amino acids.
Figure 155: Metal complex receptor 215 with tripeptide side arms.
Figure 156: A sandwich complex 216 and its displaceable dye 217.
Figure 157: Lanthanide complexes 218–220 for amino acid recognition.
Figure 158: Nonactin (221), valinomycin (222) and vancomycin (223).
Figure 159: Monesin (224a) and a chiral analogue for enantiodiscrimination of ammonium guests (224b).
Figure 160: Chiral podands (226) compared to pentaglyme-dimethylether (225) and 18-crown-6 (4).
Figure 161: Lasalocid A (228).
Figure 162: Lasalocid derivatives (230) of Sessler et al.
Figure 163: The Coporphyrin I tetraanion (231).
Figure 164: Linear and cyclic peptides for ammonium ion recognition.
Figure 165: Cyclic and bicyclic depsipeptides for ammonium ion recognition.
Figure 166: α-Cyclodextrin (136a) and novocaine (236).
Figure 167: Helical diol receptor 237 by Reetz and Sostmann.
Figure 168: Ammonium binding spherand by Cram et al. (238a) and the cyclic[6]metaphenylacetylene 238b in compar...
Figure 169: Receptor for peptide backbone and ammonium binding (239).
Figure 170: Anion sensor principle with 3-hydroxy-2-naphthanilide of Jiang et al.
Figure 171: 7-bromo-3-hydroxy-N-(2-hydroxyphenyl)naphthalene 2-carboxamide (241) and its amine binding.
Figure 172: Naturally occurring catechins with affinity to quaternary ammonium ions.
Figure 173: Spiropyran (244) and merocyanine form (244a) of the amino acid receptors of Fuji et al.
Figure 174: Coumarin aldehyde (245) and its iminium species with amino acid bound (245a) by Glass et al.
Figure 175: Coumarin aldehyde appended with boronic acid.
Figure 176: Quinolone aldehyde dimers by Glass et al.
Figure 177: Chromogenic ammonium ion receptors with trifluoroacetophenone recognition motifs.
Figure 178: Chromogenic ammonium ion receptor with trifluoroacetophenone recognition motif bound on different m...
