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Search for "zinc oxide" in Full Text gives 10 result(s) in Beilstein Journal of Organic Chemistry.
Polymer and small molecule mechanochemistry: closer than ever
- José G. Hernández
Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128
- mechanically labile bonds or not, and whether it is a hydrocarbon [50], contains heteroatoms [51], or is inorganic in nature. With regards to the latter, ceramic piezoelectric materials such as barium titanate (BaTiO3) or zinc oxide (ZnO) are materials that can accumulate electric charge in the structure in
Graphical Abstract
Figure 1: Representation of (a) cavitation and elongational flow caused by pulsed ultrasonication, (b) mixer ...
Scheme 1: (a) Mechanochemical activation of anthracene–endoperoxide mechanophore incorporated in the cross-li...
Scheme 2: Mechanochemical activation of dendronized polymer-based compound 4 by ultrasonication and ball mill...
Figure 2: Structure of cellulose and chitin and approximation to the structure of lignin.
Figure 3: Tensile forces by ball milling change the conformation of a chitin model compound. This deformation...
Figure 4: (a) Representation of a collision between the ball and a particle of a chitin sample and (b) mechan...
Figure 5: (a) Ultrasound-induced ATRP using piezoelectric BaTiO3 and (b) mechanochemical atom transfer radica...
Figure 6: Mechanochemical solid-state complexation of organic capsule 5 with fullerenes C70 in a planetary ba...
Scheme 3: Comparative mechanochemical dissociation of the central C–C bond in TASN derivatives 6 and 8.
Valorisation of plastic waste via metal-catalysed depolymerisation
- Francesca Liguori,
- Carmen Moreno-Marrodán and
- Pierluigi Barbaro
Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53
- Table 3, wherein the catalyst productivity is reported for comparison as molBHET⋅gcat.−1⋅h−1. Despite that both catalyst and PET were insoluble in EG at the reaction temperature, most systems displayed substantial activity. Thus, sulfated titania, zinc oxide and mixed oxides (SO42−/TiO2, SO42−/ZnO and
Graphical Abstract
Figure 1: Potential classification of plastic recycling processes. The area covered by the present review is ...
Figure 2: EG produced during glycolytic depolymerisation of PET using DEG + DPG as solvent and titanium(IV) n...
Scheme 1: Simplified representation of the conversion of 1,4-PBD to C16–C44 macrocycles using Ru metathesis c...
Figure 3: Main added-value monomers obtainable by catalytic depolymerisation of PET via chemolytic methods.
Scheme 2: Hydrogenolytic depolymerisation of PET by ruthenium complexes.
Scheme 3: Depolymerisation of PET via catalytic hydrosilylation by Ir(III) pincer complex.
Scheme 4: Catalytic hydrolysis (top) and methanolysis (bottom) reactions of PET.
Scheme 5: Depolymerisation of PET by glycolysis with ethylene glycol.
Figure 4: Glycolysis of PET: evolution of BHET yield over time, with and without zinc acetate catalyst (196 °...
Scheme 6: Potential activated complex for the glycolysis reaction of PET catalysed by metallated ILs and evol...
Scheme 7: One-pot, two-step process for PET repurposing via chemical recycling.
Scheme 8: Synthetic routes to PLA.
Scheme 9: Structures of the zinc molecular catalysts used for PLA-methanolysis in various works. a) See [265], b) ...
Scheme 10: Depolymerisation of PLLA by Zn–N-heterocyclic carbene complex.
Scheme 11: Salalen ligands.
Scheme 12: Catalytic hydrogenolysis of PLA.
Scheme 13: Catalytic hydrosilylation of PLA.
Scheme 14: Hydrogenative depolymerisation of PBT and PCL by molecular Ru catalysts.
Scheme 15: Glycolysis reaction of PCT by diethylene glycol.
Scheme 16: Polymerisation–depolymerisation cycle of 3,4-T6GBL.
Scheme 17: Polymerisation–depolymerisation cycle of 2,3-HDB.
Scheme 18: Hydrogenative depolymerisation of PBPAC by molecular Ru catalysts.
Scheme 19: Catalytic hydrolysis (top), alcoholysis (middle) and aminolysis (bottom) reactions of PBPAC.
Scheme 20: Hydrogenative depolymerisation of PPC (top) and PEC (bottom) by molecular Ru catalysts.
Scheme 21: Polymerisation-depolymerisation cycle of BEP.
Scheme 22: Hydrogenolysis of polyamides using soluble Ru catalysts.
Scheme 23: Catalytic depolymerisation of epoxy resin/carbon fibres composite.
Scheme 24: Depolymerisation of polyethers with metal salt catalysts and acyl chlorides.
Scheme 25: Proposed mechanism for the iron-catalysed depolymerisation reaction of polyethers. Adapted with per...
Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage
- Gagandeep Kour Reen,
- Ashok Kumar and
- Pratibha Sharma
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review
- Vânia André,
- Sílvia Quaresma,
- João Luís Ferreira da Silva and
- M. Teresa Duarte
Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239
- achieve a controlled release of biologically active copper ions and it has shown to be an effective antifungal agent against representative yeast and mold [135]. Friščić et al. also reported the synthesis of coordination polymers and BioMOFs using LAG by grinding together zinc oxide and fumaric acid. In
Graphical Abstract
Figure 1: a) Detailed supramolecular packing of a gabapentin–Er network; b) view along the b-axis of the supr...
Figure 2: a) Mechanochemical reactivity between the excipient MgO and carboxylic acid NSAID molecules; b) NSA...
Figure 3: Mechanochemical reaction to form Cu3(BTC)2 and the structure of Cu3(BTC)2·(HKUST-1) as reported by ...
Figure 4: Mechanochemical syntheses of coordination polymers from ZnO and fumaric acid. Reprinted with permis...
Figure 5: Mechanochemical synthesis of pillared MOFs from ZnO, fumaric acid and two auxiliary ligands (bipy a...
Figure 6: a) Synthesis of ZIF-8; b) fragment of the crystal structure of ZIF-8. Reprinted with permission fro...
Figure 7: a) Mechanochemical reaction of salicylic acid with Bi2O3 yielding bismuth mono-, di- and trisalicyl...
Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles
- Franziska Klitsche,
- Julian Ramcke,
- Julia Migenda,
- Andreas Hensel,
- Tobias Vossmeyer,
- Horst Weller,
- Silvia Gross and
- Wolfgang Maison
Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77
- effector-conjugates of tripodal catecholates and their immobilization on ZnO NPs. Results and Discussion Zinc oxide belongs to the most intensively investigated inorganic compounds, due to its outstanding functional properties combined with manifold morphologies, no toxicity and easy preparation [16]. It
Graphical Abstract
Figure 1: A) Schematic drawing of a bifunctional anchor molecule and its immobilization on a nanoparticle (NP...
Scheme 1: Synthesis of tripodal catecholates for surface immobilization. PEG-triscatecholate 3 was synthesize...
Scheme 2: Synthesis of tripodal catecholate platforms 11 and 13 for surface functionalization.
Figure 2: Catecholates for the immobilization on ZnO NPs.
Figure 3: A) XRD pattern of ZnO NPs obtained by the colloidal suspension of Zn(acac)2. B) TEM image of pure Z...
Figure 4: A) TGA data of catecholates 3, 13 and 14 immobilized on ZnO NPs: pure ZnO NPs treated with MOPS buf...
Figure 5: A) TGA data of catecholates 3 and 14 immobilized on ZnO NPs: pure ZnO NPs treated with MOPS buffer ...
Figure 6: TEM images of ZnO NPs. A) ZnO NPs coated with monomeric PEG-catecholate 14 after washing with water...
Electrochemical oxidation of cholesterol
- Jacek W. Morzycki and
- Andrzej Sobkowiak
Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45
- immobilized on carbon nanotubes [59], metal nanoparticles [60] or graphene [61], and additionally decorated with metal nanoparticles [62] or modified with ionic liquids [63]. The application of composite electrodes, including silica sol–gel matrix with Prussian Blue [64], carbon nanotubes with zinc oxide
- nanoparticles [65], and zinc oxide nanorods directly grown on silver [66], has also been reported on. The “cholesterol self-powered biosensor” [67], in which the cathodic process is determined by cholesterol oxidase and on an anode phenothiazine-mediated oxidation of cholesterol as well as immobilization of
Graphical Abstract
Figure 1: Preferential sites of cholesterol electrooxidation.
Scheme 1: Functionalization of the cholesterol side chain.
Scheme 2: Oxidation of cholestane-3β,5α,6β-triol triacetate (3) with the Gif system.
Scheme 3: Electrochemical oxidation of cholesteryl acetate (1a) with dioxygen and iron–picolinate complexes.
Scheme 4: Electrochemical chlorination of cholesterol catalyzed by FeCl3.
Scheme 5: Electrochemical chlorination of Δ5-steroids.
Scheme 6: Electrochemical bromination of Δ5-steroids in different solvents.
Scheme 7: Direct electrochemical acetoxylation of cholesterol at the allylic position.
Scheme 8: Direct anodic oxidation of cholesterol in dichloromethane.
Scheme 9: A plausible mechanism of the electrochemical oxidation of cholesterol in dichloromethane.
Scheme 10: The electrochemical formation of glycosides and glycoconjugates.
Scheme 11: Efficient electrochemical oxidation of cholesterol to cholesta-4,6-dien-3-one (24).
Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens
- Véronique Nardello-Rataj and
- Loïc Leclercq
Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273
- nanoparticles Various nanoparticles have been successfully developed as antimicrobial agents. As an example, zinc oxide and titanium dioxide nanoparticles have been prepared by chemical and sol–gel methods [91]. Biocidal applications of these nanoparticles may lead to valuable discoveries in various fields such
Graphical Abstract
Scheme 1: Principle of resistance mechanisms through selection of the most resistant micro-organism.
Figure 1: Chemical structure of carbendazim.
Scheme 2: Chemical structure of benomyl and its decomposition in aqueous solution.
Figure 2: Chemical structure of enilconazole.
Figure 3: Chemical structure of chloramidophos.
Scheme 3: The complex problem of pentachlorophenol (PCP) degradation.
Figure 4: Chemical structure of DCPE.
Figure 5: Chemical structures of some biocides used in [59].
Figure 6: Chemical structure of miconazole nitrate.
Figure 7: Chemical structures of triclosan and butylparaben.
Figure 8: Chemical structure of ciprofloxacin hydrochloride.
Figure 9: Chemical structure of benzethonium chloride.
Figure 10: Chemical structure of benzalkonium chlorides.
Scheme 4: Multiple equilibria of CD with benzalkonium chloride (BZK) and fluorometholone.
Scheme 5: Competition between co-micellization and biocidal activity observed for didecyldimethylammonium chl...
Scheme 6: Proposed antimicrobial mechanism of encapsulated didecyldimethylammonium chloride by CDs: (1) diffu...
Scheme 7: Inhibition of co-micellization process observed for didecyldimethylammonium chloride, octaethyleneg...
Scheme 8: Schematic representation of biocide release from a chemically cross-linked CD network.
Scheme 9: Proposed Trojan horse mechanism of silver nanoparticles capped by β-CD.
Scheme 10: Proposed mechanism of copper nanoparticles immobilized on carbon nanotube and embedded in water-ins...
Scheme 11: Advantages and drawback of the physicochemical and biopharmaceutical properties of CDs/biocides inc...
Silver and gold-catalyzed multicomponent reactions
- Giorgio Abbiati and
- Elisabetta Rossi
Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46
- amines in the presence of phenylacetylene, gave the corresponding coupling products in very good to excellent yields, apart from the reactions with furfural, which obtained low yields. An intriguing catalytic system composed of zinc oxide supported Au NP, activated by LED irradiation (plasmon mediated
Graphical Abstract
Scheme 1: General reaction mechanism for Ag(I)-catalyzed A3-coupling reactions.
Scheme 2: A3-coupling reaction catalyzed by polystyrene-supported NHC–silver halides.
Figure 1: Various NHC–Ag(I) complexes used as catalysts for A3-coupling.
Scheme 3: Proposed reaction mechanism for NHC–AgCl catalyzed A3-coupling reactions.
Scheme 4: Liu’s synthesis of pyrrole-2-carboxaldehydes 4.
Scheme 5: Proposed reaction mechanism for Liu’s synthesis of pyrrole-2-carboxaldehydes 4.
Scheme 6: Gold-catalyzed synthesis of propargylamines 1.
Scheme 7: A3-coupling catalyzed by phosphinamidic Au(III) metallacycle 6.
Scheme 8: Gold-catalyzed KA2-coupling.
Scheme 9: A3-coupling applied to aldehyde-containing oligosaccharides 8.
Scheme 10: A3-MCR for the preparation of propargylamine-substituted indoles 9.
Scheme 11: A3-coupling interceded synthesis of furans 12.
Scheme 12: A3/KA2-coupling mediated synthesis of functionalized dihydropyrazoles 13 and polycyclic dihydropyra...
Scheme 13: Au(I)-catalyzed entry to cyclic carbamimidates 17 via an A3-coupling-type approach.
Scheme 14: Proposed reaction mechanism for the Au(I)-catalyzed synthesis of cyclic carbamimidates 17.
Figure 2: Chiral trans-1-diphenylphosphino-2-aminocyclohexane–Au(I) complex 20.
Scheme 15: A3-coupling-type synthesis of oxazoles 21 catalyzed by Au(III)–salen complex.
Scheme 16: Proposed reaction mechanism for the synthesis of oxazoles 21.
Scheme 17: Synthesis of propargyl ethyl ethers 24 by an A3-coupling-type reaction.
Scheme 18: General mechanism of Ag(I)-catalyzed MCRs of 2-alkynylbenzaldehydes, amines and nucleophiles.
Scheme 19: General synthetic pathway to 1,3-disubstituted-1,2-dihydroisoquinolines.
Scheme 20: Synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 29.
Scheme 21: Synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 35 and 36.
Scheme 22: Rh(II)/Ag(I) co-catalyzed synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 40.
Scheme 23: General synthetic pathway to 2-amino-1,2-dihydroquinolines.
Scheme 24: Synthesis of 2-amino-1,2-dihydroquinolines 47.
Scheme 25: Synthesis of tricyclic H-pyrazolo[5,1-a]isoquinoline 48.
Scheme 26: Synthesis of tricyclic H-pyrazolo[5,1-a]isoquinolines 48.
Scheme 27: Cu(II)/Ag(I) catalyzed synthesis of H-pyrazolo[5,1-a]isoquinolines 48.
Scheme 28: Synthesis of 2-aminopyrazolo[5,1-a]isoquinolines 53.
Scheme 29: Synthesis of 1-(isoquinolin-1-yl)guanidines 55.
Scheme 30: Ag(I)/Cu(I) catalyzed synthesis of 2-amino-H-pyrazolo[5,1-a]isoquinolines 58.
Scheme 31: Ag(I)/Ni(II) co-catalyzed synthesis of 3,4-dihydro-1H-pyridazino[6,1-a]isoquinoline-1,1-dicarboxyla...
Scheme 32: Ag(I) promoted activation of the α-carbon atom of the isocyanide group.
Scheme 33: Synthesis of dihydroimidazoles 65.
Scheme 34: Synthesis of oxazoles 68.
Scheme 35: Stereoselective synthesis of chiral butenolides 71.
Scheme 36: Proposed reaction mechanism for the synthesis of butenolides 71.
Scheme 37: Stereoselective three-component approach to pirrolidines 77 by means of a chiral auxiliary.
Scheme 38: Stereoselective three-component approach to pyrrolidines 81 and 82 by means of a chiral catalyst.
Scheme 39: Synthesis of substituted five-membered carbocyles 86.
Scheme 40: Synthesis of regioisomeric arylnaphthalene lactones.
Scheme 41: Enantioselective synthesis of spiroacetals 96 by Fañanás and Rodríguez [105].
Scheme 42: Enantioselective synthesis of spiroacetals 101 by Gong [106].
Scheme 43: Synthesis of polyfunctionalized fused bicyclic ketals 103 and bridged tricyclic ketals 104.
Scheme 44: Proposed reaction mechanism for the synthesis of ketals 103 and 104.
Scheme 45: Synthesis of β-alkoxyketones 108.
Scheme 46: Synthesis of N-methyl-1,4-dihydropyridines 112.
Scheme 47: Synthesis of tetrahydrocarbazoles 115–117.
Scheme 48: Plausible reaction mechanism for the synthesis of tetrahydrocarbazoles 115–117.
Scheme 49: Carboamination, carboalkoxylation and carbolactonization of terminal alkenes.
Scheme 50: Oxyarylation of alkenes with arylboronic acids and Selectfluor as reoxidant.
Scheme 51: Proposed reaction mechanism for oxyarylation of alkenes.
Scheme 52: Oxyarylation of alkenes with arylsilanes and Selectfluor as reoxidant.
Scheme 53: Oxyarylation of alkenes with arylsilanes and IBA as reoxidant.
Synthesis and spectroscopic properties of 4-amino-1,8-naphthalimide derivatives involving the carboxylic group: a new molecular probe for ZnO nanoparticles with unusual fluorescence features
- Laura Bekere,
- David Gachet,
- Vladimir Lokshin,
- Wladimir Marine and
- Vladimir Khodorkovsky
Beilstein J. Org. Chem. 2013, 9, 1311–1318, doi:10.3762/bjoc.9.147
- patterns. Keywords: fluorescence; hydrogen bond; 1,8-naphthalimide; one- and two-photon absorption; zinc oxide; Introduction 1,8-Naphthalimide derivatives are useful for a variety of applications owing to their strong fluorescence, electroactivity and photostability. These compounds can be employed as
Graphical Abstract
Scheme 1: Synthesis and structures of 1,8-naphthalimides.
Figure 1: Normalized absorption (solid curves) and fluorescence (dashed curves) spectra of 4: (1) in cyclohex...
Figure 2: Normalized fluorescence spectra of 4 in ethanol (5 × 10−5 M): (solid line) neutral solution; (dashe...
Figure 3: Normalized fluorescence spectra of 4 in ethanol at different concentrations: (solid line) 10−4 M; (...
Scheme 2: Possible ionization and complexation of 4 in ethanol.
Figure 4: Fluorescence decay profile of 4 from a 10−5 M solution in ethanol (excitation at 450 nm, detection ...
Figure 5: Normalized one- and two-photon spectra of dye 4 in toluene. Solid curves: one-photon absorption and...
Figure 6: (a) HOMO and (b) LUMO of 4.
Figure 7: Fluorescence spectra of 4 ethanol (5 × 10−5 M) (dashed curve) before and after the addition of ZnO ...
Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains
- Rohan J. Kumar,
- Jegadesan Subbiah and
- Andrew B. Holmes
Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122
- -assembly behaviour. The architecture of the devices was glass/ITO/poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate)/active layer/ZnO nanoparticles/Al. Zinc oxide nanoparticles were used as an electron transport layer. The spin-coating velocity was varied to control film thickness. The average results
Graphical Abstract
Figure 1: N-ethylhexyl-substituted (1) [20] and target free N–H (2) cyanopyridone structures.
Scheme 1: Synthesis of the cyanopyridone 2, reagents and conditions: (i) Pd(PPh3)4, Cs2CO3, toluene, reflux, ...
Figure 2: (a) Chloroform (solid line) and thin-film (dashed line) UV–vis absorption and emission spectra and ...
Figure 3: The concentration dependence of (a) the NH 1H NMR chemical shift and (b) the vinyl proton chemical ...
Figure 4: AFM height image of observed nanostructures of films drop cast from (a) 10 mg/mL and (b) 1 mg/mL ch...
Figure 5: Dimeric structures of 2. (a) centrosymmetric dimer of 2; (b) bond-rotated centrosymmetric dimer of 2...
Figure 6: Schematic representation of self-complementary interactions leading to one-dimensional chains.
