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Search for "fuel cells" in Full Text gives 15 result(s) in Beilstein Journal of Organic Chemistry.
Recent advances in the electrochemical synthesis of organophosphorus compounds
- Babak Kaboudin,
- Milad Behroozi,
- Sepideh Sadighi and
- Fatemeh Asgharzadeh
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- generates an electric current. Some of its applications include batteries (e.g., lithium-ion batteries) and fuel cells. These cells are usually in a divided state. Electrolytic cell These cells require an external voltage to drive chemical reactions. They use electrical energy to carry out a non-spontaneous
Graphical Abstract
Scheme 1: Electrosynthesis of phenanthridine phosphine oxides.
Scheme 2: Electrosynthesis of 1-aminoalkylphosphine oxides.
Scheme 3: Various electrochemical C–P coupling reactions.
Scheme 4: Electrochemical C–P coupling reaction of indolines.
Scheme 5: Electrochemical C–P coupling reaction of ferrocene.
Scheme 6: Electrochemical C–P coupling reaction of acridines with phosphites.
Scheme 7: Electrochemical C–P coupling reaction of alkenes.
Scheme 8: Electrochemical C–P coupling reaction of arenes in a flow system.
Scheme 9: Electrochemical C–P coupling reaction of heteroarenes.
Scheme 10: Electrochemical C–P coupling reaction of thiazoles.
Scheme 11: Electrochemical C–P coupling reaction of indole derivatives.
Scheme 12: Electrosynthesis of 1-amino phosphonates.
Scheme 13: Electrochemical C–P coupling reaction of aryl and vinyl bromides.
Scheme 14: Electrochemical C–P coupling reaction of phenylpyridine with dialkyl phosphonates in the presence o...
Scheme 15: Electrochemical P–C bond formation of amides.
Scheme 16: Electrochemical synthesis of α-hydroxy phosphine oxides.
Scheme 17: Electrochemical synthesis of π-conjugated phosphonium salts.
Scheme 18: Electrochemical phosphorylation of indoles.
Scheme 19: Electrochemical synthesis of phosphorylated propargyl alcohols.
Scheme 20: Electrochemical synthesis of phosphoramidates.
Scheme 21: Electrochemical reaction of carbazole with diphenylphosphine.
Scheme 22: Electrochemical P–N coupling of carbazole with phosphine oxides.
Scheme 23: Electrochemical P–N coupling of indoles with a trialkyl phosphite.
Scheme 24: Electrochemical synthesis of iminophosphoranes.
Scheme 25: Electrochemical P–O coupling of phenols with dialkyl phosphonate.
Scheme 26: Electrochemical P–O coupling of alcohols with diphenylphosphine.
Scheme 27: Electrochemical P–S coupling of thiols with dialkylphosphines.
Scheme 28: Electrochemical thiophosphorylation of indolizines.
Scheme 29: Electrosynthesis of S-heteroaryl phosphorothioates.
Scheme 30: Electrochemical phosphorylation reactions.
Scheme 31: Electrochemical P–Se formation.
Scheme 32: Electrochemical selenation/halogenation of alkynyl phosphonates.
Scheme 33: Electrochemical enantioselective aryl C–H bond activation.
Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts
- Mandeep K. Chahal
Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257
- , cyclam (tetraazacyclotetradecane), phthalocyanines, corroles and their supramolecular frameworks have been widely used as both homogeneous and heterogeneous electrocatalysts for various energy conversion and storage techniques, such as fuel cells, water splitting devices, and rechargeable metal–air
Graphical Abstract
Figure 1: Chemical structures of the main tetrapyrrolic macrocycles studied in this review for their role as ...
Figure 2: Calix[4]pyrroles 3 and 4 and an their acyclic analogue 5 used for the transformation of Danishefsky...
Figure 3: Calixpyrrole-based organocatalysts 11 and 12 for the diastereoselective addition reaction of TMSOF ...
Figure 4: (a) Chemical structures of macrocyclic organocatalysts used for the synthesis of cyclic carbonates ...
Figure 5: Cuprous chloride-catalyzed aziridination of styrene (22) by chloramine-T (23) providing 1-tosyl-2-p...
Figure 6: Chemical structures of the various porphyrin macrocycles (18, 25–41) screened as potential catalyst...
Figure 7: Organocatalytic activity of distorted porphyrins explored by Senge and co-workers. Planar macrocycl...
Figure 8: Chemical structures of H2EtxTPP (x = 0, 2, 4, 6, 8) compounds with incrementally increasing nonplan...
Figure 9: Chemical structures of OxP macrocycles tested as potential organocatalysts for the conjugate additi...
Figure 10: a) Fundamental structure of the J-aggregates of diprotonated TPPS3 53 and b) its use as a catalyst ...
Figure 11: Chemical structures of amphiphilic porphyrin macrocycles used as pH-switchable catalysts based on i...
Figure 12: a) Chemical structures of porphyrin macrocycles for the cycloaddition of CO2 to N-alkyl/arylaziridi...
Figure 13: Electron and energy-transfer processes typical for excited porphyrin molecules (Por = porphyrin mac...
Figure 14: Proposed mechanism for the light-induced α-alkylation of aldehydes with EDA in the presence of H2TP...
Figure 15: a) Chemical structures of porphyrins screened as photoredox catalysts, b) model reaction of furan (...
Figure 16: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoreductants for the red light-induced C–H aryla...
Figure 17: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoredox catalyst for (a) α-alkylation of an alde...
Figure 18: Corrole macrocycles 98–100 as photoredox catalysts for C–H arylation and borylation reactions. Adap...
Figure 19: Proposed catalytic cycle of electrocatalytic generation of H2 evolution using tetrapyrrolic macrocy...
Figure 20: a) Chemical structures of tetrapyrrolic macrocycles 109, 73, and 110 used for oxygen reductions in ...
Figure 21: a) Absorption spectra (left) of the air-saturated DCE solutions containing: 5 × 10−5 M H2TPP (black...
Figure 22: Chemical structures of N,N’-dimethylated saddle-distorted porphyrin isomers, syn-Me2P 111 and anti-...
Figure 23: Reaction mechanisms for the two-electron reduction of O2 by a) syn-Me2Iph 113 and b) anti-Me2Iph 114...
Figure 24: O2/H2O2 interconversion using methylated saddle-distorted porphyrin and isophlorin (reduced porphyr...
Figure 25: Chemical structures of distorted dodecaphenylporphyrin macrocycle 117 and its diprotonated form 118...
New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)
- Fátima C. Teixeira,
- António P. S. Teixeira and
- C. M. Rangel
Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145
- . Romão Ramalho, 59, 7000-671 Évora, Portugal 10.3762/bjoc.20.145 Abstract A new paradigm for energy is underway demanding decarbonized energy systems. Some of them rely on emerging electrochemical devices, crucial in hydrogen technologies, including fuel cells, CO2 and water electrolysers, whose
- N115, in the same experimental conditions. The Nafion-doped membrane with compound TP2 with a 1.0 wt % loading showed the highest proton conductivity with 84 mS·cm−1. Keywords: electrolyser; fuel cells; Nafion-modified membranes; phosphonates; proton exchange membranes; triazine; Introduction
- exchange membrane devices [5][6], such as proton exchange membrane fuel cells (PEMFCs) [3][7][8][9], due to their high-power density and high power-to-weight ratio, and CO2 electrolysers, which can reduce the polluting gas CO2 and produce syngas from the co-electrolysis of CO2 and water [10][11], or water
Graphical Abstract
Figure 1: General synthesis of triazinephosphonate compounds.
Scheme 1: Synthesis of diethyl phenylphosphonates 2, 4 and 6.
Scheme 2: Synthesis of (4-hydroxyphenyl)methylphosphonate 7 starting from [4-(benzyloxy)phenyl]methanol (8).
Scheme 3: Synthesis of diethyl [hydroxy(4-hydroxyphenyl)methyl]phosphonate (11) and tetraethyl [(4-hydroxyphe...
Scheme 4: Synthesis of diethyl phenylphosphonates 16 and 14.
Scheme 5: Synthesis of 4-aminophenyltriazinephosphonate derivatives TP1–TP3.
Figure 2: Partial view of 1H and 31P NMR spectra of 4-aminophenyltriazinephosphonate derivatives TP1–TP3.
Scheme 6: Synthesis of (4-hydroxyphenyl)triazinephosphonate derivatives TP4–TP6.
Figure 3: Partial view of 1H and 31P NMR spectra of (4-hydroxyphenyl)triazinephosphonate derivatives TP4–TP6.
Scheme 7: Attempted synthesis of triazinephosphonate TP7.
Figure 4: Preparation of the new doped membranes.
Figure 5: Comparison of in-plane proton conductivity vs RH of Nafion doped membranes, at 60 °C.
Photoredox catalysis harvesting multiple photon or electrochemical energies
- Mattia Lepori,
- Simon Schmid and
- Joshua P. Barham
Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81
- hand, PEC reactions require tailor-made reactors that present technical challenges, although in principle these challenges are surmountable by adapting engineering from the already well-established fields of PEC water splitting/fuel cells/photovoltaic fields. So far, the examples of large-scale
Graphical Abstract
Figure 1: Oxidative and reductive activations of organic compounds harvesting photoredox catalysis.
Figure 2: General catalytic cycles of radical ion conPET (left) and radical ion e-PRC (right).
Figure 3: “Beginner’s guide”: comparison between advantages, capacities, and prospectives of conPET and PEC.
Figure 4: A) conPET reductive dehalogenation of aryl halides with PDI. B) Reductive C–H arylation with pyrrol...
Figure 5: A) Chromoselective mono- and disubstitution or polybrominated pyrimidines with pyrroles. B) Sequent...
Figure 6: A) Synthesis of pyrrolo[1,2-a]quinolines. B) Synthesis of ullazines.
Figure 7: A) Reductive phosphorylation of aryl halides via conPET. B) Selected examples from the substrate sc...
Figure 8: A) Reductive dehalogenation of aryl halides via conPET and selected examples from the substrate sco...
Figure 9: A) Reductive C–H arylation of aryl halides via conPET (top) and selected examples from the substrat...
Figure 10: A) Reductive hydrodehalogenation of aryl halides with Mes-Acr-BF4. B) Selected examples from the su...
Figure 11: A) Reductive hydrodechlorination of aryl chlorides with 4-DPAIPN. B) Proposed formation of CO2•−. C...
Figure 12: A) Reductive conPET borylation with 3CzEPAIPN (top) and selected examples from the substrate scope ...
Figure 13: Scale-up of conPET phosphorylation with 3CzEPAIPN.
Figure 14: A) Borylation of 1d. B) Characteristics and structure of PC1 with green and red parts showing the l...
Figure 15: A) Reductive C–H arylation scope with polysulfide conPET (top) and selected examples from the subst...
Figure 16: Scale-up of A) C–H arylation and B) dehaloborylation with polysulfide photocatalysis in continuous-...
Figure 17: A) Formation of [Ir1]0 and [Ir2]0 upon PET between [Ir1]+ and Et3N. B) Mechanism of multi-photon ta...
Figure 18: A) Reductive hydrodehalogenation of aryl halides via multi-photon tandem photocatalysis. B) Selecte...
Figure 19: A) Carbonylative amidation of aryl halides in continuous flow. B) Selected examples from the substr...
Figure 20: A) General scheme for reductive (RQ) and oxidative quenching (OQ) protocols using [FeIII(btz)3](PF6)...
Figure 21: A) Carbonylative amidation of alkyl iodides with [IrIII(ppy)2(dtbbpy)]PF6. B) Selected examples fro...
Figure 22: A) Carboxylative C–N bond cleavage in cyclic amines. B) Selected examples from the substrate scope....
Figure 23: A) Formal reduction of alkenes to alkanes via transfer hydrogenation. B) Selected examples from the...
Figure 24: A) Birch-type reduction of benzenes with PMP-BPI. B) Selected examples from the substrate scope (sc...
Figure 25: Proposed mechanism of the OH− mediated conPET Birch-type reduction of benzene via generation of sol...
Figure 26: Reductive detosylation of N-tosylated amides with Mes-Acr-BF4. B) Selected examples from the substr...
Figure 27: A) Reductive detosylation of N-tosyl amides by dual PRC. B) Selected examples from the substrate sc...
Figure 28: A) Mechanism of the dual PRC based on PET between [Cu(dap)2]+ and DCA. B) Mechanism of the dual PRC...
Figure 29: A) N–O bond cleavage in Weinreb amides with anthracene. B) N–O bond cleavage in Weinreb amides rely...
Figure 30: A) Pentafluorosulfanylation and fluoride elimination. B) Mechanism of the pentafluorosulfanylation ...
Figure 31: A) α-Alkoxypentafluorosulfanylation (top) and selected examples from the substrate scope (bottom). ...
Figure 32: A) Oxidative amination of arenes with azoles catalyzed by N-Ph PTZ. B) Selected examples from the s...
Figure 33: A) C(sp3)–H bond activation by HAT via chloride oxidation by *N-Ph PTZ•+. B) Proposed mechanism for...
Figure 34: A) Recycling e-PRC C–H azolation of electron-rich arenes with pyrazoles using Mes-Acr+ as a photoca...
Figure 35: A) Radical ion e-PRC direct oxidation of unactivated arenes using TAC+ as an electro-activated phot...
Figure 36: A) Radical ion e-PRC direct oxidation of unactivated arenes using TPA as an electro-activated photo...
Figure 37: Proposed mechanism (top) and mode of preassembly (bottom).
Figure 38: A) Possible preassemblies of reactive (left) vs unreactive (right) arenes. B) Calculated spin densi...
Figure 39: A) Recycling e-PRC C(sp2 )–H acetoxylation of arenes using DDQ as a photocatalyst. B) Proposed cata...
Figure 40: Gram scale hydroxylation of benzene in a recirculated flow setup.
Figure 41: A) Radical ion e-PRC vicinal diamination of alkylarenes using TAC+ as an electro-activated photocat...
Figure 42: A) Sequential oxygenation of multiple adjacent C–H bonds under radical ion e-PRC using TAC+ as an e...
Figure 43: A) Enantioselective recycling e-PRC cyanation of benzylic C–H bonds using ADQS as photocatalyst. B)...
Figure 44: Proposed tandem mechanism by Xu and co-workers.
Figure 45: A) Enantioselective recycling e-PRC decarboxylative cyanation using Cu(acac)2, Ce(OTf)3 and a box l...
Figure 46: A) Enantioselective recycling e-PRC benzylic cyanation using Cu(MeCN)4BF4, box ligand and anthraqui...
Figure 47: A) Radical ion e-PRC acetoxyhydroxylation of aryl olefins using TAC+ as an electro-activated photoc...
Figure 48: Selected examples from the substrate scope.
Figure 49: Photoelectrochemical acetoxyhydroxylation in a recirculated flow setup.
Figure 50: A) Radical ion e-PRC aminooxygenation of aryl olefins using TAC+ as an electro-activated photocatal...
Figure 51: A) Recycling e-PRC C–H alkylation of heteroarenes with organic trifluoroborates using Mes-Acr+ as p...
Figure 52: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using CeCl3·7H2O as catalyst. B) ...
Figure 53: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using Fe(NH4)2(SO4)2·6H2O as cata...
Figure 54: A) Recycling e-PRC C–H alkylation of heteroarenes with alkyl oxalates and 4CzIPN as photocatalyst. ...
Figure 55: A) Recycling e-PRC decarboxylative C–H carbamoylation of heteroarenes using 4CzIPN as photocatalyst...
Figure 56: A) Photoelectrochemical HAT-mediated hydrocarbon activation via the chlorine radical. B) Proposed m...
Figure 57: A) Selected examples from the substrate scope. B) Gram and decagram scale semi-continuous flow PEC ...
Figure 58: A) Photoelectrochemical HAT-mediated dehydrogenative coupling of benzothiazoles with aliphatic C–H ...
Figure 59: A) Photoelectrochemical HAT activation of ethers using electro-activated TAC+ as photocatalyst. B) ...
Figure 60: Selected examples from the substrate scope.
Figure 61: A) Photoelectrochemical HAT-mediated synthesis of alkylated benzimidazo-fused isoquinolinones using...
Figure 62: A) Decoupled photoelectrochemical cerium-catalyzed oxydichlorination of alkynes using CeCl3 as cata...
Figure 63: Proposed decoupled photoelectrochemical mechanism.
Figure 64: A) Decoupled photoelectrochemical ring-opening bromination of tertiary cycloalkanols using MgBr2 as...
Figure 65: A) Recycling e-PRC ring-opening functionalization of cycloalkanols using CeCl3 as catalyst. B) Prop...
Figure 66: Selected examples from the substrate scope of the PEC ring-opening functionalization.
Figure 67: A) Radical ion e-PRC reduction of chloro- and bromoarenes using DCA as catalyst and various accepto...
Figure 68: A) Screening of different phthalimide derivatives as catalyst for the e-PRC reduction of aryl halid...
Figure 69: Screening of different organic catalysts for the e-PRC reduction of trialkylanilium salts.
Figure 70: A) e-PRC reduction of phosphonated phenols and anilinium salts. B) Selected examples from the subst...
Figure 71: A) ConPET and e-PRC reduction of 4-bromobenzonitrile using a naphthalene diimide (NDI) precatalyst ...
Figure 72: A) Radical ion e-PRC reduction of phosphinated aliphatic alcohols with n-BuO-NpMI as catalyst. B) C...
Figure 73: Selected examples from the substrate scope.
Figure 74: A) Recycling e-PRC reductive dimerization of benzylic chlorides using a [Cu2] catalyst. B) Proposed...
Figure 75: A) Decoupled photoelectrochemical C–H alkylation of heteroarenes through deamination of Katritzky s...
Figure 76: Proposed mechanism by Chen and co-workers.
Chemical syntheses and salient features of azulene-containing homo- and copolymers
- Vijayendra S. Shetti
Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139
- polyanilines and can be a useful proton-conducting membrane material in methanol fuel cells. Also, as azulenes are known to contravene Kasha’s rule, it is intriguing to explore, how their presence in the polymers can favor the energy utilization from higher excited states. This may lead to a new dimension in
Graphical Abstract
Figure 1: Chemical structure, numbering scheme, and resonance form of azulene.
Scheme 1: Synthesis of polyazulene-iodine (PAz-I2) and polyazulene-bromine (PAz-Br2) complexes.
Scheme 2: Synthesis of ‘true polyazulene’ 3 or 3’ by cationic polymerization.
Scheme 3: Synthesis of 1,3-polyazulene 5 by Yamamoto protocol.
Scheme 4: Synthesis of 4,7-dibromo-6-(n-alkyl)azulenes 12–14.
Scheme 5: Synthesis of (A) 4,7-diethynyl-6-(n-dodecyl)azulene (16) and (B) 4,7-polyazulene 17 containing an e...
Scheme 6: Synthesis of directly connected 4,7-polyazulenes 18–20.
Scheme 7: Synthesis of (A) tert-butyl N-(6-bromoazulen-2-yl)carbamate (27), (B) dimeric aminoazulene 29, and ...
Figure 2: Iminium zwitterionic resonance forms of poly[2(6)-aminoazulene] 31.
Scheme 8: Synthesis of poly{1,3-bis[2-(3-alkylthienyl)]azulene} 33–38.
Scheme 9: Synthesis of polymer ruthenium complexes 40–43.
Scheme 10: Synthesis of 4,7-polyazulenes 45 containing a thienyl linker.
Scheme 11: Synthesis of azulene-bithiophene 48 and azulene-benzothiadiazole 52 copolymers. Conditions: (a): (i...
Scheme 12: Synthesis of azulene-benzodithiophene copolymer 54 and azulene-bithiophene copolymer 56.
Scheme 13: Synthesis of (A) 5,5’-bis(trimethylstannyl)-3,3’-didodecyl-2,2’-bithiophene (60) and (B) azulene-bi...
Scheme 14: Synthesis of 1,3-bisborylated azulene 67.
Scheme 15: Synthesis of D–A-type azulene-DPP copolymers 69, 71, and 72. Conditions: (a) Pd(PPh3)4, K2CO3, Aliq...
Scheme 16: Synthesis of the key precursor TBAzDI 79.
Scheme 17: Synthesis of TBAzDI-based polymers 81 and 83. Conditions: (a) P(o-tol)3, Pd2(dba)3, PivOH, Cs2CO3, ...
Scheme 18: Synthesis of (A) 1,3-dibromo-2-arylazulene 92–98 and (B) 2-arylazulene-thiophene copolymers 99–101.
Scheme 19: Synthesis of (A) poly[2,7-(9,9-dialkylfluorenyl)-alt-(1’,3’-azulenyl)] 106–109, (B) 1,3-bis(7-bromo...
Scheme 20: Synthesis of azulene-fluorene copolymers 117–121 containing varying ratios of 1,3- and 4,7-connecte...
Scheme 21: Synthesis of (A) 2,6-dibromoazulene (125), (B) azulene-fluorene copolymer 126, and (C) azulene-fluo...
Scheme 22: Synthesis of 2-arylazulene-fluorene copolymers 131–134.
Scheme 23: Synthesis of azulene-fluorene-benzothiadiazole terpolymers 136–138.
Scheme 24: Synthesis of azulene-carbazole-benzothiadiazole-conjugated polymers 140–144.
Scheme 25: Synthesis of (A) azulene-2-yl methacrylate (146) and (B) the triazole-containing azulene methacryla...
Scheme 26: Synthesis of (A) azulene methacrylate polymer 151 and (B) triazole-containing azulene methacrylate ...
Scheme 27: Synthesis of azulene methyl methacrylate polymers 154, 155 (A and B) and azulene-sulfobetaine metha...
Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes
- Savva A. Ponomarev,
- Roman V. Larkovich,
- Alexander S. Aldoshin,
- Andrey A. Tabolin,
- Sema L. Ioffe,
- Jonathan Groß,
- Till Opatz and
- Valentine G. Nenajdenko
Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27
- contains at least one fluorine atom [6][7][8]. Fluorinated functional materials have also found wide application as durable ion exchange membranes, e.g., in fuel cells [9][10][11], as thermoplastic polymers [12][13][14], in electronic and optoelectronic technologies [15], and in liquid crystal display
Graphical Abstract
Scheme 1: Scope of the nitrostyrenes 1 in the Diels–Alder reaction with CPD (dr = exo:endo).
Figure 1: The structure assignment of norbornenes 2 by 1H (a) and NOE (b) NMR spectroscopy.
Figure 2: 13C NMR spectrum of the mixture of exo- and endo-isomers of norbornene 2l.
Figure 3: The predicted reaction pathway for the Diels–Alder reaction of nitrostyrene 1h with CPD is displaye...
Scheme 2: The Diels–Alder reaction of nitrostyrene 1h with spiro[2.4]hepta-4,6-diene.
Scheme 3: Diels–Alder reaction of nitrostyrenes 1 with CHD (dr = exo:endo). (а) Reaction under microwave acti...
Scheme 4: Kinetic study of reactions of 1h with CPD and CHD.
Figure 4: Kinetic curves for the reactions of nitrostyrene 1h with CPD (50–130 °C) and CHD at 110 °C.
Scheme 5: The Diels–Alder reaction of the nitrostyrene 1h with 1-methoxy-1,3-cyclohexadiene.
Scheme 6: Selected chemical transformations of norbornenes 2 (dr = exo:endo).
A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions
- Pezhman Shiri and
- Jasem Aboonajmi
Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52
- and capable to perform over a wide temperature range, increases the attractiveness of carbon nanomaterials [56]. Carbon materials have been used in different areas, including water purification, gas separation, fuel cells, photocatalysis, catalyst supports, etc. [57][58][59][60][61][62]. Different
Graphical Abstract
Scheme 1: Chemical structure of the catalysts 1a and 1b and their catalytic application in CuAAC reactions.
Scheme 2: Synthetic route to the catalyst 11 and its catalytic application in CuAAC reactions.
Scheme 3: Synthetic route of dendrons, illustrated using G2-AMP 23.
Scheme 4: The catalytic application of CuYAu–Gx-AAA–SBA-15 in a CuAAC reaction.
Scheme 5: Synthetic route to the catalyst 36.
Scheme 6: Application of the catalyst 36 in CuAAC reactions.
Scheme 7: The synthetic route to the catalyst 45 and catalytic application of 45 in “click” reactions.
Scheme 8: Synthetic route to the catalyst 48 and catalytic application of 48 in “click” reactions.
Scheme 9: Synthetic route to the catalyst 58 and catalytic application of 58 in “click” reactions.
Scheme 10: Synthetic route to the catalyst 64 and catalytic application of 64 in “click” reactions.
Scheme 11: Chemical structure of the catalyst 68 and catalytic application of 68 in “click” reactions.
Scheme 12: Chemical structure of the catalyst 69 and catalytic application of 69 in “click” reactions.
Scheme 13: Synthetic route to, and chemical structure of the catalyst 74.
Scheme 14: Application of the cayalyst 74 in “click” reactions.
Scheme 15: Synthetic route to, and chemical structure of the catalyst 78 and catalytic application of 78 in “c...
Scheme 16: Synthetic route to the catalyst 85.
Scheme 17: Application of the catalyst 85 in “click” reactions.
Scheme 18: Synthetic route to the catalyst 87 and catalytic application of 87 in “click” reactions.
Scheme 19: Chemical structure of the catalyst 88 and catalytic application of 88 in “click” reactions.
Scheme 20: Synthetic route to the catalyst 90 and catalytic application of 90 in “click” reactions.
Scheme 21: Synthetic route to the catalyst 96 and catalytic application of 96 in “click” reactions.
Scheme 22: Synthetic route to the catalyst 100 and catalytic application of 100 in “click” reactions.
Scheme 23: Synthetic route to the catalyst 102 and catalytic application of 23 in “click” reactions.
Scheme 24: Synthetic route to the catalysts 108–111.
Scheme 25: Catalytic application of 108–111 in “click” reactions.
Scheme 26: Synthetic route to the catalyst 121 and catalytic application of 121 in “click” reactions.
Scheme 27: Synthetic route to 125 and application of 125 in “click” reactions.
Scheme 28: Synthetic route to the catalyst 131 and catalytic application of 131 in “click” reactions.
Scheme 29: Synthetic route to the catalyst 136.
Scheme 30: Application of the catalyst 136 in “click” reactions.
Scheme 31: Synthetic route to the catalyst 141 and catalytic application of 141 in “click” reactions.
Scheme 32: Synthetic route to the catalyst 144 and catalytic application of 144 in “click” reactions.
Scheme 33: Synthetic route to the catalyst 149 and catalytic application of 149 in “click” reactions.
Scheme 34: Synthetic route to the catalyst 153 and catalytic application of 153 in “click” reactions.
Scheme 35: Synthetic route to the catalyst 155 and catalytic application of 155 in “click” reactions.
Scheme 36: Synthetic route to the catalyst 157 and catalytic application of 157 in “click” reactions.
Scheme 37: Synthetic route to the catalyst 162.
Scheme 38: Application of the catalyst 162 in “click” reactions.
Scheme 39: Synthetic route to the catalyst 167 and catalytic application of 167 in “click” reactions.
Scheme 40: Synthetic route to the catalyst 169 and catalytic application of 169 in “click” reactions.
Scheme 41: Synthetic route to the catalyst 172.
Scheme 42: Application of the catalyst 172 in “click” reactions.
Olefin metathesis in multiblock copolymer synthesis
- Maria L. Gringolts,
- Yulia I. Denisova,
- Eugene Sh. Finkelshtein and
- Yaroslav V. Kudryavtsev
Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21
- electronics, fuel cells, gene and drug delivery [8][9][15][38][39][40]. Compared with diblock and triblock copolymers, not to speak about polymer blends, multiblock copolymers often demonstrate superior mechanical properties, biocompatibility, biodegradability, compatibilizing ability, and tendency to form
Graphical Abstract
Scheme 1: Multiblock copolymer synthesis by sequential ROMP, replotted from [51].
Figure 1: The most known commercially available catalysts for olefin metathesis.
Scheme 2: Multiblock copolymer synthesis by combining ROMP and NMP, replotted from [56].
Figure 2: A highly fluorescent multiblock copolymer for bioimaging and in vivo tumor targeting [60].
Scheme 3: Multiblock copolymer synthesis by combining ROMP and click reactions replotted from [61].
Scheme 4: Multiblock copolymer synthesis by combining ADMET and other reactions, replotted from [63,64].
Scheme 5: Synthesis of multiblock bottle-brush copolymers by ROMP, replotted from [68].
Scheme 6: Sacrificial synthesis of multiblock copolymers, replotted from [70].
Scheme 7: Synthesis of supramolecular multiblock copolymers, replotted from [74].
Figure 3: The multiblock copolymer capable of post-functionalization [76].
Figure 4: Multiblock copolymers synthesized by macromolecular cross metathesis.
Scheme 8: Macromolecular cross metathesis.
Figure 5: Changes in the DSC thermograms during MCM of PBD and polyesters (left) [84] and PNB–PCOE (right) mediat...
Figure 6: The 13C NMR spectrum recorded after 8 h of the reaction between PCOE, PNB, and Gr1; the homo- and h...
Scheme 9: Elementary reactions of MCM between PNB and PCOE, replotted from [90].
Figure 7: The 1H NMR spectrum recorded after 24 h of the reaction between PCOE, PNB, and Gr1 in CDCl3. The ca...
Scheme 10: Post-modification of multiblock copolymers by hydrogenation (A) [85] and epoxidation (B) [101] of C=C double...
Figure 8: Integral distribution functions for the lamella thickness of crystallites in thermally fractionated...
Spectroelectrochemical studies on the effect of cations in the alkaline glycerol oxidation reaction over carbon nanotube-supported Pd nanoparticles
- Dennis Hiltrop,
- Steffen Cychy,
- Karina Elumeeva,
- Wolfgang Schuhmann and
- Martin Muhler
Beilstein J. Org. Chem. 2018, 14, 1428–1435, doi:10.3762/bjoc.14.120
- utilization in fuel cells (FCs) converting chemical into electrical energy [5]. In alkaline FCs (AFCs) and proton exchange membrane FCs (PEMFCs), H2 and O2 are converted to H2O, heat and electricity. Since the development of anion exchange membranes the research interest in AFCs has increased again, because
Graphical Abstract
Figure 1: CVs of the electrooxidation of 1 M glycerol over Pd/NCNT and Pd/OCNT in 1 M KOH at 1000 rpm at a sc...
Figure 2: CVs of the electrooxidation of 1 M glycerol over Pd/NCNT-NH3 and Pd/OCNT-He in 1 M NaOH at 1000 rpm...
Figure 3: Comparison of IR spectra recorded at 0.77 and 1.17 V vs RHE (further potentials are shown in Supporting Information File 1, Figu...
An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone
- Cristina Mozo Mulero,
- Alfonso Sáez,
- Jesús Iniesta and
- Vicente Montiel
Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40
- medium as an optimal reaction medium [5]. Currently, developments in nanostructured materials and polymeric solid exchange membranes have led the field of polymer electrolyte membrane fuel cells (PEMFC) to become a mature technology [18][19][20]. In this regard, a polymer electrolyte membrane
Graphical Abstract
Figure 1: Characterisation of Pd/C electrocatalyst. a) TEM micrograph. b) Energy dispersive X-ray analysis (E...
Figure 2: SEM images of (a) Pd0.02/C/T and (b) Pd0.20/C/T electrodes, with different magnifications.
Figure 3: Cyclic voltammetric behaviour of Pd0.20/C/T electrode in 0.5 M H2SO4. Scan rate: 50 mV s−1. Startin...
Figure 4: Scheme of all components of the electrochemical reactor including reactions involved in both anode ...
Figure 5: Fractional conversion of benzophenone as a function of coulombic passed charge using the PEMER; 0.5...
Figure 6: Plot of cell voltage versus time obtained from a preparative electrosynthesis performed at 10 mA cm...
Figure 7: Fractional conversion of benzophenone as a function of coulombic charge passed; 0.5 M benzophenone ...
Figure 8: Comparison of fractional conversion (XR) and product yield (η) between Pd0.02/C/T, Pd0.20/C/T and Pd...
Figure 9: Fractional conversions of benzophenone and product yield of diphenylmethanol at both electrodes. (a...
Figure 10: (a) General scheme of a PEMER; (b) itemisation of the main parts of PEMER: 1) endplates, 2) gas dif...
Synthesis and stability of strongly acidic benzamide derivatives
- Frederik Diness,
- Niels J. Bjerrum and
- Mikael Begtrup
Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38
- conditions applied to common chemical transformations has not been described. With the prospect of using these strong benzoic acid derivatives for enhancing proton conductivity in proton-exchange membrane (PEM) fuel cells [3][40] we have examined their compatibility with chemical transformations as well as
- benzimidazole was chosen as model nucleophile for polybenzimidazole, a polymer commonly applied as a membrane in PEM fuel cells [40]. These reactions provided the 4-benzimidazolyl derivatives 13 and 14 in good yields and the N-triflylbenzamide group proved to be stable under these reaction conditions
- -triflylbenzamide 9d. Neither the mono-substituted N-triflylbenzamides 9a and 9b nor the 4-bromo-N,N’-bis(triflyl)benzimidamide (12) were stable in heated methanolic phosphoric acid, which is commonly used for operating PEM fuel cells (Figure 3) [44]. However, most surprisingly, the pentafluoro N-triflylbenzamide
Graphical Abstract
Figure 1: Acid strength (pKa) of various organic acids in acetonitrile or water (nr = not reported) [12-14].
Figure 2: Examples of functional molecules containing an N-triflylbenzamide.
Scheme 1: Synthesis of the strongly acidic benzamide derivatives.
Scheme 2: SNAr reactions of fluoro-substituted benzamide derivatives.
Scheme 3: Cross-coupling reactions of N-triflylbenzoic acid derivatives.
Scheme 4: Hydrolysis rates of the 4-bromobenzoic acid derivatives.
Figure 3: Content (percent) of super acids (0.5 mg/mL) over time (hours) in H3PO4/H2O/MeOH 17:3:20 at 50 °C.
Recent advances in metathesis-derived polymers containing transition metals in the side chain
- Ileana Dragutan,
- Valerian Dragutan,
- Bogdan C. Simionescu,
- Albert Demonceau and
- Helmut Fischer
Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296
- . In addition, the film exhibited high methanol and base tolerance making it suitable for applications in fuel cells and anion-conducting devices. Owing to their high phosphorescent propensity, complexes based on iridium have been grafted onto polymers for the application as light-emitting diodes (LEDs
- features recommend these privileged scaffolds as important hybrid materials having a strong impact on a host of current high-tech applications, as fuel cells, light-emitting diodes (LED), magnetic nanomaterials, catalysts, biosensors, for energy generation and storage. The mainstay of the synthesis of
Graphical Abstract
Scheme 1: Synthesis of homopolymers containing ferrocenyl and tetraethylene glycol groups.
Scheme 2: Synthesis of redox-robust triazolylbiferrocenyl polymers 4.
Scheme 3: Synthesis of cobaltocenium-containing polymers by ROMP.
Scheme 4: Cobaltocenium-appending copolymers by the ROMP approach (X = PF6, Y = BPh4 or Cl).
Scheme 5: Cobalt-containing polymers by click and ROMP approach.
Scheme 6: Synthesis of new cobalt-integrating block copolymers.
Scheme 7: Two alternative routes for the synthesis of redox-active cobalticenium-tethered polyelectrolytes.
Scheme 8: Oxanorbornene monomers for the synthesis of Ru-containing polymers by ROMP.
Scheme 9: ROMP synthesis of Ru-containing homopolymers.
Scheme 10: Synthesis of diblock copolymers incorporating ruthenium.
Scheme 11: Synthesis of Ru triblock copolymers.
Scheme 12: Synthesis of cross-linked Ru-containing triblock copolymers.
Scheme 13: Synthesis of Ir-containing homopolymers by ROMP.
Scheme 14: Monomers for Ir- and Os-containing ROMP polymers.
Scheme 15: ROMP block copolymers integrating Ir in their side chains.
Scheme 16: Synthesis of Rh-containing block copolymers.
Scheme 17: Access to rhodocenium-containing metallopolymers by ROMP.
Scheme 18: Synthesis of homopolymers equipped with Cu coordination centers.
Scheme 19: Synthesis of Cu-containing copolymers (spacer = –(CH2)5–; >C=O).
Scheme 20: Synthesis of polynorbornene bearing a polyoxometalate (POM) cluster in the side chain.
Scheme 21: Synthesis of Eu-containing copolymers by a ROMP-based route.
Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current
- Alicja Schlange,
- Antonio Rodolfo dos Santos,
- Ulrich Kunz and
- Thomas Turek
Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165
- for direct methanol fuel cells (DMFCs). This kind of fuel cell has attracted great attention during recent years as a future power source for portable and stationary applications [13][14][15]. One of the advantages of methanol as fuel is its high energy density. Additionally it offers easy storage and
- /air batteries or fuel cells, or even in other processes. Experimental Reagents Carbon nanotubes (MWCNT, Baytubes®, C 150) with inner diameter of 2–6 nm and outer diameter of 5–20 nm were obtained from Bayer MaterialScience AG. Ethylene glycol (EG), HNO3, HCl and NaOH were purchased from Sigma-Aldrich
Graphical Abstract
Figure 1: Experimental setup for catalyst synthesis in the tubular flow reactor; 1: Reaction mixture reservoi...
Figure 2: Measured temperature profile along the tubular reactor.
Figure 3: TGA weight loss curves for pristine CNT, HNO3 oxidized CNT, Pt/CNT-oil bath and Pt/CNT-tubular reac...
Figure 4: TEM micrographs of catalyst samples: a) Pt/CNT tubular reactor and b) Pt/CNT oil bath.
Figure 5: X-ray diffraction patterns for the as-received CNT and the three Pt/CNT samples taken at intervals ...
Figure 6: Comparison of performance in DMFC with Pt/CNT oil bath and Pt/CNT tubular reactor samples as cathod...
Advances in synthetic approach to and antifungal activity of triazoles
- Kumari Shalini,
- Nitin Kumar,
- Sushma Drabu and
- Pramod Kumar Sharma
Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79
- triazoles Triazoles have been suggested as water replacements in proton conductors used in fuel cells. Once doped into membranes, these triazoles improve the conductivity of the membranes under anhydrous conditions. Due to their amphoteric nature, these compounds act as proton acceptors and donors. Their
Graphical Abstract
Figure 1: Isomeric forms of triazole.
Scheme 1: Copper catalyzed azide–alkyne cycloaddition.
Scheme 2: Ruthenium catalyzed azide–alkyne cycloaddition.
Scheme 3: Copper-sulfate catalyzed azide–alkyne cycloaddition.
Scheme 4: Azide–dimethylbut-2-yne-dioate cycloaddition.
Figure 2: Triazole compound 3 with most potent antifugal activity against various strains [20].
Figure 3: Triazole compounds 4 and 5 showing antifungal activity against Candida albicans [31].
Figure 4: Triazole compound 6 with the highest activity against Aspergillus flavus, Aspergillus versicolor, A...
Figure 5: Triazole compound 7 exhibiting an MIC of 25 µg/mL against Aspergillus niger [33].
Figure 6: Triazole compound 8 showing the most significant activity against Aspergillus niger and Fusarium ox...
Figure 7: Ergosterol biosynthesis inhibitor pathway.
Figure 8: Fluconazole (9).
Figure 9: Itraconazole (10).
Figure 10: Voriconazole (11).
Figure 11: Posaconazole (12).
Figure 12: Ravuconazole (13).
A convenient method for preparing rigid-core ionic liquid crystals
- Julien Fouchet,
- Laurent Douce,
- Benoît Heinrich,
- Richard Welter and
- Alain Louati
Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51
- /hydrophobicity…). Important emerging applications include those in separation and extraction processes, and in various electrochemical devices, such as lithium ion batteries, fuel cells, and capacitors, as well as in synthesis and catalysis [1][2][3][4][5]. Liquid crystals are characterised by both mobility and
Graphical Abstract
Scheme 1: 1-[4-(dodecyloxy)phenyl]-3-methyl-1H-imidazol-3-ium mesogenic salts.
Scheme 2: Synthesis of the imidazole A. Reaction conditions: (i) aryl iodide (1.37 mmol), imidazole (1.69 mmo...
Scheme 3: Synthesis of methyl imidazolium 1a. Reaction conditions: (i) MeI in sealed tube, 54 h at RT.
Figure 1: ORTEP view of compound 1a with partial labelling. The closest molecules are represented (with lower...
Figure 2: Packing diagram of compound 1a in projection in the (b,c) lattice plane. Large spheres represent th...
Scheme 4: Anion metathesis in water/CH2Cl2 as solvent.
Figure 3: Spectra of absorption (red line) and emission (blue line) of 1a.
Figure 4: TGA measurements of the compounds 1a–e (rate 10 °C·min−1, in air).
Figure 5: Phase transition temperatures of compounds 1a–e.
Figure 6: Powder X-ray diffraction pattern of compound 1a in the liquid crystal state (T = 120 °C).
Figure 7: The melting process involves the ruffling of the ionic sublayer. In the smectic phase, the ruffling...
Figure 8: Comparison of the molecular area S and of the ionic sublayer thickness dc (including mesogenic segm...
Figure 9: Variation with the counter-ion of the molecular area S and of the ionic sublayer thickness dc (incl...
Figure 10: Cyclic voltammogram of 1a in CH3CN (0.1 M NBu4PF6): (i), (ii) cathodic and anodic range of the volt...
