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Search for "carbon nanotube" in Full Text gives 13 result(s) in Beilstein Journal of Organic Chemistry.
Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study
- Yasuhiro Oishi,
- Motoharu Kitatani and
- Koichi Kusakabe
Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49
- sensor chips and specifically binds to the antibody. The antigen is then detected by observing the change in the vibrational frequency before and after the injection of the antigen. The immobilization of a protein using a PASE linker on carbon nanotube [1], graphite [4], and graphene [5] has been
Graphical Abstract
Figure 1: (a) Molecular structure of 1-pyrenebutanoic acid succinimidyl ester (PASE). The black, white, red, ...
Figure 2: (a) Local structures around the butyl chain in conformation 1, the structure at activation barrier ...
Figure 3: Structure of PASE on graphene at the activation barrier top [9]. Detailed values of the torsion angle ...
Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges
- Eiichi Kayahara,
- Yoshiyuki Mizuhata and
- Shigeru Yamago
Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38
- Eiichi Kayahara Yoshiyuki Mizuhata Shigeru Yamago Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan 10.3762/bjoc.20.38 Abstract A dication of [5]cycloparaphenylene ([5]CPP2+) was selectively encapsulated by neutral [10]CPP to form the shortest double-layer carbon nanotube
Graphical Abstract
Figure 1: Structures of a) [10]CPP⊃C60, (b) [n+5]CPP⊃[n]CPP, and (c) [10]CPP⊃[5]CPP2+ (this work).
Figure 2: 1H NMR spectra (CD2Cl2, 25 °C) of a) a mixture of [8]–[12]CPPs and [5]CPP2+[B(C6F5)4−]2 before and aft...
Figure 3: Cyclic voltammograms of [10]CPP⊃[5]CPP2+[B(C6F5)4−]2, [10]CPP, and [5]CPP2+[B(C6F5)4−]2 in Bu4N+ B(C...
Figure 4: UV–vis–NIR spectra of [10]CPP⊃[5]CPP2+[B(C6F5)4−]2 (black), [10]CPP (blue), and [5]CPP2+[B(C6F5)4−]2...
Figure 5: Top and side view of [10]CPP⊃[5]CPP2+ complexes a) 1, b) 2, and c) 3 obtained by DFT calculation at...
Figure 6: HOMO−1, HOMO, LUMO, and LUMO+1 orbitals of [10]CPP⊃[5]CPP2+ (1), [5]CPP2+, and [10]CPP.
Figure 7: X-ray crystal structure of [10]CPP⊃[5]CPP2+[B(C6F5)4]2. a) Side and b) top views of ORTEP drawings....
Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles
- Periklis X. Kolagkis,
- Eirini M. Galathri and
- Christoforos G. Kokotos
Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36
- . immobilized carbon nanotubes on sulfonated polyacrylamide creating polymer/carbon nanotube composites, which could also be employed in the synthesis of BIMs [115][116]. This methodology used a catalyst loading of 5 mol % under reflux conditions (85 °C) in acetonitrile for 30–40 minutes with product yields
Graphical Abstract
Scheme 1: Examples of BIMs used for their medicinal properties.
Scheme 2: Mechanisms for the synthesis of BIMs using protic or Lewis acids as catalysts.
Scheme 3: Synthesis of bis(indolyl)methanes using DBDMH.
Scheme 4: Competition experiments and synthesis of bis(indolyl)methanes using DBDMH.
Scheme 5: Proposed mechanism for formation of BIM of using DBDMH.
Scheme 6: Synthesis of bis(indolyl)methanes using I2.
Scheme 7: General reaction mechanism upon halogen bonding.
Scheme 8: Synthesis of bis(indolyl)methanes using I2, introduced by Ji.
Scheme 9: Synthesis of bis(indolyl)methanes using Br2 in CH3CN.
Scheme 10: Βidentate halogen-bond donors.
Scheme 11: Synthesis of bis(indolyl)methanes using bidentate halogen-bond donor 26.
Scheme 12: Proposed reaction mechanism.
Scheme 13: Synthesis of bis(indolyl)methanes using iodoalkyne as catalyst.
Scheme 14: Proposed reaction mechanism.
Scheme 15: Optimized reaction conditions used by Ramshini.
Scheme 16: Activation of the carbonyl group by HPA/TPI-Fe3O4.
Scheme 17: Synthesis of BIMs in the presence of nanoAg-Pt/SiO2-doped silicate.
Scheme 18: Mechanism of action proposed by Khalafi-Nezhad et al.
Scheme 19: Activation of the carbonyl group by the Cu–isatin Schiff base complex.
Scheme 20: Optimum reaction conditions published by Jain.
Scheme 21: Organocatalytic protocol utilizing nanoparticles introduced by Bankar.
Scheme 22: Activation of the carbonyl group by the AlCl3·6H2O-SDS-SiO2 complex.
Scheme 23: Optimal reaction conditions for the aforementioned nano-Fe3O4 based catalysts.
Scheme 24: Nanocatalytic protocol proposed by Kaur et al.
Scheme 25: Microwave approach introduced by Yuan.
Scheme 26: Microwave approach introduced by Zahran et al.
Scheme 27: Microwave irradiation protocol introduced by Bindu.
Scheme 28: Silica-supported microwave irradiation protocol.
Scheme 29: Proposed mechanism for formation of BIM by Nongkhlaw.
Scheme 30: Microwave-assisted synthesis of BIMs catalyzed by succinic acid.
Scheme 31: Proposed mechanism of action of MMO-4.
Scheme 32: Catalytic approach introduced by Muhammadpoor-Baltork et al.
Scheme 33: Reaction conditions used by Xiao-Ming.
Scheme 34: Ultrasonic irradiation-based protocol published by Saeednia.
Scheme 35: Pyruvic acid-mediated synthesis of BIMs proposed by Thopate.
Scheme 36: Synthesis of BIMs using [bmim]BF4 or [bmim]PF6 ionic liquids.
Scheme 37: Synthesis of BIMs utilizing In(OTf)3 in octylmethylimidazolium hexafluorophosphate as ionic liquid.
Scheme 38: FeCl3·6H2O-catalyzed synthesis of BIMs with use of ionic liquid.
Scheme 39: Synthesis of BIMs utilizing the [hmim]HSO4/EtOH catalytic system.
Scheme 40: Synthesis of BIMs utilizing acidic ionic liquid immobilized on silica gel (ILIS-SO2Cl).
Scheme 41: The [bmim][MeSO4]-catalyzed reaction of indole with various aldehydes.
Scheme 42: The role of [bmim][MeSO4] in catalyzing the reaction of indole with aldehydes.
Scheme 43: Synthesis of BIMs utilizing FeCl3-based ionic liquid ([BTBAC]Cl-FeCl3) as catalyst.
Scheme 44: Synthesis of BIMs using [Msim]Cl at room temperature.
Scheme 45: [Et3NH][H2PO4]-catalyzed synthesis of bis(indolyl)methanes.
Scheme 46: PILs-catalyzed synthesis of bis(indolyl)methanes.
Scheme 47: FSILs-mediated synthesis of bis(indolyl)methanes.
Scheme 48: Possible “release and catch” catalytic process.
Scheme 49: Synthesis of bis(indolyl)methanes by [DABCO-H][HSO4].
Scheme 50: Synthesis of bis(indolyl)methanes by [(THA)(SO4)].
Scheme 51: Synthesis of BBSI-Cl and BBSI-HSO4.
Scheme 52: Synthesis of BIMs in the presence of BBSI-Cl and BBSI-HSO4.
Scheme 53: Chemoselectivity of the present method.
Scheme 54: Synthesis of BIMs catalyzed by chitosan-supported ionic liquid.
Scheme 55: Proposed mechanism of action of CSIL.
Scheme 56: Optimization of the reaction in DESs.
Scheme 57: Synthesis of BIMs using ChCl/SnCl2 as DES.
Scheme 58: Synthesis of BIMs derivatives in presence of DES.
Scheme 59: BIMs synthesis in choline chloride/urea (CC/U).
Scheme 60: Flow chemistry-based synthesis of BIMs by Ley.
Scheme 61: Flow chemistry-based synthesis of BIMs proposed by Nam et al.
Scheme 62: Amino-catalyzed reaction of indole with propionaldehyde.
Scheme 63: Aminocatalytic synthesis of BIMs.
Scheme 64: Proposed mechanism for the aminocatalytic synthesis of BIMs.
Scheme 65: Enzymatic reaction of indole with aldehydes.
Scheme 66: Proposed mechanism for the synthesis of BIMs catalyzed by TLIM.
Scheme 67: Proposed reaction mechanism by Badsara.
Scheme 68: Mechanism proposed by D’Auria.
Scheme 69: Photoinduced thiourea catalysis.
Scheme 70: Proposed mechanism of photoacid activation.
Scheme 71: Proposed mechanism of action for CF3SO2Na.
Scheme 72: Proposed mechanism for the synthesis of BIMs by Mandawad.
Scheme 73: Proposed mechanism for the (a) acid generation and (b) synthesis of BIMs.
Scheme 74: a) Reaction conditions employed by Khaksar and b) activation of the carbonyl group by HFIP.
Scheme 75: Activation of the carbonyl group by the PPy@CH2Br through the formation of a halogen bond.
Scheme 76: Reaction conditions utilized by Mhaldar et al.
Scheme 77: a) Reaction conditions employed by López and b) activation of the carbonyl group by thiourea.
Scheme 78: Infrared irradiation approach introduced by Luna-Mora and his research group.
Scheme 79: Synthesis of BIMs with the use of the Fe–Zn BMOF.
Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations
- Laura Abella,
- Gerard Novell-Leruth,
- Josep M. Ricart,
- Josep M. Poblet and
- Antonio Rodríguez-Fortea
Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10
- have been published that record the dynamic behavior of a wide range of molecules and chemical reactions. One such process was the dimerization of C60 fullerene in a carbon nanotube peapod, i.e., hybrid structures consisting of fullerene molecules encapsulated in single-walled carbon nanotubes (SWCNT
- analyzed the interaction between C60 and the nanotube within the peapod. Next, we have found that some dimeric C60–C60 fullerene structures inside the carbon nanotube are thermodynamically favorable. Experiments indicate that, besides C60 sensitization via a singlet excited state, the [2 + 2] cycloaddition
- can also be activated through the formation of C60+• radical cation [3][9]. This mechanistic proposal for phase 1, which to our knowledge has not yet been explored in detail inside a carbon nanotube, is analyzed here and compared to the non-activated C60 dimerization. Finally, some intermediates for
Graphical Abstract
Scheme 1: Proposed radical cation mechanism for the dimerization of two C60 cages inside a metallic carbon na...
Figure 1: DFT-optimized structures of C60 dimers 1-D2h, 1-Cs and nanotubular C120-NT-D5d fullerene.
Figure 2: Energy profiles for the dimerization of 2 C60 and C60 + C60•+ fullerenes in the gas phase. All ener...
Figure 3: Energy profiles for the dimerization of 2 C60 (neutral) and C60 + C60•+ (radical cation) fullerenes...
Figure 4: Proposed sequence of C60 dimers up to the formation of dimer HPR-Cs•+.
Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio
- Keiko Kojima,
- Nodoka Kosugi,
- Hirokuni Jintoku,
- Kazufumi Kobashi and
- Toshiya Okazaki
Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7
- 305-8571, Japan 10.3762/bjoc.20.7 Abstract We successfully prepared a surfactant-assisted carbon nanotube (CNT) liquid crystal (LC) dispersion with double-walled CNTs (DWCNTs) having a high aspect ratio (≈1378). Compared to dispersions of single-walled CNTs (SWCNTs) with lower aspect ratio, the
- . Keywords: aqueous dispersion; bar-coating; carbon nanotube; coffee-ring effect; liquid crystal; Introduction Carbon nanotubes (CNTs) are cylindrical carbon structures with high electrical conductivity and tensile strength in the direction of the tube, anticipated as durable and highly conductive fibers
- carbon nanotube dispersions with high aspect ratios, we utilized DWCNTs obtained from Shenzhen Nanotech Port Co. Ltd. Supporting Information File 1 provides characterization details. Briefly, the Raman G/D ratio was approximately 37 (Supporting Information File 1, Figure S1d), indicating high
Graphical Abstract
Figure 1: (a) Size distribution of DWCNTs in dispersion by DCS measurements. (b) Optical microscopy image of ...
Figure 2: (a) Phase diagram of the DWCNT dispersion. The nematic phase, biphasic state and isotropic phase ar...
Figure 3: Observed tactoid aspect ratio R/r as a function of tactoid volume Rr2. Filled circle and open circl...
Figure 4: (a, b) POM images of the DWCNT film at (a) 0° and (b) 45° under crossed polarizers (white double ar...
Figure 5: (a) Photograph of the DWCNT film. Thicknesses were measured at 7 spots along the yellow dashed line...
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.
Adhesion, forces and the stability of interfaces
- Robin Guttmann,
- Johannes Hoja,
- Christoph Lechner,
- Reinhard J. Maurer and
- Alexander F. Sax
Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12
Graphical Abstract
Figure 1: Left: The graphs of an interaction potential Vint composed of an attractive component Vatt and a re...
Figure 2: From left to right: An external pulling force acting on the system in its equilibrium structure inc...
Figure 3: Potential functions (thin lines) and the first derivatives (thick lines). Left: For constant ΔV the...
Figure 4: Left: The disk covering the atoms of molecule B seen by an atom in molecule A expands with increasi...
Figure 5: Demonstration of the contact zone and the reduced contact zone of an adsorbate/adsorbent complex wi...
Figure 6: The contact zone of an (8.0)-CNT/tetracene complex. The bold black lines in the traverse section re...
Figure 7: The separation of tetracene from graphene. Top row: Mode S1 (left), mode S2 (right). Bottom row: mo...
Figure 8: The slope functions for the separation of tetracene from graphene for the four separation modes. Re...
Figure 9: Boiling points of straight-chain primary alcohols, straight-chain primary amines and straight-chain...
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
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...
Mechanochemistry of nucleosides, nucleotides and related materials
- Olga Eguaogie,
- Joseph S. Vyle,
- Patrick F. Conlon,
- Manuela A. Gîlea and
- Yipei Liang
Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81
- : specifically, solid solutions, cocrystals, polymorph transitions, carbon nanotube dissolution and inclusion complex formation. Keywords: DNA; green chemistry; mechanochemistry; nucleoside; nucleotide; Introduction Several definitions of mechanochemistry have been attempted since Ostwald included it as one of
Graphical Abstract
Figure 1: Examples of equipment used to perform mechanochemistry on nucleoside and nucleotide substrates (not...
Figure 2: Ganciclovir.
Scheme 1: Nucleoside tritylation effected by hand grinding in a heated mortar and pestle.
Scheme 2: Persilylation of ribonucleoside hydroxy groups (and in situ acylation of cytidine) in a MBM.
Scheme 3: Nucleoside amine and carboxylic acid Boc protection using an improvised attritor-type mill.
Scheme 4: Nucleobase Boc protection via transient silylation using an improvised attritor-type mill.
Scheme 5: Chemoselective N-acylation of an aminonucleoside using LAG in a MBM.
Scheme 6: Azide–alkyne cycloaddition reactions performed in a copper vessel in a MBM.
Figure 3: a) Custom-machined copper vessel and zirconia balls used to perform CuAAC reactions (showing: upper...
Scheme 7: Thiolate displacement reactions of nucleoside derivatives in a MBM.
Scheme 8: Selenocyanate displacement reactions of nucleoside derivatives in a MBM.
Scheme 9: Nucleobase glycosidation reactions and subsequent deacetylation performed in a MBM.
Scheme 10: Regioselective phosphorylation of nicotinamide riboside in a MBM.
Scheme 11: Preparation of nucleoside phosphoramidites in a MBM using ionic liquid-stabilised chlorophosphorami...
Scheme 12: Preparation of a nucleoside phosphite triester using LAG in a MBM.
Scheme 13: Internucleoside phosphate coupling linkages in a MBM.
Scheme 14: Preparation of ADPR analogues using in a MBM.
Scheme 15: Synthesis of pyrophosphorothiolate-linked dinucleoside cap analogues in a MBM to effect hydrolytic ...
Figure 4: Early low temperature mechanised ball mill as described by Mudd et al. – adapted from reference [78].
Scheme 16: Co-crystal grinding of alkylated nucleobases in an amalgam mill (N.B. no frequency was recorded in ...
Figure 5: Materials used to prepare a smectic phase.
Figure 6: Structures of 5-fluorouracil (5FU) and nucleoside analogue prodrugs subject to mechanochemical co-c...
Scheme 17: Preparation of DNA-SWNT complex in a MBM.
Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry
- Katharina Hiebler,
- Georg J. Lichtenegger,
- Manuel C. Maier,
- Eun Sung Park,
- Renie Gonzales-Groom,
- Bernard P. Binks and
- Heidrun Gruber-Woelfler
Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52
- interface populated by catalyst particles. They deposited metallic Pd onto carbon nanotube–inorganic oxide hybrid nanoparticles and used them in emulsions for the hydrodeoxygenation of a phenolic compound and the hydrogenation and etherification of an aldehyde. The advantages of such a system include a high
Graphical Abstract
Figure 1: Targeted integrated multistep synthesis of valsartan (1) and sacubitril (2).
Scheme 1: Suzuki–Miyaura coupling of phenylboronic acid 3 with various bromoarenes 4a–e (a: R1 = H, R2 = CH3; ...
Figure 2: Particle size distribution of Ce0.495Sn0.495Pd0.01O2–δ after size reduction via milling and separat...
Figure 3: Optical microscope images of fresh aqueous dispersions, 0.05 wt %, of (a) Ce0.495Sn0.495Pd0.01O2–δ ...
Figure 4: Photos of vessels containing cyclohexane-in-water emulsions stabilised by particles of Ce0.495Sn0.4...
Figure 5: Optical microscopy images of cyclohexane-in-water emulsions of Figure 4 after one month for particle concen...
Figure 6: (top) Mean emulsion droplet diameter after 30 min as a function of particle concentration for syste...
Figure 7: Mean particle diameter in aqueous dispersions as a function of Ce0.495Sn0.495Pd0.01O2–δ concentrati...
Figure 8: Variation of the zeta potential and pH value of aqueous dispersions of Ce0.495Sn0.495Pd0.01O2–δ par...
Figure 9: (a) Appearance of octane-in-water emulsions with time at 0.05 wt % of Ce0.495Sn0.495Pd0.01O2–δ (lef...
Figure 10: (a) Variation of droplet diameter with particle concentration for octane-in-water emulsions stabili...
Figure 11: (a) Variation of droplet diameter with particle concentration for toluene-in-water emulsions stabil...
Enabling technologies and green processes in cyclodextrin chemistry
- Giancarlo Cravotto,
- Marina Caporaso,
- Laszlo Jicsinszky and
- Katia Martina
Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30
- depicted in Scheme 11, the synthesis generated in situ azomethine ylides which include both a β-CD unit and a DOTAMA tris(t-butyl ester) moiety. The toxicity assessment, cell viability and permeability of single-walled carbon nanotube (SWCNT) platform, was evaluated on five human cell lines. No-toxicity
Graphical Abstract
Figure 1: (a) Multihorn-flow US reactor, (b) Cavitational turbine, (c) Pilot-scale BM, (d) High-pressure MW r...
Figure 2: Trends in CD papers and CD use in green chemical processes.
Figure 3: Distribution of energy efficient methods in CD publications.
Figure 4: Document type dealing with CD chemistry under non-conventional techniques (conference proceedings a...
Figure 5: Document type dealing with sustainable technologies in CD publications.
Scheme 1: Synthesis of 6I-(p-toluenesulfonyl)-β-CD.
Scheme 2: Example of CuAAC with 6I-azido-6I-deoxy-β-CD and phenylacetylene.
Scheme 3: Synthesis of 6I-benzylureido-6I-deoxy-per-O-acetyl-β-CD.
Scheme 4: Synthesis of 3I-azido-3I-deoxy-altro-α, β- and γ-CD.
Scheme 5: Synthesis of 2-2’ bridged bis(β-CDs). Reaction conditions: 1) TBDMSCl, imidazole, dry pyridine, sti...
Scheme 6: Insoluble reticulated CD polymer.
Scheme 7: CD-HDI cross linked polymers.
Scheme 8: Derivatization of 6I-(p-toluenesulfonyl)-β-CD by tosyl displacement.
Scheme 9: Synthetic scheme for the preparation of heptakis(6-amino-6-deoxy)-β-CD, heptakis(6-deoxy-6-ureido)-...
Scheme 10: Structure of CD derivatives obtained via MW-assisted CuAAC.
Scheme 11: Preparation of SWCN CD-DOTA carrier.
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
- , the following antimicrobial mechanism was proposed: i) the carbon nanotube embedded in water-insoluble cyclodextrin polyurethane polymers pierce the bacterial cell membrane by direct contacts, and ii) the copper nanoparticles release copper inside the bacterial cell. The combination of these two steps
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...
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
- demonstrate, for the first time, a simple and cost-effective method for the preparation of carbon-nanotube-supported Pt catalysts by using a continuously operated tubular flow reactor. The heating concept was realized by passing electrical current directly through the reactor wall. The experimental setup is
- , washed several times with deionised water to a desired pH value of 7 and finally dried in an oven at 60 °C for 24 h. Preparation of electrocatalysts Carbon nanotube supported Pt catalysts were synthesized by the polyol synthesis method (ethylene glycol mediated reaction). The procedure was as follows
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...
