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Search for "aqueous medium" in Full Text gives 104 result(s) in Beilstein Journal of Organic Chemistry.
Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study
- Stiliyana Pereva,
- Stefan Dobrev,
- Tsveta Sarafska,
- Valya Nikolova,
- Silvia Angelova,
- Tony Spassov and
- Todor Dudev
Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221
- 3. The enthalpies estimated for the subsequent binding process of water molecules to γ-CD in both the gas phase (ΔH1) and aqueous medium (ΔH78) at both levels of theory are presented in Table 1. The two sets of calculations using different basis sets (M062X/6-31G(d,p) and M062X/6-311++G(d,p)//M062X
Graphical Abstract
Figure 1: Chemical structure of γ-CD (A); M062X/6-31G(d,p) optimized conformers of nonhydrated γ-CD in two pr...
Figure 2: Schematic representation of γ-CD–nH2O complexes (where n = 1–7) with water molecules/clusters locat...
Figure 3: M062X/6-31G(d,p) optimized structures of the most stable (a/b structures from Figure 2) γ-CD–nH2O (n = 1–7)...
Figure 4: DSC curve (A) and TG analysis for γ-CD (B). Compared to our previous studies, the hydrated γ-cyclod...
Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds
- Ka-Lung Hung,
- Leong-Hung Cheung,
- Yikun Ren,
- Ming-Hin Chau,
- Yan-Yi Lam,
- Takashi Kajitani and
- Franco King-Chi Leung
Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142
- Abstract In the design of photoharvesting and photoresponsive supramolecular systems in aqueous medium, the fabrication of amphiphilic photoswitches enables a noninvasive functional response through photoirradiation. Although most aqueous supramolecular assemblies are driven by high-energy and biodamaging
- moiety. The excellent photoswitchability in organic medium and the photoresponsiveness in aqueous medium, driven by visible light, were investigated by UV–vis absorption spectroscopy. The assembled supramolecular nanostructures were confirmed by electron microscopy, while the supramolecular packing was
- found in nature in order to enable different biological functions in a precise manner, e.g., actin in biological molecular motors, the cytoskeleton, and cell membrane [5][6][7][8]. Mimicking natural supramolecular assemblies in aqueous medium, the intrinsic supramolecular dynamicity, stimuli
Graphical Abstract
Scheme 1: Illustration of the reversible visible-light-controlled ring closure and thermal-driven ring-openin...
Scheme 2: Synthetic pathway to DAn.
Figure 1: UV–vis-absorption-spectral changes of DAn in THF solution (20 μM). (a) DA11, (c) DA7, (e) DA6 solut...
Figure 2: UV–vis absorption spectra of DAn in aqueous solution (43 μM). (a) DA11 (inset: enlarged 400–480 nm ...
Figure 3: TEM images of freshly prepared aqueous solutions before irradiation of (a) DA11 (0.25 wt %, 4.1 mM)...
Figure 4: Photograph of a freshly prepared aqueous DA11 solution (82.0 mM) ejected into a shallow pool of CaCl...
Figure 5: Photographs of macroscopic soft scaffolds prepared from aqueous solutions of (a) DA11 (32.9 mM), (c...
Figure 6: Macroscopic soft DAn scaffolds fabricated by the shear-flow method. Images taken during fluorescenc...
Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide
- Vishnu Selladurai and
- Selvakumar Karuthapandi
Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105
- selenious acid containing polyaniline via chemical oxidation of aniline with SeO2 as oxidant [45]. Further, Tanini et al. described that selenium dioxide has potential to oxidize aniline to form nitrobenzene in aqueous medium [46]. These findings irrevocably confirmed that aniline undergoes significant
Graphical Abstract
Scheme 1: Reported synthetic methods for the selenation of aromatic compounds.
Scheme 2: Reaction of selenium dioxide with aniline.
Scheme 3: Reaction of selenium dioxide with o-anisidine.
Scheme 4: Reaction of methyl anthranilate with SeO2.
Scheme 5: Reaction mechanism for the formation of diaryl monoselenides.
Scheme 6: Reaction mechanism for the formation of oxamides.
Scheme 7: Reaction mechanism for the formation of quinone 10.
Figure 1: Molecular structure of 3. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O...
Figure 2: Molecular structure of 9. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O...
Figure 3: Molecular structure of 13. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): ...
Figure 4: Molecular structure of 10. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å) a...
Figure 5: Molecular structure of 11. Thermal ellipsoids drawn at 50% probability. Selected bond angles (°): C...
Figure 6: Molecular structure of 12. Thermal ellipsoids drawn at 50% probability. Selected bond angles (°): C...
Figure 7: Relative energy levels of arylamines and SeO2.
Figure 8: Computationally optimized structure of aniline (a), o-anisidine (b), and methyl anthranilate (c), w...
Scheme 8: Resonance structures for the delocalization of the nitrogen lone pair into the π-system.
Synthesis and characterization of water-soluble C60–peptide conjugates
- Yue Ma,
- Lorenzo Persi and
- Yoko Yamakoshi
Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71
- very small hydrodynamic diameter in a neutral aqueous medium, as shown by DLS analysis. Visible-light-induced 1O2 generation by C60–oligo-Lys (5a) was confirmed by ESR spin trapping. This suggests the high potential of 5a as a basis for a fullerene-derived PS in biological applications. Experimental
Graphical Abstract
Figure 1: a) Synthesis of C60–oligopeptide conjugates 5a–c and b) synthesis of compound 3. Fulleropyrrolidine...
Figure 2: Structure of C60–oligo-Lys (5a), C60–oligo-Glu (5b), and C60–oligo-Arg (5c) and images of dissolved...
Figure 3: DLS diagrams of C60–peptide conjugates 5a (1 mM, in Milli-Q® water), 5b (1 mM, in Milli-Q® water or...
Figure 4: UV–vis spectra of C60–peptide conjugates 5a and 5b (20 μM in Milli-Q® water for 5a and in pH 9.0 TR...
Figure 5: 1H NMR spectrum of C60–peptide conjugate 5a in D2O (above) and of the precursor monoadduct in CDCl3...
Figure 6: 13C NMR spectrum of C60–peptide conjugate 5a in D2O and of the precursor monoadduct in CDCl3 at 150...
Figure 7: a) X-band ESR spectra of the 4-oxo-TEMP adduct with 1O2 generated by C60–oligo-Lys (5a) and rose be...
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
- of just 0.5 mol %, while providing satisfying yields (60–96%) in just 1 hour. The employment of a green aqueous medium, the mild reaction conditions and the relatively broad substrate scope are some of the benefits that render this protocol more efficient than previous halogen-bonding methodologies
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.
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
- Michio Yamada
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- pyrrolidine at 0 °C, the pentafulvene derivative 36 was obtained with 63% yield via an additional ring-opening process. Similar skeletal transformation reactions were observed for azulene derivatives bearing similar substructures. The reaction of 1 with TCNE in an aqueous medium containing a surfactant
Graphical Abstract
Scheme 1: Pathway of the [2 + 2] CA–RE reaction of an electron-rich alkyne with TCNE or TCNQ. EDG = electron-...
Scheme 2: Reaction pathway for DMA-appended acetylene and TCNEO.
Scheme 3: Pathway of the [2 + 2] CA–RE reaction between 1 and DCFs.
Scheme 4: Sequential double [2 + 2] CA–RE reactions between 1 and TCNE.
Scheme 5: Divergent chemical transformation pathways of TCBD 6.
Scheme 6: Synthesis of 12.
Scheme 7: [2 + 2] CA–RE reaction of 1 with 14. TCE = 1,1,2,2-tetrachloroethane.
Scheme 8: Autocatalytic model proposed by Nielsen et al.
Scheme 9: Synthesis of anthracene-embedded TCBD compound 19.
Scheme 10: Sequence of the [2 + 2] CA–RE reaction between dibenzo-fused cyclooctyne or cyclooctadiyne and TCNE...
Scheme 11: [2 + 2] CA–RE reaction between the CPP derivatives and TCNE. THF = tetrahydrofuran.
Scheme 12: [2 + 2] CA–RE reaction between ethynylfullerenes 31 and TCNE and subsequent thermal rearrangement.
Scheme 13: Pathway of the [2 + 2] CA–RE reaction between TCNE and 34, followed by additional skeletal transfor...
Scheme 14: Synthesis scheme for heterocycle 38 from the reaction between TCNE and 1 in water and a surfactant.
Scheme 15: Synthesis scheme of the CDA product 41.
Scheme 16: Synthesis of rotaxanes 44 and 46 via the [2 + 2] CA–RE reaction.
Scheme 17: Synthesis of a CuI bisphenanthroline-based rotaxane 50.
Figure 1: Structures of the chiral push–pull chromophores 51–56.
Figure 2: Structures of the axially chiral TCBD 57 and DCNQ 58 bearing a C60 core.
Figure 3: Structures of the axially chiral SubPc–TCBD–aniline conjugates 59 and 60 and the subporphyrin–TCBD–...
Figure 4: Structures of 63 and the TCBD 64.
Figure 5: Structures of the fluorophore-containing TCBDs 65–67.
Figure 6: Structures of the fluorophore-containing TCBDs 68–72.
Figure 7: Structures of the urea-containing TCBDs 73–75.
Figure 8: Structures of the fullerene–TCBD and DCNQ conjugates 76–79 and their reference compounds 80–83.
Figure 9: Structures of the ZnPc–TCBD–aniline conjugates 84 and 85.
Figure 10: Structures of the ZnP–PCBD and TCBD conjugates 86–88.
Figure 11: Structures of the porphyrin-based donor–acceptor conjugates (89–104).
Figure 12: Structures of the porphyrin–PTZ or DMA conjugates 105–112.
Figure 13: Structures of the BODIPY–Acceptor–TPA or PTZ conjugates 113–116.
Figure 14: Structures of the corrole–TCBD conjugates 117 and 118.
Figure 15: Structure of the dendritic TCBD 119.
Figure 16: Structures of the TCBDs 120–126.
Figure 17: Structures of the precursor 127 and TCBDs 128–130.
Figure 18: Structures of 131–134 utilized for BHJ OSCs.
Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups
- Dayanne Martins,
- Roberta Lamosa,
- Talis Uelisson da Silva,
- Carolina B. P. Ligiero,
- Sérgio de Paula Machado,
- Daphne S. Cukierman and
- Nicolás A. Rey
Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125
- stability in aqueous medium. Thus, the electronic absorption spectra of hdz-CH3 and hdz-NO2 were recorded in a 10% DMSO/buffer solution (pH 7.4) immediately after preparation and at regular time intervals. The UV–vis spectrum of hdz-CH3 between 250 and 450 nm (Figure 6A) shows two multicomponent absorptions
Graphical Abstract
Scheme 1: Structure of (A) 3-methylsalicylaldehyde 3,4,5-trimethoxybenzoyl hydrazone (hdz-CH3) and (B) 3-nitr...
Figure 1: ORTEP representation of the new N-acylhydrazones synthesized in the present work, drawn with therma...
Figure 2: (A) Superposition of molecular structures and stacked motifs of (B) hdz-CH3 and (C) hdz-NO2.
Figure 3: Overlap of the experimental (carbon atoms colored in gray) and theoretical structures (calculated w...
Figure 4: Mid-infrared spectra of the compounds. Experimental conditions: KBr pellets, room temperature. Calc...
Figure 5: 1H NMR (400 MHz) spectra of (A) hdz-CH3 and (B) hdz-NO2 in DMSO-d6 at 25 °C.
Figure 6: Electronic absorption spectra in a selected wavelength region for a solution of hdz-CH3 in 10% DMSO...
Figure 7: Electronic absorption spectra of hdz-NO2 in selected wavelength regions. Experimental conditions: l...
Scheme 2: General scheme for the synthesis of the studied hydrazones.
Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach
- Dileep Kumar Singh and
- Rajesh Kumar
Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71
- -free conditions, and under microwave irradiation. (1) Reactions in water In recent years, organic reactions in aqueous medium have grown in popularity due to their low cost and environmental friendliness. The use of water as a solvent medium for the synthesis of pyrrole derivatives using various
Graphical Abstract
Figure 1: Various pyrrole containing molecules.
Scheme 1: Various synthestic protocols for the synthesis of pyrroles.
Figure 2: A tree-diagram showing various conventional and green protocols for Clauson-Kaas pyrrole synthesis.
Scheme 2: A general reaction of Clauson–Kaas pyrrole synthesis and proposed mechanism.
Scheme 3: AcOH-catalyzed synthesis of pyrroles 5 and 7.
Scheme 4: Synthesis of N-substituted pyrroles 9.
Scheme 5: P2O5-catalyzed synthesis of N-substituted pyrroles 11.
Scheme 6: p-Chloropyridine hydrochloride-catalyzed synthesis of pyrroles 13.
Scheme 7: TfOH-catalyzed synthesis of N-sulfonylpyrroles 15, N-sulfonylindole 16, N-sulfonylcarbazole 17.
Scheme 8: Scandium triflate-catalyzed synthesis of N-substituted pyrroles 19.
Scheme 9: MgI2 etherate-catalyzed synthesis and proposed mechanism of N-arylpyrrole derivatives 21.
Scheme 10: Nicotinamide catalyzed synthesis of pyrroles 23.
Scheme 11: ZrOCl2∙8H2O catalyzed synthesis and proposed mechanism of pyrrole derivatives 25.
Scheme 12: AcONa catalyzed synthesis of N-substituted pyrroles 27.
Scheme 13: Squaric acid-catalyzed synthesis and proposed mechanism of N-substituted pyrroles 29.
Figure 3: Reusability of catalyst γ-Fe2O3@SiO2-Sb-IL in six cycles.
Scheme 14: Magnetic nanoparticle-supported antimony catalyst used in the synthesis of N-substituted pyrroles 31...
Scheme 15: Iron(III) chloride-catalyzed synthesis of N-substituted pyrroles 33.
Scheme 16: Copper-catalyzed Clauson–Kaas synthesis and mechanism of pyrroles 35.
Scheme 17: β-CD-SO3H-catalyzed synthesis and proposed mechanism of pyrroles 37.
Figure 4: Recyclability of β-cyclodextrin-SO3H.
Scheme 18: Solvent-free and catalyst-free synthesis and plausible mechanism of N-substituted pyrroles 39.
Scheme 19: Nano-sulfated TiO2-catalyzed synthesis of N-substituted pyrroles 41.
Figure 5: Plausible mechanism for the formation of N-substituted pyrroles catalyzed by nano-sulfated TiO2 cat...
Scheme 20: Copper nitrate-catalyzed Clauson–Kaas synthesis and mechanism of N-substituted pyrroles 43.
Scheme 21: Synthesis of N-substituted pyrroles 45 by using Co catalyst Co/NGr-C@SiO2-L.
Scheme 22: Zinc-catalyzed synthesis of N-arylpyrroles 47.
Scheme 23: Silica sulfuric acid-catalyzed synthesis of pyrrole derivatives 49.
Scheme 24: Bismuth nitrate-catalyzed synthesis of pyrroles 51.
Scheme 25: L-(+)-tartaric acid-choline chloride-catalyzed Clauson–Kaas synthesis and plausible mechanism of py...
Scheme 26: Microwave-assisted synthesis of N-substituted pyrroles 55 in AcOH or water.
Scheme 27: Synthesis of pyrrole derivatives 57 using a nano-organocatalyst.
Figure 6: Nano-ferric supported glutathione organocatalyst.
Scheme 28: Microwave-assisted synthesis of N-substituted pyrroles 59 in water.
Scheme 29: Iodine-catalyzed synthesis and proposed mechanism of pyrroles 61.
Scheme 30: H3PW12O40/SiO2-catalyzed synthesis of N-substituted pyrroles 63.
Scheme 31: Fe3O4@-γ-Fe2O3-SO3H-catalyzed synthesis of pyrroles 65.
Scheme 32: Mn(NO3)2·4H2O-catalyzed synthesis and proposed mechanism of pyrroles 67.
Scheme 33: p-TsOH∙H2O-catalyzed (method 1) and MW-assisted (method 2) synthesis of N-sulfonylpyrroles 69.
Scheme 34: ([hmim][HSO4]-catalyzed Clauson–Kaas synthesis of pyrroles 71.
Scheme 35: Synthesis of N-substituted pyrroles 73 using K-10 montmorillonite catalyst.
Scheme 36: CeCl3∙7H2O-catalyzed Clauson–Kaas synthesis of pyrroles 75.
Scheme 37: Synthesis of N-substituted pyrroles 77 using Bi(NO3)3∙5H2O.
Scheme 38: Oxone-catalyzed synthesis and proposed mechanism of N-substituted pyrroles 79.
pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene
- Nan Yang,
- Yi-Yan Zhu,
- Wei-Xiu Lin,
- Yi-Long Lu and
- Wen-Rong Xu
Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45
- water. The anionic bowl-shaped tribenzotriquinacene derivative TBTQ-C6 was incorporated into the polycationic CS-TPE to form electrostatically induced host–guest supra-amphiphiles, which further self-assembled into supramolecular nanoparticles in aqueous medium driven by the hydrophobic effect. As
- . The fluorescence properties of CS-TPE and TBTQ-C6/CS-TPE with three different Rf in aqueous medium were investigated by fluorescence spectrophotometry. The fluorescence emission of CS-TPE was significantly enhanced with the increase of its Rf/DL (Figure 7a). This may be caused by the increased
- labelling of hydrophobic TPE fluorogens, reducing the affinity of the CS chains to the aqueous medium and resulting in the entanglement or wrapping of the TPE fluorogens by polymer chains. As a result, the RIR process was enhanced, greatly increasing the fluorescence. In addition, the fluorescence intensity
Graphical Abstract
Scheme 1: (a) Synthesis route to CS-TPE. (b) Structure of TBTQ-C6. (c) Construction of TBTQ-C6/CS-TPE supramo...
Figure 1: Partial 1H NMR spectra (400 MHz, CD3COOD/D2O, 25 °C) of (a) CS, (b) CS-TPE-2%, (c) CS-TPE-10%, and ...
Figure 2: (a) Optical images of CS-TPE under daylight (top) and 365 nm UV light (bottom) in the solid state; ...
Figure 3: TEM images of (a) CS-TPE-2%, (b) CS-TPE-10%, and (c) CS-TPE-20% assemblies at pH 5.3; TEM images of...
Figure 4: (a, c, e) Optical transmittance and (b, d, f) transmittance as a function of [TBTQ-C6] at 293 nm of...
Figure 5: (a, c, e) Optical transmittance and (b, d, f) CS-TPE concentration-dependent optical transmittance ...
Figure 6: TEM images of (a) TBTQ-C6/CS-TPE-10% in aqueous solution at pH 5.3, (b) after adjustment of the sol...
Figure 7: (a) Fluorescence spectra of CS-TPE with different Rf in aqueous solutions at pH 5.3 and 10.4; (b) f...
Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme
- Josipa Matić,
- Tana Tandarić,
- Marijana Radić Stojković,
- Filip Šupljika,
- Zrinka Karačić,
- Ana Tomašić Paić,
- Lucija Horvat,
- Robert Vianello and
- Lidija-Marija Tumir
Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40
- membrane (Figure S26, Supporting Information File 1). The compound showed not to be toxic to the HeLa cells as no visible damage was detected. Interactions of Phen-Py-1 and Phen-Py-2 with ds-polynucleotides and enzyme dipeptidyl peptidase III in an aqueous medium Interactions of Phen-Py-1 and Phen-Py-2
- by a distortion of polynucleotide helicity upon addition of Phen-Py-1, or this change was a result of uniform orientation of the dye with respect to DNA chiral axis. Binding of Phen-Py-1 to enzyme dipeptidyl peptidase III in an aqueous medium Binding of Phen-Py-1 to dipeptidyl peptidase (DPPIII
Graphical Abstract
Scheme 1: Novel pyrene–phenanthridine conjugates Phen-Py-1 (longer, flexible linker) and Phen-Py-2 (shorter, ...
Scheme 2: Synthesis of Phen-Py-1 and Phen-Py-2 by amide formation; Reagents and conditions: 1. TFA–H2O mixtur...
Figure 1: 2D (left) and 3D (right) representation of fluorescence emission spectra of Phen-Py-1 (c = 2 × 10−6...
Figure 2: Most representative structures of the conjugates Phen-Py-1 and Phen-Py-2 at different pH conditions...
Figure 3: UV–vis titration of Phen-Py-1 with ct-DNA,; changes in the UV–vis spectra of Phen-Py-1 at λ = 350 n...
Figure 4: . Experimental (■) and calculated (–) (by Scatchard equation Table 2) fluorescence intensities of compound ...
Figure 5: Comparison of spectra of DNA-dye complex (r = 0.5, black) and sum of DNA and dye spectra (red) of a...
Figure 6: Fluorimetric titration of Phen-Py-1, λexc = 352 nm, c = 1 × 10−6 mol dm−3 with dipeptidyl peptidase...
Figure 7: A: ITC titration: raw titration data from the experimental injections of human DPP III enzyme mutan...
CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview
- Dileep Kumar Singh
Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29
- -base analogues 41a,b were also obtained by the treatment with HCl in dioxane. The conjugation of carbohydrate with porphyrin improves the solubility of porphyrin in aqueous medium and also improves the optical and medicinal properties of porphyrins [30]. Considering these properties of glycoporphyrins
Graphical Abstract
Figure 1: Alkyne–azide "click reaction".
Figure 2: β- and meso-triazole-linked porphyrin.
Scheme 1: Synthesis of β-triazole-linked porphyrins 3a–c.
Scheme 2: Synthesis of β-triazole-bridged porphyrin-coumarin conjugates 11–20.
Scheme 3: Synthesis of β-triazole-bridged porphyrin-xanthone conjugates 23–27 and xanthone-bridged β-triazolo...
Scheme 4: Synthesis of meso-triazoloporphyrins 32a–c and triazole-bridged diporphyrins 34.
Scheme 5: Synthesis of meso-triazole-linked porphyrin-ferrocene conjugates 37a–d.
Scheme 6: Synthesis of meso-triazole-linked porphyrin conjugates 40a,b and 41a,b.
Scheme 7: Synthesis of meso-triazole-linked glycoporphyrins 43a–c.
Scheme 8: Synthesis of meso-triazole-linked porphyrin-coumarin conjugates 44–48.
Scheme 9: Synthesis of meso-triazole-bridged porphyrin-DNA conjugate 50.
Scheme 10: Synthesis of meso-linked porphyrin-triazole conjugates 53 and 57.
Scheme 11: Synthesis of meso-triazole-linked porphyrin-corrole conjugate 60.
Scheme 12: Synthesis of porphyrin conjugates 64a,b and 67a,b. Reaction conditions: (i) CuSO4, sodium ascorbate...
Scheme 13: Synthesis of meso-triazole-bridged porphyrin-quinolone conjugates 70a–e.
Scheme 14: Synthesis of meso-triazole-linked porphyrin-fluorescein dyad 73.
Scheme 15: Synthesis of meso-triazole-linked porphyrin-carborane conjugates 76a,b.
Scheme 16: Synthesis of meso-triazole-bridged porphyrin-BODIPY conjugates 78 and 80.
Scheme 17: Synthesis of meso-triazole-linked cationic porphyrin conjugates 85 and 87. Reaction conditions: (i)...
Scheme 18: Synthesis of meso-triazole-cobalt-porphyrin diimine-dioxime conjugate 91. Reactions conditions: (i)...
Scheme 19: Synthesis of triazole-linked porphyrin-bearing N-doped graphene hybrid 96.
Scheme 20: Synthesis of meso-triazole-linked porphyrin-fullerene dyads 100a–d and 104a,b.
Scheme 21: Synthesis of meso-triazole-bridged diporphyrin conjugates 107 and 108.
Scheme 22: Synthesis of porphyrin-ruthenium (II) conjugates 112a,b and 116a,b. Reaction conditions: (i) Zn(OAc)...
Scheme 23: Synthesis of meso-triazole-linked porphyrin dyad 119 and triad 121.
Scheme 24: Synthesis of di-triazole-bridged porphyrin-β-CD conjugate 126.
Scheme 25: Synthesis of meso-triazole-bridged porphyrin star trimer 129.
Scheme 26: Synthesis of 1,2,3-triazole-linked porphyrin-β-CD conjugates 131a,b.
Scheme 27: Synthesis of tritriazole-bridged porphyrin-lantern-DNA sequence 134.
Scheme 28: Synthesis of meso-triazole-linked porphyrin-polymer conjugates 137 and 139.
Scheme 29: Synthesis of triazole-linked capped porphyrin 142; Reaction conditions: method A: 10% H2O in THF, C...
Scheme 30: Synthesis of meso-tetratriazole-linked porphyrin-maleimine conjugates 145a–c.
Scheme 31: Synthesis of meso-tetratriazole-linked porphyrin-cholic acid complex 148a,b.
Scheme 32: Synthesis of meso-tetratriazole-linked porphyrin conjugates 151–153.
Scheme 33: Synthesis of meso-tetratrizole-porphyrin-carborane conjugates 155, 156 and 158a–c.
Scheme 34: Synthesis of meso-tetratriazole-porphyrin-cardanol conjugates 160 and 162.
Scheme 35: Synthesis of meso-tetratriazole-linked porphyrin-BODIPY conjugate 164.
Scheme 36: Synthesis of meso-tetratriazole-linked porphyrin-β-CD conjugates 166a,b.
Scheme 37: Synthesis of tetratriazole-bridged meso-arylporphyrins 171a–c and 172a–c.
Scheme 38: Synthesis of octatriazole-bridged porphyrin-β-CD conjugate 174 and porphyrin-adamantane conjugates ...
Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene
- Konstantin Lebedinskiy,
- Volodymyr Lobaz and
- Jindřich Jindřich
Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170
- parameters is impossible. ITC (isothermal titration calorimetry) is a popular technique for evaluating supramolecular interaction with CDs [38], mainly in the aqueous medium. We performed the titrations of tetracene DMSO solution by the series of CDs used in the solubility experiments (Figure 7, Figure 8
Graphical Abstract
Scheme 1: The synthesis of 6A-azido-6A-deoxy-per-6-O-tert-butyldimethylsilyl-β-cyclodextrin.
Scheme 2: The synthesis of β-cyclodextrin dimers with permethylated secondary rims.
Scheme 3: The synthesis of β-cyclodextrin dimers with permethylated primary rims.
Figure 1: The fragments of 1H NOESY NMR spectra of 4 (a), 10 (b), and 9 (c) indicating the interaction betwee...
Figure 2: The fragment of the 1H NMR spectrum of compounds 9 (green); 10 (red); 12 (blue) representing the si...
Figure 3: Other cyclodextrins that were used in the solubilization experiments with tetracene.
Figure 4: The tetracene UV absorbance dependence on concentration at 476 nm.
Figure 5: The relative concentrations of tetracene in DMSO solutions with hosts 4, 5, 10, 12, 13–18 referred ...
Figure 6: "Tail-to-tail" (a) and "head-to-head" (b) orientation of two cyclodextrin moieties and primary-rim ...
Figure 7: Isotherms of the titration of tetracene with "dimeric" CD solutions in DMSO at 298 K (circles – 10;...
Figure 8: Isotherms of the titration of tetracene with "monomeric" CD solutions in DMSO at 298 K (circles – 16...
Supramolecular approaches to mediate chemical reactivity
- Pablo Ballester,
- Qi-Qiang Wang and
- Carmine Gaeta
Beilstein J. Org. Chem. 2022, 18, 1463–1465, doi:10.3762/bjoc.18.152
- -workers [19] reported an efficient photocatalytic supramolecular system based on a self-assembled nanosystem. The self-assembled system was obtained in an aqueous medium by inclusion of ammonium benzoyl-ʟ-alaninate (G) in a tetraphenylethylene-embedded pillar[5]arene (m-TPEWP5). The resulting worm-like
Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis
- Prodip Howlader and
- Michael Schmittel
Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62
- aromatic walls that offer van-der-Waals and π–π stacking interactions in order to compensate for the absence of a strong electrostatic interaction. These non-covalent/ionic interactions play an important role in encapsulating aromatic organic molecules, especially in aqueous medium. Along this rationale
- tetraphenylethene (TPE) units which act as an aggregation-induced emissive (AIE) fluorophore [65]. The newly designed TPE-based tetraimidazole donor 19 has been treated with 180°/120° trans-Pt(II) acceptors which led to the coordination-driven self-assembly of 3D discrete molecular cages in aqueous medium (Figure 5
Graphical Abstract
Figure 1: Butterfly 1 (Figure was reprinted with permission from [45]. Copyright 2012 American Chemical Society. ...
Figure 2: Synthesis of the three-component heteroleptic molecular boat 8 and its use as a catalyst for the Kn...
Figure 3: Synthesis of the two-component triangle 14 and three-component heteroleptic prism 15 [59]. Figure was a...
Figure 4: Catalytic Michael addition reaction using the urea-decorated molecular prism 15 [59].
Figure 5: Self-assembly of two-component tetragonal prismatic architectures with different cavity size. Figur...
Figure 6: Construction of artificial LHS using rhodamine B as an acceptor and 24b as donor generating a photo...
Figure 7: Synthesis of supramolecular spheres with varying [AuCl] concentration inside the cavity. Figure was...
Figure 8: Hydroalkoxylation reaction of γ-allenol 34 in the presence of [AuCl]-encapsulated molecular spheres ...
Figure 9: Two-component heteroleptic triangles of different size containing a BINOL functionality. Figure was...
Figure 10: Asymmetric conjugate addition of chalcone 42 with trans-styrylboronic acid (43) catalyzed by BINOL-...
Figure 11: Encapsulation of monophosphoramidite-Rh(I) catalyst into a heteroleptic tetragonal prismatic cage 47...
Figure 12: (a) Representations of the basic HETPYP, HETPHEN, and HETTAP complex motifs. (b) The three-componen...
Figure 13: Two representative four-component rotors, with a (top) two-arm stator and (bottom) a four-arm stato...
Figure 14: Four-component rotors with a monohead rotator. Figure was adapted with permission from [94]. Copyright ...
Figure 15: (left) Click reaction catalyzed by rotors [Cu2(55)(60)(X)]2+. (right) Yield as a function of the ro...
Figure 16: A supramolecular AND gate. a) In truth table state (0,0) two nanoswitches serve as the receptor ens...
Figure 17: Two supramolecular double rotors (each has two rotational axes) and reference complex [Cu(78)]+ for...
Figure 18: The slider-on-deck system (82•X) (X = 83, 84, or 85). Figure is from [98] and was reprinted from the jo...
Figure 19: Catalysis of a conjugated addition reaction in the presence of the slider-on-deck system (82•X) (X ...
Figure 20: A rotating catalyst builds a catalytic machinery. For catalysis of the catalytic machinery, see Figure 21. F...
Figure 21: Catalytic machinery. Figure was adapted from [100] (“Evolution of catalytic machinery: three-component n...
Figure 22: An information system based on (re)shuffling components between supramolecular structures [99]. Figure ...
Figure 23: Switching between dimeric heteroleptic and homoleptic complex for OFF/ON catalytic formation of rot...
Figure 24: A chemically fueled catalytic system [112]. Figure was adapted from [112]. Copyright 2021 American Chemical S...
Figure 25: (Top) Operation of a fuel acid. (Bottom) Knoevenagel addition [112].
Figure 26: Development of the yield of Knoevenagel product 118 in a fueled system [112]. Figure was reprinted with ...
Figure 27: Weak-link strategy to increased catalytic activity in epoxide opening [119]. Figure was adapted from [24]. C...
Figure 28: A ON/OFF polymerization switch based on the weak-link approach [118]. Figure was reprinted with permissi...
Figure 29: A weak-link switch turning ON/OFF a Diels–Alder reaction [132]. Figure was reprinted with permission fro...
Figure 30: A catalyst duo allowing selective activation of one of two catalytic acylation reactions [133] upon subs...
Figure 31: A four-state switchable nanoswitch (redrawn from [134]).
Figure 32: Sequential catalysis as regulated by nanoswitch 138 and catalyst 139 in the presence of metal ions ...
Figure 33: Remote control of ON/OFF catalysis administrated by two nanoswitches through ion signaling (redrawn...
A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments
- Constantine V. Milyutin,
- Andrey N. Komogortsev,
- Boris V. Lichitsky and
- Valeriya G. Melekhina
Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61
- solvents excluding acetic acid, DMSO and DMF. Initially, UV irradiation of compound 12a was carried out at a wavelength of 365 nm in a solution of DMSO in common glassware for 24 h. However, subsequent water treatment did not allow the isolation of the target product 14a. Due to the fact that aqueous
- medium accelerates the decomposition of target α-hydroxy-1,2-diketone 14a. Subsequently, we used DMF as a solvent for carrying out the studied photoreaction. Unexpectedly, the starting pyrazole 12a was isolated unchanged after 24 hours of UV irradiation, indicating that DMF also is not suitable for the
Graphical Abstract
Scheme 1: Photochemical transformations of 3-hydroxypyran-4-one derivatives.
Scheme 2: Synthesis and study of the photochemical behavior of compound 16.
Scheme 3: Photoreaction of compound 12a.
Figure 1: 1H NMR monitoring of the photoreaction of compound 12a under UV irradiation (365 nm) in DMSO-d6 sol...
Scheme 4: Proposed mechanism for the photoreaction of compound 11a.
Scheme 5: Synthesis of compounds 15a–l. Reaction conditions: 1) 12a–l (0.5 mmol), AcOH (25 mL), UV irradiatio...
Figure 2: The X-ray crystal structure of compound 15a.
Scheme 6: Synthesis of compounds 15m–o. Reaction conditions: 1) 12m–o (0.5 mmol), AcOH (25 mL), UV irradiatio...
Figure 3: The X-ray crystal structure of compound 15m.
Scheme 7: Synthesis of compound 18.
Figure 4: The X-ray crystal structure of compound 18.
Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides
- Md Imran Hossain,
- Md Imdadul H. Khan,
- Seong Jong Kim and
- Hoang V. Le
Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47
- % water, 95% methanol mixture in the presence of DIPEA overnight, no degradation was observed. Conclusion We have developed a method for the synthesis of 3,4,5-trisubstituted isoxazoles in aqueous medium under mild basic conditions at room temperature. The reaction proceeds via a [3 + 2]-cycloaddition of
Graphical Abstract
Figure 1: Routes to isoxazoles.
Figure 2: Possible products of the reaction between nitrile oxides and 1,3-diketones. Path D (C-trapping) pro...
Figure 3: Reactions between various arylhydroximoyl chlorides and 1,3-diketones. The reactions were performed...
Figure 4: Reactions between various phenyl hydroximoyl chlorides and β-ketoesters or β-ketoamides. The reacti...
Figure 5: Reactions between 4-fluorophenyl hydroximoyl chloride (1a) and diethyl malonate (2j) or dibenzyl ma...
Figure 6: Reactions between phenyl hydroximoyl chlorides 1a,c and 4,4,4-trifluoro-1-phenyl- (2l) and 4,4,4-tr...
Figure 7: 1H NMR spectra of 1-phenyl-1,3-butanedione (2a) in methanol-d4 (top) and in CDCl3 (bottom).
Figure 8: A plausible mechanism for the formation of the 3,4,5-trisubstituted isoxazoles 3 in the presence of...
Figure 9: Structures of β-lactamase-resistant antibiotics oxacillin, cloxacillin, dicloxacillin, and flucloxa...
Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water
- Zhihang Bai,
- Krishnasamy Velmurugan,
- Xueqi Tian,
- Minzan Zuo,
- Kaiya Wang and
- Xiao-Yu Hu
Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45
- supramolecular self-assembled nanosystem based on host–guest interactions between water-soluble tetraphenylethylene-embedded pillar[5]arene (m-TPEWP5) and ammonium benzoyl-ʟ-alaninate (G) in an aqueous medium. The obtained assembly of m-TPEWP5 and G showed aggregation-induced emission (AIE) via the blocking of
- photochemical catalytic reaction in aqueous medium. In addition, our group [30] reported the construction of a supramolecular photocatalytic system with a two-step FRET process through the supramolecular assembly of water-soluble pillar[5]arene and TPE derivatives as donor and EsY and Nile Red (NiR) as
- of 31% was achieved [30]. This result suggested that m-TPEWP5G-EsY self-assembled nanosystem could be used as a nanoreactor for organic photocatalytic reactions in an aqueous medium. The nature of the interaction between m-TPEWP5G and EsY was evaluated by 1H NMR titration studies in D2O (Figure S5 in
Graphical Abstract
Scheme 1:
Graphical representation of the fabrication of supramolecular m-TPEWP5![[Graphic 5]](/bjoc/content/inline/1860-5397-18-45-i7.svg?max-width=637&scale=1.18182)
G-EsY self-assembled photocat...
Figure 1: 1H NMR (400 MHz, D2O, 298 K) spectra of m-TPEWP5 (1.0 mM), m-TPEWP5 (1.0 mM) + G (1.0 mM), and G (1...
Figure 2: (a) Fluorescence spectra of m-TPEWP5 (1 × 10−5 M) with different concentrations of G (0 to 1.2 equi...
Figure 3:
TEM images of (a) m-TPEWP5![[Graphic 15]](/bjoc/content/inline/1860-5397-18-45-i17.svg?max-width=637&scale=1.18182)
G; (b) m-TPEWP5![[Graphic 16]](/bjoc/content/inline/1860-5397-18-45-i18.svg?max-width=637&scale=1.18182)
G-EsY. [m-TPEWP5] = 1 × 10−4 M, [G] = 1 × 10−4 M, [EsY] = ...
Figure 4:
(a) Normalized absorption and emission spectra of the EsY acceptor and the m-TPEWP5![[Graphic 25]](/bjoc/content/inline/1860-5397-18-45-i27.svg?max-width=637&scale=1.18182)
G donor assembly...
Scheme 2:
Products from 2-bromo-1-phenylethanone dehalogenation reactions in the presence of m-TPEWP5![[Graphic 43]](/bjoc/content/inline/1860-5397-18-45-i45.svg?max-width=637&scale=1.18182)
G-EsY na...
Figure 5:
Proposed mechanism for the 2-bromo-1-phenylethanone dehalogenation reaction mediated by m-TPEWP5![[Graphic 48]](/bjoc/content/inline/1860-5397-18-45-i50.svg?max-width=637&scale=1.18182)
G-E...
Menadione: a platform and a target to valuable compounds synthesis
- Acácio S. de Souza,
- Ruan Carlos B. Ribeiro,
- Dora C. S. Costa,
- Fernanda P. Pauli,
- David R. Pinho,
- Matheus G. de Moraes,
- Fernando de C. da Silva,
- Luana da S. M. Forezi and
- Vitor F. Ferreira
Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43
- ). The studies showed that the emulsion, prepared by sonication, of an equimolar mixture of lithium perfluorooctane sulfonate (LiFOS) and perfluorohexane (PFH) in aqueous medium resulted in a significant increase of the reaction rate, when compared to other reaction conditions [109]. As an example, using
- , contributing significantly to the progress of the synthesis studies in aqueous medium. The Diels–Alder reaction using menadione (10) was also studied by Bendiabdellah and co-workers, who reported the intramolecular Diels–Alder domino reactions promoted by Lewis acids [110]. The reaction involving menadione (10
Graphical Abstract
Figure 1: Natural bioactive naphthoquinones.
Figure 2: Chemical structures of vitamins K.
Figure 3: Redox cycle of menadione.
Scheme 1: Selected approaches for menadione synthesis using silver(I) as a catalyst.
Scheme 2: Methylation approaches for the preparation of menadione from 1,4-naphthoquinone using tert-butyl hy...
Scheme 3: Methylation approach of 1,4-naphthoquinone using i) rhodium complexes/methylboronic acid and ii) bi...
Scheme 4: Synthesis of menadione (10) from itaconic acid.
Scheme 5: Menadione synthesis via Diels–Alder reaction.
Scheme 6: Synthesis of menadione (10) using p-cresol as a synthetic precursor.
Scheme 7: Synthesis of menadione (10) via demethoxycarbonylating annulation of methyl methacrylate.
Scheme 8: Furan 34 used as a diene in a Diels–Alder reaction for the synthesis of menadione (10).
Scheme 9: o-Toluidine as a dienophile in a Diels–Alder reaction for the synthesis of menadione (10).
Scheme 10: Representation of electrochemical synthesis of menadione.
Figure 4: Reaction sites and reaction types of menadione as substrate.
Scheme 11: DBU-catalyzed epoxidation of menadione (10).
Scheme 12: Phase-transfer catalysis for the epoxidation of menadione.
Scheme 13: Menadione epoxidation using a hydroperoxide derived from (+)-norcamphor.
Scheme 14: Enantioselective Diels–Alder reaction for the synthesis of asymmetric quinone 50 catalyzed by a chi...
Scheme 15: Optimized reaction conditions for the synthesis of anthra[9,1-bc]pyranone.
Scheme 16: Synthesis of anthra[9,1-bc]furanone, anthra[9,1-bc]pyridine, and anthra[9,1-bc]pyrrole derivatives.
Scheme 17: Synthesis of derivatives employing protected trienes.
Scheme 18: Synthesis of cyclobutene derivatives of menadione.
Scheme 19: Menadione reduction reactions using sodium hydrosulfite.
Scheme 20: Green methodology for menadiol synthesis and pegylation.
Scheme 21: Menadione reduction by 5,6-O-isopropylidene-ʟ-ascorbic acid under UV light irradiation.
Scheme 22: Selected approaches of menadione hydroacetylation to diacetylated menadiol.
Scheme 23: Thiele–Winter reaction catalyzed by Bi(OTf)3.
Scheme 24: Carbonyl condensation of menadione using resorcinol and a hydrazone derivative.
Scheme 25: Condensation reaction of menadione with thiosemicarbazide.
Scheme 26: Condensation reaction of menadione with acylhydrazides.
Scheme 27: Menadione derivatives functionalized with organochalcogens.
Scheme 28: Synthesis of selenium-menadione conjugates derived from chloromethylated menadione 84.
Scheme 29: Menadione alkylation by the Kochi–Anderson method.
Scheme 30: Menadione alkylation by diacids.
Scheme 31: Menadione alkylation by heterocycles-substituted carboxylic acids.
Scheme 32: Menadione alkylation by bromoalkyl-substituted carboxylic acids.
Scheme 33: Menadione alkylation by complex carboxylic acids.
Scheme 34: Kochi–Anderson method variations for the menadione alkylation via oxidative decarboxylation of carb...
Scheme 35: Copper-catalyzed menadione alkylation via free radicals.
Scheme 36: Nickel-catalyzed menadione cyanoalkylation.
Scheme 37: Iron-catalyzed alkylation of menadione.
Scheme 38: Selected approaches to menadione alkylation.
Scheme 39: Menadione acylation by photo-Friedel–Crafts acylation reported by Waske and co-workers.
Scheme 40: Menadione acylation by Westwood procedure.
Scheme 41: Synthesis of 3-benzoylmenadione via metal-free TBAI/TBHP system.
Scheme 42: Michael-type addition of amines to menadione reported by Kallmayer.
Scheme 43: Synthesis of amino-menadione derivatives using polyalkylamines.
Scheme 44: Selected examples for the synthesis of different amino-substituted menadione derivatives.
Scheme 45: Selected examples of Michael-type addition of complex amines to menadione (10).
Scheme 46: Addition of different natural α-amino acids to menadione.
Scheme 47: Michael-type addition of amines to menadione using silica-supported perchloric acid.
Scheme 48: Indolylnaphthoquinone or indolylnaphthalene-1,4-diol synthesis reported by Yadav et al.
Scheme 49: Indolylnaphthoquinone synthesis reported by Tanoue and co-workers.
Scheme 50: Indolylnaphthoquinone synthesis from menadione by Escobeto-González and co-workers.
Scheme 51: Synthesis of menadione analogues functionalized with thiols.
Scheme 52: Synthesis of menadione-derived symmetrical derivatives through reaction with dithiols.
Scheme 53: Mercaptoalkyl acids as nucleophiles in Michael-type addition reaction to menadione.
Scheme 54: Reactions of menadione (10) with cysteine derivatives for the synthesis of quinoproteins.
Scheme 55: Synthesis of menadione-glutathione conjugate 152 by Michael-type addition.
Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions
- Surendran Amrutha,
- Sankaran Radhika and
- Gopinathan Anilkumar
Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31
- original Sonogashira coupling. Both, iron and cobalt catalysts are considered environmentally friendly as they are non-toxic and inexpensive, and thus have significance in modern organic synthesis. The use of an aqueous medium in Fe-catalyzed reactions represents the most reasonable and green option for
- cross-coupling reactions Homogeneous green protocols Tsai et al. discussed an efficient, simple and environmentally friendly method for the coupling of arylynols 3 with an aryl halide [21]. This strategy discloses a one pot reaction catalyzed by FeCl3 in an aqueous medium associated with the cationic
- of Fe3+ ions into the solution directly interacts with the nitrogen atom of the hexaphenylbenzene (HPB)-based derivative and reduces the oxidation state from Fe(III) to Fe(0) which is further oxidized by the aqueous medium. Hence the aggregates of HPB can act as a good stabilizing agent. Similarly
Graphical Abstract
Scheme 1: One pot Sonogashira coupling of aryl iodides with arylynols in the presence of iron(III) chloride h...
Scheme 2: The iron-catalyzed Sonogashira coupling of aryl iodides with terminal acetylenes in water under aer...
Scheme 3: Sonogashira coupling of aryl halides and phenylacetylene in the presence of iron nanoparticles.
Scheme 4: Sonogashira coupling catalyzed by a silica-supported heterogeneous Fe(III) catalyst.
Scheme 5: Suggested catalytic cycle for the Sonogashira coupling using a silica-supported heterogeneous Fe(II...
Scheme 6: Chemoselective iron-catalyzed cross coupling of 4-bromo-1-cyclohexen-1-yltrifluromethane sulfonate ...
Scheme 7: Fe-catalyzed Sonogashira coupling between terminal alkynes and aryl iodides.
Scheme 8: Iron-catalyzed domino Sonogashira coupling and hydroalkoxylation.
Scheme 9: Sonogashira coupling of aryl halides and phenylacetylene in the presence of Fe(III) acetylacetonate...
Scheme 10: Sonogashira coupling of aryl iodides and alkynes with Fe(acac)3/2,2-bipyridine catalyst.
Scheme 11: Sonogashira cross-coupling of terminal alkynes with aryl iodides in the presence of Fe powder/ PPh3...
Scheme 12: α-Fe2O3 nanoparticles-catalyzed coupling of phenylacetylene with aryl iodides.
Scheme 13: Sonogashira cross-coupling reaction between phenylacetylene and 4-substituted iodobenzenes catalyze...
Scheme 14: One-pot synthesis of 2-arylbenzo[b]furans via tandem Sonogashira coupling–cyclization protocol.
Scheme 15: Suggested mechanism of the Fe(III) catalyzed coupling of o-iodophenol with acetylene derivatives.
Scheme 16: Fe3O4@SiO2/Schiff base/Fe(II)-catalyzed Sonogashira–Hagihara coupling reaction.
Scheme 17: Sonogashira coupling using the Fe(II)(bdmd) catalyst in DMF/1,4-dioxane.
Scheme 18: Synthesis of 7-azaindoles using Fe(acac)3 as catalyst.
Scheme 19: Plausible mechanistic pathway for the synthesis of 7-azaindoles.
Scheme 20: Synthesis of Co@imine-POP catalyst.
Scheme 21: Sonogashira coupling of various arylhalides and phenylacetylene in the presence of Co@imine-POP cat...
Scheme 22: Sonogashira coupling of aryl halides and phenylacetylene using Co-DMM@MNPs/chitosan.
Scheme 23: Sonogashira cross-coupling of aryl halides with terminal acetylenes in the presence of Co-NHC@MWCNT...
Scheme 24: Sonogashira cross-coupling of aryl halides with terminal acetylenes in the presence of Co nanoparti...
Scheme 25: Sonogashira coupling reaction of aryl halides with phenylacetylene in the presence of Co nanopartic...
Scheme 26: PdCoNPs-3DG nanocomposite-catalyzed Sonogashira cross coupling of aryl halide and terminal alkynes.
Scheme 27: Sonogashira cross-coupling of aryl halides and phenylacetylene in the presence of graphene-supporte...
Scheme 28: Sonogashira cross-coupling with Pd/Co ANP-PPI-graphene.
Scheme 29: Pd-Co-1(H)-catalyzed Sonogashira coupling reaction.
Scheme 30: The coupling of aryl halides with terminal alkynes using cobalt hollow nanospheres as catalyst.
Scheme 31: A plausible mechanism for the cobalt-catalyzed Sonogashira coupling reaction.
Scheme 32: Sonogashira cross-coupling reaction of arylhalides with phenylacetylene catalyzed by Fe3O4@PEG/Cu-C...
Scheme 33: Plausible mechanism of Sonogashira cross-coupling reaction catalyzed by Fe3O4@PEG/Cu-Co.
Scheme 34: Sonogashira coupling reaction of para-substituted bromobenzenes with phenylacetylene in the presenc...
Scheme 35: Possible mechanism for the visible light-assisted cobalt complex-catalyzed Sonogashira coupling. (R...
Scheme 36: Sonogashira cross-coupling of aryl halides and phenylacetylene using cobalt as additive.
Scheme 37: Plausible mechanism of Sonogashira cross-coupling reaction over [LaPd*]. (Reproduced with permissio...
1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis
- Ruan Carlos B. Ribeiro,
- Patricia G. Ferreira,
- Amanda de A. Borges,
- Luana da S. M. Forezi,
- Fernando de Carvalho da Silva and
- Vitor F. Ferreira
Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5
- -4-sulfonic acid (15) by oxidation with nitric acid in an aqueous medium (Scheme 1A). In 1894, Böniger developed [44] the first reaction of β-NQS with phenylamines. He synthesized β-NQS using a modified method developed by Witt, which quickly reacted with different amines to form colored products
Graphical Abstract
Figure 1: Naphthoquinones are commonly used in organic synthesis.
Figure 2: Some important natural and synthetic naphthoquinones.
Scheme 1: Synthetic studies of BNQs and reactions with amines.
Scheme 2: Methods described for the synthesis of β-NQS.
Figure 3: Drugs detected using β-NQSNa.
Scheme 3: Reactions between β-NQS and amines.
Scheme 4: Isomerization of 4-arylamino-1,2-naphthoquinones.
Scheme 5: Synthesis of unsymmetrical 2-amino-4-imino compounds.
Scheme 6: Synthesis of bis(isoxazolyl)naphthoquinones from β-NQS.
Scheme 7: The reaction of β-NQS with 30 followed by cycle condensation.
Scheme 8: Synthesis of 4-(2-amino-5-selenothiazoles)-1,2-naphthoquinones.
Scheme 9: Synthesis of amino- and phenoxy-1,2-naphthoquinones.
Scheme 10: Synthesis of 4-semicarbazide-1,2-naphthoquinone.
Scheme 11: Reactions of 4-azido-1,2-naphthoquinone.
Figure 4: Modifications that can be easily carried out from the products of β-NQS 8.
Scheme 12: Derivatives of 1,2-naphthoquinones obtained from β-NQS.
Scheme 13: Oximes as well as 4-amino- and 4-phenoxy-1,2-naphthoquinone as potential anti-inflammatory agents.
Scheme 14: Synthesis of triazoles from β-NQS.
Scheme 15: Synthesis of naphtho[1,2-d]oxazoles from β-NQS.
Scheme 16: A) Arylation and vinylation of β-NQS catalyzed by Ni(II) salts. B) Transformation of the 1,2-dicarb...
Scheme 17: Benzo[a]carbazole and benzo[c]carbazoles fused with 1,2-naphthoquinone.
Scheme 18: Synthesis of 1,2-naphthoquinones having a C=C bond from β-NQS. Method A: NaOH, EtOH/H2O, 40 °C, 2 h...
Scheme 19: C=C bond formation from β-NQS and substituted acetonitriles.
Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds
- Sumana Mandal,
- Raju D. Chaudhari and
- Goutam Biswas
Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153
- same experiments (Scheme 2) [38]. Cyclization of biallyl ether 5 in presence of mercuric acetate (Hg(OAc)2) in an aqueous medium was reported to synthesize a diastereomeric mixture of 2,6-disubstituted-p-dioxane 6. The outcome of the reaction was much generalized with no detailed discussion about the
Graphical Abstract
Scheme 1: Schematic representation of Hg(II)-mediated addition to an unsaturated bond.
Scheme 2: First report of Hg(II)-mediated synthesis of 2,5-dioxane derivatives from allyl alcohol.
Scheme 3: Stepwise synthesis of 2,6-distubstituted dioxane derivatives.
Scheme 4: Cyclization of carbohydrate alkene precursor.
Scheme 5: Hg(II)-mediated synthesis of C-glucopyranosyl derivatives.
Scheme 6: Synthesis of C-glycosyl amino acid derivative using Hg(TFA)2.
Scheme 7: Hg(OAc)2-mediated synthesis of α-ᴅ-ribose derivative.
Scheme 8: Synthesis of β-ᴅ-arabinose derivative 18.
Scheme 9: Hg(OAc)2-mediated synthesis of tetrahydrofuran derivatives.
Scheme 10: Synthesis of Hg(TFA)2-mediated bicyclic nucleoside derivative.
Scheme 11: Synthesis of pyrrolidine and piperidine derivatives.
Scheme 12: HgCl2-mediated synthesis of diastereomeric pyrrolidine derivatives.
Scheme 13: HgCl2-mediated cyclization of alkenyl α-aminophosphonates.
Scheme 14: Cyclization of 4-cycloocten-1-ol with Hg(OAc)2 forming fused bicyclic products.
Scheme 15: trans-Amino alcohol formation through Hg(II)-salt-mediated cyclization.
Scheme 16: Hg(OAc)2-mediated 2-aza- or 2-oxa-bicyclic ring formations.
Scheme 17: Hg(II)-salt-induced cyclic peroxide formation.
Scheme 18: Hg(OAc)2-mediated formation of 1,2,4-trioxanes.
Scheme 19: Endocyclic enol ether derivative formation through Hg(II) salts.
Scheme 20: Synthesis of optically active cyclic alanine derivatives.
Scheme 21: Hg(II)-salt-mediated formation of tetrahydropyrimidin-4(1H)-one derivatives.
Scheme 22: Cyclization of ether derivatives to form stereoselective oxazolidine derivatives.
Scheme 23: Cyclization of amide derivatives induced by Hg(OAc)2.
Scheme 24: Hg(OAc)2/Hg(TFA)2-promoted cyclization of salicylamide-derived amidal auxiliary derivatives.
Scheme 25: Hg(II)-salt-mediated cyclization to form dihydrobenzopyrans.
Scheme 26: HgCl2-induced cyclization of acetylenic silyl enol ether derivatives.
Scheme 27: Synthesis of exocyclic and endocyclic enol ether derivatives.
Scheme 28: Cyclization of trans-acetylenic alcohol by treatment with HgCl2.
Scheme 29: Synthesis of benzofuran derivatives in presence of HgCl2.
Scheme 30: a) Hg(II)-salt-mediated cyclization of 4-hydroxy-2-alkyn-1-ones to furan derivatives and b) its mec...
Scheme 31: Cyclization of arylacetylenes to synthesize carbocyclic and heterocyclic derivatives.
Scheme 32: Hg(II)-salt-promoted cyclization–rearrangement to form heterocyclic compounds.
Scheme 33: a) HgCl2-mediated cyclization reaction of tethered alkyne dithioacetals; and b) proposed mechanism.
Scheme 34: Cyclization of aryl allenic ethers on treatment with Hg(OTf)2.
Scheme 35: Hg(TFA)2-mediated cyclization of allene.
Scheme 36: Hg(II)-catalyzed intramolecular trans-etherification reaction of 2-hydroxy-1-(γ-methoxyallyl)tetrah...
Scheme 37: a) Cyclization of alkene derivatives by catalytic Hg(OTf)2 salts and b) mechanism of cyclization.
Scheme 38: a) Synthesis of 1,4-dihydroquinoline derivatives by Hg(OTf)2 and b) plausible mechanism of formatio...
Scheme 39: Synthesis of Hg(II)-salt-catalyzed heteroaromatic derivatives.
Scheme 40: Hg(II)-salt-catalyzed synthesis of dihydropyranone derivatives.
Scheme 41: Hg(II)-salt-catalyzed cyclization of alkynoic acids.
Scheme 42: Hg(II)-salt-mediated cyclization of alkyne carboxylic acids and alcohol to furan, pyran, and spiroc...
Scheme 43: Hg(II)-salt-mediated cyclization of 1,4-dihydroxy-5-alkyne derivatives.
Scheme 44: Six-membered morpholine derivative formation by catalytic Hg(II)-salt-induced cyclization.
Scheme 45: Hg(OTf)2-catalyzed hydroxylative carbocyclization of 1,6-enyne.
Scheme 46: a) Hg(OTf)2-catalyzed hydroxylative carbocyclization of 1,6-enyne. b) Proposed mechanism.
Scheme 47: a) Synthesis of carbocyclic derivatives using a catalytic amount of Hg(II) salt. b) Proposed mechan...
Scheme 48: Cyclization of 1-alkyn-5-ones to 2-methylfuran derivatives.
Scheme 49: Hg(NO3)2-catalyzed synthesis of 2-methylenepiperidine.
Scheme 50: a) Preparation of indole derivatives through cycloisomerization of 2-ethynylaniline and b) its mech...
Scheme 51: a) Hg(OTf)2-catalyzed synthesis of 3-indolinones and 3-coumaranones and b) simplified mechanism.
Scheme 52: a) Hg(OTf)2-catalyzed one pot cyclization of nitroalkyne and b) its plausible mechanism.
Scheme 53: Synthesis of tricyclic heterocyclic scaffolds.
Scheme 54: HgCl2-mediated cyclization of 2-alkynylphenyl alkyl sulfoxide.
Scheme 55: a) Hg(OTf)2-catalyzed cyclization of allenes and alkynes. b) Proposed mechanism of cyclization.
Scheme 56: Stereoselective synthesis of tetrahydropyran derivatives.
Scheme 57: a) Hg(ClO4)2-catalyzed cyclization of α-allenol derivatives. b) Simplified mechanism.
Scheme 58: Hg(TFA)2-promoted cyclization of a γ-hydroxy alkene derivative.
Scheme 59: Synthesis Hg(II)-salt-mediated cyclization of allyl alcohol for the construction of ventiloquinone ...
Scheme 60: Hg(OAc)2-mediated cyclization as a key step for the synthesis of hongconin.
Scheme 61: Examples of Hg(II)-salt-mediated cyclized ring formation in the syntheses of (±)-fastigilin C and (...
Scheme 62: Formal synthesis of (±)-thallusin.
Scheme 63: Total synthesis of hippuristanol and its analog.
Scheme 64: Total synthesis of solanoeclepin A.
Scheme 65: a) Synthesis of Hg(OTf)2-catalyzed azaspiro structure for the formation of natural products. b) Pro...
Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands
- Janina-Miriam Noy,
- Fan Chen and
- Martina Stenzel
Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148
- ((4-carboxybutyl)triphenylphosphonium bromide), which was chosen as a target agent for the herein conducted studies, and covalently coupled to PPM-NP and MPM-NP particles. The reaction was conducted in aqueous medium, using 5 equiv excess of TPP-COOH to RAFT-end group. The pH was first adjusted to 5.2
Graphical Abstract
Figure 1: (I) DLS of PPM-NP4, MPM-NP2, PPM-NP4-TPP and MPM-NP2-TPP and (II) TEM of PPM-NP4-TPP and MPM-NP2-TPP...
Figure 2: Representative 31P NMR (top) and 1H NMR (bottom) spectrum of PP3-TPP conjugation product in D2O.
Scheme 1: Synthesis of TPP-based PISA particles based on zwitterionic 2-methacryloyloxyethyl phosphorylcholin...
Figure 3: Penetration of PPM-NP4-TPP and MPM-NP2-TPP micelles and fluorescence intensity profile on (A I, II)...
Figure 4: Growth effects of PPM-NP4-TPP and MPM-NP2-TPP on SW982 spheroids after 3 and 6 days of incubation (c...
Figure 5: Cell viability of SW982 spheroids after 6 days treatment with PPM-NP4, PPM-NP-TPP, MPM-NP2 and MPM-...
Figure 6: Cell localization of PPM-NP4-TPP (I) and MPM-NP2-TPP (II) into (A) mitochondria and (B) lysosomes u...
Figure 7: Cytotoxicity study of PPM-NP4-TPP and MPM-NP2-TPP on SW982 cells in relation to the concentration o...
Asymmetric organocatalyzed synthesis of coumarin derivatives
- Natália M. Moreira,
- Lorena S. R. Martelli and
- Arlene G. Corrêa
Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128
- synthesis of biologically relevant coumarins in aqueous medium [21]. Catalysis is one of the fundamental pillars of green chemistry [22], and the transition-metal-catalyzed synthesis of coumarins has been reviewed by Sharma et al. [23]. More recently, Kanchana et al. published an account on the palladium
Graphical Abstract
Figure 1: Coumarin-derived commercially available drugs.
Figure 2: Inhibition of acetylcholinesterase by coumarin derivatives.
Scheme 1: Michael addition of 4-hydroxycoumarins 1 to α,β‐unsaturated enones 2.
Scheme 2: Organocatalytic conjugate addition of 4-hydroxycoumarin 1 to α,β-unsaturated aldehydes 2 followed b...
Scheme 3: Synthesis of 3,4-dihydrocoumarin derivatives 10 through decarboxylative and dearomatizative cascade...
Scheme 4: Total synthesis of (+)-smyrindiol (17).
Scheme 5: Michael addition of 4-hydroxycoumarin (1) to enones 2 through a bifunctional modified binaphthyl or...
Scheme 6: Michael addition of ketones 20 to 3-aroylcoumarins 19 using a cinchona alkaloid-derived primary ami...
Scheme 7: Enantioselective reaction of cyclopent-2-enone-derived MBH alcohols 24 with 4-hydroxycoumarins 1.
Scheme 8: Sequential Michael addition/hydroalkoxylation one-pot approach to annulated coumarins 28 and 30.
Scheme 9: Michael addition of 4-hydroxycoumarins 1 to enones 2 using a binaphthyl diamine catalyst 31.
Scheme 10: Asymmetric Michael addition of 4-hydroxycoumarin 1 with α,β-unsaturated ketones 2 catalyzed by a ch...
Scheme 11: Catalytic asymmetric β-C–H functionalization of ketones via enamine oxidation.
Scheme 12: Enantioselective synthesis of polycyclic coumarin derivatives 37 catalyzed by an primary amine-imin...
Scheme 13: Allylic alkylation reaction between 3-cyano-4-methylcoumarins 39 and MBH carbonates 40.
Scheme 14: Enantioselective synthesis of cyclopropa[c]coumarins 45.
Scheme 15: NHC-catalyzed lactonization of 2-bromoenals 46 with 4-hydroxycoumarin (1).
Scheme 16: NHC-catalyzed enantioselective synthesis of dihydrocoumarins 51.
Scheme 17: Domino reaction of enals 2 with hydroxylated malonate 53 catalyzed by NHC 55.
Scheme 18: Oxidative [4 + 2] cycloaddition of enals 57 to coumarins 56 catalyzed by NHC 59.
Scheme 19: Asymmetric [3 + 2] cycloaddition of coumarins 43 to azomethine ylides 60 organocatalyzed by quinidi...
Scheme 20: Synthesis of α-benzylaminocoumarins 64 through Mannich reaction between 4-hydroxycoumarins (1) and ...
Scheme 21: Asymmetric addition of malonic acid half-thioesters 67 to coumarins 66 using the sulphonamide organ...
Scheme 22: Enantioselective 1,4-addition of azadienes 71 to 3-homoacyl coumarins 70.
Scheme 23: Michael addition/intramolecular cyclization of 3-acylcoumarins 43 to 3-halooxindoles 74.
Scheme 24: Enantioselective synthesis of 3,4-dihydrocoumarins 78 catalyzed by squaramide 73.
Scheme 25: Organocatalyzed [4 + 2] cycloaddition between 2,4-dienals 79 and 3-coumarincarboxylates 43.
Scheme 26: Enantioselective one-pot Michael addition/intramolecular cyclization for the synthesis of spiro[dih...
Scheme 27: Michael/hemiketalization addition enantioselective of hydroxycoumarins (1) to: (a) enones 2 and (b)...
Scheme 28: Synthesis of 2,3-dihydrofurocoumarins 89 through Michael addition of 4-hydroxycoumarins 1 to β-nitr...
Scheme 29: Synthesis of pyrano[3,2-c]chromene derivatives 93 via domino reaction between 4-hydroxycoumarins (1...
Scheme 30: Conjugated addition of 4-hydroxycoumarins 1 to nitroolefins 95.
Scheme 31: Michael addition of 4-hydroxycoumarin 1 to α,β-unsaturated ketones 2 promoted by primary amine thio...
Scheme 32: Enantioselective synthesis of functionalized pyranocoumarins 99.
Scheme 33: 3-Homoacylcoumarin 70 as 1,3-dipole for enantioselective concerted [3 + 2] cycloaddition.
Scheme 34: Synthesis of warfarin derivatives 107 through addition of 4-hydroxycoumarins 1 to β,γ-unsaturated α...
Scheme 35: Asymmetric multicatalytic reaction sequence of 2-hydroxycinnamaldehydes 109 with 4-hydroxycoumarins ...
Scheme 36: Mannich asymmetric addition of cyanocoumarins 39 to isatin imines 112 catalyzed by the amide-phosph...
Scheme 37: Enantioselective total synthesis of (+)-scuteflorin A (119).
A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles
- Pezhman Shiri,
- Ali Mohammad Amani and
- Thomas Mayer-Gall
Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114
- aryl selenide anion to the antimony atom takes place to give 5-selanyltriazole 85 and Ph2Sb–SeAr. Ph2Sb–SeAr is hydrolyzed in aqueous medium to give selenol 90 and Ph2SbOH. Selenol 90 is oxidized in air and transformed into diselenide 84. Therefore, only 0.5 equiv of diaryl diselenide were necessary
Graphical Abstract
Figure 1: Some significant triazole derivatives [8,23-27].
Scheme 1: A general comparison between synthetic routes for disubstituted 1,2,3-triazole derivatives and full...
Scheme 2: Synthesis of formyltriazoles 3 from the treatment of α-bromoacroleins 1 with azides 2.
Scheme 3: A probable mechanism for the synthesis of formyltriazoles 5 from the treatment of α-bromoacroleins 1...
Scheme 4: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 8 from the reaction of aryl azides 7 with enamino...
Scheme 5: Proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles from the reaction of a...
Scheme 6: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reaction of primary amines 10 with 1,...
Scheme 7: The proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reacti...
Scheme 8: Synthesis of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side chain.
Scheme 9: Mechanism for the formation of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side ch...
Scheme 10: Synthesis of fully decorated 1,2,3-triazole compounds 25 through the regioselective addition and cy...
Scheme 11: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazole compounds 25 through the...
Scheme 12: Synthesis of 1,4,5-trisubstituted glycosyl-containing 1,2,3-triazole derivatives 30 from the reacti...
Scheme 13: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 34 via intramolecular cyclization reaction of ket...
Scheme 14: Synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of aldehydes 35, amines 36, and α...
Scheme 15: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of...
Scheme 16: Synthesis of functionally rich double C- and N-vinylated 1,2,3-triazoles 45 and 47.
Scheme 17: Synthesis of disubstituted 4-chloro-, 4-bromo-, and 4-iodo-1,2,3-triazoles 50.
Scheme 18: a) A general route for SPAAC in polymer chemistry and b) synthesis of a novel pH-sensitive polymeri...
Scheme 19: Synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkynes 57, azides 58, and propargyli...
Scheme 20: A reasonable mechanism for the synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkyne...
Scheme 21: Synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 22: A reasonable mechanism for the synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 23: Synthesis of sulfur-cycle-fused 1,2,3-triazoles 75 and 77.
Scheme 24: A reasonable mechanism for the synthesis of sulfur-cycle-fused 1,2,3‐triazoles 75 and 77.
Scheme 25: Synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, organic azides 83, and ...
Scheme 26: A mechanism for the synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, org...
Scheme 27: Synthesis of trisubstituted triazoles containing an Sb substituent at position C5 in 93 and 5-unsub...
Scheme 28: Synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-butyltosyl disulfide 97...
Scheme 29: A mechanism for the synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-bu...
Scheme 30: Synthesis of triazole-fused sultams 104.
Scheme 31: Synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 32: A reasonable mechanism for the synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 33: Synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 34: A reasonable mechanism for the synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 35: Synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 36: A probable mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 37: Synthesis of fully decorated triazoles 125 via the Pd/C-catalyzed arylation of disubstituted triazo...
Scheme 38: Synthesis of triazolo[1,5-a]indolones 131.
Scheme 39: Synthesis of unsymmetrically substituted triazole-fused enediyne systems 135 and 5-aryl-4-ethynyltr...
Scheme 40: Synthesis of Pd/Cu-BNP 139 and application of 139 in the synthesis of polycyclic triazoles 142.
Scheme 41: A probable mechanism for the synthesis of polycyclic triazoles 142.
Scheme 42: Synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-membered rings 152–154.
Scheme 43: A probable mechanism for the synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-...
Scheme 44: Synthesis of fully functionalized 1,2,3-triazolo-fused chromenes 162, 164, and 166 via the intramol...
Scheme 45: Ru-catalyzed synthesis of fully decorated triazoles 172.
Scheme 46: Synthesis of 4-cyano-1,2,3-triazoles 175.
Scheme 47: Synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 and azides 177 and ...
Scheme 48: Mechanism for the synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 a...
Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones
- Jan Bartáček,
- Jan Svoboda,
- Martin Kocúrik,
- Jaroslav Pochobradský,
- Alexander Čegan,
- Miloš Sedlák and
- Jiří Váňa
Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84
- stereocentres, in an aqueous medium (Scheme 19) [54] by the addition of phenylboronic acid to 3-methyl-2-cyclohexenone using the L9/Pd(TFA)2 catalytic system. Compared to the reaction in DCE (93% yield, 92% ee,) [47], a slightly lower yield and significantly lower enantioselectivity were obtained in water as
- first heterogeneous catalytic system for the addition of arylboronic acids to cyclic enones was introduced by O’Reilly and co-workers [56]. The micellar nanoreactor was tested for the preparation of flavanones. The main advantages of such catalytic system were short reaction times in an aqueous medium
Graphical Abstract
Scheme 1: Synthesis of optically pure 4-phenylchroman-2-one [34].
Scheme 2: Synthesis of (R)-tolterodine [3].
Scheme 3: Catalytic cycle of the Pd(II)-catalysed 1,4-addition of organoboron reagents to enones [3,26,35].
Scheme 4: Enantioselective β-arylation of cyclohexanone [38].
Scheme 5: Application of L2/Pd(OAc)2 in the total synthesis of terpenes [8].
Scheme 6: Plausible catalytic cycle for the addition of phenylboronic acid to 2-cyclohexenone catalysed by L3...
Scheme 7: Microwave-assisted addition of phenylboronic acid to 2-cyclohexenone catalysed by L4/Pd2(dba)3·CHCl3...
Scheme 8: Plausible catalytic cycle of the addition of phenylboronic acid to 2-cyclohexenone catalysed by pal...
Scheme 9: Proposed catalytic cycle for the addition of phenylboronic acids to 2-cyclohexenone catalysed by Pd...
Scheme 10: Usage of addition reactions of boronic acids to various chromones in the syntheses of potentially a...
Scheme 11: Multigram-scale synthesis of ABBV-2222 [6].
Scheme 12: Application of the asymmetric addition of phenylboronic acid to a chromone derivative for the total...
Scheme 13: Plausible catalytic cycle for the addition of phenylboronic acid to 3-methyl-2-cyclohexenone cataly...
Scheme 14: Total syntheses of naturally occurring terpenoids [10,11].
Scheme 15: Use of the L9/Pd(TFA)2 catalytic system for the synthesis of intermediates of biologically active c...
Scheme 16: Usage of a Michael addition catalysed by L9/Pd(TFA)2 in the total synthesis of (–)-ar-tenuifolene [12].
Scheme 17: Synthesis of terpenoids by Michael addition to 3-methyl-2-cyclopentenone [13].
Scheme 18: Rh-catalysed isomerisation of 3-alkyl-3-arylcyclopentanones to 1-tetralones [53].
Scheme 19: Addition reaction of phenylboronic acid to 3-methyl-2-cyclohexenone catalysed by L9/Pd(TFA)2 in wat...
Scheme 20: Micellar nanoreactor PdL10c for the synthesis of flavanones [58].
Scheme 21: Plausible catalytic cycle for the desymmetrisation of polycyclic cyclohexenediones by the addition ...
Scheme 22: Attempt to use the catalytic system L2/Pd(TFA)2 for the addition of phenylboronic acid to 3-methyl-...
Scheme 23: Ring opening of an enantioenriched tetrahydropyran-2-one derivative as alternative strategy to line...
Scheme 24: Synthesis of biologically active compounds from addition products [14-16].
Scheme 25: Chiral 1,10-phenantroline derivative L15 as ligand for the Pd-catalysed addition reactions of pheny...
Scheme 26: The Rh-catalysed addition reaction of phenylboronic acid to a 3-substituted enone [20].
Scheme 27: Underdeveloped methodologies [14,15,65-67].
Scheme 28: Flowchart for the selection of the proper catalytic system.
