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Search for "properties" in Full Text gives 2309 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads
Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121
- synthesized and characterized (Figure 1). Their photophysical properties were comprehensively examined by steady-state and time-resolved emission and absorption spectroscopy. Furthermore, time-dependent density functional theory (TD-DFT) calculations were performed to support the experimental findings
- structural characterization A series of π-orthogonal D–A molecules based on the Pe–PTZ framework were synthesized to systematically modulate the electronic properties and spatial arrangement between the donor and acceptor units. Structural features were designed to ensure orthogonality between the Pe and PTZ
- shown in Supporting Information File 1. Energy levels and steady-state optical properties Time-dependent density functional theory (TD-DFT) calculations were performed to gain insights into the electronic structures of Pe–PTZ derivatives at B3LYP/6-31+G(d,p) level of theory (Figure 2) [18]. The
pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality
Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120
- –N rotation and C–N/C–C rotation by adjusting the pH of the solvent and the pKa of the amidine. Herein, we report our findings on the structural properties of an ortho-disubstituted benzamidine. Similar to DiBA, an ortho-disubstituted benzamidine has two types of stereoisomers: E/Z isomers arising
- usefulness of the single-atom substitution strategy on DiBA. By replacing the oxygen atom of DiBA with a nitrogen atom (and thus NH), which has been shown to be photo-responsive when replaced with sulfur or selenium, the pH-responsive property was acquired. Such minimal changes in physical properties can be
Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer
Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119
- largest cyclic array in the series. The oxidative fusion reaction with [bis(trifluoroacetoxy)iodo]benzene (PIFA) afforded a cyclophane-type aza[5]helicene-incorporated macrocycle, the structure of which was unambiguously revealed by X-ray diffraction analysis. Its optical properties have been investigated
- in detail. Keywords: cyclophane; fluorescence; heterohelicene; intramolecular oxidative coupling; Introduction Conjugated macrocyclic polyarenes have attracted significant attention due to their stimuli-responsive optoelectronic properties, dynamic structural changes, and host–guest interactions [1
- an aza[5]helicene-incorporated macrocycle. The resulting cyclophane-like structure and its optical properties have been analyzed in detail. Results and Discussion Synthesis and characterization Synthesis We obtained o-phenylene-pyrrole-thiophene hybrid icosamer 4 during our attempt to synthesize
Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins
Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118
- pharmacophore, and molecules containing this group exhibit a wide range of biological activities, including antitumor, anti-HIV, anti-obesity, anti-inflammatory, antidiabetic, anticancer, and antitubercular properties [1][2]. Among these molecules, bicyclic compounds with the dihydrooxadiazole connected to
- known for their anticancer, anti-inflammatory, antidiabetic, antimicrobial, adrenoreceptor modulating, anticonvulsant, antiplatelet, anti-HIV, and other activities [5][6]. Modifying hydantoins at the N1, N3, and C5 positions make it possible to achieve better pharmacological properties. In this paper
- similarities, the molecules produced by the first method are markedly different from those produced by the latter. This is primarily due to the presence of conformational flexibility, which has a substantial impact on the compounds’ biological properties. Hybrid compounds are believed to exhibit enhanced
Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent CyreneTM under one-pot conditions
Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117
- it is negative in the Ames test [25]. Recently, we determined key physicochemical properties of CyreneTM and showed that it has a negligible vapor pressure (<9.6 kPa) and low viscosity (<6.8 mPa·s) at typical transition-metal-catalyzed reaction temperatures (30–140 °C) [26]. CyreneTM has been
Azobenzene protonation as a tool for temperature sensing
Beilstein J. Org. Chem. 2025, 21, 1528–1534, doi:10.3762/bjoc.21.115
- changes in their absorption and photochemical properties. While azobenzene protonation has been recently used as a tool in photoswitching studies, the factors influencing protonation itself have received little attention. Here, we report a strong temperature dependence of azobenzene protonation in 1,2
- they all typically result in significant changes in the absorption spectrum and/or alter the stability of the metastable isomer. In sensing, azobenzenes have been utilized, e.g., through changes in isomerization kinetics [17][18] or colorimetric properties. The colorimetric sensors are effective for
Calcium waste as a catalyst in the transesterification for demanding esters: scalability perspective
Beilstein J. Org. Chem. 2025, 21, 1520–1527, doi:10.3762/bjoc.21.114
- % (3g) was obtained after 4 hours of reaction with trans-3-hexen-1-ol at a catalyst loading of 5 wt %. The yield of esters (3h) using 3-buten-1-ol at 1 wt % catalyst loading was moderate (51%) after 4 hours. Despite the weakly acidic properties, phenol was involved in the transesterification reaction
- , under these conditions, the inertness of alcohols 2j and 2k in the transesterification of both soybean oil and esters with less-hindered structures was probably due to their poor nucleophilic properties. The CS600 catalyst was investigated in the transesterification of low-molecular-weight esters
Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones
Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113
- tetrazolium structure in the MTT dye results in the formation of a coloured formazan that can be detected by spectrophotometry. Cytotoxic properties of the studied compounds were assessed on non-cancer as well as cancer cell lines. Cytotoxicity was established by measurement of 50% inhibition of cell growth
Highly distinguishable isomeric states of a tripodal arylazopyrazole derivative on graphite through electron/hole-induced switching at ambient conditions
Beilstein J. Org. Chem. 2025, 21, 1496–1507, doi:10.3762/bjoc.21.112
- electronic and optical properties of switchable states. The applicability of molecular switches relies on the efficiency, reversibility, and the half-life associated with different non-equilibrium states. Typically, the half-life of the Z isomer of AB is a few days [17]. Chemical modifications of AB
Copper catalysis: a constantly evolving field
Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109
- harness their Lewis-acidic and weakly oxidizing properties, respectively. In addition, microwave irradiation increases the reaction rate considerably. Furthermore, the use of a solid Cu(I) catalyst immobilized on an aminated silica support allows for a heterogeneous and cost-effective process, featuring
Wittig reaction of cyclobisbiphenylenecarbonyl
Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107
- containing one or two exocyclic olefin units. Owing to the transformation of carbonyl groups, the resulting products exhibit several unique physical and chemical properties: (1) the enhancement of configurational stability, (2) the appearance of fluorescence, and (3) the reductive carbon–carbon-bond
- . Consequently, figure-eight molecules often exhibit fascinating properties, such as unusual rearrangement reactions [9] and efficient circularly polarized luminescence (CPL) [10][11][12]. Cyclobisbiphenylenecarbonyl (CBBC) 1 is a figure-eight macrocycle, which is readily synthesized from commercially available
- peripherally modified CBBC derivatives have also been prepared and were shown to have fascinating properties [17][18][19][20][21]. For example, carbazole-substituted donor–acceptor-type CBBC derivatives exhibit both efficient circularly polarized luminescence (CPL) and thermally activated delayed fluorescence
Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications
Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106
- helical architectures, have attracted considerable attention due to their intrinsic chirality and tunable optoelectronic properties. Among them, nitrogen-doped helicenes (azahelicenes) and their heteroatom-co-doped counterparts – such as B/N-, O/N-, S/N-, and Se/N-doped helicenes – have emerged as highly
- , emphasizing their potential as next-generation chiral optoelectronic materials and outlining future directions toward multifunctional integration and quantum technological applications. Keywords: azahelicene; chiroptical properties; circularly polarized luminescence (CPL); heteroatom containing
- ; optoelectronic applications; Introduction Helicenes, a class of non-planar polycyclic aromatic hydrocarbons characterized by ortho-fused aromatic rings forming a helical framework, have attracted significant attention due to their inherent chirality, unique optoelectronic properties, and wide-ranging
Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds
Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105
- resistance [1][2][3][4]. In addition to their conventional use, azodyes have unique optical properties, defined by the E/Z isomerization [5][6] and by the tautomeric proton exchange [3][7][8][9][10][11], when a OH or NH group is present on a suitable position in the molecule. Both processes are strongly
- influenced by the structural variations and the environment (temperature, solvent properties, acidity and presence of other molecules). The E/Z isomerization of the azodyes, caused by light irradiation [12][13][14] or electrochemically [15][16], has paved the way for the development of innovative materials
- ][44][45] and systems for energy storage [46][47]. The phototautomerism of azodyes refers to the reversible isomerization process that occurs upon exposure to light, leading to exchange of a proton [48][49]. The obtained tautomeric forms have different optical and chemical properties, which make these
N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B
Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103
- isolation of five phenolic siderophores with some of them exhibiting antimicrobial properties, including pseudomonins A–C and pseudomobactins A and B [15]. In this study we report the isolation and structural characterization of two previously undescribed as natural products (1 and 2) and two new compounds
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- ]. The first to recognise that these unique physicochemical properties may have valuable applications in medicinal chemistry were Carreira, Rogers-Evans, Müller and colleagues, who together reported that 3-substituted oxetanes can serve as isosteric replacements for carbonyl and gem-dimethyl groups
- the phosphonates 126 as HWE reagents in one example. 2 Derivatisation of 3-oxetanone Because of the highly beneficial properties of oxetanes as isosteric replacements, there is a strong need for a convenient access to 3-substituted oxetanes. Besides constructing the 4-membered ring de novo, another
- high yields. Further transformations were also investigated such as a Suzuki coupling (at the aryl group) or oxidation to sulphoxides and sulphones, demonstrating the versatility of these products. In addition, their medicinally relevant physicochemical properties such as lipophilicity, clearance and
Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer
Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100
- principles. (a) BDE of C–H. (b) Direct functionalization of C–H catalyzed by transition-metal. (c) Direct functionalization of C–H via HAT process. (a) Amidyl radical-enabled hydrogen atom transfer. (b) Substituent effects to amidyl radical properties. (c) This review: generation of amidyl radical and
Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes
Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99
- design beyond all-hexagon polycyclic aromatic hydrocarbons (PAHs). Among these, π-conjugated scaffolds featuring embedded azulene units have gained considerable attention due to their unique optical and electronic properties. This review provides an overview of representative azulene-embedded
- nanographenes, with a particular focus on the synthetic strategies. Additionally, it explores selected aspects of aromaticity and spectroscopic properties. Keywords: azulene; nanographenes; non-alternant; non-benzenoid; polycyclic aromatic hydrocarbons; Introduction The discovery of graphene and fullerenes
- has sparked a continuously growing interest in synthesis of new carbon-rich unsaturated molecules and materials [1]. Graphene is a revolutionary material with exceptional properties, driving advancements across various scientific, industrial, and technological fields like organic electronics [2
Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents
Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98
- 3,3-dialkylated oxindoles in moderate to high yields. The substrate scope was extensively evaluated, and a variety of N-arylacrylamides with different electronic properties and steric demands were successfully converted into the corresponding oxindoles. Substrates with both electron-donating and
- incorporation of fluorinated motifs such as trifluoromethyl and difluoroalkyl groups offers unique physicochemical properties, and has become a burgeoning area of research. In 2018, Zeng’s group reported a novel electrochemical trifluoromethylation/cyclization reaction of N-arylacrylamides catalyzed by bromide
Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates
Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96
- -centered radical from diisopropyl H-phosphonate (2a). In addition, the anion affects the redox properties of the copper ion, and thus the optimal choice is important to achieve both sufficient oxidative properties and catalyst recycling by reoxidation with O2. The employment of Mn(acac)3 and FeCl3, which
Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers
Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95
- display good solubility in CHCl3 and THF and adsorption properties for CO2 gas. Results and Discussion Selective monoformylation Initially, we tried introducing formyl groups into a fully π-fused [4.3.3]propellane via organometal species, which had been effective for functional π-extended systems [57][58
- transition and decomposition. Then, gas adsorption properties [46][69][70][71][72] were evaluated after the samples were activated in vacuo at 120 °C (Figure 3 and Figures S801 and S802 in Supporting Information File 1). Their chemical structures did not necessarily contain branched or ladder-type
- connections, but all of them displayed CO2 adsorption properties at 298 K probably due to the 3D components. The uptake values at standard temperature and pressure (STP) were 15–29 cm3·g−1 at 90 kPa. In this series, a sample with higher T90 and CY values tended to exhibit a higher adsorption capacity for CO2
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- architecture. Although extensive research has explored its pharmacological properties and various synthetic approaches, significant challenges remain in the efficient synthesis of borrelidin and its analogs. Existing literature largely focuses on total synthesis, bioactivity, and structural modifications
Gold extraction at the molecular level using α- and β-cyclodextrins
Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89
- the inclusion of complex aurate ions such as tetrabromoaurate, dicyanoaurate and a few other tetrahaloaurates. The review describes the properties of self-assembly of cyclodextrins with these ions, with highlight to α-CD and, more recently, β-CD, requiring the use of a co-former/precipitating agent
- because of its unique properties. Gold is soft, ductile, malleable, and a good conductor of heat and electricity, having the lowest electrochemical potential amidst metals. This means that cationic gold (in any form) can accept electrons from any reducing agent to form metallic gold while, in turn
- , metallic gold is easily reduced to Au− [2]. Adding to the aforementioned properties, the excellent resistance against corrosion makes gold a vital element for use in a wide range of electronic applications. Some common devices that contain gold include smartphones, in which it is used in the circuit boards
A versatile route towards 6-arylpipecolic acids
Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88
- . It contains a six-membered ring and is, like its five-membered correlate, known for its secondary structure inducing properties, which are particularly useful in the design of peptide conformations. We present a new and improved way to generate enantiomerically pure pipecolic acid derivatives with
- -inducing properties in peptides [22][23][24]. Furthermore, derivatives of pipecolic acid are known for their bioactivity as secondary metabolites [25][26][27] and for being building blocks for piperidine alkaloids [28] with a variety of uses. Results and Discussion Addressing specific positions in the ring
- amount of water was added to activate the boronic species and to dissolve the inorganic base under otherwise inert conditions. The reaction mixture was then stirred at room temperature overnight. Under these conditions, a variety of boronic acids with different steric and electronic properties was
Supramolecular assembly of hypervalent iodine macrocycles and alkali metals
Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87
- demonstrates several atoms (e.g., Cl, I, S, P etc.) that exhibit hypervalent properties. Among these atoms, iodine has gained significant attention, particularly in the form of hypervalent iodine reagents. In organic chemistry, these reagents are valued for their distinct reactivities, safe handling, high
Recent advances in synthetic approaches for bioactive cinnamic acid derivatives
Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85
- Cinnamic acid derivatives represent a significant class of biologically active compounds exhibiting a broad spectrum of activities, such as antifungal, antidengue, antimetastatic, antimicrobial, antibacterial, and anticancer properties. Their preparation has attracted considerable attention due to their
- flavor, fragrance, and therapeutic activities (Figure 1). Several reported activities of cinnamic acid include antibacterial and antifungal properties [1][2][3][4], antidengue [5], antimetastatic [6], neuroprotective synergy and angiogenesis effects [7], antileishmaniasis [8], anticancer [9], thromboxane
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