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Search for "properties" in Full Text gives 2245 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies
Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261
- antioxidant properties were determined by oxygen radical absorbance capacity assay (ORAC-FL), expressed as Trolox equivalents (TE) and using fluorescein as probe. Additionally, the study investigated the ability of the compounds to activate the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway in
- were also remarkable, yielding a value 2-fold higher than melatonin (ORAC = 2.45 TE). Natural polyphenols have shown promising potential in inhibiting β-amyloid aggregation and also antioxidant properties, suggesting their effectiveness in preventing AD. To address this, Lambruschini et al. [36
- antioxidant properties and notable inhibition of Aβ1-42 self-aggregation (65.6% of inhibition). These findings suggest FATH 5a as a potential lead compound for further investigation in AD therapy. In 2016, the same group developed ferulic acid–tacrine–melatonin hybrids (FATMHs) and lipoic acid–tacrine
Surprising acidity for the methylene of 1,3-indenocorannulenes?
Beilstein J. Org. Chem. 2024, 20, 3144–3150, doi:10.3762/bjoc.20.260
- less of an azocorannulene and more a pentaphenylpyrrole, which explains its ease of synthesis and the physical properties [21][22]. The graph with four benzene elements and a CpH core is evident in the commercially available tetrabenzofluorene, TBF (Scheme 3, lower). The parent and the phenyl TBF
- an “azacorannulene”. Working from graph structures based on chemically stable (“group elementary”) nodes is a useful principle in molecular design and chemical synthesis. Such a perspective is important to understand fundamental physical organic molecular properties as well as to predict desirable
Hypervalent iodine-mediated intramolecular alkene halocyclisation
Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258
- 4 [9][10] (Figure 1). Halogenated cyclised structures have also been found to exhibit medicinal and pharmaceutical properties, including antibacterial [11], antibiotic [12], and enzyme inhibition [13] among others. The general mechanism for the HVI-mediated halocyclisation of alkenes proceeds
Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts
Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257
- and separation technology [3][4][5][6][7][8]. Conversely, porphyrins are connected via methine (=CH-) bridges, resulting in an 18 π-electron macrocyclic system affording macrocyclic planarity as well as unique photophysical and electrochemical properties (Figure 1b). While corroles share similarities
- that function as hydrogen-bond donors and acceptors. Additionally, the nitrogen atoms in the pyrrole units of the porphyrin structure can also act as Lewis bases, capable of donating electron pairs. These properties enable tetrapyrrolic macrocycles to act as effective binding sites or catalytically
- affect the optical and electronic properties, as well as the reactivity of porphyrins, mainly introducing non-planarity with easier access to the inner pyrrolic –NHs and –N-lone pairs. Additionally, these alterations potentially increase Lewis basicity that further improves interactions with substrates
Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction
Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256
- potential in anticancer drug design. However, it should be taken into account that the sulfonyl group can radically change the pharmacokinetic properties of a drug, so the effect it may have on its ADMET properties should be determined in an additional study. Conclusion A novel synthetic strategy has been
Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy
Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254
- molecular system. Herein, we present the synthesis of mono-, bis-, and tris-norbornadiene derivatives with alkynylbenzene and alkynylnaphthalene core units, along with studies of their photochemical properties. The target compounds were synthesized by Sonogashira–Hagihara coupling reactions of 2
- ], azobenzenes [16][17][18][19], dihydroazulenes [20][21], or azaborines [22][23]. However, the most prominent feasible MOST system is the [2 + 2] photocycloaddition–cycloreversion cycle between norbornadiene (1a) and quadricyclane (2a), which has several advantageous properties (Scheme 1) [8][14][24]. In
- , such as realized in bis- and tris-norbornadienes 1b–f (Figure 1) [7][12][30][34][35]. In this particular case, derivatives with only one substituent at the norbornadiene double bond exhibited favorable storage properties because of a lower molecular weight, however, their absorption still lies in the
Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond
Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253
- structure of a molecule defines its properties and reactivity, and therefore dictates how it interacts with other molecules. Microorganisms need to communicate with each other and the environment, secreting signals of friendship, disdain, and many other sentiments in between. Natural products are the
- properties. Specifically, Qian and co-workers examined 7395 bacterial genomes and identified more than ten thousand potential cationic NRPs. They focused on a few promising candidates after bioinformatic-based dereplication and found two NRPs, brevicidine and laterocidine, that worked in an animal thigh
Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures
Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252
- ][15]. A variety of unique rotaxane-based architectures (e.g., mechano-responsive material, polymers exhibiting pump-like motion, and biomimetic sequential reactors) exhibiting conventionally unaddressed unique properties have been developed based on modern synthetic chemistry [16][17][18][19][20][21
- typical ring molecules [31][32][33][34][35]. Meanwhile, the studies on CD-based rotaxane are generally divided into two aspects: (1) the construction of a complicated small-molecule framework and the evaluation of its properties, and (2) the development of a polymer material (e.g., polyrotaxane) with a
- materials and fabricate polymer materials featuring a defined rotaxane structure. In this review, this issue is discussed in three sections: (1) synthesis and structure of CD-based (poly)rotaxanes, (2) structural control of the (poly)rotaxane framework, and (3) properties and applications of rotaxane-based
Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety
Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251
- chemistry. This type of chromophores is of particular interest in the fields of organic electronics, photonics, and optoelectronics due to their unique optical and electronic properties [1][2][3][4][5][6][7][8][9][10][11][12][13]. Among heteroaromatic push–pull molecules, stilbazole derivatives
- pyridine as an acceptor. The introduction of additional substituents to stilbazole makes it possible to change the optical properties of this molecular framework within a wide range [16][17][18][19]. This approach has found many applications in the synthesis of compounds that are used in various optical
- , full-color fluorescence of organic molecules is achieved by extending π-conjugated systems or by introducing combinations of donor and acceptor groups, which changes the electronic properties and consequently the emission spectra [35][36][37][38][39][40][41][42][43][44]. This approach is synthetically
Tailored charge-neutral self-assembled L2Zn2 container for taming oxalate
Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250
- ready receptor preparation by metal complexation. The reason for the underrepresentation is the competitive nature and excellent ligand properties of oxalate which not only is associated with the aforementioned diseases but also poses a serious hazard for metal-driven self-assemblies because the dianion
- equiv oxalate alone. The competition experiments clearly show that the host favors and binds oxalate selectively over all other guests of this study. Conclusion Oxalate as highly competitive dianion with excellent coordinating and chelating properties was successfully recognized by a charge-neutral self
Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins
Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248
- to serve as a proton source for redox reactions at the metal. 3. The electronic properties of the porphyrin, especially the low oxidation potential, should not be increased. We have chosen four-fold meso-3,4,5-trimethoxyphenyl-substituted Ni porphyrin as the electron-rich system, however, the post
- phenyl group of the porphyrin and the perfluoroalkyl chain. The oxygen atom, especially in the 2-position, should even improve the electronic properties of the porphyrin. Results and Discussion Our synthesis started with the readily available fluorinated symmetric diols HO–CH2–(CF2)n–CH2–OH (n = 2,4,6
gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides
Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247
- Poznań, Poland 10.3762/bjoc.20.247 Abstract The incorporation of fluorine atoms within the structure of organic compounds is known to exert a significant impact on their electronic properties, thereby modulating their reactivity in diverse chemical transformations. In the context of our investigation
4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions
Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246
- potential chiral dopants. Our long-term goal would be to provide a structure–property relationship of this class of molecules by i) modification of the aryl and ii) and/or acetal moieties (Scheme 1) and to elucidate the possible role of fluorine on their physical properties, with comparison to their non
- enantiomers (R,R)-3/(S,S)-3, (R,R)-4/(S,S)-4 were obtained by slow evaporation from n-heptane solution and structures were determined by X-ray diffraction, which allowed the correlation of the chiroptical properties with the configuration (Figure 2 and Figure 3). The HTP of all enantiomers were measured with
- relationship of 4,6-diheteroaryl-5,5-difluoro-1,3-dioxanes as potential chiral dopants. The syntheses of chiral 4,6-diphenyl-5,5-difluoro-1,3-dioxanes 3 and 4 as dopants for cholesteric liquid crystals. Synthesis of rac-2 as precursor of rac-3 and rac-4. Comparison of the physical properties of enantiopures (R
The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives
Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244
- transport properties was most clearly observed in compound 3b which has a 60-fold improvement in mobility compared to 2b. This study demonstrates that the choice of the solubilising group has a profound effect on the hole mobility on these organic semiconductors. Keywords: Knoevenagel condensation; organic
- diodes (OLEDs) [3], and organic photovoltaic devices (OPVs)[4][5][6]. The charge transporting properties of organic semiconductors are key to the success of the devices and research focusing upon increasing this remains an important goal to enhance the commercial viability of the technologies. Typically
- ][16][17], high electron affinity, excellent self-assembling properties [18][19][20], and thermal and photochemical stabilities [21]. The excellent charge carrier mobility of PDIs has been explained by the intermolecular π–π interactions with an interplanar distance (3.3–3.5 Å) [22][23][24][25] that
Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts
Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243
- N-arylation could be controlled by adjusting the steric and/or electronic properties of the diaryliodonium salt and the amide. This approach was helpful in the formation of O-arylimidates previously unattainable using metal-catalyzed methods. S-Arylation The aryl sulfide moiety is widely present in
- thiols, sulfoxides and sulfilimines have received significant attention in chemical biology and synthetic chemistry due to their versatile properties. Traditional approaches to sulfilimine synthesis typically include the oxidative imination of sulfides, often relying on transition-metal catalysts, which
- xanthates, with yields spanning from 65% to 91%. The promising biological properties of the S-aryl O-alkyl xanthates, makes them desirable targets for synthesis
Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions
Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241
- , and triazolobenzodiazepine under solvent- and catalyst-free conditions. Purposefully, this approach produced various bioactive scaffolds using environmentally friendly, mild, and simple conditions. Due to their bioactive moieties, these compounds with exclusive fluorescence properties may attract
- compounds with antibiotic, antiviral, and anticancer properties that are found in many drugs and natural products [1][2][3][4][5][6]. Pyrroles' biological properties manifest when they are fused to other heterocycles [7][8][9][10][11][12]. Among them, seven-membered heterocycles of the benzodiazepine
- -fused benzodiazepines, benzoxazepines, or benzothiazepines exhibit unique biological and pharmacological properties [22][23]. For example, midazolam is a hypnotic-sedative drug with anxiolytic, muscle relaxant, and anticonvulsant properties [24], flumazenil is made to induce general anesthesia for
N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity
Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240
- sodium tert-butanolate afforded the desired deprotected indigo-N-rhamnoside 5d (α/β = 2:1). In contrast to the antiproliferative properties of the akashins, 5d showed no significant activity against human cancer cell lines. The glycosylation of 13 can be explained as follows (Scheme 9): Reaction of tetra
- lower level as compared to β-33b. For compound β-33b, the mitochondrial properties and cell viability of melanoma (A375) and squamous cell carcinoma cells (A431) of the skin were studied [31]. Glucoside β-33b resulted in a decrease of the cell viability. In addition, activation of caspases-3 and -7 and
Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates
Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238
- heating, acting both as base and acid. This dual role activates the amide moiety and the ethynyl group, respectively. Using larger amounts of ammonium acetate substantially prolongs the reaction time due to its dissociation properties. Consequently, the yield of 5a increased to 92% by increasing the
Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide
Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237
- /bjoc.20.237 Abstract The chemosensor properties of a bimetallic terbium(III)/copper(II) complex functionalized with a 4-(2-pyridyl)-1,2,3-triazole ligand for the detection of Cu2+ ions and, aqueous and gaseous hydrogen sulfide was investigated. The 4-(2-pyridyl)-1,2,3-triazole ligand functions both as
- detecting aqueous H2S are in development [8][9][10][11][12][13][14], lack of sensitivity, selectivity, and cost effectiveness remain major challenges. For a number of years we have explored the properties of lanthanide-based chemosensors (Ln = Eu3+ or Tb3+) due to their significant advantages over
- H2S gas resulted in no modulation of luminescent intensity. With this in mind, it was therefore of interest to investigate the luminescent properties of [Tb(triazole-DPA)3·3Cu]3+, Tb.1·Cu, in the presence of aqueous and gaseous hydrogen sulfide. Results and Discussion The Tb.1 complex was synthesized
Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines
Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236
- (small-molecule concept) offer a distinctive advantage in the synthesis of new biologically active molecules, as they are synthetic bioisosters of purine bases. Imidazo[1,2-a]pyrimidine derivatives exhibit a wide range of pharmacological properties [4][5][6]. For example, this scaffold is a key
- desired pharmacological properties. Therefore, the design and synthesis of new compounds of this class with improved ADMET (absorption, distribution, metabolism, excretion, toxicity) pharmacological properties is an urgent task. Molecular docking was carried out to identify potential binding positions of
Mechanochemical difluoromethylations of ketones
Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235
- structures can improve physicochemical and biological properties [19][20][21][22][23][24][25][26][27]. Among these groups, the difluoromethyl moiety has gained considerable attention [28][29][30]. Commonly, it is synthesized by the reaction of a nucleophile with difluorocarbene. However, the generation of
C–C Coupling in sterically demanding porphyrin environments
Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234
- ][5]. Nonplanar porphyrins offer a marked difference in chemical and physical properties when compared to their planar compatriots [6], with relatively smaller HOMO–LUMO gaps resulting in an observed bathochromic shift in the UV–vis absorption spectrum [7]. The phenomenon of nonplanarity results from
- ] and almost planar [19] dodecasubstituted porphyrins have been reported. Despite the increasing interest in the chemical and physical properties of nonplanar porphyrins only limited synthetic methods are available for the functionalization of these macrocycles [6]. An attractive approach to accomplish
- literature procedure [35]. With initial success in the synthesis porphyrin 26, this Suzuki coupling reaction was performed on 13, for a range of boronic acids/esters as shown in Figure 2 and Scheme 2. Boronic acids/esters were chosen based on their electronic properties (activating/deactivating) as well as
Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction
Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233
- amides in moderate three-step yields. Keywords: amine; chirality transfer; [1,3]-proton shift reaction; tetrafluoroethylene fragment; Introduction A fluorine atom has quite peculiar chemical and physical properties compared to others, and hence changes in molecular properties resulting from the
- with a tetrafluoroethylene fragment exhibit significantly different molecular properties compared to monofluorinated, difluorinated, or trifluoromethylated molecules [8][9]. Therefore, more and more tetrafluoroethylenated molecules having a variety of applications, such as bioactive substances (Figure
Copper-catalyzed yne-allylic substitutions: concept and recent developments
Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232
- ester was also a suitable substrate for the reaction (Scheme 20, 20p). In addition, the presence of substituents such as hydroxy or chlorine groups on the anthrones had no impact on the reaction (Scheme 20, 20q–t). Chiral coumarins, renowned for their bioactive properties, form the cornerstone of
Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones
Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228
- and Suzuki–Miyaura cross-coupling reactions followed by Brønsted acid-mediated cycloisomerisation. The developed methodology tolerates various functional groups and leads to moderate up to quantitative yields of the final products. The impact of different functional groups on the optical properties
- reactions (Figure 1). Polycondensed heterocycles containing a uracil moiety have also been studied in recent years. For example, compound A exhibits antitumor and antimicrobial properties (Figure 2) [66][67]. Compounds A and B are used as starting materials for the synthesis of polyaromatic derivatives of
- other compounds with medicinal or photophysical properties [52][53][54][55]. Compounds A are related to the class of natural products known as coumestans, while B resembles flavins. While the medical potential of coumestans is still the subject of current research, interesting photocatalytic properties
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