Search results
Search for "stability" in Full Text gives 1417 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Recent advances in controllable/divergent synthesis
Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73
- in chloroform or dichloromethane (DCM), converting entirely into the thermodynamically stable [1 + 1] isomer 39. This work demonstrates a solvent-driven approach for dynamically interconverting macrocycle sizes, governed by thermodynamic stability and solubility differences. In the same year, Chauhan
- control regioselectivity. It profoundly influences reaction kinetics, stability of intermediates, and reaction equilibria. Through precise temperature modulation, chemists can effectively steer the formation of regioisomers, often achieving desired selectivity with minimal alterations to other reaction
Dicarboxylate recognition based on ultracycle hosts through cooperative hydrogen bonding and anion–π interactions
Beilstein J. Org. Chem. 2025, 21, 884–889, doi:10.3762/bjoc.21.72
- than 50 atoms in the macrocyclic skeleton are denoted as ultracycles [1]. These very large macrocycles are prevalent in nature and exhibit unique functions. For instance, the archaeal lipid GDGT-0 enables archaea to thrive in extreme environments [2]; cycloamyloses enhance the stability of drug
Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters
Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69
- detrimental to reactivity leading to substrate degradation. Given the ease of access and enhanced stability of pinacol esters to column chromatography, this motif was advanced for further reaction design. Cyclic voltammetry analysis of 1a indicates that single-electron-transfer processes with the excited
Substituent effects in N-acetylated phenylazopyrazole photoswitches
Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66
- often show higher quantum yields and increased thermal half-life of the metastable state. For the half-life, the choice of the heterocycle is crucial, as revealed through density functional theory (DFT) calculations, which showed that a 5-membered ring promotes the stability of the Z isomer [30]. Within
- these, azo-photoswitches based on a 1,3,5-trimethylpyrazole ring (phenylazopyrazole; PAP) became particularly popular, showing almost quantitative back and forward photoswitching and high thermal stability [31]. Moreover, 1H-pyrazole derivatives [32] and arylazopyrazolium [33] compounds were
- further issue, we observed some instability at acidic pH during analysis. Thus, we tested the stability of NAc-PAP-H (1 mM, MeOH, ambient conditions, 2 h) at pH 2, 12, and in the presence of DBU (10−2 M) and found that the acetyl group was lost (cf. Supporting Information File 1, section 2.4). UV–vis
4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches
Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65
- , while density functional theory (DFT) calculations provided insights into their electronic properties, including reactivity and stability. This comprehensive approach, integrating synthesis, biological evaluation, and computational methods, highlights the potential of 4-(1-methylamino)ethylidene-1,5
- affinity (EA), electronegativity (χ), hardness (η), and softness (S), were determined for the studied compounds and are summarized in Table 4. A detailed comparison of these parameters highlights significant differences in the chemical stability and reactivity of the compounds, reflecting their unique
- electronic characteristics and potential functional roles. As reported in Table 4, compound 5c demonstrates the highest reactivity and lowest stability, as evidenced by its smallest ΔEL-H (3.397 eV), highest softness (0.589), and lowest hardness (1.699 eV). Conversely, compound 5d is the most stable, with
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- lower efficiency (e.g., some electrolytic cells). Role of electrolytes in organic electrochemical reactions Electrolytes are crucial for conductivity and reaction stability in organic electrochemical reactions. They are categorized as supporting electrolytes, which enhance conductivity, reduce
- processes and can work well as the anode and cathode. This electrode has high stability in the electrochemical environment and is easy to clean, but caution should be taken when using it as a cathode because of low H2 overpotential. Platinum electrodes are very popular and valuable as cathodes in the
- cathode at constant current for 1 hour (Scheme 4). Platinum is usually used as the cathode for its ease of use, and a carbon plate electrode as the anode because of its cheapness and stability at high voltages. Further studies showed that using a reticulated vitreous carbon (RVC) electrode as the anode
Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones
Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59
- transfer hydrocyanation of alkenes proceeds via (boron) isocyanides [50]. If calcium cyanide would be preferred over isocyanide, hydrocyanation would hardly be possible. A principally conceivable "hydroisocyanation" of hydrazone is therefore precluded. The relative stability of alkaline earth metal
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- simulation (MD) [54] over 10 ns to determine the relative stability of the complexes (Supporting Information File 1, Figure S17 and Figure S18). The most stable receptor–ligand complexes so obtained were then submitted to a MM-GBSA calculation to deliver IFD binding energies (Table 3 and Supporting
Origami with small molecules: exploiting the C–F bond as a conformational tool
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
- . It should be noted that one of the reasons why C-2 fluorinated nucleosides (e.g., 67 and 68) have become especially popular in the field of medicinal chemistry [133][134][135][136][137], is that the presence of fluorine at C-2 confers enhanced stability towards hydrolysis, through destabilising the
Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex
Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52
- modify a series of peptide and protein-related properties such as stability, specificity, and folding. In this regard, fluorinated amino acids are particularly important. Incorporation of fluorinated groups into the sequence of peptides and proteins can, for instance, regulate the respective
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- , including non-toxicity, bench-stability, structural diversity, straightforward preparation, and broad commercial availability. Significant contributions include Sawamura's work with alkyl–9-BBN [32][33][34][35][36][37] as a nucleophile. These developments have collectively transformed copper-catalyzed AAA
- low configurational stability of the chiral secondary organometallic 9 and organocopper species 10 [38]. Therefore, the development of a more broadly applicable catalytic system that could accomplish copper-catalyzed stereoselective allylic alkylation with chiral secondary nucleophiles represents a
- breakthrough in this process was the discovery of a solvent effect: switching from Et2O/hexane to THF at −50 °C after organocopper species formation dramatically enhances configurational stability. Further investigations into the stability of the secondary organocopper species 14a revealed the critical
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- , combining the specificity of antibodies with the potency of cytotoxic drugs to enhance therapeutic efficacy while minimizing off-target effects. The development of new chemical methods for bioconjugation is essential to generate ADCs and to optimize their stability, efficacy, and safety. Traditional
- stability, and/or a shorter ADC half-life [14]. Optimization of the drug/antibody ratio (DAR) and payload distribution/location thus becomes significant for ideal ADC design. Given the complexity of biological macromolecules, there are inherent limitations in terms of the types of reactions that can be used
- contains four un-buried interchain disulfide bonds. Thus, rebridging allows the disulfide bonds to be reformed after conjugation, but one may question whether this could affect the long-term stability or functionality of the ADC, particularly if the new bonds do not perfectly mimic the properties of native
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- preserved, with chemical modifications focusing on massarilactone H rather than massarilactone D. These modifications should target other regions of the molecule, such as the number and position of acyl substituents. Future research should investigate the stability and selectivity of these compounds, as
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- showing how formaldehyde or paraformaldehyde can be used in the AAA coupling of three components for the synthesis of propargylamines [58][59][60][61]. However, the problems associated with the stability of the imine/enamine intermediate generated from formaldehyde must still be addressed. Several
- reaction by metal catalysis is an option to avoid the problems regarding iminium or aminal stability. This is an important issue in AAA coupling when formaldehyde is used as the C1 source. Finally, a later work proposes a catalysis-free protocol for the synthesis of propargylamines by an AHA coupling
- of an N–C bond, where the stability of the leaving carbocation is the main factor that affects the rate of this step. Next, intermediate 37 is attacked by the phosphorus compound, giving product 35 with retention of the configuration. This mechanism was confirmed when compound 36a was isolated as
Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles
Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44
- that, the use of 3-fold excess of amine 2a led to the same results. Apparently, the stability of salt 3a is connected with high acidity of the starting furanone 1a and its recovery is only possible under the action of strong acids (HCl, H2SO4). Further, we investigated the chemical behavior of
Binding of tryptophan and tryptophan-containing peptides in water by a glucose naphtho crown ether
Beilstein J. Org. Chem. 2025, 21, 541–546, doi:10.3762/bjoc.21.42
- as well indicated by the lower binding affinity of 1 to the acetylated analogues of peptides 2 and 3. In the case of peptide 4, acetylation of its N-terminus did not affect the stability of the complex with receptor 1. This suggests that 1 interacts with the N-terminal ammonium in 4 to a much lesser
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- -purity color and improved stability, has been observed. OLED materials have attracted considerable research because they found commercial uses for flat panel displays and solid-state lighting applications. Currently, the design of efficient and highly stable blue fluorescent emitters remains a challenge
- to suppress undesirable fluorescence self-quenching [15]. Not only do bulky substituents disrupt intermolecular interactions of this type, they can also provide higher chemical stability and reduce or prevent the photodimerization and photo-oxidation to which all acenes are prone [13]. Furthermore
Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction
Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36
- , wavelengths etc.). The biggest advantage, especially in photopharmacology and when used in photoswitchable materials, is the inverted thermodynamic stability of the two switching states (isomers). The Z isomer is more stable than the E form. However, one disadvantage that it shares with the frequently used
- spectra [1]. Moreover, the ethylene bridge creates a cyclic 8-membered core, inverting the thermodynamically stability in favor of the Z boat conformation compared to parent azobenzene, which has a stable E configuration [1][2][3][4]. Preceding studies including azobenzene-based photopharmacophores showed
- that, in most cases, the sterically demanding Z configuration is biologically inactive, while the stretched E configuration is biologically active [5][6][7]. Because of the inverted thermodynamic stability compared to azobenzene, the stable Z configuration of the diazocine can be administered and
Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages
Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30
- demonstrating enzyme-like rate accelerations remain rare. This perspective will briefly highlight some of the key advances in traditional cavity catalysis, by cavity type, in order to contextualize the recent development of robust organic cage catalysts, which can exploit stability, functionality, and reduced
- , which can act as an oxidation catalyst (Figure 7C) [44]. The long-standing challenges of synthesis, stability, solubility and internal functionalization are beginning to be tackled, and the remainder of this Perspective will discuss specifics of these hard-earned advances and the opportunities they
- ) [38]. To capture both stability and solubility, we turned to Mastalerz’s post-functionalization chemistry [286][300][304][306][358][359][360][361][362], in which imines are oxidized by a Pinnick oxidation to amides [286][360][363][364], an approach gaining popularity [46][262]. Importantly, we were
Unraveling aromaticity: the dual worlds of pyrazole, pyrazoline, and 3D carborane
Beilstein J. Org. Chem. 2025, 21, 412–420, doi:10.3762/bjoc.21.29
- , exceptional thermal and chemical stability, and robust synthetic versatility [16][17] – make carborane derivatives essential components in various fields. These include pharmaceuticals [18][19][20][21][22], boron neutron capture therapy (BNCT) [23][24][25][26], organometallic ligands [27], and functional
- boron cluster, referred as pyrazoleCC, pyrazoleCB, and pyrazoleBB, respectively (Figure 1). Among these isomers, pyrazoleBB is the most stable, followed by pyrazoleCB and pyrazoleCC by 19.2 and 24.5 kcal mol−1, respectively. This order of stability correlates with the length of the fusing bond between
The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation
Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27
- the inversion at the anomeric sp3 carbon centre by the attack of the acceptor moiety. Crich β-mannosylations are classic illustrations for the same [38][39]. On the other hand, the stability of the carbocation contributes towards the reaction to proceed via the dissociative two-step SN1 reaction
- -2 position of glycosyl donors which can contribute towards 1,2-trans glycosylations without affecting the reactivity of the donor. They introduced carbamate ester moieties as alternative protecting groups. The N-phenylcarbamoyl (PhCar) moiety showed high stability in the pH range of 1–12 and it
Red light excitation: illuminating photocatalysis in a new spectrum
Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22
- palladium complexes. The authors have focused on the photooxidation of β-citronellol (28), a key step in the production of industrial compounds like rose oxide (Scheme 10). Remarkably, the silicon phthalocyanins demonstrated exceptional stability under red-light irradiation, achieving up to 87% conversion
- integrity over extended reaction times, even under high substrate concentrations and continuous flow conditions, achieving high turnover numbers of over 50000. This stability allowed for solvent-free reactions, significantly enhancing the sustainability of the process. Additionally, the authors have
- , Goddard et al. have developed a second generation of cyanin dyes. For example, in the case of the photocatalyzed trifluoromethylation of alkenes, it has been shown that the stability of the photocatalyst was crucial for achieving efficient and faster conversion. In their study, the authors have reported
Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity
Beilstein J. Org. Chem. 2025, 21, 277–285, doi:10.3762/bjoc.21.20
- ] reported a stable heptacene dication in concentrated sulfuric acid, a stability attributed to the intermolecular Coulomb repulsion between the charged molecules, which prevents the dimerization of the acene. This exciting finding suggests possible modes of kinetic stabilization of oxidized species of π
- independent ring currents. Conclusion Two [3]naphthylene isomers with different fusion topologies, linear (1) and angular (2), have been studied in their oxidized forms. The first oxidized states of both molecules attend to a concatenation of aromatic NAP and antiaromatic CBD units, in which the stability of
- angular dication preserves the aromatic–antiaromatic confinement of the neutral and radical cation species. This is an unusual case scarcely described in 1D π-conjugated polycyclic molecules, where the stability of the linear dication is attributed to the formation of a global ring current. Experimental
Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene
Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19
- improving the stability of inverted perovskite solar cells [23]. On the other hand, benzo[rst]pentaphene-5,8-dione (BPP-dione) is known as an oxidation product of BPP [24][25], but to the best of our knowledge, the detailed optical properties of this BPP derivative have not been previously described in the
Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory
Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16
- analysis of the thermal back reaction revealed activation parameters, highlighting how the substitution position of the aryl group affects the thermal stability. Additionally, density functional theory calculations identified M06 and MPW1PW91 as the most accurate functionals for predicting the thermal back
- ][26][27], photomechanical materials [28][29][30][31][32], and so on. As seen in these representative application examples, the thermal stability of the colorless and colored isomers is one of the essential properties of molecular photoswitches. For example, the photochemically reversible-type (P-type
- replacing the rotor pyridyl group of a hydrazone switch with a phenyl group afforded long-lived negative photochromic compounds [49]. In addition, Hecht and co-workers reported that the thermal stability of indigos can be tuned by N-functionalization [50][51]. They revealed that the introduction of electron
Other Beilstein-Institut Open Science Activities
