Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• species distribution curves for 1 were plotted (Figure 5). This is reflected by logD at different pH values (Table 1). At pH 5, the protonated species dominates, with logD = −0.76. At pH 7.4, approximately 90% will be present in the protonated form, alongside 10% of the neutral species (see Figure 5

• in ultrapure water. The stability of 1 was assessed based on peak areas. The experiment was performed in triplicate. Distribution coefficients The pH-dependent octanol/buffer distribution coefficients of 1 were determined at 25 ± 0.5 °C using the following buffers: 50 mM sodium citrate (pH 5.00, I

• h in a temperature-controlled incubator at 25 °C. The concentration of 1 in the buffer solution before and after partitioning, ci and cw, respectively, was determined by HPLC, from which distribution coefficients, D, were calculated according to where Vw and Vo are the volume of the buffer solution

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• distribution is located at the donor groups and slightly at the dicyanovinylene unit in the HOMO. The distribution in the HOMO−1 mainly is over the donor groups (Figure 7 and Figure S17, Supporting Information File 1). The LUMO is delocalized over the dicyanovinylene unit and slightly over the indanone group

Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene

• Dmitry N. Platonov,
• Alexander Yu. Belyy,
• Rinat F. Salikov,
• Kirill S. Erokhin and
• Yury V. Tomilov

Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2

• isomer of anion 2 we analyzed the structure of its highest occupied molecular orbital (HOMO) and the distribution of the electrophilic Fukui function (f–) [28] – the difference in electron density between the anion and the derived radical by abstraction of one electron (Figure 2). Both approaches

• revealed that the α-position is most nucleophilic. Notably, anion 1 demonstrated similar HOMO and Fukui function distribution (see Supporting Information File 1), however, all positions would lead to the very same products. The potassium salt of anion 2 was generated in an acetonitrile solution from hexa

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• -methylcyclohexanone (54), this reagent markedly alters the product distribution compared to PCl5 [63] (Scheme 11B). However, since the reaction conditions differ significantly, it remains unclear whether the product distribution is driven by the reagent itself or by the reaction conditions employed. In 2007, Prati

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

• Giuseppe Granata,
• Loredana Ferreri,
• Claudia Giovanna Leotta,
• Giovanni Mario Pitari and
• Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

• of compound 3 in DMSO-d6 (400.13 MHz, 297 K). Intensity-weighted mean hydrodynamic diameter (left), and zeta potential distribution (right) of compound 3 (1 mg/mL water), after vortex and sonication. Antiproliferative effects by compound 3 and its chemical precursor 1. A) Results on proliferative

Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

• Kaylen D. Lathrum,
• Emily M. Hanneken,
• Katelyn R. Grzelak and
• James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

• orientation, the distribution of nitrogen atom centers within the ring system appears essential for eliciting bioactivity. Orientation of isoquinoline and N3-triazole subunit nitrogen atoms is identical between 17 and 35 as well as between 18 and 36. In contrast, 34 showed toxicity towards Gram-positive

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• space is shown in Figure 8a. The distribution of these selected solvents with other organic solvents in the 3D Hansen solubility space is determined by three Hansen solubility parameters (HSPs): dispersion (δD), polarity (δP), and hydrogen bonding (δH). As is well established, information about their

• aromatic aldehydes exhibit a Z-configuration [112][113] and it appears that endo-coupling of the Z-configured C,N-diphenylnitrone with maleimide is more favorable. Indeed, the distribution of the cis/trans product is also found to be significantly influenced by the nature of the substituents present in the

• synthetic methods for cycloaddition reactions. In this study, a series of natural organic compounds from diverse classes and an acetonide [129] derivative were selected for investigation, with a focus on their potential catalytic effects in relation to the alteration of cis/trans product distribution under

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• regulatory role in chemical transformations, exerting kinetic modulation through solvation effects on activation barriers and reaction rates, dictating thermodynamic equilibria that govern product distribution, and enabling precise reaction pathway regulation via selective stabilization of critical

A m-quaterphenyl probe for absolute configurational assignments of primary and secondary amines

• Yuka Takeuchi,
• Mutsumi Kobayashi,
• Yuuka Gotoh,
• Mari Ikeda,
• Yoichi Habata,
• Tomohiko Shirai and
• Shunsuke Kuwahara

Beilstein J. Org. Chem. 2025, 21, 2211–2219, doi:10.3762/bjoc.21.168

• a P twist. Based on a Boltzmann distribution analysis (T = 298 K), the relative populations of the P and M conformers in (S)-3a were determined to be 48:52. (Table S3 in Supporting Information File 1). In contrast, the P conformers were found to predominate in (S)-3b (Figure S21 and Table S4 in

• described above, the C6–C1–C1'–C6' dihedral angles in all conformers of (S)-3a–g and (R)-3h were approximately constant (plus or minus ca. 42 degree). The range of distribution of the angles was also small, ranging from +39.8 to +43.9 degrees, or −40.2 to −45.8 degrees (Figure 5). In the solid state of (S

• )-3a–g and (R)-3h using MMFF. All local minimum conformers were then optimized with DFT using the B3LYP/6-31G* model [47]. The lower energy conformers with relative energies ranging from 0.0 to 10.0 kJ/mol were selected. By the Bolzmann distribution based on the energy difference of the conformers at

Solar thermal fuels: azobenzene as a cyclic photon–heat transduction platform

• Jie Yan,
• Shaodong Sun,
• Minghao Wang and
• Si Wu

Beilstein J. Org. Chem. 2025, 21, 2036–2047, doi:10.3762/bjoc.21.159

• significant photothermal energy storage capacity of 430 J/g (Figure 5c). This study presents potential implications for energy distribution and utilization in domestic consumer applications, and for photothermal-assisted insulation strategies. Azobenzene small molecule derivative solar thermal fuels

Understanding the origin of stereoselectivity in the photochemical denitrogenation of 2,3-diazabicyclo[2.2.1]heptene and its derivatives with non-adiabatic molecular dynamics

• Leticia A. Gomes and
• Steven A. Lopez

Beilstein J. Org. Chem. 2025, 21, 2007–2020, doi:10.3762/bjoc.21.156

• surface hopping (FSSH) [92][93] to investigate the photochemical pathways of compounds 1, 3, and 5 along the potential energy surfaces (PESs) of both ground and three excited states. The initial nuclear positions and velocities were sampled based on the Wigner distribution [108] at 300 K. All quantum

Systematic pore lipophilization to enhance the efficiency of an amine-based MOF catalyst in the solvent-free Knoevenagel reaction

• Pricilla Matseketsa,
• Margret Kumbirayi Ruwimbo Pagare and
• Tendai Gadzikwa

Beilstein J. Org. Chem. 2025, 21, 1854–1863, doi:10.3762/bjoc.21.144

• extent of alkyl grafting, the –CH2– content in the pores of KSU-1n-Hex and KSU-1C14 is still greater than for KSU-1iPr and KSU-1t-Bu, assuming a uniform distribution of alkyl chains. Additionally, although the introduction of large alkyl substituents in a MOF is associated with a reduction in pore

• distribution of intermediate versus product during the reaction. Both these behaviors, increased efficiency and different intermediate:product distributions, call to mind the effect of lipophilic pockets in enzyme catalysis, and they offer a view to the possibilities that can be achieved in enzyme-inspired

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• two isomers do not overlap, only one isomer is excited by the irradiation wavelength, enriching the other isomer until an equilibrium is reached. This equilibrium is called a photostationary state (PSS) [1]. The isomeric distribution at equilibrium can also be called photostationary distribution (PSD

• ). It must be noted, though, that in literature both PSS and PSD are used to indicate the photostationary distribution [2]. We will use the PSS notation throughout the review. Often, the two absorption spectra overlap, and both isomers are excited to different extents at the same time. The extent of

Research progress on calixarene/pillararene-based controlled drug release systems

• Liu-Huan Yi,
• Jian Qin,
• Si-Ran Lu,
• Liu-Pan Yang,
• Li-Li Wang and
• Huan Yao

Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139

• prepared a novel supramolecular ternary polymer DiCh@a-CD-bisSC4A and binary polymers DiCh@bisSC4A Compared to binary DiCh@bisSC4A, ternary DiCh@a-CD-bisSC4A has not only a larger polymer size but also a better size distribution and topological structure due to the integration of quasi rotaxanes with

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• tubular, continuous tank, bubbling and injection nitration reactor – directly governs thermodynamic control, product distribution, process scalability, and quality assurance [4][5]. Batch systems remain prevalent for low-throughput fine chemicals due to their operational flexibility, whereas continuous

• compliance or specific product distribution patterns. Nitration solvents: The selection of solvents for nitration reactions significantly influences reaction kinetics, selectivity, and process safety, requiring careful consideration of both chemical compatibility and operational parameters. Traditional batch

• nitration process using continuous-flow, several approaches are listed in the literature, e.g., external numbering up, internal numbering up and sizing up [74]. In the numbering-up approach, ensuring a uniform flow distribution in parallel channels is difficult. The numbering-up approach inherently

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• regioselectivity of the cycloaddition reaction between nitrile oxides and C=N bonds can be rationalized by considering the relative electronegativities of the terminal elements and the distribution of electron density in the frontier orbitals of the reagents [35]. The electrons are preferentially located on the

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• -formylpiperidine and aminophenol (2a-o-hydrol) (see Figure 1a). To better understand the influence of the reaction conditions on product distribution, we plotted conversion versus selectivity in Figure 1b. Crudes were analysed by 1H NMR spectroscopy, as shown in Figure S1 (Supporting Information File 1), to

• in the preparation (theoretical loading). This suggests that optimum catalyst distribution and activity is achieved with 5 wt % supported CuCl. The two catalysts were also characterised by FTIR and DR UV–vis spectroscopy, to obtain information about the grafted aminopropyl ligand and inserted copper

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• relative Gibbs’ free energies suggest a distribution of 88% E and 12% KE. The theoretical results for acetonitrile show that the tautomer fractions are almost equal, which reflects to the existing experimental ΔG values in acetonitrile, obtained by two different approaches (−0.15 [53] and 0.25 [56] kcal

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• ], [4.3.3]_Br and [4.3.3]_2Br. To gain insight into the different reactivity between [3.3.3] and [4.3.3], theoretical calculations were performed at the ωB97X-D/6-31G(d,p) level of theory (Figures S901–S903 in Supporting Information File 1). Although distribution of the highest occupied molecular orbitals

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• C–H bond. Example of combinations of C–H bonds and DGs that are considered identical because of symmetry of the DG. Example of combinations of C–H bonds and DGs that are considered identical because of resonance structures of the DG. A: Distribution of correct (green) and wrong (red) predictions for

• black cross. B: Distribution of correct (green), semi-correct (yellow), and wrong (red) predictions for the same molecules, evaluated with an energy threshold of 1.0 kcal·mol−1. Molecules with five potential reaction sites that are predicted wrong by the QM workflow. The experimentally observed and

A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

• Ashutosh Nath,
• John Mark Awad and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

• . A comprehensive DFT investigation of reactant 6 was carried out to analyze the transition state of the IMDA reaction for a Br-substituted diene and its charge distribution (Figure 2). The diene has a notable positive charge (+0.318, +0.098, 6a), (+0.334, +0.082, 6h) and (+0.316, +0.074, 6r) whereas

Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• good yield with this straightforward methodology (and without the need for toluene reflux), and to determine the distribution of products obtained for this synthetic approach, by exhaustive analysis of reaction mixtures by HPLC, MS and NMR. Ultimately, 14 aminated derivatives of 5-chloro-3-(4

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• macrocycle’s cavity, we considered the charge distribution on three iodine atoms, three carbonyl carbon atoms and six oxygen atoms that constitute a small cavity within the macrocycle. The Mulliken charge distribution diagram of HIM 1 (Figure 3, middle) shows that the summation of the overall charge on three

• curcumscribe the small cyclic core represented by blue color. Three carbonyl amides project outward. B) DFT image of 1 displaying the distribution of Mulliken charges on iodine (purple), oxygen (red), and carbon (grey); benzyl groups are ommited for clarity. C) Calculated electrostatic potential map showing

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• change from the D3 symmetry as observed in TTM to a C2 symmetry in the orbital distribution in the ground state. In spite of this break in symmetry to C2 – where all relevant transitions will be allowed – an enhancement of the respective absorption bands or an improvement in the ϕ has not been observed

• . However, one can observe a loss of the vibronic features in the fluorescence signal, indicating that the emission occurs from a CT state, in agreement with the DFT orbital distribution in the ground state geometry (see Figure 2e for different orbital location in HDMO and SOMO). Interestingly, successive

• -shaped distribution for ϕ. The bathochromic shift in λem has previously been described to result from the better stabilization of the CT excited state for stronger donors, and therefore a stabilization of the highest occupied molecular orbital (HOMO) when only considering the acceptor moiety (see also

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• density distribution in the charge transfer (CT) excited state is facilitated by the presence of an electron-rich moiety and an electron-poor part in the same molecule, increasing the lifetime in the excited state. One of the representative classes of molecules demonstrating dual use in materials

• 5a (3.9 eV) as a consequence of the extended π conjugation compared with 4a and 6a (4.4 and 4.4 eV, respectively). Interestingly, compound 6a, which possesses the weakest sulfur-based acceptor, showed an inversion in the LUMO distribution, localizing it in the TBA core – this behavior of the named