Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• . Additionally, some substrates proved incompatible with this reaction protocol. 2-Carboxybenzaldehyde did not result in the recovery of any solid product by simple filtration, probably due to its high solubility in water. Use of aliphatic aldehydes presented a significant challenge, as only the product 3z from

• File 1, Figure S251) in various solvents, including polar aprotic solvents (EtOAc, CH2Cl2, CHCl3, DMSO, and MeCN) and polar protic solvents (MeOH and H2O). However, the use of a non-polar solvent like hexane was not feasible due to the compounds' low solubility in this solvent. The 5-arylidene derived

Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

• Udyogi N. K. Conthagamage,
• Lilia Lopez,
• Zuliah A. Abdulsalam and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

• caused by rotaxane 2, which lacks azobenzene switches, and axle 3, which lacks the macrocycle. Attempts to study the macrocycle alone without the axle were hindered by its very low solubility in the aqueous buffer. This study highlights both the potential and the limitations of rotaxane 1 as a membrane

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• , entry 1). However, methanol proved to be an ineffective solvent due to the rapid decomposition of NaBH4 and poor solubility of substrate 3. Most of the starting material was recovered unchanged after complete decomposing NaBH4. In contrast, when ethanol (Table 2, entry 2) or isopropanol (Table 2, entry

• solubility of the starting materials in methanol, which prevented efficient conversion. Subsequently, the substrates were introduced as THF solutions into NaOMe in methanol. Under these conditions, the cyclization did occur to form the corresponding Na salts of 3-hydroxy-TTs. Upon aqueous work-up and

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

• but not limited to methyl laurate, has found application in a variety of direct and indirect food additive applications [94]. The Hansen solubility parameter is a numerical expression that quantifies a molecule's cohesive energy density from non-polar, polar, and hydrogen-bonding interactions. It is a

• 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

• similarity in solubility properties can be obtained from the distance between solvents. The identification of problematic and non-problematic solvents is facilitated by the size and color of the specific sphere representing a particular solvent. As demonstrated by the figure, the position of methyl laurate

Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs

• Guang-Wei Zhang,
• Yong Zhang,
• Le Shi,
• Chuang Gao,
• Hong-Yu Li and
• Lei Xue

Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181

• (Figure S3) in Supporting Information File 1. WDG exhibited poor solubility, which hindered the direct acquisition of its single crystal structure for characterization. However, after Boc (tert-butyloxycarbonyl) protection, a single crystal structure (CCDC Number: 2339028) of the modified compound was

• by the two structural analogs, we added a commercially available tetrabutylammonium salt (TBAI) to the body dissolved in CDCl3 (TBAI has a good solubility in CDCl3) and studied the interaction between the receptor and iodide ion by 1H NMR titration, UV–vis absorption spectroscopy and fluorescence

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• larger aromatic walls in the form of triphenylene walls. To ensure that the targeted hosts display low aqueous solubility required for solid state sequestrants, we exchanged the O(CH2)3SO3Na groups for OMe groups. Accordingly, we targeted the preparation of W1 and W2 (Scheme 1) which contain large π

• ) for 1 hour using a ThermoMixer™ (T = 25 °C, 800–1000 rpm). For the experiments with acridine orange (100 μM, 2.4 mL) and methylene violet (38 μM, 6.4 mL) lower concentrations were used due to solubility issues. Following incubation, the samples were centrifuged (11,000 rpm, 10 min for methylene blue

• was between 240 and 1000 μM. This experiment was not conducted with methylene violet due to solubility issues and aggregation of methylene violet at higher concentrations. Time course of removal of methylene blue and methylene violet from water using H2 and G2W1. Another critical parameter in solid

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

• ligands could enhance catalytic activity and efficiency while enabling fine control over chemo-, regio-, stereo-, and enantioselectivity of reactions. Ligands enhance both the thermal/chemical stability and solubility profiles of catalysts in specific reaction media. Thus, ligands function as a regulatory

Pd-catalyzed dehydrogenative arylation of arylhydrazines to access non-symmetric azobenzenes, including tetra-ortho derivatives

• Loris Geminiani,
• Kathrin Junge,
• Matthias Beller and
• Jean-François Soulé

Beilstein J. Org. Chem. 2025, 21, 2234–2242, doi:10.3762/bjoc.21.170

• reported in Buchwald–Hartwig reactions, enhances yield by facilitating the reduction of Pd(II) to Pd(0) and improving the solubility of the base [56]. To ensure the generality of the conditions, 1-bromo-2-(trifluoromethoxy)benzene was also tested, yielding the desired azobenzene 3c in 69% yield with the

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• physicochemical and early ADME characterization study, in the framework of which logP, pKa and logk values were calculated. Following that, kinetic solubility and in vitro gastrointestinal membrane-specific permeability measurements were carried out to assess the lead-likeness of the compounds. Subsequently, the

• results of physicochemical and early ADME characterization for hydrazones 7 and 9, and target compounds 3 and 10 are summarized in Table 2 and Table 3, respectively (individual column charts on kinetic solubility, permeability, and membrane retention measurements can be found in Supporting Information

• surface area (TPSA) values fell in a desirable range (40–90 Å2) (see the extended table on physicochemical parameters in Supporting Information File 1, Table S1). Based on their pKa values, all compounds are non-ionizable or slightly basic. Kinetic solubility was considered good above 30 µM, moderate

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• isolated and structurally characterised (using, where appropriate, HMBC, COSY and nOe NMR methods; see Figure 3). In general, the yields of these products were rather low, which may stem from poor (co-)substrate solubility in some cases; and/or competitive O–H insertion into adventitious water. On the

• tag (C17 and C18) were used. The reactions were assembled from stock solutions, with some variation in stock concentrations to improve solubility. After 24 h, the reaction products were analysed by LC–MS, and promising reactions selected for mass-directed purification. Seven additional intermolecular

• products were obtained (see Figure 3 and Table 2). The marked improvement in product yields, compared to those observed with D1–3, may reflect the change to the workflow, i.e., variation in stock concentration to improve solubility. The diversity of the obtained products was increased by the multiple

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• . Interestingly, for the cyclization of 3b, only compound MC3 was obtained in 85% yield, which is probably attributed to larger steric hindrance deriving from bis(trifluoromethyl)phenyl groups. These macrocycles show good solubility in common solvents, and their chemical structures have been unambiguously

• existence of inherent chirality for both MC1 and MC3, chiral resolutions using chiral high-performance liquid chromatography (HPLC) were performed. Due to insufficient solubility, MC3 failed in chiral separation via preparative chiral columns. Fortunately, two enantiomers of MC1 were successfully isolated

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

• variable and rely solely on MOF modification to create a lipophilic environment in the pores. However, because solvents improve the solubility of the reactants and products, making it easier for the reagents to reach the active sites, we were concerned that performing the reaction under neat conditions

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

• solubility, this can be improved through derivatization. Water-soluble calixarene derivatives can be obtained through functional modifications, including the introduction of sulfonic acid, amine, and carboxylic acid groups [57][58][59]. These water soluble macrocycle derivatives can be used to increase the

• solubility of drugs. The modified CAs encapsulate drug molecules within the host through host–guest interactions. The interactions between the drug and the calixarene enhance the solubility of the drug [60]. Further functionalization of these CAs' upper and lower rims with diverse moieties (e.g., amides

• dual modifications [69]. These derivatives have emerged as a research hotspot due to their unique combination of water solubility, biocompatibility, and host–guest encapsulation capability [47][52][70]. The aggregation behavior of amphiphilic CAs is closely related to the size of the macrocycle, the

Thermodynamics and polarity-driven properties of fluorinated cyclopropanes

• Matheus P. Freitas

Beilstein J. Org. Chem. 2025, 21, 1742–1747, doi:10.3762/bjoc.21.137

• delocalization interactions. Among the compounds shown in Figure 1, 1.2.3-c.c. is the most polar, with a calculated dipole moment of 4.17 D. Polarity is a key molecular property, as it influences solubility, lipophilicity, and various material characteristics. For example, liquid crystals used in LCD devices

• intramolecular forces in fluorinated systems but also provide a molecular framework for the design of advanced applications. Fluorinated cyclopropanes exhibit considerable potential in pharmaceuticals, where polarity influences drug solubility and activity, and in material sciences, particularly for the

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

• multifunctionality stemming not only from its strong proton-donating capacity but also its unique capability to stabilize reactive intermediates through preferential solvation effects. The optimal solvent choice must balance multiple factors: substrate solubility, nitrating reagent compatibility, temperature control

Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides

• Tsun-Yi Chiang,
• Mei-Huei Lin,
• Chun-Wei Chang,
• Jinq-Chyi Lee and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2025, 21, 1671–1677, doi:10.3762/bjoc.21.131

• -naphthylmethyl ether (Nap) protecting group was removed from disaccharide 10 using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in a DCM/H2O (9:1) mixture, giving a 94% yield of disaccharide acceptor 11. To enhance solubility, the trimethylsilyl (TMS) group was selectively added at the less hindered 2-O

Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

• Natalia Lebedeva,
• Fedor Kliuev,
• Olesya Zvereva,
• Klim Biriukov,
• Evgeniya Podyacheva,
• Maria Godovikova,
• Oleg I. Afanasyev and
• Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

• synthesis of imines and enamines [36][37]. In our reducing system H3PO2 could act as an effective reductant due to its high solubility in neat conditions (Table 1, line 1) (in form of morpholinium hypophosphite). Nonetheless reductive potential of hypophosphite is pH-dependent (−1.65 V at pH 14 vs −0.5 V at

• media. Finally, the combination of H3PO2 and KH2PO2 1:1 with the ratio of H2PO2− to amine 1:2 is optimal balance between solubility of reductant, acidity of the medium and stability of the reducing system providing the highest efficiency of the interaction. Under optimized reaction conditions, the

• system is more efficient than the earlier described usage of the pure NaH2PO2: higher solubility of the potassium, rubidium and cesium salts compared to the sodium and lithium and a proper pH of the reaction medium. Acidic catalysis strongly accelerates the rate of hemiaminal and iminium ion formation

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• and evaporation of the solvent to afford a crude product, which was recrystallized from THF to give 5 in 58% yield. Due to its poor solubility in common organic solvents, the 1H NMR spectrum could only be recorded in DMSO. At room temperature, the 1H NMR spectrum in DMSO-d6 exhibited broad signals in

• primarily localized on the aza[5]helicene moieties, while the orbital coefficients are distributed to the bridging thiophene and o-phenylene units in LUMO, indicating a charge-transfer (CT)-like transition. However, further optical characterization of compound 5 was limited due to its poor solubility in

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

• generated nitrile oxide seems to be less significant. It was found that the low solubility of products containing aromatic substituents in non-polar solvents allows for their isolation by washing the crude reaction mixture with diethyl ether to remove organic impurities and then with water to eliminate

• triethylamine hydrochloride. This method has proven to be simple and effective in most cases, with the exception of compound 5g. The moderate solubility of this compound in diethyl ether led to partial precipitation from the reaction mixture. It is worth noting that chromatographic purification is also possible

• for compounds 5a–l. However, in most cases, this method is more laborious due to the similarity in the retention factor values of the initial imines 2 and the reaction products. In this way, products 5i and 5j with good solubility in diethyl ester were isolated. A comparative analysis of compounds 5a

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• been characterized as an ideal solvent for click reactions, the limited solubility of most organic substrates could limit its application. Thus, the transformations of either water-insoluble or solid compounds require a solvent to establish high reaction performance, i.e. homogeneous solutions with low

• ) were tested in the conversion of 1.15 mmol benzyl azide (1a) and 1 mmol phenylacetylene (2a) in 2.5 mL CyreneTM at 30 °C. All the selected Cu salts catalyzed the cycloaddition; however, Cu chlorides and oxides resulted in unexpectedly low product yields after 0.5 h. The solubility of Cu oxides was

• formation; thus, keeping water content below 1% is necessary to maintain high reaction efficiency. The negative effect could be due to the decreased solubility of 2a at higher water content [42][43][44]. Hereafter, the readily available CuI was selected as a catalyst precursor to facilitate click reactions

Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• with electron-withdrawing groups (EWG)-substituted iodonium salts produced benzamides 2bc–be, 2bg–bj in 18–67% yields. The benzamide 2bj was isolated in only 18% yield probably due to the low solubility of bis(3,5-ditrifluoromethyl)iodonium triflate (1j) in MeCN/H2O mixture. The highest yields were

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

• , reflux conditions did not improve reaction conversion, as shown in entries 3 and 4 (Table 1) and we consistently observed a decrease in reaction yield. This effect is likely due to the lower solubility of O2 in the refluxing solvent, which may negatively impact the reaction outcome. As previously

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• structures, enhance solubility, and expand functional diversity [6]. Substituting carbon atoms with electron-deficient nitrogen atoms introduces new opportunities to fine-tune redox potentials, charge-transport behavior, and intermolecular interactions [7]. These modifications have proven especially valuable

• characterized a series of length-variable aza[n]helicenes 31a–f via a one-pot intramolecular cyclodehydrogenation [45] (Table 9). Notably, compounds 31e and 31f represent the first examples of triple-layered heterohelicenes with fully conjugated frameworks. All members of the series demonstrate high solubility

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• , pyridinyl, furyl, isopropyl, and cyclohexyl substituents were introduced into position 3; cyano and various carbonyl groups were added to position 4 and cyclic amine residues were added to position 5 which increase the solubility of the synthesized compounds 3 (Scheme 2). An analysis of the yields of

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• structurally diversified target molecules 65–68 under optimized reaction conditions. In these cases, the high polarity of the radical intermediates of CF3CH2OH and 4-methylbenzonitrile, combined with the poor solubility of adamantane, may explain the possible reasons behind the reaction process [91]. Amidyl