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

• scans) and 151 MHz for 13C NMR (20,480 scans), using an overnight experiment in DMSO-d6 at a concentration of 0.1 M. Specifically, the spectra showed either an absence of expected signals or a lack of signal multiplicity, which was apparent in both the 1H NMR and, more prominently, in the 13C NMR

• spectra (Scheme 7b). A remarkable feature of the 13C NMR spectra of compounds 3n and 4n in DMSO is the attenuation/absence of peaks corresponding to the carbon atoms at the ortho and meta positions of the six-membered ring. It is known that quaternary carbon atoms have very long relaxation times, but this

• behavior is not expected from hydrogen-bonded carbon atoms in aromatic rings. Since peak intensities depend on spin-lattice relaxation times, the absence of peaks implies some degree of molecular rigidity, which could be related to two factors: the viscosity of DMSO and the conjugation between the six

Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

• Liangyu Liu,
• Wanqiu Lu,
• Quanping Guo and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

• electrospray ionization mass spectrometry (HRESIMS) data for all compounds matched the calculated exact masses for their respective molecular formulas. NMR spectroscopic analysis in appropriate deuterated solvents (e.g., DMSO-d6, D2O) fully corroborated the amino acid sequence and cyclic connectivity

Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds

• Vasudevan Dhayalan

Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200

• presence of NHC (10 mol %) and 4CzIPN (2 mol %) and Na2HPO4 in DMSO at rt for 10–24 h. The key to success lies in the photocatalytic dual system, which combines two organocatalysts (NHC/4CzIPN) and visible light irradiation to permit a novel umpolung single-electron reduction of respective imino ester 2

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

• groups by sodium borohydride and then converted to chloromethyl groups by treatment with thionyl chloride, to give compound 2. The reaction of compound 2 with thiourea in THF gave compound 3 as a white solid in 96% yield. Compound 3 was characterized by 1H and 13C NMR in DMSO-d6 as a solvent (Figure 1

• (DMSO-d6). 1H NMR (400.13 MHz, DMSO-d6, 297 K) δ 0.83 (t, J = 6.6 Hz, 12H, 4 × dodecyl CH3), 1.22 (br s, 72H, 36 × dodecyl CH2), 1.34 (br s, 8H, 4 × dodecyl CH2), 1.82 (t, 8H, 4 × dodecyl CH2), 3.13 (d, J = 14.3 Hz, 4H, 2 × ArCH2Ar), 3.78 (t, 8H, 4 × dodecyl OCH2), 4.23 (s, 8H, 4 × ArCH2S), 4.26 (d, J

• = 14.3 Hz, 4H, 2 × 4 ArCH2Ar), 6.66 (s, 8H, 8 × ArH); 13C NMR (100.6 MHz, DMSO-d6, 297 K) δ 13.9 (q, dodecyl CH3), 22.2, 26.2, 29.0, 29.5, 29.8, 30.1 (t, dodecyl CH2), 31.5 (t, ArCH2Ar), 34.7 (t, CH2S), 75.0 (t, OCH2), 127.8 (d, ArH), 128.8 (s, ArC-CH2S), 135.0 (s, ArC-CH2S), 156.0 (s, ArCO), 169.4 (s, C

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

• modification of the base-catalyzed conditions reported by Kwok [53], where a stoichiometric plus additional catalytic amount of tetraethylammonium hydroxide base in DMSO solvent was used to promote tandem trimethylsilyl deprotection and cycloaddition in one preparation (Figure 3). Isolated yields of this

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

• same amount of DMSO but no axle over five irradiation cycles alternating 370 nm and 467 nm light. As seen in Figure 7a, the release occurs only in vesicles containing axle 3, ruling out nonspecific effects such as membrane degradation from direct light exposure or solvent heating (HEPES buffer and

• small amounts of DMSO). We also monitored the absorption spectra of LUVs suspended in HEPES buffer in the presence of DMSO and observed no changes (Supporting Information File 1, Figure S23), confirming that the liposomes did not undergo chemical degradation in the absence of axle 3. In contrast, LUVs

• reversible photoswitching of the azobenzene. When irradiating axle 3 in solution using DMSO as solvent, we observed similar irreversible changes in its absorption, indicating a degradation of the axle upon light exposure (Supporting Information File 1, Figure S23d). We then investigated which wavelength was

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

• K2CO3 in DMSO to give the desired product [26]. Route III, previously elaborated in our group, utilizes the nucleophilic substitution of the Cl atom in 3-chlorothiophene-2-carboxylates by methyl thioglycolate in the presence of KOt-Bu, followed by KOt-Bu-mediated cyclization to the 3-hydroxy-TTs [27

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

• (h), and DMSO (p) according to the guidelines outlined in the CHEM21 solvent selection guide [92]. A series of risk assessments was conducted, including ecological and environmental risk assessments, as well as pesticide similarity and biodegradability assessments of methyl laurate in comparison with

• were measured using Bruker ultrashield plus biospin 400 MHz NMR spectrometer and chloroform-d (CDCl3) or hexadeuterodimethyl sulfoxide (DMSO-d6) as a solvent. Chemical shifts (δ) are reported in ppm and J values in hertz. The elemental analyses were performed using a Leco CHNS-932 elemental analyzer

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

• -1,4-dione was reduced with Na2S2O4 to triphenylene-1,4-diol (3) which was immediately treated with MeI under basic conditions (NaOH, DMSO) to give the known 1,4-dimethoxytriphenylene (W2) in 31% yield [47]. We also selected commercially available W3 and W4 to prepare comparators G2W3 and G2W4 to

• insoluble in water as required for their use as solid state sequestrants. Unlike most acyclic CB[n]-type receptors, G2W1–G2W4 are soluble in organic solvents (G2W1 and G2W2: soluble in CHCl3, CH2Cl2, DMSO, and TFA but insoluble in methanol, acetone, acetonitrile, and hexane; G2W3: soluble in DMSO and TFA

• but insoluble in CHCl3, CH2Cl2, methanol, acetone, acetonitrile, and hexane; G2W4: soluble in CHCl3, CH2Cl2, acetonitrile, DMSO, and TFA but insoluble in methanol, acetone, and hexane). The new hosts G2W1–G2W4 were fully characterized spectroscopically (1H and 13C NMR, IR, MS) and the data is in

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• ready availability of enamine 9a; however, direct double halogenation of 6 may also be possible using an excess of halogenation agent in DMSO [31]. The Baeyer–Villiger oxidation using H2O2 in MeCN gave the desired chiral lactones 11a and 11b in moderate to good yield following an acidic workup to cleave

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

• dihydrochromenone skeleton 24 (Scheme 6, path a). When DMSO was employed instead, the strongly coordinating solvent diverted the reaction towards 5-exo-dig cyclization, furnishing a Z-configured tetrasubstituted alkene product 26 (Scheme 6, path b). The isocoumarin-fused dihydrochromenones prepared by this strategy

Research towards selective inhibition of the CLK3 kinase

• Vinay Kumar Singh,
• Frédéric Justaud,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Blandine Baratte,
• Thomas Robert,
• Stéphane Bach,
• Chada Raji Reddy,
• Nicolas Levoin and
• René L. Grée

Beilstein J. Org. Chem. 2025, 21, 2250–2259, doi:10.3762/bjoc.21.172

• kinase activities are expressed in % of maximal activity, i.e., measured in the absence of inhibitor but with an equivalent dose of DMSO (solvent of the tested compounds). ATP concentration used in the kinase assays was 10 µM (values are means, n = 2). Kinases are from human origin (Homo sapiens) except

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

• using widely accepted strategies [46][47]. DMSO-d6 or CDCl3 were used as the solvents and tetramethylsilane (TMS) as the internal standard. Chemical shifts (δ) and coupling constants (J) are given in ppm and in Hz, respectively. High-resolution mass spectra were recorded on an Agilent 2750 GC/Q-TOF mass

• KGaA, Darmstadt, Germany), adjusting the pH with HCl. Water for buffer and eluent preparation were provided by a Millipore Milli-Q water purification system. Kinetic aqueous solubility assay. All compounds were dissolved in DMSO to make stock solutions at 10 mM concentration. In the case of 7i, 7j, and

• (E)-9b, the highest concentration achieved in DMSO was 0.5 mM, while for (E)-9a it was 1 mM (DMSO solubility results of the compounds can be found in Supporting Information File 1). 5 μL of the stock solutions was pipetted into a 96-well plate containing 495 μL PBS (pH 6.5) in each well to achieve

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• that this report provided a switchable and green synthetic methodology for skeletally diverse indoles. Divergent electrochemical cyclization of 2-ethynylanilines was developed to synthesize indoles and iodoindoles (Scheme 4) [188]. Treatment of 2-ethynylanilines 10 with KI in DMSO/H2O in an undivided

• generation of 12a in Cu rod electrodes, the Cu anode was expected to liberate Cu+ into the reaction mixture. The reaction of this Cu+ with DMSO and I− afforded (DMSO)nCuI, which was coordinated with C≡C to give B. The intermediate C was obtained by cyclization of B and deprotonation. Further protonation of C

• afforded 12a and regenerated (DMSO)nCuI. Notably, this reaction, using KI as the only additive and performing under ambient conditions in a non-volatile aqueous solvent, was a simple, selective, efficient and sustainable electrosynthesis of indole derivatives. 3-Selenylindoles were also formed by

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

Further elaboration of the stereodivergent approach to chaetominine-type alkaloids: synthesis of the reported structures of aspera chaetominines A and B and revised structure of aspera chaetominine B

• Jin-Fang Lü,
• Jiang-Feng Wu,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162

• 1H and 13C NMR are methanol-d4 that is different from Tan’s work [21] who used DMSO-d6 to record 1H and 13C NMR spectra of (–)-chaetominine (1). Thus we undertook the synthesis of the proposed structures of aspera chaetominines A (12) and B (13). By adopting our first-generation strategy [57][58][61

• incorrect. It is worth noting that compound 12 has been obtained in our previous investigation [65]. However, the 1H and 13C NMR spectra were recorded in DMSO-d6 which prevent a direct comparison with the data of aspera chaetominine A. We next addressed the synthesis of aspera chaetominine B (13). Employing

• (–)-isochaetominine C (6), whose absolute configuration is tentatively assigned as 2R,3R,11S,14R. It is worth noting that compound 13 has been obtained in our previous investigation [63]. However, the 1H and 13C NMR spectra were recorded in DMSO-d6 which prevent a direct comparison with the data of aspera

Switchable pathways of multicomponent heterocyclizations of 5-amino-1,2,4-triazoles with salicylaldehydes and pyruvic acid

• Yana I. Sakhno,
• Oleksander V. Buravov,
• Kostyantyn Yu. Yurkov,
• Anastasia Yu. Andryushchenko,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2030–2035, doi:10.3762/bjoc.21.158

• substituents. The peaks of the proton of the carboxyl group is not recognized, probably due to exchange processes. The signals of the CH2 group in the range around δ = 2.5 ppm are not always clearly identifiable, as they partially or completely overlap with the remaining DMSO signal. Compounds 4g–j are

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• a final concentration of 0.5 mg/mL. Plates were incubated for 3 hours at 37 °C in a CO2 incubator to allow for formazan crystal formation. Subsequently, 150 μL of dimethyl sulfoxide (DMSO) was added to each well to solubilize the formazan. Plates were shaken for 15 minutes, and absorbance was

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

• of the MOF product digested in D2SO4/DMSO-d6 (Figure 2B). Conversions were estimated by selecting the “same” proton in the starting material and in the products and integrating the corresponding peaks and setting the total to 100% (see Supporting Information File 1). We observed that the reactions

• -synthesis modification (PSM). A) Schematic representation of the reaction of KSU-1 with aliphatic isocyanates and the estimated conversions at –OH and –NH2. B) The corresponding 1H NMR spectra of the MOF reaction products digested in a solution of D2SO4 in DMSO-d6. A) Schematic representation of the

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

• , however, it leads to a poor Z–E PSS and poor resistance to fatigue. This is most likely due to internal relaxation processes prevailing over photoswitching. One interesting finding was the strong dependency of the thermal half-life on concentration in DMSO. The authors hypothesised the aggregation of 109

Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp²)–C(sp²) bond scission of styrenes

• Prafull A. Jagtap,
• Manish M. Petkar,
• Vaishnavi R. Sawant and
• Bhalchandra M. Bhanage

Beilstein J. Org. Chem. 2025, 21, 1799–1807, doi:10.3762/bjoc.21.142

• employed an I2/DMSO-facilitated C–C bond-scission strategy of styrenes, followed by C–N bond formation and subsequent [4 + 2] annulation. Jiang and co-workers developed a method for synthesizing 4-substituted quinolines using vinyl azides as dual synthons, facilitating both the C–C and C–N bond cleavage

pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality

• Ryota Kimura,
• Satoshi Ichikawa and
• Akira Katsuyama

Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120

• bond rotation was investigated by variable temperature nuclear magnetic resonance (VT-NMR) spectra (Figure 3) in DMSO-d6 [27]. In the case of the molecular form of amidine 1 (Figure 3a), the signals corresponding to the two methyl groups resulting from the amidine E/Z isomerism were observed separately

• protonated form calculated by the DFT method. Comparison of VT-NMR spectra of a) amidine 1 and b) its trifluoroacetate salt 1-H+ in DMSO-d6 (400 MHz). Separation and isolation of amidine E/Z isomers by RP-HPLC. The mobile phase contained CF3CO2H to protonate the amidine moiety. Kinetic analysis of the

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

• -phenylene and aza[5]helicene segments, and between the o-phenylene and thiophene segments, were 37.52° and 44.28°, respectively. Four NH sites of the aza[5]helicene moiety formed hydrogen bonds with DMSO molecules in the crystal lattice, as observed in aza[n]helicenes recently reported [28], while the other

• emission spectra of 4 were measured in DMSO (Figure 5a). As observed for other o-phenylene-bridged cyclic heteroarenes in previous reports, compound 4 exhibited a broad featureless absorption band up to 450 nm, with emission peaked at 546 nm. The red-shifted emission is likely due to a significant

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

• compounds in two-fold serial (50–100 μM) dilutions. Only DMSO + PBS (phosphate-buffered saline) was used as a control, since the studied compounds were soluble only in DMSO. Cell viability was measured using the standard MTT test [42]. Absorbance was measured at 540 nm using a Multiskan™ FC microplate

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

• used for click reactions such as chlorinated hydrocarbons [15][16], toluene [16], tetrahydrofuran (THF) [17][18], N,N-dimethylformamide (DMF) [19][20], N-methylpyrrolidone (NMP) [21], dimethyl sulfoxide (DMSO) [17][19][22], or acetonitrile [23] are classified into Class 1 and 2, of which applications

• -dioxane) or low (DMF, NMP, DMSO) (Figure 1). While low conversion was still detected in biomass-originated 2-MeTHF, MeLev, and EtLev established better performance. When their corresponding 4-alkoxy derivatives were applied, moderate (Me-4MeOV) or slightly lower (Et-4EtOV) conversions could be observed

• is lower than that obtained in the conventional organic medium DMSO (E-factor = 104, [46]) and higher than the one calculated by Citarella (E-factor = 24, [39]) for the CyreneTM-based protocol. However, they used a 15 times higher substrate loading. Conclusion In conclusion, we have demonstrated that