Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• %. Synthesis of S/R-3 Under an argon atmosphere. S-2 (197 mg, 0.389 mmol) in tetrahydrofuran (1.7 mL) was treated with a dropwise addition of 1 M TBAF solution (16.7 mL, 16.7mmol), and the resulting solution was stirred at room temperature for 2 hours. After the addition of water, the mixture was extracted

• . Under an argon atmosphere, a mixture of R-3 (16 mg, 0.043 mmol), 4 (39 mg, 0.084 mmol), and CuI (2.4 mg, 0.013 mmol ) were dissolved in degassed dichloromethane (10 mL) and diisopropylamine (10 mL). The reaction mixture was refluxed for 28 hours. After cooling to room temperature, water was added, and

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

• are in the range of 254–339 °C. The mass loss between 0 and 150 °C indicates the presence of water or an organic solvent in the structure of compound 2b. The Td values of the dyes are generally resistant to moderate to high temperatures. This result supports their potential use as optical dyes

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• be noted that in the presence of water, the reaction would undergo transamination with the pyridinium nitrogen moiety while inducing chirality on the ring. Hydrogenation of carbocyclic aromatic rings: In 2021, Andersson and co-workers reported a rhodium-catalyst precursor capable of operating in both

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• Hiroshige Ogawa Hugh Nakamura The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, New Territories, Hong Kong SAR, China 10.3762/bjoc.22.3 Abstract Radical reactions, which have been reported in large numbers in recent years, have exerted major influence across fields

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

• can subsequently undergo hydrolysis in the presence of trace water to furnish the corresponding ketone (see Scheme 27, formation of ketone 167) [92]. Furthermore, Melloni were the first to demonstrate that highly hindered internal alkynes resist double HCl addition (Scheme 25) [93]. In cases where a

• hydrochlorination–alkyne addition sequence with respect to Johnson, Fañanás, and Rodríguez works (Scheme 49) [167]. Acetyl chloride reacts with water to give HCl which then readily protonates trisubstituted alkene 250 [168][169]. Subsequent trapping of the tertiary aliphatic cation 251 by the adjacent alkyne

• electronic attributes. Further improvement of the reaction was achieved by fine-tuning the Mo-metathesis catalyst (Scheme 60A–C). Schrock and Hoveyda also demonstrated that adding small amounts of HB(pin) helps remove residual water, significantly enhancing the reaction efficiency [193]. This technique can

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• a mixture of acetic anhydride (3.4 mL, 36.0 mmol) and 100% nitric acid (0.6 mL, 13.2 mmol) at 0 °C, and the mixture was stirred at this temperature for 30 min. Then the reaction mixture was poured into ice-water (50 mL) and extracted with CH2Cl2 (3 × 20 mL). The combined organic phase was washed

• with water (30 mL), brine (30 mL), dried over Na2SO4 and solvent removed in vacuo. Product 4f (0.71 g, 2.37 mmol, 79%) was isolated by column chromatography on silica gel (Rf = 0.55, petroleum ether/ethyl acetate, 5:1). Reaction in divided electrochemical cell (experimental details for Scheme 4

• anodic and cathodic compartments were separately evaporated under water-jet vacuum. The yield of 2a was determined according to 1H NMR spectroscopy using 1,1,2,2-tetrachloroethane as an internal standard. Reaction under constant potential electrolysis (experimental details for Scheme 4, reaction 2): In a

Total synthesis of asperdinones B, C, D, E and terezine D

• Ravi Devarajappa and
• Stephen Hanessian

Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210

• equivalents of H2SO4 in water to obtain a mixture of six C-prenylated tryptophans from which the 7-prenyl isomer could be isolated in 4% yield after chromatography on a 10 g scale [27]. This direct prenylation method was then adapted for the synthesis of terezine D (6), which was isolated as a pale-yellow

Tandem hydrothiocyanation/cyclization of CF₃-iminopropargyl alcohols with NaSCN in the presence of AcOH

• Ruslan S. Shulgin,
• Ol’ga G. Volostnykh,
• Anton V. Stepanov,
• Igor’ A. Ushakov,
• Alexander V. Vashchenko and
• Olesya A. Shemyakina

Beilstein J. Org. Chem. 2025, 21, 2694–2702, doi:10.3762/bjoc.21.207

• ionic liquid- [16] or lactic acid-catalyzed [17] reactions of alkynoates, KSCN and water under ultrasound conditions as well as by the reactions of alkynoates, KSCN and water using deep eutectic solvents [18]. Reddy and co-workers [19] proposed an approach to thiocyano enones through the

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• room temperature (ca 3 h). The crystalline product separated was filtered, washed with diluted hydrochloric acid (5%, 2 × 50 mL) and water (2 × 50 mL), then air-dried to give crude 7 (17.6 g of off-white solid). The two-phase filtrate was separated, the strongly acidic aqueous phase was washed with DCM

• (15 mL) crude 19 (2.32 g, 6 mmol) was added, the solution obtained was stirred at room temperature for 40 min. It was evaporated in vacuo, the residue was dissolved in DCM (20 mL), washed with water (2 × 15 mL), dried over Na2SO4, and evaporated in vacuo. The oily residue was purified by dry-column

• ) dissolved in water (7.5 mL) was added and the solution was stirred at room temperature for 19 h. Water (15 mL) was added to the yellow solution and the ethanol was removed by evaporation in vacuo. Water (10 mL) was added and the solution was neutralized with aqueous HCl solution (0.50 mL of conc. HCl

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

• ) [63]. Glacial acetic acid (AcOH) was initially selected as a hydrophilic (polar) protic solvent due to its high dipole moment, which makes it ideal for microwave reactions, as well as its ability to facilitate simple work-up procedures by simple addition of water [64]. Using sodium acetate (NaOAc) as

• . 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

• aldehyde 1, activated by protonation of the oxygen atom through structure ii, forming the intermediate aldol iii. In the presence of EDDA, water elimination occurs in intermediate iv, yielding the Knoevenagel adducts 3 or 4. Synthesis of novel imidazo[1,2-a]pyridine–thiazolidinone hybrids To further

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

• –220 nm and a maximum below 200 nm. CD spectroscopy revealed that cyclic topology shifts characteristic peaks and stabilizes secondary structures through cooperative ring size/sequence/solvent effects [30]. TFE disrupts the hydrogen-bonding network of water, reduces solvent polarity, and enhances the

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• their concentrations, particularly in water. To maintain anion levels within acceptable ranges, their removal from the environment is often necessary [1][2]. Current technologies for removing anions from aqueous solutions include chemical coprecipitation [3], ion-exchange [4], or membrane filtration [5

• example, an amphiphilic poly(methyl methacrylate)-based polymer modified with calix[4]pyrrole was found to form micelles in water that capture anions from caesium salts and can be precipitated from solution upon heating [11]. Similarly, a hydrogel composed of poly(vinyl alcohol) cross-linked by a “Texas

• -sized” molecular box has been used to extract various anions from water [12]. Another family of macrocyclic compounds suitable for anion recognition and binding are bambusurils (BUs). BUs act as very potent anion receptors in both organic solvents and water. Furthermore, their portals can be variously

Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies

• Zhi-Qi Cao,
• Jin-Bao Qiao and
• Yu-Ming Zhao

Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198

• follows: Commercially available compounds 31 and 32 were converted to the C2-symmetric 33 over 13 steps, enabling construction of the AB bicyclic skeleton in the target molecules. Compound 33 then underwent Mukaiyama hydration to adjust the C15 oxidation state, followed by water-promoted consecutive

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

• -NH2). Size and zeta potential measurements: DLS and ELS measurements were performed on a sample of compound 3 (1 mg) dissolved in 1 mL pure water. The colloidal solution was centrifuged at 10,000 rpm for 10 min and the supernatant was collected and analyzed by a Zetasizer NanoZS90 analyzer (Malvern

• 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

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

• -methyltriazolium (MTA) group. The amphiphilic spacer carries an ortho-dimethoxybenzene group on each side as stoppers to prevent the macrocycle from slipping off. These stoppers are connected to terminal polyethylene glycol (PEG) chains designed to interact with the membrane–water interface (Figure 1). Effect of

• transition to a more ordered membrane. EYPC/Chol bilayers form liquid-ordered (Lo) phases, characterized by increased thickness, rigidity, and reduced water permeability [16]. In EYPC/Chol 8:2 LUVs, rotaxane 1-E induced 29% release, more than rotaxane 1-Z, which caused only 16% release (Table 1, Figure 4a

• previous molecular dynamics simulations of rotaxane 1 in POPC bilayers, a major component of EYPC [16], showed that rotaxane 1 disrupts lipid packing and promotes water accumulation within the bilayer [15]. These effects enhance membrane permeability to hydrophilic molecules such as sulforhodamine B. The

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

• the nucleophilic substitution of the nitro group in 2-nitrobenzonitriles using Na2S in a DMF/water medium, followed by alkylation of the resulting 2-cyanophenylthiolates and subsequent cyclization [31]. However, in our case, the reaction of ester 1 with Na2S in either acetone or a DMF/water mixture

• reactions, probably involving ester hydrolysis or alkylating agent decomposition, can be avoided by omitting the external base. In addition, Na2S2O4 was investigated as a reductant in a DMF/water 9:1 (v/v) mixture at room temperature (Table 2, entry 6). In the presence of both K2CO3 and the alkylating agent

The intramolecular stabilizing effects of O-benzoyl substituents as a driving force of the acid-promoted pyranoside-into-furanoside rearrangement

• Alexey G. Gerbst,
• Sofya P. Nikogosova,
• Darya A. Rastrepaeva,
• Dmitry A. Argunov,
• Vadim B. Krylov and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2025, 21, 2456–2464, doi:10.3762/bjoc.21.187

• ] and vaccines [15][16][17][18]. That is why new efficient and stereoselective methods for the synthesis of both Galf-containing mono- and oligosaccharide derivatives are highly demanded. It is a well-known fact that galactofuranose form constitutes only 5% in water solution of unprotected ᴅ-galactose

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• 30% and a selectivity of 70% at −100 °C (Scheme 21). 2.3 Wolff rearrangement The Wolff rearrangement is the transformation of α-diazoketones into acids or their derivatives through heating, catalysis, or UV irradiation in the presence of water, alcohols, ammonia, amines, etc. The Wolff rearrangement

• ketone 154 with UV-C (200–280 nm) light yielded approximately equal amounts of products 155 and 156 (1.25:1 after 85% conversion). In the presence of water (CH3CN/H2O 10:1), a crystalline cyclooctene compound 157 was obtained by irradiation of 154. However, compound 156 was not detected. When irradiating

• 154 with UV-A (315–400 nm) in the presence of water (CH3CN/H2O 10:1), cycloheptene compound 158 was obtained, but compound 155 could not be detected. These results are consistent with the selective conversion of ketone 155 to acid 158 by UV-A irradiation and the selective transformation of ketone 156

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

• , toxicity, pesticide similarity, and biodegradability of methyl laurate in comparison with a series of conventional organic solvents, water, some fatty acids and their derivatives. The findings of this investigation revealed that methyl laurate exhibited better green solvent properties when evaluated

• troublesome [21][22]. It is evident that this class of solvents may be accompanied by a number of drawbacks. For instance, they are frequently expensive, exhibit negligible or non-existent biodegradability, and there is a lack of data concerning their potential toxicity. Conversely, while water is regarded as

• involved a comparative analysis of these vegetable oils and derivatives with water and a range of commonly employed organic solvents in organic transformations. Results and Discussion The requisite starting compounds, nitrones 1a–f and a selection of N-substituted maleimide derivatives 2b–d were

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• base results in the deprotonation of the ammonium site and shuttling of the macrocycle to the urea site. Whereas, upon addition of acid, the macrocycle returns to the protonated BAA site. Notably, the rotaxane exhibited high fluorescence intensity due to aggregation in acetonitrile with high water

• cannot undergo the photocyclization reaction when the macrocycle is in the BAA site due to conformational restraint. This system was used to form water-soluble nanoparticles to investigate their biological applications. The obtained nanoparticles exhibited bright red photoluminescence and the ability to

• revealed that while azobenzene photoisomerization can directly induce some degree of lipid packing reorganization, the dominant effect arises from changes in the position of the rotaxane within the membrane. Specifically, in the trans isomer, the macrocycle resides closer to the membrane–water interface

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

• Suvenika Perera Peter Y. Zavalij Lyle Isaacs Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States 10.3762/bjoc.21.176 Abstract Contamination of water bodies by micropollutants including industrial dyes is a worldwide health and

• environmental concern. We report the design, synthesis, and characterization of a series of methylene-bridged glycoluril dimers G2W1–G2W4 that are insoluble in water and that differ in the nature of their aromatic sidewalls (G2W4: benzene, G2W3: naphthalene, G2W1 and G2W2: triphenylene). We tested G2W1–G2W4

• receptor (nAChR) by a pharmacokinetic approach [1][2]. Contamination of water bodies by the improper disposal of consumer and industrial chemicals constitutes a significant threat to the health of both humans and animals [3]. Dyes are a significant class of water pollutants which are commonly used by the

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

• radical initiated intramolecular cascade cyclization of 1,n-enynes to provide structurally diverse heterocycles (Scheme 4) [11]. Solvent selection dictated divergent reaction pathways under I2/TBHP oxidation. When an acetonitrile/water mixed solvent was used, iodine radical addition to the alkyne

• and co-workers achieved an innovative gold-catalyzed cascade cycloisomerization of 3-allyloxy-1,6-diynes to access cyclopropane- and cyclobutane-fused benzofurans/chromanols (Scheme 5) [12]. In this study, solvent polarity and trace water were identified as key parameters governing the reaction

• pathway. In THF with trace water, water served as a nucleophile that participated in the reaction, triggering hydroxylation of cyclopropanation intermediate 19 and affording cyclopropane-fused chromanol products 20 (Scheme 5, path a). In anhydrous 1,2-dichloroethane (DCE), gold(I)-catalyzed

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

• the presence of water, highlighting its robustness. Keywords: azo compounds; cross-coupling; domino catalysis; palladium; phosphine ligands; Introduction Azobenzenes are a widely studied class of compounds known for their distinctive photoresponsive properties, rendering them valuable in a variety

• batch of Cs2CO3 showed a dramatic reduction in product yield (Table 1, entry 12). Control experiments with varying amounts of water (0–10 equiv) demonstrated that a small amount of water is crucial for the reaction (Supporting Information File 1, Table S7 and Table 1, entry 11). This effect, previously

• addition of 2 equivalents of water (Table 1, entries 12 and 13). Finally, the oxidant t-Bu-OO-t-Bu could be replaced by O2, yielding compound 3a with GC yields of up to 79% (Table 1, entry 14, 75% isolated yield). In reactions giving <70% isolated yield, no single side-product dominates; the missing mass

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

• 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

• ). Analytical methods. All samples of the kinetic solubility and in vitro permeability assays were analyzed on a Waters Alliance 2695 Separations Module equipped with a 2996 PDA detector, using a Water Xterra RP 18 chromatographic column (100 × 4.6 mm, 3.5 µm) at 45 °C, applying 1.2 mL/min flow rate. For a 7

• -minute long gradient program, eluents A (0.1% formic acid in water) and B (0.1% formic acid in acetonitrile) were used as follows: initial conditions with 30% B were kept for 1 minute, then 90% B was achieved within 3 minutes, kept for further 1 minute, finally the initial condition was adjusted and

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

• cationic resonance G quickly. The nucleophilic attack of D2O formed H, which underwent dedeuteration and elimination of DI to form 30a with reduction of deuterated water to generate deuteroxyl ions (OD−) and deuterium gas (D2) at the cathode. This method, using iodide salts as electrolyte and redox

• reaction of nitrile, xanthene, terminal alkyne and water to synthesize oxazole was established by Li in 2023 (Scheme 12) [219]. After examining the reaction carefully, the optimized reaction conditions were obtained as follows: a mixture of alkyne 31 (0.3 mmol), xanthene 32 (0.45 mmol), CH3CN (5.0 mL), H2O

• (Scheme 13) [255]. Under electrolysis (graphite as electrodes, tetra-n-butylammonium salt (TBAPF6) as electrolyte, N,N,N,N-tetramethylethylenediamine (TMEDA) as mediator, 4.28 V), the four-component reaction of alkynes 35, NaSO2CF3, nitriles and residual water proceeded efficiently to form titled