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

• disubstitution processes involving sulfur-to-nitrogen displacement, likely promoted by the nucleophilic character of the amine. These limitations are likely due to the reaction conditions employed, including the high temperature and acidic environment, which may favor side reactions over the desired

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

• . Nucleophilic substitution of the nitro group with sulfur nucleophiles, including thioacetate or disulfide anions as well as thioacetamide, yielded bis(thiophen-3-yl)disulfide and sulfide derivatives. The disulfide served as a suitable precursor for the preparation of 3-alkylthio-substituted thiophene-2,5

• cyclization to furnish the TT framework [2][23][24]. Despite the wide structural diversity of TT derivatives, 3-hydroxy-substituted analogues remain rare, with only a few synthetic strategies described for their preparation, as illustrated in Scheme 1. One such route involves sulfur insertion into a thiophen

• isolation of compounds 2 and 3 in analytically pure form allowed their structure to be established thanks to elemental analysis and HRMS. It was found that compounds 2 and 3 are dimeric derivatives of the starting thiophene, linked by sulfur bridges located at the C-3 position instead of the nitro group

Catalytic enantioselective synthesis of selenium-containing atropisomers via C–Se bond formations

• Qi-Sen Gao,
• Zheng-Wei Wei and
• Zhi-Min Chen

Beilstein J. Org. Chem. 2025, 21, 2447–2455, doi:10.3762/bjoc.21.186

• ]. Selenium is a non-metallic element, but compared with sulfur of the same main group, selenium has a larger atomic radius, smaller electronegativity, and exhibits certain metallic properties. Due to the special physical and chemical properties of selenium between metal and nonmetal, selenium not only has

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

[3 + 2] Cycloaddition of thioformylium methylide with various arylidene-azolones in the synthesis of 7-thia-3-azaspiro[4.4]nonan-4-ones

• Daniil I. Rudik,
• Irina V. Tiushina,
• Anatoly I. Sokolov,
• Alexander Yu. Smirnov,
• Alexander R. Romanenko,
• Alexander A. Korlyukov,
• Andrey A. Mikhaylov and
• Mikhail S. Baranov

Beilstein J. Org. Chem. 2025, 21, 1791–1798, doi:10.3762/bjoc.21.141

• single either cis or trans stereoisomers, dependent on the heterocycle core used. Keywords: arylidene-azolones; cycloaddition; nitrogen heterocycles; sulfur heterocycles; thioformylium methylide; Introduction Spirocyclic derivatives of heterocycles occupy an important place in modern organic and

• (trimethylsilyl)methyl sulfide (compound I, Scheme 1) by the action of fluorides [21]. It reacts with a wide variety of compounds to form five-membered sulfur-containing heterocycles [22][23][24]. In particular, it can be used for the synthesis of 3,4-disubstituted tetrahydrothiophenes [25]. Partially substituted

• transformations. For example, compound 7e underwent both sulfone formation and S/O atoms exchange in the heterocyclic core. For derivatives 6 and 8, any oxidation conditions resulted in even more complex product mixtures (presumably due to the additional sulfur atom in the second ring), whose structures could not

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

• , imines, sulfur-containing groups, or alkyl chains) significantly expands their multifunctionality and broadens their application scope. Notably, CAs can be readily modified into amphiphilic macrocycles that can self-assemble with guests, and it exhibits superior advantages over crown ethers and

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

• usefulness of the single-atom substitution strategy on DiBA. By replacing the oxygen atom of DiBA with a nitrogen atom (and thus NH), which has been shown to be photo-responsive when replaced with sulfur or selenium, the pH-responsive property was acquired. Such minimal changes in physical properties can be

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Marcin Palusiak,
• Heinz Heimgartner,
• Marta Denel-Bobrowska and
• Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

• ]. Thiocarbonyl S-methanides (thiocarbonyl ylides) 1, which were first reported in the 1980s by R. Huisgen and co-workers contributed to a substantial extension of mechanistic interpretations of cycloaddition reactions and to rapid development of methods applied not only for the synthesis of sulfur heterocycles

• but also for the synthesis of sulfur-containing organic compounds in general [2][5][6]. Thiocarbonyl S-methanides 1 belong to the class of so-called S-centered, electron-rich 1,3-dipoles and in numerous studies, thermal decomposition of 1,3,4-thiadiazolines 2, which are easily accessible via [3 + 2

• five-membered heterocycles via [3 + 2]-cycloaddition reactions. Depending on the type of the dipolarophile used in these reactions, the target heterocycles may contain only one sulfur atom (cycloadditions with C=C or C≡C dipolarophiles) or more heteroatoms (cycloadditions with C=S, C=O, C=N, N=N, S=O

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

• emitters. Boron–nitrogen co-doping strategies, in particular, have facilitated the development of materials with ultra-narrowband emissions, near-unity photoluminescence quantum yields, and electroluminescence dissymmetry factors (|gEL|) exceeding 10−3. Likewise, heteroatom co-doping with oxygen, sulfur

• helicenes. Particular attention is given to multi-heteroatom systems co-doped with elements such as boron, oxygen, sulfur, and selenium, highlighting their influence on CPL performance and structure–property relationships. We classify the nitrogen-doped helicenes into only N-containing helicenes, B,N

• and 17b, among which compound 17b exhibited red-shifted emission (538–632 nm in CHCl3) and the largest Stokes shift (192 nm), attributed to extended conjugation and sulfur incorporation [30] (Table 4). These findings collectively underscore how structural modulation and heteroatom doping can tailor

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

• analogy with an aza-Michael reaction first with the addition of iminoiodinane accompanied with reorganization of double bonds including attack of the negatively charged sulfur atom on nitrogen with subsequent elimination of iodobenzene as good leaving group. The diversity of the structure of the target

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• dehydrogenated using sulfur in trichlorobenzene at 220 °C to yield the azulene-containing isomer of benzo[a]pyrene 9 in 18% isolated yield. Bestmann and Ruppert reported the synthesis of a dinaphthoazulene 14, a non-alternant isomer of benzo[a]perylene (Scheme 2) [34]. In their method, bisylide 10 was reacted

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

• detected by LC–MS from the reaction mixture. The X-ray structure of 6t indicated that the diene and dienophile are perpendicular to each other which prevents them from being properly aligned for the IMDA reaction. The transition state of the IMDA is electronically destabilized by the sulfur group of the

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• . Furthermore, Sato and co-workers (2019) employed an air-stable Ni nanoparticle supported on sulfur-modified gold (SANi) to convert alkynes to the corresponding cinnamic acids 285–287 (Scheme 70B) [120]. In addition, the SANi catalyst could be recycled without significant loss of activity. By generating CO in

Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• photoreductants, and we considered triarylsulfonium salts Ar3S+X− as suitable probes. Such derivatives are photoreactive molecules characterized by a positively charged sulfur atom bonded to three aromatic moieties [20][21][22][23], mainly employed as photoacid generators in cationic polymerization [19]. Apart

Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• : the formation of compound 31 was always observed, and brevicolline ((±)-1) was not formed. Interestingly, our attempts made for the transformation of compound 31 by dehydrogenative aromatization to brevicolline ((±)-1) by using several reagents (DDQ, Pd/C, MnO2, CuCl2, I2, elemental sulfur, KMnO4

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

• of D–A structures makes them the ideal structures to further understand the structure–property relationship of D–A molecules for optimizing their photocatalytic performance by simpler modification of the different D–A subunits. In particular, D–A structures featuring sulfur-based acceptors and

• nitrogen donors have gained increasing attention for their use as photoredox catalysts. This study introduces a new family of D–A molecules by exploring various sulfur-based acceptors and nitrogen donors, including a novel tribenzo[b,d,f]azepine (TBA) unit and 5H-dibenz[b,f]azepine (IMD). Our findings

• diverse scaffolds have been reported in the literature, the identification and use of novel PCs with tunable and diverse optical and redox properties can pave the way to uncharted reactivity. In this context, sulfur-based cores, widely used as acceptors in photoelectric materials [9][10][11][12][13][14

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• double methylene insertions into nitrogen–boron bonds [53]. Copper-catalyzed substrate-controlled carbonylative synthesis of α-keto amides and amides [54]. Divergent sulfur(VI) fluoride exchange linkage of sulfonimidoyl fluorides and alkynes [55]. Modular and divergent syntheses of protoberberine and

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• synthesis of various organophosphorus compounds through the formation of phosphorus–carbon, phosphorus–nitrogen, phosphorus–oxygen, phosphorus–sulfur, and phosphorus–selenium bonds. The impact of different electrodes is also discussed in this matter. Graphite, platinum, RVC, and nickel electrodes have been

• , phosphorus–sulfur, and phosphorus–selenium bonds. The impact of different electrodes is also discussed in this matter. Graphite, platinum, reticulated vitreous carbon (RVC), and nickel electrodes have been used extensively for the electrochemical synthesis of organophosphorus compounds. Review

• ). Although using other solvents improved the solubility, it reduced the reaction yield. Ammonium thiocyanate is used as a sulfur source in the presence of DBU as a base and n-Bu4NBF4 as an electrolyte. When electron-donating groups were present at the C2-benzene ring, the reaction yield was higher than when

New advances in asymmetric organocatalysis II

• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60

• , or sulfur. The year 2000 is typically regarded as the birth of organocatalysis, which was at that time regarded as a new mode of action for chemical catalysts. In that year, List and MacMillan et al. published their landmark studies on proline- and imidazolidine-catalyzed aldol, Mannich, and

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• moderate to good yields. Subsequently, we investigated the scope of cyclobutanones and their analogues in the domino cyclization to access structurally diverse spirotetrahydroquinoline derivatives (Scheme 2). Heterocyclic analogues incorporating oxygen or sulfur atoms within the four-membered ring proved

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• pyridine sulfur trioxide (1.1838 g, 7.437 mmol) was dissolved in dry pyridine (57 mL). The resulting mixture was heated at 90 °C under N2 for 18 h and then cooled to rt. The precipitate was collected by first decanting some of the solvent and then the remaining mixture was transferred to a 50 mL centrifuge

• %; c) dry pyridine, pyridine sulfur trioxide complex (20 equiv), 90 °C, 18 h, 68%. Thermodynamic parameters (Ka (M−1), ∆H° (kcal/mol) determined for the C1·guest, M1·guest and M0·guest complexes by ITC. Conditions: 298.0 K, phosphate-buffered saline, pH 7.4. Supporting Information The X-ray crystal

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• scaffolds – alkanes – then we will progress to ethers, alcohols, sugars, amines (and their derivatives), carbonyl compounds, peptides, and finally sulfur-containing compounds. By arranging the material in this way, we hope that newcomers to the field might be able to readily envisage ways to apply these

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• only when aliphatic disulfides are used because of the higher Lewis basicity of the alkylated sulfur atom, which poisons the copper catalyst. When the reaction was carried out with paraformaldehyde and other solvents (such as DMF, 1,4- dioxane, toluene, and DCE) the yield was very low (between 0–34

• %), but when DMSO is used as solvent and reagent, the yield was greatly improved. The proposed mechanism involves the activation of the disulfide component by CuBr2 as the Lewis acid (Scheme 14). The copper(II) center coordinates the sulfur atom of the disulfide allowing for the electrophilic addition to

• " of the methyl sulfur group in intermediate 22 for the cleavage of the C–S bond. In the end, the C–C bond is formed between intermediate 23 and the enol form from the methyl ketone 18. Sodium carbonate is added to prevent too much acidification of the reaction medium and to deprotonate the NH that

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• such as zinc as proposed by Furuyama et al. [35]. In this way, the authors have developed a series of phthalocyanin zinc complexes with electron-rich sulfur atoms at the non-peripheral positions of the phthalocyanin ring. This functionalization allows the destabilization of the highest occupied

Synthesis of disulfides and 3-sulfenylchromones from sodium sulfinates catalyzed by TBAI

• Zhenlei Zhang,
• Ying Wang,
• Xingxing Pan,
• Manqi Zhang,
• Wei Zhao,
• Meng Li and
• Hao Zhang

Beilstein J. Org. Chem. 2025, 21, 253–261, doi:10.3762/bjoc.21.17

• this study, we report the synthesis of corresponding disulfides under the catalysis of TBAI (tetrabutylammonium iodide) using sodium alkyl or aromatic sulfinates as sulfur sources. Sodium sulfinates are more stable than sulfonyl hydrazides, sulfonyl chlorides, and thiols, and there is no need to add