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

• -dioxides, we aimed at elaborating a synthetic procedure for the preparation of their pyrrole-fused counterparts, 2,9-dihydro[1,2,3]thiadiazino[5,6-g]indole 1,1-dioxide derivatives. The simple and versatile process led, via Fischer indole cyclization of the corresponding hydrazones, to a wide structural

• synthetic process led, via Fischer indole cyclization of the corresponding hydrazones, to several novel 2,9-dihydro[1,2,3]thiadiazino[5,6-g]indole 1,1-dioxide derivatives, containing new tri-, tetra- and pentacyclic ring systems. The hydrazone intermediates and new target compounds were investigated

Synthesis of triazolo- and tetrazolo-fused 1,4-benzodiazepines via one-pot Ugi–azide and Cu-free click reactions

• Xiaoming Ma,
• Zijie Gao,
• Jiawei Niu,
• Wentao Shao,
• Shenghu Yan,
• Sai Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 2202–2210, doi:10.3762/bjoc.21.167

• , the reaction of 0.2 mmol each of 1a and 2a led to the formation of Int-I which then reacted with 0.2 mmol each of 9 and 4 to form 1,5-DS-T 5b which consequently underwent lactamization to form 6a followed by an intramolecular click reaction to afford highly condensed polycyclic product 8a in 92

• spectra are provided in Supporting Information File 1. To evaluate the scalability of this protocol, we performed the synthesis of diazepine 8a on a gram scale with 10 mmol of 1a, which led to the formation of product 8a in 91% yield (Scheme 8). Conclusion We have developed a new synthetic method to

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

• avoid side reactions and promoted exclusive transformation of formaldehyde into glycolic acid. The use of E. coli K-12 strains as host cells and paraformaldehyde as the starting material, led to production of GA with high conversion even at rather high concentrations (Scheme 8) [36]. Using a CuII-based

• groups through hydrogenolysis, neutralization with cyclohexylamine and treatment with ion-exchange resin led to dihydroxyacetone phosphate. This 4-step method was more efficient than the previously reported dismutation of fructose-1,6-diphosphate [84] and 3-chloro-1,3-propanediol [85] which required more

• HFO with benzoic acid amide or furan-2-carboxamide in 1:1 molar ratio at 70 °C for 4–8 h (Scheme 42, path c) [132]. The reaction of HFO with 2-methylfuran in a 1:2.2 molar ratio in diethyl ether solution at room temperature in the presence of catalytic amounts of perchloric acid for 5 hours led to the

The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• (Scheme 3) [31][32]. Oxidation state adjustment of 48 led to the ketone 49. Starting from this common intermediate, firstly, base-promoted double bond migration and oxidation at the γ-position gave tertiary alcohol 50. Deprotection of acetyl in 50 followed by selective oxidation delivered (−)-cyrneine B

• reduction of 72, affording the hydroxyketone 74 in 57% yield with 91% ee. Protection of the secondary alcohol in 74 followed by Beckmann rearrangement led to lactam 75. Oxidation state modifications and functional group transformations of 75 afforded ketone 76. Next, the 1,2-addition of 76 with vinyl iodine

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

• (Scheme 3a). The optical rotation of this mixture is zero confirming that the reaction led to two enantiomers in almost equal quantities. To take advantage of this protocol, the enantiomeric excess (ee) of (+)-7, prepared in four steps from ʟ-Trp [63], was determined to be 98.7%. It is worth mentioning

Discovery of cytotoxic indolo[1,2-c]quinazoline derivatives through scaffold-based design

• Daniil V. Khabarov,
• Valeria A. Litvinova,
• Lyubov G. Dezhenkova,
• Dmitry N. Kaluzhny,
• Alexander S. Tikhomirov and
• Andrey E. Shchekotikhin

Beilstein J. Org. Chem. 2025, 21, 2062–2071, doi:10.3762/bjoc.21.161

• towards all tested cancer cell lines. However, no clear correlation between structure and activity was observed. For example, elongation of the alkyl substituents (N,N-diethylamino derivative 9b) led to a complete loss of antiproliferative activity, while its cyclic analog 9c showed the lowest IC50 value

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

• light-harvesting carbazole units with photoresponsive azobenzene units in a unique macromolecular architecture (Figure 4c) [48]. The resulting cross-linked polycarbazole structure led to a high solar thermal storage capacity of 179.9 J/g and an extended half-life at 60 °C, increasing from 7 min for the

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

• multicomponent reaction of the same starting materials led to the formation of only tetrahydrotriazolopyrimidine derivatives. Keywords: 5-amino-1,2,4-triazole; heterocyclization; multicomponent reaction; salicylaldehyde; ultrasonication; Introduction Multicomponent reactions (MCRs) are a powerful tool for the

• at reflux in acetic acid for 3 h for aminotriazole 1a or in n-BuOH for 7 h in case of aminotriazole 1b led to the formation of oxygen-bridged 2-(methylthio or methoxy)-11,12-dihydro-5H-5,11-methanobenzo[g][1,2,4]triazolo[1,5-c][1,3,5]oxadiazocine-5-carboxylic acids 4a–j (Scheme 2, Table 1). It should

• case of aldehyde 2b, the MCR always led to the formation of a mixture of products 5d and 6d. Attempts to synthesize 5d and 6d as individual compounds under various conditions were unsuccessful. In addition, it was found that compounds 5 can be converted into oxygen-bridged heterocycles 4 after 1 hour

α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

• Vladyslav O. Honcharov,
• Yana I. Sakhno,
• Olena H. Shvets,
• Vyacheslav E. Saraev,
• Svitlana V. Shishkina,
• Tetyana V. Shcherbakova and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157

• biochemical processes [47]. However, there are only a few studies in the literature on multicomponent reactions based on KGA. In 1992, Gein et al. [48] reported a multicomponent reaction involving KGA, aromatic aldehydes, and aromatic amines. This led to the formation of pyrrolone derivatives I, which showed

• anti-inflammatory activity [49][50] (Scheme 1, pathway A). In an earlier study by our research group, Sakhno et al. [51] described a three-component Doebner-type reaction involving KGA, aromatic aldehydes, and 3-amino-5-methylisoxazole, which led to the formation of [2-aryl-4-hydroxy-1-(5

• isocyanide (4) in a molar ratio of 1:2:2:2 in MeOH and subsequent stirring at a temperature of 45 °C for 24 hours led to the formation of N1,N5-bis(2-(tert-butylamino)-1-(4-chlorophenyl)-2-oxoethyl)-N1,N5-bis(4-chlorophenyl)-2-oxopentanediamide (6a) in 55% yield (Scheme 2, pathway B; Table 2). Compounds 5

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

• molecular dynamics (NAMD) simulations of a series of diazabicyclo[2.1.1]hexenes. The minimum energy path showed stepwise σCN bond breaking and led directly to a minimum energy crossing point, corresponding to the inversion product. We also performed NAMD simulations on halogenated derivatives to test the

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• substrate (Figure 1b). This led to the successful development of a novel dual NHC/light-mediated reduction process using either the simple tertiary amine, NEt(iPr)2 (DIPEA) or the widely available silane HSiEt3, as the only reductant. Moreover, interesting insights into the reaction mechanism supported by

• reactions were carried out. As expected, conducting the reaction in the absence of the terminal reductant, DIPEA, led to a complex reaction mixture (Table 1, entry 2), while performing the reaction in the dark resulted only in recovered starting material (Table 1, entry 3). To our surprise, however

• , switching from MeCN to the chlorinated solvents DCM, DCE and chlorobenzene led to a decline in the formation of the fully reduced product 2 with O-benzoylated species 3 being obtained as the major product (38% in DCM, 35% in DCE, 38% in PhCl cf. 6–8% of 2, Table 1, entries 10–12). Significant reduction of 1

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

• Miao Xiao,
• Liuyang Pu,
• Qiaoli Shang,
• Lei Zhu and
• Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

• stereoselectively access the syn-anti-cyclopentanol ring system with three vicinal stereogenic centers at C11, C12, and C8 via the oxidative radical cyclization that led to the asymmetric total synthesis of compound 4. Results and Discussion First generation asymmetric total synthesis of tricyclic-PGDM methyl ester

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• enhanced the reaction performance. However, excessively bulky substituents at C4 and substitutions at both C4 and C5 hindered the coordination between substrate and catalyst, and led to reduced enantioselectivity. As to the structure of 128, the electronic effect of the bromo-substituted pyridine moiety

• 212. Four subsequent steps, including oxidation of propargylic alcohol and cyclization between the hydroxy group and ynone, provided compound 213 with a pyranone ring. Treatment of 213 with Me3SnOH hydrolyzed the methyl ester, and intramolecular Yamaguchi esterification then led to lactone 214, which

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

• exploited. A high-throughput synthetic approach was harnessed to identify substrate/co-substrate/catalyst combinations, which led to the productive formation of intermolecular reaction products. Overall, the approach enabled the synthesis of thirty diverse reactive probes. The probes were screened for

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

• , synthetic chemistry, and medicine. This surge in interest has led to the development of innovative synthetic routes aimed at producing new members of these compounds [22]. For instance, fosfomycin [23] stands out as a broad-spectrum antibiotic currently employed in clinical settings, while thiotepa has been

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• sustainable alternative; however, unfortunately, the electrochemical application is limited to only a few examples (Scheme 3). The electroreductive coupling of imines was first reported in the early 20th century by Law [42]. However, this initial method led to the formation of vicinal diamines with low to

• times higher than the batch protocol. Moreover, the significantly shorter residence time in the flow setup led to an improved space-time yield (STY), a key metric for comparing reactors of different volumes. Under these conditions, the STY of the flow process was 112.2 times higher than that achieved in

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• for interconversion. However, steric repulsion between the C-1 substitutions and the terminal arene moieties in the M-conformational diastereomer resulted in the P-conformational diastereomer being thermodynamically favored. This led to the formation of (P)-helicene products following DDQ-mediated

• reaction produced the imine 16a which, upon treatment with Pd(PPh3)2Cl2 and KHMDS, led to furan ring formation and the generation of hetero[7]helicene 17a while maintaining the stereochemical configuration. Through this methodology, a range of elongated [7]- and [8]heterohelicenes 17b–d incorporating both

• demonstrated the successful construction of planarly chiral macrocycles with 12- to 14-membered ansa chains with high enantioselectivity when using NH2 as the directing group (see 33a,b). However, extending the ansa chain to 15 members led to the loss of planar chirality due to insufficient steric hindrance to

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

• internal standard to the catalysis reactions. Interestingly, performing the reaction without dodecane revealed significantly lower conversions (Table 2B). This led us to a modified hypothesis; namely that in a lipophilic environment, such as a lipophilicized pore or one containing a hydrophobic solvent

• substitution, to isopropyl, then tert-butyl, subsequent increases in lipophilicity with n-hexyl and tetradecyl resulted in decreased conversions; a trend that can be more clearly perceived in Figure 4A. The combined dodecane-free results led us to speculate that it would be better to remove solvent as a

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

• led to a strong decrease in the thermal half-life, suggesting water is also involved in the Z–E thermal isomerisation process [70]. Bridged indigos have also been reported for which the Z-isomers are unstable. By bridging the two nitrogen atoms, these compounds show planar chirality and can be

• the thermal stability from hundreds of years to a few days. The addition of a further hydrogen-bond acceptor on the stator led to the discovery of hydrazones with a thermal stability of thousands of years (Scheme 34, left) [111]. The extra H-bond in 106-E and 107-E raises the energy of the linear

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

• conditions, the reaction led to a complete suppression in the yield of 3a and 3a′. The above results reveal that O2 plays a remarkable role in this transformation. Subsequently, the reaction was performed using N-methylaniline (1a′) under the optimized conditions (reaction 2), which afforded product 3a′ in

[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

• , proved to be a more promising derivatization approach (Scheme 4). Thus, the short-term action of hydrogen peroxide successfully converted compounds 7e, 7c, and 9e to their corresponding sulfoxides 11e, 11c, and 13e. However, prolonged oxidation led not only to sulfone formation but also to deeper

Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue

• Mai Uchibori,
• Nanami Murate,
• Kanako Shima,
• Tatsunori Sakagami,
• Ko Kanehisa,
• Gary James Richards,
• Akiko Hori and
• Osamu Kitagawa

Beilstein J. Org. Chem. 2025, 21, 1748–1756, doi:10.3762/bjoc.21.138

• racemic quinolinones rac-1 in Figure 2 (single crystals of rac-2a were obtained from slow evaporation of hexane/methanol (1:1) mixture at room temperature) [37]. That is, in contrast to rac-1, in which homochiral layered polymer chains were formed, crystallization of quinoline-2-thione rac-2a led to the

• unstable and standing for a long period in the solution state resulted in several decomposed products). Conclusion We found that crystallization of racemic and optically pure C–N atropisomeric N-(halophenyl)quinolin-2-one derivatives led to the formation of homochiral layered polymer chains, which consist

Preparation of a furfural-derived enantioenriched vinyloxazoline building block and exploring its reactivity

• Madara Darzina,
• Anna Lielpetere and
• Aigars Jirgensons

Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136

• successful as the reaction was stopped at the spirocycle 4d formation stage (Table 1, entry 9). The removal of the N-Alloc group in unsaturated ester S-3d was performed using a Pd catalyst and pyrrolidine as a nucleophile. The use of Pd(PPh3)4 as the catalyst led to a fast consumption of the starting

Convenient alternative synthesis of the Malassezia-derived virulence factor malassezione and related compounds

• Karu Ramesh and
• Stephen L. Bearne

Beilstein J. Org. Chem. 2025, 21, 1730–1736, doi:10.3762/bjoc.21.135

• intent of using the benzyl group to protect the indole nitrogen rather than the Boc group. However, Pd-catalyzed hydrogenation of 25d led to a mixture of products, of which some were consistent with reduction of the indole ring. With respect to the scalability of the synthesis, the reactions can be

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• [50], and trichloroacetimidates [51][52]. However, the monosaccharide components were mostly fully benzylated or acetylated, so that the 1,1'-glycosylation reactions led to the formation of symmetric nonreducing products [53]. For instance, the tetrabenzylated chloride donor 1 was reacted with the

• presence of boron trifluoride etherate as promoter to afford the β,α-1,1'-linked disaccharide 12 in 52% yield (Scheme 2). The electron-withdrawing effect of the 2-azido group in the structurally similar donor 13 led to a significant drop in efficiency and the formation of the desired disaccharide 14 along

• -configuration on the glycosyl acceptor side was “retained” from the 1,2-orthoester progenitor. The nature of the protecting groups proved to be critical for the glycosylation outcome: the use of bulkier benzoyl esters, as in the phenyl 1,2-orthoester 19, led to a lower yield (36%) of the 1,1'-linked product 20