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

• 88, enabling its stable isolation and subsequent affordance of the spirocyclic indole-derived imine product 92 (Scheme 19, path b). The suppression of Wagner–Meerwein rearrangement was attributed to the lower Lewis acidity of PPh₃ relative to NFSI, which emerged as the critical determinant in this

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

• %, surpassing the performance of traditional approaches in similar contexts. Similarly, tri-ortho-substituted azobenzenes 5b and 5c were prepared in 42% and 47% yields, respectively. However, the isolation of these compounds in pure form remains challenging due to contamination with biphenyl side-products

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

• oxidation without isolation) produce 5,5'-oxybis(furan-2(5H)-one) and 5,5 '-(oxybis(methylene))bis-2-furfural [127][128][129] (Scheme 42, path a). The antimicrobial agent 5-chloro-2(5H)-furanone was synthesized by reaction of HFO with thionyl chloride in 30% yield [130], or with phosphorus chloride in 70

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

• Hamigera tarangaensis, and show cytotoxicity against various tumor cells. Notably, compound 11 exhibits 100% inhibition against herpes and polio viruses without significant host cell cytotoxicity [38]. Since their isolation, the synthesis of 11 and 12 have been reported by many groups [39][40][41][42][43

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

• fungus Aspergillus versicolour SCSIO XWS04 F52 [32]. All these alkaloids distinguish each other only by alkyl substituent at C11 and by relative stereochemistries at C2, C3, C11, and C14. Soon after the report of the isolation, structural elucidation, and bioactivity of (–)-chaetominine by Tan and co

• structures of aspera chaetominines A and B and revision of stereochemistry of aspera chaetominine B Several years after we have had accomplished the abovementioned investigations, Liu and co-workers reported the isolation and structural elucidation of two new alkaloids, aspera chaetominines A (12) and B (13

Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• propose the biosynthetic pathway, which has not yet been reported in Duh’s isolation report (Scheme 1a). In our proposal, the linear sesquiterpenoid trans-nerolidol (1) with a chiral tertiary alcohol undergoes dihydroxylation to generate triol 2, which further proceeds a C–C bond cleavage to afford

• rearrangement under the conditions of H2SO4/MeOH, since their isolation of the natural products [32]. However, other critical bioinspired transformations have not yet been explored, which prompted us to initiate this study. Guided by this biogenetic proposal, we conducted a series of reactions to probe 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

• also was described in several other publications [13][14][15]. On the other hand, three-component reactions of aminoazoles, salicylaldehyde, and esters (or amides) of acetoacetic acid with isolation of other types of heterocylic compounds were described in some papers [16][17]. Our early works were

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

• substituted 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoic acids containing a pharmacophore quinoxalinone moiety. The tandem Ugi/aza-Wittig combination was also carried out in a one-pot procedure without isolation of the intermediate. Keywords: α-ketoglutaric acid; aza-Wittig reaction; multicomponent reaction

• sufficiently electrophilic carbonyl carbon atom with the elimination of triphenylphosphine oxide via the aza-Wittig reaction. It should be noted that the best method for the isolation of quinoxalinones 9 was column chromatography using an elution gradient of hexane/ethyl acetate 3:1 to hexane/ethyl acetate 1:2

• with the addition of 0.1% formic acid. The use of other eluents such as acetonitrile and different ratios of hexane/ethyl acetate, dichloromethane/methanol as well as the application of methods for the isolation of triphenylphosphine oxide by complexation with calcium and magnesium salts [54][55] or

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

• higher reduction potential of this comparatively electron-rich compound. Purification of the crude reaction mixture from 1 by column chromatography allowed for the isolation of pure product 5 as a colorless oil in 59% yield. A control reaction performed under the same conditions in the dark resulted only

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

• soluble racemic products, which resulted in the isolation of chiral products with exceptional enantiopurity. Moreover, this method accommodated [1,1'-biphenyl]-2,2'-diamines 62 with ortho-substitutions, which underwent either dynamic kinetic resolution or kinetic resolution to produce chiral substituted

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

• , -Br, and -F (1f–h), were next evaluated using the optimized conditions, resulting in the isolation of the corresponding quinolines 3f–h and their 4-substituted analogs 3f′–h′ with satisfactory yields ranging from 73% to 86%. ortho-Substituted arylamines 1i and 1j showed sensitivity, likely due to

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

• nitrogen source followed by thin-layer chromatography and reversed-phase (RP)-HPLC to isolate and purify the compound from a complex mixture of indole alkaloids [11], (ii) prepared by aerobic incubation of indole-3-pyruvic acid at pH 7.4, 37 °C for 24 h followed by isolation and purification using RP-HPLC

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

• ][19][20][21][22][23][24][25]. The availability of complex biomolecules containing nonreducing disaccharides is limited, as their isolation from natural sources is challenging and often fails to ensure the homogeneity of the isolates or the integrity of biomolecules bearing labile functional groups

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• )-4 was obtained by the same procedure of (Sp)-4. HRMS (APCI+) (m/z): [M + H]+ calcd. for C38H22, 479.1794; found, 479.1816. [α]D25 = +278.68 (c 0.04, CHCH3). Synthesis and isolation of cyclic dimer (Sp)-6 and trimer (Sp)-7 A mixture of (Sp)-4 (18.2 mg, 0.038 mmol), 1,4-diiodobenzene (5, 13.2 mg

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

• 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

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

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

• further the applicability of the present synthetic method. Due to the excellent solvating power of CyreneTM, the “one-pot” synthesis of 1,2,3-triazoles could be proposed to eliminate the preparation and isolation steps of azide components. This could open an even greener and facile protocol for CuAAC

• demonstrated. The protocol was tested for a wide range of substrates, and successful synthesis and isolation of nineteen 1,2,3-triazole derivatives 3a–h, 5b–f, and 6a–f with moderate to excellent isolated yields (50–96%) and purity (>98%) was shown. Experimental The sources of chemicals are listed in

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

• CH2Cl2 led to isolation of a colorless, crystalline material with a narrow melting point of 107‒109 °C (yield 66%). The 1H NMR spectrum registered for the purified product perfectly fitted with that one of the crude mixture and thereby confirmed formation of a single product with a single set of the Me‒S

• selectivity, and in all cases formation of insertion products of both types, i. e., thioaminals 9 and dithioacetales 10, was observed (see Table 1). Chromatographic separation enabled the isolation of pure compounds, and the more stable dithioacetals 10 formed the more polar fraction. The less polar fraction

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

• dependence on the molar ratio of iodonium salt to isonitrile (Table 1, entries 14–21). In case of excess of the isonitrile we observed multiple addition and formation of oligomerized products which hindered the isolation of the product 2aa (Supporting Information File 1, 2.2 Preliminary and Additional

• conditions: 2-isocyano-1,3-dimethylbenzene (0.2 mmol), iodonium salt 1 (0.2 mmol), Na2CO3 (0.34 mmol), [Ru(bpy)3](PF6)2 (0.004 mmol), MeCN (2 mL), H2O (200 μL), under irradiation by blue LED (465 nm, 20 W) for 10 h. bDetermined by 1H NMR spectroscopy after isolation as a mixture of amides or a single amide

N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B

• Joy E. Rajakulendran,
• Emmanuel Tope Oluwabusola,
• Michela Cerone,
• Terry K. Smith,
• Olusoji O. Adebisi,
• Adefolalu Adedotun,
• Gagan Preet,
• Sylvia Soldatou,
• Hai Deng,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103

• isolation of five phenolic siderophores with some of them exhibiting antimicrobial properties, including pseudomonins A–C and pseudomobactins A and B [15]. In this study we report the isolation and structural characterization of two previously undescribed as natural products (1 and 2) and two new compounds

• purification by a reversed-phase high pressure liquid chromatography (HPLC) system which led to the isolation of four compounds, trivially named pseudomonins D–G (1–4) and three known compounds 5–7 (Figure 1). Compound 1 was isolated as a yellow oil. The molecular formula C11H13NO5 (Δ: −0.7 ppm, 6 degrees of

• Compact Data Analyst (Bruker software) to provide accurate and high-resolution mass per charge of molecular ions in the sample and generate molecular formulae using a Bruker Smart Formula manually. Microbial isolation and identification The Pseudomonas sp. UIAU-6B strain was isolated from a sediment

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• benefits, such as (i) improved reactions rates and yields in catalyst and solvent-free reactions, which enables easy isolation, and simplified work-up procedure; (ii) the neat reactions of the substrates eliminates solvents and thus reduces environmental and hazard impact; (iii) the HHP conditions enable

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• E [30] and daphnepapytone C [31] from the 2020s (Figure 4). Most of these compounds possess intriguing biological activities and selected examples from this list are discussed in more detail in chapter 4 with regards to their isolation, bioactivity and a recent total synthesis. The aim of this work

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

• co-workers reported the oxidation of partially saturated precursor 23 using DDQ, which led to the isolation of PAH 24 in 50% yield which contains two formal azulene units (Scheme 4) [39]. However, compound 24 was found to possess a biradical structure (biradical character index, y0 = 0.49) with

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

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

• , Supporting Information File 1), but it was not stable enough for isolation. The structure of 8a was confirmed by single crystal X-ray diffraction analysis. The optimized reaction conditions were used to evaluate the substrate scope of the synthesis of imidazopyridine-fused isoquinolinones 8 (Scheme 3). The