Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• to its corresponding NHS ester 8 and residual starting material was removed by column chromatography. The Boc-protecting group was removed under anhydrous conditions in good yield and the structure of 9 was confirmed by NMR spectroscopy. Compound 9 was maintained as the TFA salt for the final step

A facile and practical method for the synthesis of trans-(±)-taxifolin and its derivatives via Darzens reaction

• Bo Peng,
• Panpan Yang,
• Maaz Khan,
• Xiaotong Lin,
• Jiang Wu,
• Peng Fu and
• Qingqing Wu

Beilstein J. Org. Chem. 2026, 22, 443–450, doi:10.3762/bjoc.22.31

• (1.2 equiv) was performed in CH3CN, using t-BuOLi (1.2 equiv) as base in the presence of a catalytic amount of ZnCl2. Due to the high efficiency of the reaction, no purification of product (±)-4a by column chromatography was necessary after post-treatment and the product could be directly used in the

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• carried out under a nitrogen atmosphere using standard Schlenk line methods. Reagents and solvents were obtained from GK Life Sciences Pvt. Ltd. and used without further purification unless otherwise stated. Thin-layer chromatography (TLC) was performed on silica-gel-coated aluminium sheets (silica gel 60

• 1.5 h. Thin-layer chromatography (TLC) was used to track the reaction progress. Upon completion of the reaction, ice-cold water was used to quench the reaction mixture, and the mixture was extracted with ethyl acetate. After two water and brine washes, the organic layer was dried over anhydrous

• magnesium sulfate (MgSO₄) and concentrated under low pressure. Column chromatography was performed to purify the crude product using a solvent ratio of petroleum ether to ethyl acetate (85:15), which yielded a yellow solid. Yield: (295 mg, 54%). mp: 156–157 °C; 1H NMR (400 MHz, CDCl3) δ 8.62 (d, J = 7.3 Hz

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• copper complex (although an extraction procedure for complex destruction using Na2S2O3 was applied), which was difficult to separate from the relatively polar free calixarene 37 using column chromatography. In line with this, when toluene-soluble CuI·P(OEt)3 was used as a catalyst (in this case heating

Design, synthesis and biological evaluation of 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines as selective cytotoxic agents against HeLa cells

• Maryna V. Kachaeva,
• Agnieszka B. Olejniczak,
• Marta Denel-Bobrowska,
• Victor V. Zhirnov,
• Yevheniia S. Velihina,
• Stepan G. Pilyo and
• Volodymyr S. Brovarets

Beilstein J. Org. Chem. 2026, 22, 390–398, doi:10.3762/bjoc.22.27

• liquid chromatography–mass spectrometry. Their anticancer activity was assessed against human cancer cell as well as non-cancer cell lines. Three compounds, 1, 3, and 9, were the most cytotoxic to HeLa cells (IC50 = 6.13 ± 1.95, 13.99 ± 1.80 and 49.92 ± 3.98 μM, respectively). However, only compounds 1

Dialkylaminoalkylation of β-ketosulfones via ring-opening of 3-sulfonylpyrrolidines

• Evgeny M. Buev,
• Alexander V. Pavlushin,
• Vladimir S. Moshkin and
• Vyacheslav Y. Sosnovskikh

Beilstein J. Org. Chem. 2026, 22, 383–389, doi:10.3762/bjoc.22.26

• extraction or column chromatography. On the other hand, upon performing the reaction with amines in acetonitrile we did not observe the formation of benzamides. Presumably, debenzoylation occurred in basic media with water traces and cesium benzoate was discarded upon work-up. The presumable mechanism of the

Spirobarbiturates with a pyrrolizidine moiety: synthesis, structure and biological evaluation

• Arthur A. Puzyrkov,
• Andrew S. Drachuk,
• Ekaterina A. Popova,
• Alexander V. Stepakov and
• Vitali M. Boitsov

Beilstein J. Org. Chem. 2026, 22, 274–288, doi:10.3762/bjoc.22.20

• mixture by preparative TLC or column chromatography. Notably, compounds 4a, 4e, and 4k were purified by crystallization. Detailed synthetic and isolation procedures for all compounds are provided in Supporting Information File 1. We regret to state that when forming a mixture of diastereomers, we were

• unable to isolate individual products either by chromatography or by recrystallization. The proposed reaction mechanism is shown in Scheme 5, where it can be seen that the intermediate azomethine ylide, acting as a 1,3-dipole, undergoes a [3 + 2] cycloaddition with N-substituted maleimides 3a–p. The

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• chromatography on silica gel with a methanol-containing eluent, isolated pyranoquinoline 14 underwent alcoholysis, converting it into the corresponding methyl ester 10 at the column outlet. These observations further support the mechanistic considerations of the four-component reaction discussed earlier

• products were also obtained via the four-component reaction using non-nucleophilic acetonitrile as solvent. However, this method requires subsequent purification by preparative chromatography, and, as noted, pyranoquinolines 14a–c readily undergo alcoholysis on silica columns with methanol-containing

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• dried crude product was purified by column chromatography using a solvent mixture of dichloromethane and n-hexane in a 1:2 volume ratio. The purified product 4 was obtained as a white solid in a yield of 2.53 g (91%). Synthesis of 5-(3-(9H-carbazol-9-yl)phenyl)-2-(p-tolyl)isoindoline-1,3-dione (1) For

• sulfate (Na2SO4) to remove any traces of water. The dried solution was then filtered to remove the drying agent and concentrated under reduced pressure to remove the solvent. The resulting crude product was purified by column chromatography using a 1:2 volume ratio of dichloromethane and n-hexane. The

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• its light-brown appearance was identical to that of the product synthesized from commercial phytic acid. High-performance liquid chromatography (HPLC) analysis results indicated that the purity of 2a derived from the extracted phytic acid was greater than 95% (Supporting Information File 1, Figure S4

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• ethanol (Scheme 5, VII). However, under these conditions only decomposition of 4g was observed, and neither deacetylated nor hydroxylated products were isolated. Interestingly, chromatography of 4g on neutral alumina resulted in elimination of the sulfonylimine group to give compounds 5g. Therefore, the

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• shaker (180 rpm) at 27 °C for 7 days using a malt extract-based production medium. Harvested mycelia (1.0 L) were extracted with acetone and ethyl acetate, and purification was guided by antibacterial activity against VRE. The crude extract (922 mg) was subjected to ODS column chromatography followed by

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• of the required imine intermediate that upon reduction yields the desired product. The free base 1 was purified on normal-phase flash column chromatography, and 1·HCl was subsequently precipitated, providing a white crystalline solid (vide infra). Characterization of 25CN-NBOH·HCl (1·HCl) in the

• (granulated, >95%) from TCI Europe N.V. (Zwijndrecht, Belgium), and molecular sieves (3 Å, Ø 3–5 mm) from BLD Pharmatech GmbH (Hamburg, Germany). Ultrapure water (18.2 MΩ·cm) was collected from a Purelab Quest (Elga LabWater, High Wycombe, UK). Thin-layer chromatography (TLC) was performed on aluminium sheets

• chromatography (Pure C-810 Flash, Büchi Labortechnik GmbH, Essen, Germany) was performed with a normal-phase silica column (25 g FlashPure EcoFlex, Büchi), employing a binary gradient from 0–100% (EtOAc/EtOH 3:1 + 2% aqueous NH3)/n-heptane. Product fractions were pooled and evaporated in vacuo, providing the

A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts

• Holly Helmers,
• Mark Horton,
• Julie Concepcion,
• Jeffrey Bjorklund and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10

• methodology of Keinan et al. [12], compound 5 was nitrated with fuming nitric acid in a mixture of glacial acetic acid and sulfuric acid. As shown in Scheme 3, this reaction yielded a mixture of 3 and 4-bromo-3-nitrotoluene (7) in a ≈3:1 ratio. Purification via column chromatography was successful in removing

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

• Celite. The Celite was thoroughly washed with dichloromethane, and the combined filtrate was washed three times with saturated aqueous NH4Cl and brine. The organic layer was dried over anhydrous sodium sulfate. The crude product was purified by silica gel column chromatography using a 1:1 mixture of

• with dichloromethane three times, and the combined organic layer was washed with saturated brine. The organic layer was dried over anhydrous sodium sulfate, after drying, the solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography using a 1:1

• chromatography using a 9:1 mixture of dichloromethane and methanol as the eluent. The eluate was evaporated, and the resulting solid was washed with methanol and dried under vacuum to afford the orange solid of R-Pt (24 mg, 47%). Data for R-Pt: Orange solid; mp 280 °C (dec); HRMS (orbitrap) m/z: [M + H]+ calcd

Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure

• Ilia A. Pilipenko,
• Mikhail V. Grigoriev,
• Olga Yu. Ozerova,
• Igor A. Litvinov,
• Darya V. Spiridonova,
• Aleksander V. Vasilyev and
• Sergey V. Makarenko

Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5

• and 9b (1.3:1 dr, according to the 1H NMR spectrum) due to the axial chirality of this molecule. The mixture was easily separated by silica gel column chromatography. Each of the isomers is characterized by the trans-configuration of the nitro- and trichloromethyl groups in the cyclopropane ring (3JH

• was carried out by column chromatography on silica gel MN Kieselgel 60 Macherey-Nagel 140–270, eluent was a mixture of solvents hexane–EtOAc, 3:1. The reaction progress and purity of the obtained compounds were controlled by TLC on Silufol UV-254 plates with 3:1 hexane–EtOAc mobile phase

One-pot synthesis of ethylmaltol from maltol

• Immanuel Plangger,
• Marcel Jenny,
• Gregor Plangger and
• Thomas Magauer

Beilstein J. Org. Chem. 2025, 21, 2755–2760, doi:10.3762/bjoc.21.212

• . Subjecting maltol (2) to trimethylsilyl chloride and triethylamine furnished the corresponding silyl ether 8d in nearly quantitative yield (Table 2, entry 4). Due to the instability of the trimethylsilyl ether functionality to flash column chromatography, methylation of 8d was followed by desilylation with

• ). Purification with flash column chromatography provided analytically pure ethylmaltol (1), which, however, displayed an off-white/yellowish color. A final vacuum distillation yielded purely white ethylmaltol (1) consistent with commercial samples. The ethylmaltol (1) thus produced was analyzed by the Central

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

• layer. High-resolution ESI mass spectra (HRMS) were recorded with a Bruker micrOTOF II instrument. Silica gel 60 Merck (15–40 μm) was used for preparative column and thin-layer chromatography. Silica gel “Silpearl UV 254” was used for preparative column and thin-layer chromatography. Analytical thin

• -layer chromatography (TLC) was carried out on Merck silica gel 60 F254 and “Silufol” TLC silica gel UV-254 aluminum sheets. All reagents were purchased from Acros and Sigma-Aldrich. Solvents were purified before use, according to standard procedures. All other reagents were used without further

• ), dried over Na2SO4, and solvent removed in vacuo. Products 2a–i were isolated by column chromatography on silica gel. Procedure for gram scale electrochemical synthesis of 2f (experimental details for Scheme 3, reaction 1): In a manner analogous to one described in [87], an undivided 50 mL

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

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• precipitated from the reaction, which allowed it to be easily isolated and purified by crystallization from MeCN. Diastereomer 4att was obtained from the filtrate also by crystallization from MeCN. Column chromatography allowed us to isolate octahydropyrido[1,2-a]pyrimidinones 4atc, 4acc in an individual form

• 5ctt (δF 79.74 ppm). All products were individually isolated by column chromatography. Carrying out these syntheses in 1,4-dioxane in the presence of acetic acid and triethylamine increased the selectivity for the formation of octahydropyrido[1,2-a]pyrimidinones 4 in the reactions with alkyl methyl

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

• are easily separable by column chromatography due to their different polarity. Next, we investigated the substrate scope and limitations of the reaction using differently substituted iminopropargyl alcohols (Table 2). The presence of alkyl substituents in the hydroxy fragment was well tolerated

• , electron ionization, electron energy: 70 eV, ion source temperature 200 °C; mass range 34–650 Da. The solvent was chloroform or acetone. Column chromatography was performed on silica gel 60 (70–230 mesh, particle size 0.063–0.200 mm or 230–400 mesh, particle size 0.040–0.063 mm, Merck). Commercially

• acetic acid. The reaction was carried out at room temperature and with vigorous stirring for 15 minutes. Next, the solvent was removed and the residue was purified using column chromatography (eluting with diethyl ether/hexane 1:8, then acetone/hexane 2:1 to give products 2 and 3. Procedure for oxidation

Recent advancements in the synthesis of Veratrum alkaloids

• Morwenna Mögel,
• David Berger and
• Philipp Heretsch

Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206

• , hydroboration/oxidation, and an oxidative cyclization protocol. The diastereomers were separable by column chromatography, leading to this faster and more scalable procedure to be performed preferentially over a six-step diastereoselective sequence. After silyl ether deprotection, the Wagner–Meerwein-type

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

• numbers: CCDC 2470493 (20e), CCDC 2470491 (21g), CCDC 2470492 (23a), CCDC 2470490 (25), CCDC 2470489 (26), CCDC 2472402 (27). All reagents were purchased from commercial sources and were used without further purification. Reactions were followed by analytical thin-layer chromatography on silica gel 60

• (100 mL), the combined organic phases were dried over Na2SO4, evaporated, and the oily residue was triturated with a little amount of acetone to afford a second crop of crude 7 (8.45 g of pale yellow solid). The two crops were purified by dry-column flash chromatography on a short silica gel column

• chromatography (short aluminum oxide column, eluent: heptane/DCM 1:1, DCM) and isomer 8 (0.62 g, 2%) was isolated as pale yellow crystals. Mp 254‒256 °C (CH3CN); IR (KBr): 1665, 1485, 1344, 1111, 1061, 859 cm−1; 1H NMR (500 MHz, CDCl3): 7.96 (d, 4J = 2.0 Hz, 1H), 7.94 (d, 3J = 8.6 Hz, 1H), 7.63 (dd, 4J = 2.1 Hz

Chemoenzymatic synthesis of the cardenolide rhodexin A and its aglycone sarmentogenin

• Fuzhen Song,
• Mengmeng Zheng,
• Dongkai Wang,
• Xudong Qu and
• Qianghui Zhou

Beilstein J. Org. Chem. 2025, 21, 2637–2644, doi:10.3762/bjoc.21.204

• , 17-deoxycortisone 5 could also be transformed into 4 in 65% yield after incubation in the Thamnostylum piriforme NBRC 6117 liquid medium (Table 1, entry 1). Notably, a major C9 α-hydroxylated side product 4' was also generated in 30% yield, which could be readily separated by column chromatography

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

• stability of the prepared materials, we compared the behavior of SG-NHCO-BU1, SG-BU1, and SG-BnBU in different solvent systems (Supporting Information File 1, Figure S3). Chloroform, dichloromethane, and methanol were investigated due to their frequent use as mobile phases in liquid chromatography; aqueous

• conditions. While SG-BnBU and SG-NHCO-BU1 are suitable for dicyanoaurate sorption from aqueous solutions, SG-NHCO-BU1 and SG-BU1 could be used for anion extraction in organic media. Experimental Materials and instruments Silica gel (Silikagel 60 (0.015–0.040 mm) for column chromatography, product number