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

• ), and brine (100 mL). After drying over anhydrous MgSO4, the solvent was removed in vacuo and the crude product was purified by flash chromatography on silica gel (EtOAc/hexane; gradient 1:10 → 1:2) to give 21 as a colorless solid (6.7 g, 80%, 2 steps); Rf = 0.5 (EtOAc/hexane 1:2); mp 50–52 °C (lit. mp

• with EtOAc (3 × 50 mL) and the combined organic layers were washed with water (100 mL) and brine (100 mL), and then dried over anhydrous MgSO4. The solvent was removed under reduced pressure and the residue was purified by flash chromatography on silica gel (EtOAc/hexane gradient 1:10 → 1:1, 1% AcOH

• ), followed by brine (40 mL). The organic layer was dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel using a gradient of EtOAc/hexane (1:10 → 1:1), affording compound 23 as a colorless viscous oil (425 mg, 50

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

• . tuberculosis [121]. The TMS-glycosides were prepared from the corresponding hemiacetals by acid-catalyzed silylation, involving a silica gel-promoted in situ anomerization of the O-TMS-β-glycoside to its more thermodynamically stable α-counterpart [121]. This protocol enabled the efficient synthesis of TMS

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

• standard. Analytical thin-layer chromatography (TLC) was performed with silica gel 60 Merck F254 plates. Column chromatography was performed with silica gel 60N (spherical neutral). Recyclable preparative high-performance liquid chromatography (HPLC) was carried out on a Japan Analytical Industry Model

• LC918R (JAIGEL 1H and 2H gel-permeation columns) using CH2Cl2 as an eluent. Recyclable chiral chromatography (HPLC) was carried out on a YMC LC Forte/R (Chiralpak® IA column). High-resolution mass spectra (HRMS) was obtained on a Bruker Daltonics microTOF II spectrometer (APCI) by using sodium formate

Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads

• Issei Fukunaga,
• Shunsuke Kobashi,
• Yuki Nagai,
• Hiroki Horita,
• Hiromitsu Maeda and
• Yoichi Kobayashi

Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121

• -catalyzed cross-coupling reactions between bromo-substituted perylene or phenothiazine precursors and appropriate donor or linker units, followed by purification via column chromatography and gel permeation chromatography (Figures S18–S21 in Supporting Information File 1). The details of the syntheses are

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

• chromatography on silica gel using DCM as eluent. Design and synthetic strategies for the target hydantoin/1,2,4-oxadiazoline spiro-compounds. Atropoisomerism of ortho-substituted spiro-compounds 5b and 5d. Cytotoxicity investigation of hydantoin/1,2,4-oxadiazolines 5 (MTT test, HCT116 cell line) and selected

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

• Commercial chemicals and solvents were used as received. If not stated otherwise, products were purified by filtration through short silica gel plugs (200–400 mesh) by using freshly distilled solvents as eluents or by recrystallization. Melting points were determined in capillaries with an Aldrich Melt-Temp

• evaporated, and the residue was analyzed by 1H NMR. Depending on the composition of the crude product, this material was either separated by preparative layer chromatography on the plates coated with silica gel (CH2Cl2 as the mobile phase) (separation of 9h and 10h) or crystallized from hexane/CH2Cl2 mixture

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

• (FWHM = 36 nm), |glum| = 1.1 × 10−3, |gEL| = 1.5 × 10−3, and an external quantum efficiency (EQE) of 0.14 – demonstrating promise for CPL-OLED applications [22]. Wanichacheva’s team reported urazole-functionalized aza[5]helicene 10, exhibiting selective Fe(III) sensing, marked solvatochromism, and a

• foundation, the same group in 2024 developed a series of structurally refined aza[7]helicenes (compounds 12a and 12b) under modified Scholl reaction conditions [25]. These products were obtained as optically active diastereomers, which were successfully separated using silica gel chromatography. Additionally

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• Fluorochem and used as received. The solvents used for the experimental synthesis (HPLC grade) were purchased from Sigma-Aldrich. All other materials were commercial products of analytical grade and used as supplied. Analytical TLC (thin-layer chromatography) was performed on Merck silica gel 60 F254

• on silica gel, using dichloromethane/ethyl acetate 6:1 as eluent to obtain the pure product as bright orange solid (0.31 g, 62% yield). 1H NMR (500 MHz, CDCl3) δ 8.93 (dd, J = 1.2 Hz, 4.6 Hz, 1H), 7.95 (d, J = 8.0 Hz, 1H), 7.87 (d, J = 8.0 Hz, 2H), 7.70 (d, J = 9.5 Hz, 1H), 7.49 (t, J = 8.0 Hz, 2H

• formed, was washed with water several times and dried. The crude material was purified by column chromatography on silica gel, eluting with dichloromethane. Evaporation of the solvent afforded the pure target compound as orange solid (0.26 g, 38% yield). 1H NMR (500 MHz, DMSO-d6) δ 14.7 (br s, 1H), 8.90

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

• solution was stirred for 10 min in an ice bath, then iodonium salt 2a or 2f (1.5–2.0 equiv) was added in one portion. The reaction vessel was removed from the ice bath and the reaction mass was stirred for 6–60 min, then transferred to a silica gel column and the corresponding 2-sulfonyl-2,3-dihydro-1,2

• (1.5 mL) was added dropwise. The reaction vessel was removed from the ice bath and the reaction mass was stirred for 10–30 min, then transferred to a silica gel column and the corresponding 2-sulfonyl-1,3-thiazole 3 was isolated. X-ray structure determination of 3aa. Crystal data for C21H21N3O3S2 (M

Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents

• Julius Krenzer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97

• in Table 1. The yield of compounds 1 after flash chromatography on silica gel under modified conditions (B) are significantly higher than under standard conditions (A). The results demonstrate the broad applicability of the optimized reaction conditions. Acid chlorides with electron-withdrawing (-CN

• ® and purified by flash chromatography on silica gel (n-hexane/acetone 3:1). Then, the crude product was suspended in n-hexane, the supernatant separated by filtration and the precipitate was dried under vacuum to afford aroyl-S,N-ketene acetal 1i (1.78 g, 4.93 mmol, 99%) as a yellow solid. Mp 159 °C

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

• Alexander S. Budnikov,
• Igor B. Krylov,
• Fedor K. Monin,
• Valentina M. Merkulova,
• Alexey I. Ilovaisky,
• Liu Yan,
• Bing Yu and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

• chromatography on silica gel. Recent approaches for the synthesis of β-ketophosphonates by the oxyphosphorylation of unsaturated compounds. The scope of the discovered copper(II)-mediated phosphorylation of enol acetates. Gram-scale synthesis of 3a. Control experiments. Proposed mechanism for copper(II) mediated

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• chromatography on silica gel because of their low polarity and poor solubility in n-hexane. On the other hand, nitration of [3.3.3] gave solely the six-fold nitrated product due to low solubility of the starting material [46]. The current reaction is the first practical method for the selective

• -shifted to ca. 34 ppm in the 13C NMR spectra due to conversion into methylene groups (Figure 2b and Figures S315 and S316 in Supporting Information File 1). However, all 1H NMR signals were broad, and gel permeation chromatography (GPC) charts indicated broad patterns due to multiple products with varying

Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• RS UHPLC coupled to a Thermo Scientific ISQ™ EC single quadruple ESI mass spectrometer. HRESIMS data were acquired on a Bruker maXis II ETD ESI-qTOF. TLC was carried out on Merck (Kenilworth, NJ, USA) silica gel 60 F254 pre-coated aluminium plates and developed plates were visualised using UV light

• at 254 and 365 nm. Reaction mixtures were pre-adsorbed onto Merck silica gel (40–63 µm, 143 Å) and Isolute™ silica (30 × 40 mm, 10 g, 55 µm, 54 Å) SPE cartridges were used for normal-phase, small-scale separations. Alltech (Lexington, KY, USA) Davisil™ C18-bonded silica (35–70 µm, 60 Å) were used for

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• was refluxed over sodium with benzophenone as an indicator and freshly distilled prior to use. Column chromatography was performed on silica gel (normal phase, 200–300 mesh) from Anhui Liangchen Silicon Material Co., Ltd. or basic aluminum oxide (pH 9–10) from Shanghai Titan Technology Co., Ltd

• . Petroleum ether (PE, 60–90 °C fraction) and ethyl acetate (EA) were used as eluent. Reactions were monitored by thin-layer chromatography (TLC) on GF254 silica gel plates (0.2 mm) from Anhui Liangchen Silicon Material Co., Ltd. The plates were visualized by UV light. 1H NMR (400 MHz) and 13C NMR (101 MHz

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• . Chemical reagents and solvents were purchased in the highest available quality from commercial suppliers (Merck/Sigma-Aldrich, ABCR) and used without further purification. Analytical thin-layer chromatography (TLC) was performed on Macherey-Nagel Polygram® SIL G/UV254 plates. 0.2 mm silica gel 60 for

• Na2SO4 and concentrated to dryness. Finally, the crude compound was purified via silica gel chromatography using 50–70% ethyl acetate in cyclohexane as gradient. General procedure B. The product obtained in general procedure A was dissolved in ethanol mixed with 4-cyanophenylacetonitrile and 8 drops of

• obtained in general procedure B was dissolved in dichloromethane and cooled to 0 °C under argon atmosphere. Then, triphenylphosphine and carbon tetrabromide were added and stirred at room temperature for two hours. Afterwards, the entire mixture was loaded on a silica gel column and eluted with 100

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• ) was carried out on aluminum plates coated with silica gel 60 F254 (Merck, Darmstadt, Germany). The TLC plates were analyzed using UV light at 254 nm. Flash chromatography was performed on silica gel 60 M from Macherey-Nagel (grain size of 40−63 μm). The conditions are given in the form “(A/B = a:b

• , Torrance, CA, USA) was used. H2O and MeCN, both containing 0.1% (v/v) TFA, served as eluents. Fmoc-protected amino acids were detected at 220 nm. For a chiral analysis, a CHIRALPAK ZWIX(−) column ((R,R)-ACHSA immobilized on 3 μm silica gel, 250 × 4 mm, Chiral Technologies Europe, Illkirch Cedex, France

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

• Olesja Koleda,
• Janis Sadauskis,
• Darja Antonenko,
• Edvards Janis Treijs,
• Raivis Davis Steberis and
• Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

• quench of a transient N-acyliminium species was found to be a major side-reaction as evidenced by the formation of an open-chain hemiaminal 10a (the hemiaminal could not be isolated due to the instability on silica gel). Screening of other supporting electrolytes revealed that basic salts (K2CO3, Na2CO3

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• Barnstead NANOpure Ultrapure Water system, producing water with a final resistance of at least 18 MΩ); and silica gel (Sigma-Aldrich, 70–230 mesh, 60 Å). For HPLC separations: acetonitrile (Fisher Scientific ACS grade); toluene (Fisher Scientific, ACS grade); and heptane (Mallinckrodt Chemicals, ACS grade

• were extracted with Et2O and washed four to six times with doubly distilled water removing the aqueous layer each time. Anhydrous MgSO4 was added to the organic layer and passed through silica gel with DCM as the eluent. The organic layer was then concentrated to dryness. Yield (isolated): 9-H-10-BnF

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• chlorine gas, with the reaction conducted by stirring the pyrazolinone with TCICA in DCM for 18 hours. Bimanes can be purified easily using column chromatography with silica gel as the stationary phase, with the compounds Cl2B, Me2B, and Me4B only requiring neat DCM as the eluent. After chromatographic

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• its enantioselectivity, aliquots of the reaction mixture were taken at defined time intervals and analyzed by HPLC using a chiral column after passing them through a short silica gel pad. Some interesting conclusions can be made from the data in Table 1. Firstly, the retro-Michael reaction occurs, to

• a one dm path length, and concentration was given in grams per 100 mL. TLC analysis was performed on glass-backed plates coated with silica gel 60 and an F254 indicator and visualized by either UV irradiation or staining with phosphomolybdic acid solution. Flash chromatography uses silica gel (230

• added to a solution of enal (2.5 mmol) and 2-phenylacetophenone (3.0 mmol) in dichloromethane (20 mL), and the mixture was stirred until the reaction was completed. Then, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography using hexane/ethyl

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• (9.1) (Scheme 9) [75]. In this case the authors used a ball-mill reactor equipped with a blue LED, and the reaction was run in a glass vial with two transparent PMMA balls. The authors noted that fluorination of the vial and the use of silica gel to adjust texture were needed to prevent reagent

• investigated. When o-terphenyl (10.1) was milled (30 Hz, PTFE balls) and irradiated (λ = 270 nm) in the presence of silica gel (bulking agent), I2 (1 equiv) as an oxidant, and K2CO3 (1 equiv) as a base in the presence of toluene, the expected product 10.2 was obtained in 81% yield after isolation upon 181 h of

Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• able to adapt this chemistry to work in situ, allowing soluble metastable imine frameworks to be trapped as amides [38]. The adapted cages were soluble, and were now stable enough to be purified by gel-permeation (size-exclusion) chromatography (useful when precipitation is not possible), which is

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• to generate an inseparable byproduct. By contrast, the byproduct derived from Boc-protected amines has a significantly different retention time on HPLC and could be removed by regular silica gel chromatography. Because the formation of 5‒7 posts a significant purification challenge, we sought to

• silica gel column chromatography. The LUMO and electrostatic charges of thalidomide and its derivatives by DFT calculation at the ωB97X-D/6-311+G** level. The synthetic route for iVeliparib-AP6. The conversion of byproduct 6 to 10 to facilitate its removal. Effects of the length and functionalization of

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• (15 g) was analyzed by LC–MS. Thereafter, it was fractionated by vacuum liquid chromatography (VLC) using silica gel as a stationary phase. The elution procedure was performed using a chromatographic scheme of two different gradients as follows: 1) n-heptane/EtOAc (1:0, 7:3, 3:7, 0:1) followed by

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• days (TLC or NMR control). After completion of the reaction, the solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel using chloroform as eluent. ((1S,4S)-Bicyclo[2.2.1]hept-5-ene-2,2-diyl)bis(phenylmethanone) (8) and phenyl((4aR,7aS)-2-phenyl