Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• -butyl group is present in the C-3 position of the pyrazole as in the case of substrate 2e, the reaction did not take place, likely due to a considerable increase in steric hindrance. We also attempted to synthesize 4-(alkenyl)-5-aminopyrazoles using an acyclic ketone, such as acetone, but unfortunately

• dichloroethane, chloroform or ethyl acetate gave lower yields but similar diastereoselectivity. More polar solvents such THF and CH3CN afforded the corresponding alcohol 5aaa with lower diastereoselectivity. When acetone was used as solvent, product 5aaa was not detected in the 1H NMR of crude reaction mixture

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

• organic base such as tetramethylethylenediamine (TMEDA) or 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) [28]. Our initial attempt to apply this method was as follows: A reaction mixture of 9,10-ANTH(Br)2, 10 equiv BnFI, and 10 equiv DBU dissolved in acetone was illuminated with a blue LED for 20 h (see

• (trifluoromethyl)benzene (1,4-C6H4(CF3)2, Central Glass Co., 99%); dimethyl sulfoxide (DMSO, Fisher Scientific, ACS grade); anhydrous magnesium sulfate (MgSO4, Fisher Scientific); Cu powder (Strem Chemicals, 99%); dichloromethane (EMD Chemicals, ACS grade); acetone (technical grade); THF (Aldrich/Merck, ACS grade

• -phase reactions) CF2C6F5I (63 µL, 0.38 mmol) was syringed into a Schlenk flask containing 9,10-ANTH(Br)2 (13.4 mg, 39.8 µmol) and 1,8-diazabicyclo(5.4.0)undec-7-ene (60 µL, 40.1 µmol) dissolved in acetone (technical grade), and degassed three times by a freeze-pump-thaw technique (3 × 10 min). The

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

• , the crystals changed their appearance from light yellow to dark orange within 15 minutes. An alternative method for solid-state irradiation involved dissolving 5–10 mg of the bimane in a minimal amount of acetone, which was then evaporated in a 25 mL round-bottomed flask, forming a seemingly amorphous

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

• recorded in CDCl3 or acetone-d6. Chemical shifts for protons are reported in ppm from tetramethylsilane as an internal reference. Chemical shifts for carbons are reported in ppm from tetramethylsilane and referenced to the solvent's carbon resonance. Specific rotations were measured using a 5 mL cell with

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

• growth, the cultures underwent extraction. The mycelia were initially soaked in acetone overnight, followed by two rounds of ultrasonic extraction with freshly added acetone for each cycle. Resultant suspensions were filtered, and the liquid was collected. The combined liquid phases underwent vacuum

• acetone/MeOH (9:1, 7:3, 1:1, 0:1) along with one last fraction of MeOH 100% using 0.1% formic acid. Nine fractions of 1 L each were eluted that were collected and evaporated separately under reduced pressure to dryness. For fractions 3, 4, 6 and 8 were further purified using a PLC 2250 preparative HPLC

• ): Pale yellow amorphous solid; UV–vis (MeOH) λmax: 368, 224, 200 nm; NMR data (1H: 500 MHz, 13C: 125 MHz, acetone-d6) comparable to the previously described spectral data [8]; HRESIMS m/z: [M + H]+ calcd for C25H28NO4+, 406.2103; found, 406.2103. Farinosone B (3): Bright yellow powder; UV–vis (MeOH) λmax

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

• acetone, allowing the pre-activation of the ruthenium complex with the successive release of an N-heterocyclic carbene ligand and a chlorine atom, which are replaced by two acetone molecules to form compound 2. Simultaneously, excitation of the osmium(II) complex in the red region (660 nm) decreases its

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• , was obtained in one-pot, presumably via generation of the aminonitrile 17 and subsequent nucleophilic attack of the phenolic hydroxy group to form the five-membered ring. Our efforts to optimize this one-pot sequence led to the best results, affording 11 in 73% isolated yield, when acetone cyanohydrin

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• structure would also be found in the solid state. Fortunately, single crystals of the complex H1 ⊃ G1 were obtained by slow evaporation of chloroform/acetone solvent (1:1, v/v) into a small amount of methanol over the course of two weeks. Indeed, analysis of the crystal structure of the complex revealed a

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• . Among various Lewis acids, only Cu(OTf)2 in combination with TMSCN was effective or a valuable alternative was the use of acetone cyanohydrin combined with a catalytic amount of TEA (5 mol %). The mechanism involves the formation of an imine facilitating the addition of the nitrile group. Among the

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• was stirred for 30 minutes. The residue was concentrated under reduced pressure, suspended in dry cold acetone, and stirred vigorously for 1 hour. The suspension was filtered and washed with a minimum amount of cold acetone to deliver the product as hydrochloride salt. 2-Phenylethan-1-amine

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• . The substrates were washed using deionised H2O, acetone, and isopropanol before being dried over a stream of compressed air. Octadecyltrichlorosilane (30 μM) was dropcast onto the substrate for 5 minutes before the substrate was washed with toluene. The substrate was then dried over compressed air. A

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• temperature, concentrated H2SO4 was slowly added until pH 6–7 according to litmus paper and left standing overnight (12 h). The precipitated crystals were filtered off, washed with water, acetone, and dried in air. The crude product was recrystallized from water with activated carbon. The yield of compound 2

• water and acetone (1:1) was slowly added to 20 mL of 24% NaOH solution. The reaction temperature was raised to 45 °C and a solution of 0.09 mol of (NH4)2S2O8 in 30 mL of water was added. After complete addition of (NH4)2S2O8, 0.01 wt % of the catalyst, PcCo, was added. The reaction mixture was stirred

• yields of compound 8 are given in Table 2. b) In a 150 mL three-neck flask equipped with a reflux condenser, a mechanical stirrer, a solution of 0.06 mol of pyridine in 20 mL of azeotropic solution of water and acetone (1:1) was slowly added to 20 mL of 24% NaOH solution, the reaction temperature was

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• –6.81 (m, 4H), 7.26–7.36 (m, 5H); 13C NMR (75.45 MHz, acetone-d6) δ 55.5, 59.3, 67.9, 70.0 (q, J = 30.2 Hz), 114.8, 117.7, 124.1 (q, J = 283.5 Hz), 128.5, 128.6, 128.7, 134.4, 139.5, 154.3, 170.2; 19F NMR (282.65 MHz, CDCl3) δ −76.83 (d, J = 9.0 Hz); IR (KBr) ν: 3454, 3315, 2955, 2924, 2854, 2360, 1741

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• ), 0.1 M, 135 h at rt, 43%, (b) 1.5 equiv mCPBA, 3.0 equiv TfOH (at 0 °C), (DCM), 0.1 M, 20 h at rt, 85%, (c) 1.0 equiv NaBArF24, (acetone), 0.5 M, 2 h at 50 °C under microwave irradiation, 72%. Gold(I)-catalyzed cyclization of propargylic amide 11 as benchmark reaction for Au–Cl activation. Determined

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• synthesis, the deprotected derivatives such as 69 are desired for the synthesis of natural products. Therefore, an easy-to-perform two-step deprotection procedure was developed that is based on methylation of the phenolic hydroxy group with an excess of MeI in acetone at rt (68), followed by oxidative

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• or scale down and partially automatize the protocol or both. The standard mass spectrometry-based chemical proteomics workflow requires up to 1 mg of total protein, acetone protein precipitation after the ‘click’ reaction to remove the excess of the biotin-containing reagent, desalting of the

• probe–proteins enrichment [94]. The underlying and unifying advantage of these protocols is the use of a mixture of hydrophilic and lipophilic carboxylate-coated magnetic beads to replace the protein acetone precipitation after CuAAC. After the ‘click’ between the probe–protein conjugates and affinity

Electrochemical allylations in a deep eutectic solvent

• Sophia Taylor and
• Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

• flash column chromatography. In between reactions, the tin electrodes were rinsed with DI water and acetone, then polished using diamond polish. This helped prevent buildup on the electrode surfaces. General C/C procedure with TBAB/EG To a 10 mL ElectraSyn 2.0 vial containing a magnetic stir bar were

• sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using flash column chromatography. The graphite electrodes were not polished in between reactions, but were rinsed with DI water and then acetone. General Sn

• column chromatography. The electrodes were washed with DI water and acetone before polishing. General C/C procedure with CC/EG To a 10 mL ElectraSyn 2.0 vial containing a magnetic stir bar were added the carbonyl compound (0.5 mmol), allyl bromide (0.6 mmol), CC/EG DES (2 mL), and 10% DI water (0.2 mL

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• situ-generated acetone imines in a (3 + 3) manner to afford meta-substituted anilines (Scheme 1C) [53][54]. Various EWGs (ester, carbamoyl, ketone, trifluoromethyl) have been successfully employed which motivated us to evaluate other possible EWGs. Results and Discussion Based on the fact, that many

• 2356151). No significant improvement in the yield was observed by varying the reaction conditions. Surprisingly, the reaction of 1,3-diketone 1a, morpholine and acetone without the use of molecular sieves and acid catalysis (conditions A) resulted in 81% yield of meta-substituted aniline 3ab. Applying the

• of acetone and amines 2 leads to the formation of acetone imine/enamine (reaction 1, Scheme 6). Nucleophilic addition of an enamine to the most electron-deficient carbonyl group (C1=O, adjacent to the EWG) of the 1,3-diketones 1 gives the acyclic carbinol I (reaction 2, Scheme 6), followed by the

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• cytotoxic effects but showed no activity. A number of natural products seem to be produced by reaction of altenuene diastereomers (or of related compounds) with C3 building blocks, i.e., with lactic acid, pyruvic acid, or with acetone (Figure 17). Alternatain D (65) was isolated from Alternaria alternata

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• to a mixture of 60 mL acetic acid and 30 mL concentrated HCl, then the reaction mixture was stirred for 16 h at 100 °C. The creamy precipitate (4.7 g, 80%) was obtained after pouring the reaction mixture into crushed ice, washed with water, acetone and dichloromethane (DCM), then dried under vacuum

Novel oxidative routes to N-arylpyridoindazolium salts

• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

• diaryldihydrophenazine was increased (10%). Thus, protonation completely suppressed the intramolecular cyclization route. Heterocyclic salts S1–S3 were obtained as amorphous solids, soluble in polar solvents (acetonitrile, DMF, acetone) and chlorinated hydrocarbons (CHCl3, CH2Cl2). The structure of new N

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• /ketalization cascades of generated (S)-34 proceeded predominantly, achieving the chemoenzymatic total synthesis of trichodimerol (2) in 27% yield from 33. In contrast, the use of acetone as the co-solvent resulted in the homodimerization of (S)-34 via Diels–Alder reaction between the cyclohexadienone moieties

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• (sodium (2,4-dinitro-5-fluorophenyl)-ʟ-alaninamide) in acetone were added. The reaction mixture was incubated at 40 ºC for 1 h with periodic agitation. The reactions were quenched by adding 10 µL of 2 M HCl and dried under a nitrogen stream. Dried samples were dissolved in 1.7 mL of MeOH and injected both

• . Afterward, 25 µL of water, 10 µL of 1 M NaHCO3 and 50 µL of 1% Marfey’s reagent in acetone were added to the reaction vial. The reaction was incubated for 1 h at 40 ºC with periodic agitation. The reaction was quenched by adding 5 µL of 2 M HCl and dried under a nitrogen stream. The dried peptides were