Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• common organic solvents. Therefore, the crude 18 was subjected to the Mallory photoreaction without purification. Photoirradiation of diarylethene 18 was performed in the presence of a catalytic amount of I2 in refluxing toluene to afford F87PHEN which was isolated by sublimation under vacuum. Absorption

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

• several chromatographic purification steps (EtOAc/n-pentane, 2% AcOH). Hence, in the here described case, the final hydrolysis and Fmoc protection resulted the enantiomerically pure isomer Fmoc-(2S,4R)-TfLeu (12a), isolated in a good yield of 40% and with excellent enantiomeric purity of 97% ee. The

• chemicals were used without further purification and obtained from commercial sources. Synthesized compounds 3,3,3-Trifluoro-2-methylpropyl 4-methylbenzene-1-sulfonate (9): 8 (5.00 g, 39.0 mmol, 1.0 equiv), was dissolved in DCM (48.8 mL). p-Toluenesulfonyl chloride (11.15 g, 58.5 mmol, 1.5 equiv) and DMAP

• purification. 1H NMR (600 MHz, CDCl3) δ 8.88 (d, J = 2.2 Hz, 1H), 8.07 (d, J = 9.3 Hz, 1H), 7.79 (dd, J = 8.2, 2.2 Hz, 1H), 7.62 (p, J = 5.7 Hz, 2H), 7.49 (dt, J = 9.0, 4.4 Hz, 1H), 7.37 (d, J = 8.1 Hz, 1H), 7.33 (dt, J = 6.3, 2.0 Hz, 1H), 7.15 (dd, J = 9.3, 2.8 Hz, 1H), 6.88 (d, J = 7.7 Hz, 1H), 6.63 (d, J

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• each as white powder after HPLC purification of the mixture formed from reaction of massarilactone D with cinnamoyl chloride in triethylamine in the presence of catalytic amounts of 4-dimethylaminopyridine. The ESIMS of compound 3 exhibited the sodium adducts at m/z 507.20 [M + Na]+ and 991.39 [2M + Na

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• ,f) often precipitated out of the reaction mixture and were sufficiently pure (>95% by HPLC) after the simple washing steps, and the more polar hydantoin products could be extracted out of the reaction mixture with ethyl acetate and did not require further chromatographic purification. The “one-pot

• of this process is promising, driven by its simplicity, moderate to high yields, and the use of environmentally friendly reagents. Notably, microwave-assisted one-pot reactions eliminate the need for column chromatography, a common step in traditional purification methods but limits scalability

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• implementation often implies fewer purification steps to achieve the target molecules, leading to a reduction of waste, when compared to traditional “step by step” synthesis. Another advantage of MCRs is that by selecting appropriate starting materials, follow-up functionalization by, e.g., post-cyclization of

• [17][18]. An important drawback of this solvent is the difficulty of its removal from the reaction crude, and extractions with water are commonly employed before purification. Depending on the reaction conditions, DMSO can be transformed into different products, e.g., under redox conditions, DMSO can

• either of the two nucleophilic nitrogen atoms present in the amidine component, thus leading to the production of both regioisomers 42a and 42b and therefore to a demanding purification process (Scheme 33). To avoid these drawbacks, Lyon et al. optimized the reaction by using free monohydrated glyoxylic

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

• purification, the 1H NMR of Cl2B showed 6% of an impurity, possibly the anti-isomer. Further purification of Cl2B reduced the impurity content to less than 3%. Topochemical photocycloaddition Upon examining the crystal structure of our first sample of Cl2B, Cl2B (A), we observed that the compound had undergone

• packing mode. Extra precautions were taken to shield the compounds from light during synthesis, purification, and storage. After crystallizing each bimane, a vial containing multiple crystals was selected for irradiation studies. Cl2B (B), which showed 5% presence of the [2 + 2] dimer after

Synthesis of electrophile-tethered preQ₁ analogs for covalent attachment to preQ₁ RNA

• Laurin Flemmich and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

• protecting groups and time-consuming purification steps, that provides preQ1 in 43% overall yield with a purity of >98% (Scheme 2). The approach is based on the cyclocondensation reaction between 2-chloro-3-cyanopropan-1-al (6) (itself obtained from chloroacetonitrile and methyl formate) and 2,6

• novel 2,6-diamino preQ1 analog 2 (DPQ1) by hydrogenation of 8 (DPQ0 [32]) (Scheme 2). In this case, however, a final purification step (by reversed-phase chromatography) was required. Notably, using the hydrogenation conditions described here, we were also able to streamline our previously reported 7

• mild reduction with methanolic sodium borohydride. Upon purification by reversed-phase chromatography using aqueous hydrobromic acid as eluent (0.5% in H2O), a considerable fraction of the alcohols was already converted to the desired bromides 4c,d. Only in the case of 4b, no deoxygenative bromination

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

• described in the literature (Scheme 5) [41][42]. Treatment of a 3:1 mixture of the anti/syn-diastereoisomers of compound 3 with 1,3-propane dithiol in the presence of a small amount of scandium triflate [43] afforded compound 18, which was used in the next step without further purification. Hydrogenolysis

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

• purification possibilities available for robust organic cages mean access to structural families via stepwise synthesis or statistical methods followed by separation is facile, as demonstrated by Otte [42][43][44] and ourselves [41]. The lack of internal functionality in cavities doesn’t just reduce the

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

• generally modest, it remains highly popular because of the convenience and the modularity of this method. When reacting 1 with an amino-PEG-OH, the purification of the reaction mixture is particularly difficult as a major byproduct co-elutes with the desired product even on HPLC. Importantly, the impurity

• sulfonate to the byproduct by reacting it with taurine allows for easy decontamination. This method may facilitate the purification of other similar reactions and improve the quality of related pomalidomide derivatives. The structures of veliparib and iVeliparib-AP6. Identification of the cryptic impurity

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• , usually proteins or lipids by the process of glycosylation producing glycoproteins or glycolipids, respectively. Nature executes these processes by enzymatic pathways [18] and is often flawless in its desired output. But the scarcity and the cumbersome purification of natural enzymes limit the use of

• in attaining the required stereospecific glycosylation outputs. Apart from the widely convenient stepwise synthesis, recently one-pot glycosylations have also made an important mark which minimise the tedious purification of the intermediate molecules in each step [53][54][55][56][57][58]. In the

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• ) with Ki values of 82.6 and 88.4 µM, respectively. Experimental All solvents were used after double distillation. Other chemicals involved in synthesis were procured from Sigma-Aldrich and Alfa Aesar and used without further purification. Melting temperatures of all the synthesized compounds were noted

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

• phase consisted of deionized water (H2O) + 0.1% formic acid as solvent A and MeCN + 0.1% formic acid as solvent B. The flow rate was set at 30 mL/min for fractions 3, 4, and 8, and 20 mL/min for fraction 6. The collected fraction volume for each run was 15 mL. In the purification of fraction 3 (1,315 mg

• ), a gradient elution was implemented, starting from 60% B and progressing to 100% B in 30 minutes. The gradient was then held at 100% B for 10 minutes, resulting in the isolation of 6 (30 mg, tR = 34 min). For the purification of fraction 4 (306 mg), a gradient elution was applied, transitioning

• solvent B from 30% to 100% over 85 minutes. Subsequently, it was maintained at 100% for 15 minutes. This purification protocol led to the isolation of 1 (9.1 mg, tR = 67 min), 3 (19.5 mg, tR = 81 min), and 5 (2.8 mg, tR = 89 min). For fraction 6 (489 mg), a gradient elution was applied starting from 50% B

Synthesis of disulfides and 3-sulfenylchromones from sodium sulfinates catalyzed by TBAI

• Zhenlei Zhang,
• Ying Wang,
• Xingxing Pan,
• Manqi Zhang,
• Wei Zhao,
• Meng Li and
• Hao Zhang

Beilstein J. Org. Chem. 2025, 21, 253–261, doi:10.3762/bjoc.21.17

• -hydroxyacetophenone and N,N-dimethylformamide dimethyl acetal (DMF-DMA) were reacted at 120 °C to give compound 3a, and without further isolation and purification, 1a, H2SO4 and TBAI were added directly to the reaction solution and the reaction was continued at 120 °C for 12 hours. In this way, the product 4a could

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

• Takeshi Fujita,
• Haruna Yabuki,
• Ryutaro Morioka,
• Kohei Fuchibe and
• Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

• JMS-T100GCV or a JEOL JMS-T200GC spectrometer. All the reactions were conducted under argon or nitrogen. Materials: Column chromatography was conducted on silica gel (Silica Gel 60 N, Kanto Chemical Co., Inc.). Toluene and N,N-dimethylformamide (DMF) were purified by a solvent-purification system

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

• substituted β-nitrostyrenes. This one-pot procedure allows the quick isolation of substituted β-nitrostyrene scaffolds with 62–83% yield under mild conditions, without the need for special precautions, inert atmosphere, and time-consuming purification techniques. Keywords: 2C-X; CuCl2; NaBH4; β-nitrostyrene

• atmosphere, special precautions, and with isolated yields up to 60% [14][15]. Due to the formation of side products, final purification of the amino derivatives requires the use of either multiple separation techniques, chromatography, or distillation [15][16][17][18] (Scheme 1). Differently from lithium

• MassLynx ver. 4.1 and data analysis was done using Waters OpenLynx browser ver. 4.1. Solvents were commercial HPLC grade and used without further purification. The substrates 2a, 7a, and 8a were commercially available and used without further purification. The substituted β-nitrostyrenes 1a and 3a–6a were

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• , involving the setup of the reaction, mixing of reactants, reaction workup, product analysis, and product purification. To perform all these basic chemistry tasks effectively, customizable HTE platforms are available from various laboratory instrument manufacturers or can be assembled using a mix of

• perform most tasks in chemical and material synthesis, the hardware currently cannot perform product purification and multistep synthesis continuously. HTE using flow platforms Flow reactions are characterized by a constant flow of reagents and products into and out of the reaction vessel. A flow platform

• products once experiments are performed. Despite this bottleneck, the landscape is evolving, with various practical tools emerging to streamline purification processes. From prepacked silica gel tubes to the precision semipreparative liquid chromatography and the versatile capabilities of various scavenger

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• 49.8 ppm were used as internal references. Mass spectra were acquired on a JEOL JMS-T100LP spectrometer. Flash column chromatography was performed using a Biotage Isolera flash purification system. Extraction and isolation The EtOAc-soluble material (2.45 g) of the methanol extract (38.06 g) from the

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• HPLC (RP-HPLC), which led to the purification of the known metabolites, ianthelliformisamines A–C (1–3) [7] and aplysterol (8) [13], and four new natural products, ianthelliformisamines D–G (4–7) (Figure 1). This extraction and isolation process was repeated twice to obtain sufficient quantities of the

• contained mixtures of polyamine-type alkaloids, which were combined for further isolation work. The following describes the purification of these fractions. Fractions 34–35 (5.0 mg) were purified by semipreparative phenyl RP-HPLC using isocratic conditions of 70% H2O (0.1% TFA)/30% MeOH (0.1% TFA) for the

• first 10 min, then a linear gradient to 10% H2O (0.1% TFA)/90% MeOH (0.1% TFA) was run over 50 min at a flowrate of 9 mL/min; 60 fractions (60 × 1 min) were collected and resulted in the purification of ianthelliformisamine A (1, 1.0 mg, tR 16 min, 0.010% dry wt). Fractions 38–40 were combined (45.0 mg

Germanyl triazoles as a platform for CuAAC diversification and chemoselective orthogonal cross-coupling

• John M. Halford-McGuff,
• Thomas M. Richardson,
• Aidan P. McKay,
• Frederik Peschke,
• Glenn A. Burley and
• Allan J. B. Watson

Beilstein J. Org. Chem. 2024, 20, 3198–3204, doi:10.3762/bjoc.20.265

• displaying an arylboronic acid and MIDA ester (22 and 23) gave no reaction, side reactions were observed with a dialkynyl germane (24), and the product derived from azide 25 was unstable to purification. To further demonstrate the compatibility and utility of germanyl alkynes in CuAAC reactions, we applied

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• yields and used directly in the next step without further purification (Scheme 2). In the case of Boc-protected hydrazones, the reaction must be carefully followed and reacted less than 2 hours in order to avoid the cleavage of the Boc group. The hydrazones 3e and 3f substituted by N-Cbz-ʟ-phenylalanine

• compounds 7e and 7f, no competition with the NH of the phenylalanine was observed. The corresponding tetrahydropyridazines 7a–f were obtained in moderate to good yields (Scheme 5). Concerning compounds 7e and 7f, each diastereomer of the 1:1 ratio mixture could be isolated after purification by flash silica

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• -disubstituted tetrazole-methanesulfonylindole derivatives, with yields ranging from 16% to 55% after purification by column chromatography. Despite some yields being modest, they are deemed reasonable considering the reaction’s structural complexity, atom economy, and the efficiency achieved in terms of time

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• it has been isolated via the lengthy iterative purification process guided by bioactivity. Rediscovery is inevitable based on such a workflow, and this is essentially due to our inability to predict the chemical structure ahead of time. Does this have to be the case? The instructions for natural

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• species. As these modifications proceeded effectively with high yields (>90%) without any taxing purification by chromatography, a simple filtration-based purification was sufficient. This synthetic method enabled a flexible molecular design of the CD-based rotaxane framework in an easy, scalable manner

• six glucose units exist in the usual CD molecules, causing the necessity of the purification step to isolate only the mono-substituted product from the mixture containing others, such as two- or three-substituted species or the starting material (CD) itself. For example, a typical mono-substituted α

Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

• David Ocklenburg and
• David Van Craen

Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250

• be volatile to simplify complex purification. Second, the solubility of the neutral host complexes usually needs to be improved by the installation of solubility groups, which must be considered during ligand design. The biggest strength of metallocages and metallocontainers, whether they are

• acetate salt results in a charge-neutral and bench-stable [L2Zn2] metallocontainer. Purification of the complex is achieved by lyophilization which accomplishes the removal of acetic acid as only byproduct of the complexation reaction and DMSO as solvent. The charge-neutral receptor is obtained as a