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

• intramolecular E2 elimination. Finally, the importance and power of the intramolecular Williamson etherification has also been demonstrated by the kilogram-scale synthesis of oxetane intermediate 41, which is a key intermediate in the preparation of the previously mentioned IDO1 inhibitor 2 (Scheme 9) [16

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

• reaction followed by the cleavage of the alkyl group to give intermediate II as a free amine. Annulation of II with CDI gave product B which is an HIV reverse transcriptase inhibitor (Scheme 1B) [17]. We have reported a three-component [3 + 2] cycloaddition followed by IMDA reaction for making heterocyclic

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

• ]pyrazine (hereafter referred to as “triazolopyrazine”) analogues, including derivatives inherited from Pfizer and newly synthesised analogues [5]. Triazolopyrazine compounds of OSM series 4 are believed to dysregulate P. falciparum ATP4ase (PfATP4), possibly as a direct inhibitor [5]. Series 4 compounds

Synthesis of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones by domino C–N coupling/hydroamination reactions

• Ruben Manuel Figueira de Abreu,
• Robin Tiedemann,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2025, 21, 1010–1017, doi:10.3762/bjoc.21.82

• leukaemia, and TAK-285 (H) is a promising HER2/EGFR inhibitor which has been tested in a phase 1 trial on humans as an anticancer agent (Figure 1) [16]. Given the significance of deazapurines as biologically active lead compounds [22], we developed a new methodology for the synthesis of uracil-based

• activities. Development of drugs based on pyrrolopyrimidines: A: Cadeguomycin. B: Tubercidin. C: Toyocamycin. D: Batzelladine A. E: Sangivamycin. F: Pemetrexed. G: Immucillin H. H: TAK-285 (tyrosine kinase inhibitor). UV–vis absorption (left) and emission (right, λex = 300 nm) spectra of compounds 4a, 4j, 4k

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• , outperforming other compounds in the group, such as 5a (IC50 = 78.65 ± 6.88 µM) and 5b (IC50 = 95.66 ± 9.93 µM). These findings suggest that pyrrolidine-2,3-dione derivative 5e holds significant potential as an effective iNOS inhibitor. Conclusion In this study, a series of 4-(1-methylamino)ethylidene-1,5

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• relationships between ligand orientation and anti-adhesive properties of the respective inhibitor. Biological testing For the adhesion-inhibition assays, type-1-fimbriated E. coli bacteria were employed where the α-ᴅ-mannoside-specific adhesion is mediated by the fimbrial lectin FimH. According to a known

• adhesion in serial dilutions leading to dose–response inhibition curves from which IC50 values for each inhibitor were deduced (cf. Supporting Information File 1, Figures S13–S16). As these values can vary between individual assays quite significantly, IC50 values for each inhibitor are compared to methyl

• orthogonally photoswitchable glycocluster combining an azobenzene α-ᴅ-mannoside and an azobenzene β-ᴅ-glucoside unit on a methyl mannoside scaffold (1) [24]. In this account, the heterobivalent glycocluster 1 was tested as inhibitor of mannose-specific bacterial adhesion in its various isomeric states (EE, EZ

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• pendant aryl moiety, is better for target-binding and hence 41 is a ≈10-fold more potent inhibitor of BACE-1 than 40. Several further examples of cyclic ethers will be examined in section 5 (sugars). The anomeric effect applies in acyclic ethers, too. Consider the non-fluorinated scaffold, Ph–O–CH3 (42

• orthogonal in 47 [84], leading to different overall molecular shapes for compounds 46 and 47. Another illustration of this phenomenon is seen with the macrocycles 48 and 49, which are simplified analogues of a known BACE-1 inhibitor [85]. In the non-fluorinated macrocycle 48, the aryl ether moiety features a

• enzyme, and the hydroxy group of 57 interacts with catalytic aspartate residues in the active site. The fluorinated pepstatin analogue 58 was predicted to be pre-organised into the bent conformation and hence be a more potent inhibitor than 57. Compound 58 was indeed found to be more potent than 57

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

• cyclic amino acids are common structural motifs in the design of small-molecule drugs and peptidomimetics [1]. For example, the clinically used anesthetics carfentanil (1) and remifentanil (2), the FDA-approved antipruritic medication defelikefalin (3), and the arginase inhibitor 4 [2] possess cyclic α,α

• -disubstituted piperidine-containing amino acid subunits. Likewise, a cyano-substituted cyclic aminal is a core structural unit of the fibroblast activation protein inhibitor 5 [3] (Figure 1). The widespread use of non-proteinogenic cyclic amino acids in drug discovery justifies both the design of new analogs

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• designing a photoswitchable drug is to place the switch at a position in the pharmacophore that allows switching of the biological effect by irradiation with light without greatly reducing the overall activity by unselective interference with the inhibitor–receptor interaction. This is a difficult task

• efficiency. In any case the light-induced geometry change via isomerization should selectively control the interaction between the inhibitor and the receptor [21]. Currently there is only one example reported in the literature for the incorporation of N-acetyl diazocines into biologically active molecules

• switching properties even in an aqueous environment and are therefore promising switches in photopharmacological applications. a) Structural similarity of N-acetyl diazocine 1 with known 17βHSD3-inhibitor tetrahydrodibenzazocine (THB) [17] and parent diazocine with steroid scaffolds [18]. b) Parent

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

• yields [27]. These reactions have been utilized in the enantioselective synthesis of aryl sulfoxides through the arylation of sulfonate anions in the presence of palladium catalysts [28][29]. They have also been used in the synthesis of the neuraminidase inhibitor (−)-oseltamivir [30] and 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

• complex as the amide coupling agent with thionyl chloride [38] (Figure 1C). Recently, benzothiazine scaffolds of phenyl acetamides were synthesized as potent inhibitors for ureolytic infections [39] (Figure 1D). Saccharine (a sweetener) was reported to be a potent carbonic anhydrase inhibitor (CAI) by

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

• Yujun Pang,
• Jinglan Yan,
• Nawaf Al-Maharik,
• Qian Zhang,
• Zeguo Fang and
• Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

• properties that can modify the activity and pharmacokinetic profiles of drugs [7]. Prominent examples include pantoprazole, a widely used proton-pump inhibitor (PPI) featuring a CF2H group; deracoxib, another drug that also incorporates a CF2H moiety in its structure; and a MET inhibitor specifically

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• concentrations in the later stages of this pathology, has been gaining attention for the treatment of this disease. In 2021, Brandão et al. [33] developed a series of molecules inspired by the oxoindole-β-lactam core, a structural motif, present in many acetylcholinesterase inhibitor drugs, through the Ugi

• showed more potency than galantamine (IC50 = 3.9 μM), a cholinesterase inhibitor in clinical use against AD. In the search for novel ligands for Alzheimer's treatment, a common strategy involves the combination of structural fragments from different molecules. This concept often yields new compounds with

• new family of ferulic acid–tacrine hybrids (FATHs), using the Ugi reaction. FATHs were selected because tacrine is a well-known cholinesterase (ChE) inhibitor, although it is hepatotoxic, and ferulic acid is a potent antioxidant. Fourteen FATH were synthesized and tested for hepatotoxicity

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

• representative studies include antibacterial, anti-inflammatory, antioxidant, selective inhibitor of COX-2 [34], and anti-HIV activity [35]. In this context, even though indole is considered a privileged scaffold present in some anticancer agents [36], a few examples of methanesulfonylindoles are studied as

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

• mentioned above, that the free NH function of indirubin is important for CDK inhibition. We have shown in our group by enzyme studies that glycoside β-33b, lacking the free NH-function, does not act as a CDK inhibitor, despite its high activity against melanoma cells and other cancers [32]. These results

• carbohydrate moiety is later hydrolytically cleaved in the cell to release the indirubin which then acts as a CDK inhibitor. A synergistic effect of plasma-activated medium (PAM) and β-33b on human skin cancer cells was observed [32][33]. With regard to viability, adhesion capacity, apoptosis and G2/M cell

• STAT3 (signal transducer and activator of transcription 3) were observed as biochemical pathways, along with downregulation of antiapoptotic XIAP (X-linked inhibitor of apoptosis protein) and surviving as well as upregulation of the proapoptotic Bcl-2 protein Puma and the cell cycle inhibitor p21. It is

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• inhibitor conformation found by docking is energetically unfavorable and therefore the expected activity of compound 5e will be much lower than that of compounds 4a–e. Molecular docking data can therefore be used to infer the structure–activity relationship. The substituent on the C-5 atom of

• Figure 5A for compound 4e. The heterocyclic nitrogen is indeed orientated towards the haem iron, with an N–Fe distance of 2.8 Å, which is slightly higher than the distance of 2.1 Å in the crystal complex with the inhibitor voriconazole. The benzene substituent on the C-6 atom is located in a hydrophobic

• probable reaction path of the interaction was suggested. Based on the docking data, N-aryl(alkyl)-7-oxo-5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidin-5-carboxamides as (S)-isomers were shown to be potent inhibitors of CYP51. These results allow us to consider these compounds as potential CYP51 inhibitor

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• RdRp inhibitor, and their evaluation in an in vitro polymerase assay, targeting SARS-CoV-2 [17]. The synthesis of the new molecules involved three modifications of the HeE1-2Tyr inhibitor, which included changing the core structure from a benzothiazole to a benzoxazole unit and simplifying it to

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• well known as a potent β-lactamase inhibitor [33][34]. It is produced by the filamentous bacterium Streptomyces clavuligerus, but in low yield. Various clavams 2–5 have been identified (Figure 2B), either through isolation as natural metabolites or obtained by synthetic methods [35][36][37][38][39][40

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

• Smaher E. Butt,
• Konrad Kepski,
• Jean-Marc Sotiropoulos and
• Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

• many organocatalysts [3][4][5], natural products (e.g., the potent α-glucosidase inhibitor (−)-codonopsinol B) [6][7], and pharmaceutical drug molecules such as saxagliptin and ramipril (Figure 1) [8]. Accordingly, the development of methods to access substituted prolines and pyrrolidines is an

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

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

• ring was isolated from Ulocladium botrytis [219] and Microsphaeropsis olivacea [167]. Its structure was unambiguously confirmed by NMR spectroscopy and by total syntheses [44][220]. Ulocladol is a tyrosine kinase (p56lck) inhibitor leading to a reduction of enzyme activity to 7% at 0.02 µg/µL) [219

• furthermore turned out to be an inhibitor of trypanothione reductase (IC50: 4.3 μM) giving rise to an activity against Trypanosoma and Leishmania sp. [225] and inhibited Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) (but not the human orthologue) with an IC50 value of 5.9 µM [227]. Altenusin

• especially active against the kinase pp60c-Src (IC50: 20 nM) [231]. Altenusin turned out to be an inhibitor of α-glucosidase and pancreatic lipase (IC50: 46.1, 21.5 µM, respectively) [238], and of neutral sphingomyelinase (nSMase) with an IC50 value of 28 µM (but not of aSMase) [230][239]. It inhibited tau

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• Supporting Information File 1). Next, we paid attention to testing the conditions we developed for the synthesis of the SO2-containing analogue 2r of potent anticancer drug enastron in gram scale (Scheme 3). Enastron is a novel dihydropyrimidine-based mitotic kinesin spindle protein KSP/Eg5 inhibitor [36

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• wide range of pharmacological activities, such as anti-inflammatory, anti-arrhythmic, antitumor, antifungal, antibacterial, and anti-HIV activities [7][8][9][10][11][12][13]. For example, two N1-substituted bioactive indazoles are found in Figure 1, danicopan (1), a complement factor D inhibitor for

• the treatment of paroxysmal nocturnal hemoglobinuria, and CPI-637 (2), an inhibitor of both cyclic-AMP response element binding protein (CBP) and adenoviral E1A binding protein [14][15][16]. The N2-substituted indazole analogs pazopanib (3), an FDA-approved tyrosine kinase inhibitor used for the

Negishi-coupling-enabled synthesis of α-heteroaryl-α-amino acid building blocks for DNA-encoded chemical library applications

• Matteo Gasparetto,
• Balázs Fődi and
• Gellért Sipos

Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168

• of recently approved drugs by the FDA [31]. Fezolinetant (an NK3 receptor antagonist) and quizartinib (FLT3 inhibitor) are just a couple of examples among the drugs reaching the market in the last year. As shown in Scheme 2, ethyl (bromozinc)acetate (1a) was synthesized in flow by pumping a solution

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• activity and thus block cancer formation [2]. Alangiumkaloids A, an isoquinolinone alkaloid isolated from Alangium salviiforlium, was reported to exhibit cytotoxic activity against cancer cells [3]. In 2018, duvelisib, a dual inhibitor of phosphoinositide-3 kinases, was firstly approved by the FDA for the