Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• 9.4), NAD+ (2 mM), glutamate dehydrogenase (1 µL of a 50% glycerol solution, 15 mg/mL), and hydrazine (0.5 µL) and incubated at room temperature for 40 min. The absorbance at 340 nm was measured and converted to glutamate concentration using the extinction coefficient for NADH of 6220 M−1 cm−1. 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

• , 143.4, 133.9, 132.2, 126.2, 123.3, 113.9, 65.6, 35.6, 34.1, 31.5, 28.4 ppm; FTIR (KBr): 2950, 2860, 1770, 1704, 1606, 1510, 1389, 1240, 1183, 1042, 931, 826, 716 cm−l. Synthetic procedure of compound 11 Compound 10 (0.4 g, 1.1 mmol) and 80% hydrazine hydrate (0.4 mL, 6.6 mmol) were added to 15 mL of

• , 1182, 1060, 941, 823, 545 cm−1. Synthetic procedure of compound 12 Bromonaphthalic anhydride (1.3 g, 4.8 mmol) was added to a stirred solution of amine 11 (1.0 g, 4.8 mmol) in ethanol (25 mL). The reaction mixture was refluxed for 2 h, and the progress of the reaction was monitored by TLC. After

• , 130.3, 129.0, 128.1, 126.1, 123.1, 122.2, 113.9, 66.1, 38.2, 34.0, 31.5, 28.1 ppm; FTIR (KBr): 2959, 2867, 1705, 1659, 1581, 1508, 1357, 1233, 1169, 1068, 945, 835, 780, 661, 555 cm−1. Synthetic procedure of compound 7 NaBH₄ (100 mg, 2.6 mmol) was added to a stirred solution of diphenyl diselenide (234

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

• spectroscopy, LC–MS and elemental analysis (Supporting Information File 1, Figures S1–S36). The IR spectra of compounds 1–5 showed the presence of NH absorption bands in the range 3381–2936 cm−1, OH at 3396 cm−1 (compound 9), and C=O at 1601–1610 cm−1 (compounds 6-8). Cytotoxic potency of the compounds 1–9

Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)

• Tin Zar Aye,
• Rubal Sharma,
• Muthu Karuppasamy,
• Daiya Suzuki,
• Haruka Nakajima,
• Yoshitane Imai,
• Mitsuhiro Arisawa,
• Mohamed S. H. Salem and
• Shinobu Takizawa

Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25

• ) relative to their oxaza[7]helicene analogues (<25 kcal/mol). After chiral HPLC separation, the enantiomers display mirror-image CD and strong solution CPL, with |glum| up to 2.6 × 10−3 and fluorescence brightness up to 30.75 M−1 cm−1. Keywords: chemoselectivity; chiroptical; circular dichroism

• . In chloroform, 5a shows a pronounced higher absorption peak at 426 nm (ε = 8.23 × 104 M−1 cm−1) with an optical indirect bandgap (Eg) of 2.78 eV. Similarly, 5b, 6a, and 6b exhibit their higher absorption peaks at 433 nm (ε = 5.59 × 104 M−1 cm−1), 407 nm (ε = 6.43 × 104 M−1 cm−1), and 414 nm (ε = 9.02

• × 104 M−1 cm−1), with corresponding optical indirect bandgaps Eg of 2.70, 2.93, and 2.85 eV, respectively (see Supporting Information File 1). The photoluminescence (PL) spectra in chloroform display emission maxima at 459 and 468 nm for 5a and 5b, compared to 439 and 447 nm for 6a and 6b. To gain

Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls

• Mark M. Gulman,
• Yuliya F. Polienko,
• Sofia Yu. Trakhininа,
• Yuri V. Gatilov,
• Tatyana V. Rybalova,
• Sergey A. Dobrynin and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22

• presence of DIPEA in chloroform under reflux (Scheme 2). These conditions ensured complete conversion in 30 minutes. The IR spectra of nitroxides 3a–f exhibit intense absorption bands in the ranges of 1354–1358 cm−1 and 1174–1178 cm−1, corresponding to the asymmetric and symmetric vibrations of the

• isolated from the reaction mixtures in each case. The IR spectra of the isolated compounds 4a–f showed characteristic absorption bands to the azido group vibrations at 2100–2116 cm−1. Absorption bands in the ranges of 1410–1420 cm−1 and 1170–1190 cm−1 were also observed, which can be assigned to the out-of

• catalytic system comprising PPh3, CuI, and Pd(PPh3)2Cl2. This procedure afforded alkynones 6a,b in the yields of 75% and 44%, respectively (Scheme 3). In the IR spectra of 6a,b intense bands were observed at 2212–2214 and 1645–1647 cm−1, assigned to vibrations of the triple bond, and the conjugated carbonyl

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

• and 1620–1680 cm−1 indicated the presence of hydroxy and carbonyl groups, respectively. Streptoquinoline A (1): The molecular formula of 1 was elucidated as C28H35NO6 based on HRESIMS measurements. The 13C NMR spectrum (in DMSO-d6) showed 28 signals, which were classified into five methyl carbons

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

• relatively high solubility. Intramolecular hydrogen bonding Previous pharmacokinetic investigations showed that 1 displays high permeability in the MDCK assay (apical–basal 29 × 10−6 cm/s and basal–apical 20 × 10−6 cm/s) [6], a well-established in vitro model for assessing blood–brain barrier (BBB

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

• of 300 nm. Fluorescence lifetimes were measured for solutions and powder samples with a HORIBA DeltaFlex spectrometer with a 370 nm LED light source for excitation. For the lifetime measurements of solution, a conventional 1 cm quartz cell was used. Optical rotation values were measured with a JASCO

• Hz, 2H), 7.45 (d, J = 8.8 Hz, 2H), 7.36 (dd, J = 1.6, 8.4 Hz, 2H), 7.202–7.198 (m, 2H), 3.74 (s, 6H), 0.17 (s, 18H); 13C NMR (100 MHz, CDCl3) δ 155.5, 133.7, 129.4, 128.9, 128.7, 128, 126.7, 121, 119.1, 114.7, 106.1, 94.2, 56.6, 0.05; IR (KBr) νmax: 3058, 1774, 1409, 1191, 1152, 969, 698, 553, 431 cm

• , 961, 882, 597, 530, 432 cm−1. The R-isomer was synthesized using a similar procedure to that of the S-isomer, except that compound R-2 (208 mg, 0.41 mmol) and TBAF (1.7 mL) in THF (17 mL) were used. The yield was 81%. Synthesis of S/R-Pt The synthesis of platinum(II) complex describe the R-enantiomer

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• method (CM)) (Scheme 1, Table 1). All syntheses were also carried out with microwave irradiation (MWI), which had a short reaction time; however, no improvement in yield was achieved (see Supporting Information File 1). The structural analyses of the compounds were performed using 1H/13C NMR and mass

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

• independent molecules. Note that crystals 2, 3, 9a and 9b have a relatively high density (dcalc/g cm−3 1.739, 1.748, 1.595 and 1.567) for crystals that do not contain heavy atoms. In the absence of hydrogen bonds in the crystals of 2, 3, 9a and 9b, multiple specific interactions of the types such as lone

• (1H), 100.53 MHz (13C) in CDCl3 using residual signals of the nondeuterated solvent (δH 7.26, δC 77.16) as the references. The vibrational spectra were measured on a Shimadzu IR-Prestige-21 Fourier-transform IR spectrometer in KBr pellets over 400–4000 cm−1 range (resolution was 2 cm−1). Mass spectra

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• chlorides (not shown) [185][186]. 1.8 Alkenyl chloride synthesis via olefin metathesis Johnson and co-workers investigated complex 287, which forms as a product of an initial metathesis cycle in the cross-metathesis (CM) with alkenyl chlorides (Scheme 55) [187][188]. The authors observed that complex 287

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

• delta (δ) units, parts per million (ppm) downfield from internal TMS (1H, 13C) or external CH3NO2 (14N negative values of δN correspond to upfield shifts). The IR spectra were recorded with a Bruker ALPHA-T spectrometer in the range of 400–4000 cm−1 (resolution 2 cm−1) as pellets with KBr or as a thin

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

• frequencies of the carbonyl function (ν 1633–1593 cm−1) and N–H, O–H groups (ν 3435–3126 cm−1), which indicates their participation in the hydrogen bond formation [67]. On the other hand, the IR spectra of hexahydrooxazolo[3,2-a]pyridones 5a–c contain intense absorption bands of the C=O function at ν 1652

• –1628 cm−1 and NH2 groups at ν 3376–3272 cm−1. The structures of the obtained heterocycles 4 and 5 contain three stereocenters, so one could expect the formation of up to 8 stereoisomers in each case. Analysis of the 19F NMR spectra showed that from two to four diastereomers of

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

• . Results and Discussion We commenced our investigation using CF3-subsituted iminopropargyl alcohol 1a and NaSCN as model substrates. The completion of the reaction was monitored using IR spectroscopy to observe the disappearance of the band at 2219 cm−1 (–C≡C–). It was found that CF3-iminopropargyl alcohol

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

• (thickness of the stationary phase: 30 mm, eluent: DCM). After evaporation of the solvent, the residue was triturated with Et2O (50 mL) to give pure 7 (25.30 g, 84%) as colorless crystals. Mp 223‒225 °C (CH3CN/EtOH 1:1 (v/v)); IR (KBr): 1638, 1604, 1574, 1501, 1354, 1300, 1175, 1063, 854 cm−1; 1H NMR (600

• 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

• -like hard substance obtained was suspended in DIPE to afford 21a as colorless crystals. Mp 76‒78 °C; IR (KBr): 3314, 2939, 1728, 1510, 1328, 1064, 853, 599 cm−1; 1H NMR (600 MHz, CDCl3): 7.94 (d, 4J = 1.9 Hz, 1H), 7.43 (dd, 4J = 2.1 Hz, 3J = 8.4 Hz, 1H), 7.39 (d, 3J = 8.4 Hz, 1H), 6.92 (s, 1H), 6.83 (s

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• through intramolecular hydrogen bonding. By comparing the data for λabs and λem, it is evident that the compounds exhibit significant Stokes shifts with values above 2,100 cm−1, reflecting their stability in the excited state [87][88][89]. The highest values of Stokes shifts were observed in polar protic

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

• characterized by FTIR spectroscopy (Supporting Information File 1, Figure S1). In comparison to crude silica gel, the diminished band corresponding to the –OH group (around 980 cm−1) and the appearance of new bands characteristic of amino groups (around 3000 cm−1) indicate the successful introduction of amino

• groups onto the silica gel surface, confirming the formation of a-SG. Upon modification of a-SG with BU1, additional bands characteristic of BU1 appeared. When comparing BU1 with the SG-NHCO-BU1 material, the C=O vibration band shifted from 1703 cm−1 to 1696 cm−1 indicating the formation of an amide bond

• . Additionally, a new absorption band at 1558 cm−1 was observed in the spectra of SG-NHCO-BU1 further confirming covalent attachment of BU1 through an amide bond. In the case of SG-BU1, a C=O vibrational band is observed at 1705 cm−1, which corresponds to the vibration of the C=O of BU1 carboxylic acid groups

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• mixture collected from the reaction medium after five minutes. Figure 13e presents the spectrum of the isolated product 3a. As demonstrated in Figure 13c and 13d, the signal attributed to the C=N stretching of starting nitrone 1a, observed at 1548 cm−1, disappears. This finding suggests that the nitrone

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• are reported in cm−1. Mass spectrometry was performed using a JEOL AccuTOF electrospray instrument (ESI). The dye uptake was quantified by UV–vis spectroscopy (Cary 100 Bio UV–visible spectrophotometer) at 25 °C. Incubation of hosts with dyes was performed using an Eppendorf ThermoMixer™ C in 1.5 mL

• ), 4.22 (d, J = 15.8 Hz, 2H), 4.03 (s, 12H), 3.72 (s, 12H), 3.37 (s, 12H), 1.78 (s, 6H), 1.72 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 154.2, 151.4, 148.9, 148.1, 128.5, 124.8, 123.9, 122.2, 108.8, 103.6, 77.4, 75.6, 61.2, 56.1, 55.9, 43.7, 36.1, 17.5, 17.4; IR (ATR, cm−1): 2935 (w), 2833 (w), 1714 (w), 1614

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• permeability (Pe) results were considered good above 10 × 10−6 cm/s, moderate under 10 × 10−6 cm/s and low, when no substance was detected on the acceptor side. Compounds with low kinetic solubility were not measured in the permeability assay. As a result, four compounds presented good permeability: (E)-7a, (E

• on a Bruker ALPHA FT-IR spectrometer in KBr pellets, ν̃ was reported in cm−1. NMR spectra were recorded at 295 K on a Bruker Avance III HD 600 (600 and 150 MHz for 1H and 13C NMR spectra, respectively) spectrometer equipped with a Prodigy cryo-probe head. Full 1H and 13C assignments were achieved

• , 20.5; IR (KBr) ν̃: 3407, 3360, 1477, 1302, 1151, 1106 cm−1; HREIMS (m/z): [M•]+ calcd for C9H12N4O2S, 240.0675; found, 240.0677. 8-Hydrazino-2-methyl-4-phenyl-2H-1,2,3-benzothiadiazine 1,1-dioxide (5b). To a mixture of 4b (4.00 g, 13.0 mmol) and pyridine (36 mL), hydrazine monohydrate (6.30 mL, 6.50 g

A m-quaterphenyl probe for absolute configurational assignments of primary and secondary amines

• Yuka Takeuchi,
• Mutsumi Kobayashi,
• Yuuka Gotoh,
• Mari Ikeda,
• Yoichi Habata,
• Tomohiko Shirai and
• Shunsuke Kuwahara

Beilstein J. Org. Chem. 2025, 21, 2211–2219, doi:10.3762/bjoc.21.168

• polarized along the long axes of the methoxybiphenyl chromophores. The CD spectrum of (S)-2a shows Cotton effects arising from exciton-coupling between the two methoxybiphenyl chromophores; λext = 278 nm (Δε1 = −0.6 dm3 mol−1 cm−1) and λext = 258 nm (Δε2 = +1.7 dm3 mol−1 cm−1). The amplitude of exciton

• -coupled CD (ACD value) [7], defined as ACD = Δε1 (first Cotton effect) − Δε2 (second Cotton effect), is measured to be −2.3 dm3 mol−1 cm−1. The direction of the twist of the two chromophores in biaryl compounds can be determined by the sign of the Cotton effect of the exciton-coupled CD. Maison [44

• , 1038, 822 cm−1; FABMS (matrix DTT/TG = 1:1) m/z: 465 [M]+ (100%); Anal. calcd for C31H31NO3: C, 79.97; H, 6.71; N, 3.01; found: C, 79.73; H, 6.75; N, 2.98. Theoretical calculations To obtain the population between M and P conformers, preliminary conformational searches were run on the structures of (S

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• intramolecular cyclization of 16 generated benzofuran 17 in 83% yield. After protecting the phenolic hydroxy group of 17, cross-metathesis (CM) with allylic alcohol 18 catalyzed by 13 furnished intermediate 19. Desilylation of 19 produced heliannuol G (20) and heliannuol H (21), with the structure of 21

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• –3.69 (m, 2H, OCH2), 4.07–4.09 (m, 2H, OCH2); 31P{1H} NMR (CDCl3, δ, ppm, J, Hz) 32.04 (s); IR (liquid, cm−1): 762 (m, oxirane), 858 (m,oxirane), 927 (m, oxirane), 1019 (m), 1139 (w), 1166 (w, P=O), 1240 (m, oxirane), 1316 (m, R-P(O)OR), 1349 (s, P=O), 1425 (w), 1455 (m), 1647 (m), 2932 (m), 3004 (m

• ), 3.75–3.84 (m, 2H, OCH2), 4.13–4.23 (m, 2H, OCH2); 31P{1H} NMR (CDCl3, δ, ppm, J, Hz) −0.1 (s); IR (liquid, cm−1): 598 (w), 763 (m, oxirane), 865 (m, oxirane), 921 (m, oxirane), 1021 (m, P(O)(OR)2), 1140 (w, P(O)(OR)2), 1168 (s, P(O)(OR)2), 1185 (w), 1261 (m), 1350 (m, P=O), 1430 (w), 1455 (m), 1644 (w

• -oxirane), 3.14–3.24 (m, 3H, CH-oxirane), 3.84–3.95 (m, 3H, OCH2), 4.22–4.36 (m, 3H, OCH2); 31P{1H} NMR (CDCl3, δ, ppm, J, Hz) −1.2 (s); IR (liquid, cm−1): 599 (w), 700 (w), 763 (m, oxirane), 797 (m, oxirane), 869 (m, oxirane), 918 (m, oxirane), 1024 (m), 1139 (w, P=O), 1166 (s, P=O), 1259 (m), 1349 (m, P

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• EtOAc/petrol 1:4, to give the tosylate 3 (1.30 g, 79%) as an amorphous solid; Rf 0.57 (EtOAc/petrol 1:1); IR (film, cm−1) νmax: 2943, 1708, 1647, 1611, 1599, 1494, 1468, 1455, 1425, 1359, 1314, 1292, 1258, 1178, 1119, 1023, 976, 936, 885, 831, 816, 776, 752; 1H NMR (400 MHz, CDCl3) δ 7.66–7.59 (m, 2H

• aldehyde 4 (562 mg, 41%) as needles; mp 94–96 °C; Rf 0.35 (EtOAc/petrol 1:1); IR (film, cm−1) νmax: 2942, 1712, 1614, 1581, 1495, 1472, 1260, 1190, 1177, 1122, 1096, 1064, 1019, 815, 785, 755; 1H NMR (400 MHz, CDCl3) δ 9.44 (t, J = 1.0 Hz, 1H), 7.69–7.62 (m, 2H), 7.36–7.28 (m, 3H), 7.20 (dd, J = 7.5, 1.0

• (film, cm−1) νmax: 2941, 1784, 1694, 1612, 1495, 1471, 1434, 1377, 1352, 1281, 1247, 1181, 1138, 1092, 1072, 1041, 993, 932, 870; 1H NMR (400 MHz, CDCl3) δ 7.30 (td, J = 7.5, 1.0 Hz, 1H), 7.21 (br d, J = 7.5 Hz, 1H), 7.07 (td, J = 7.5, 1.0 Hz, 1H), 6.84 (br d, J = 7.5 Hz, 1H), 5.07 (d, J = 7.5 Hz, 1H

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

• stirred. After that, the reaction mixture was left to stir in the ice bath for 24 hours, allowing it to slowly reach room temperature. Diffusion mixing technique: A small vial (15 mL volume, diameter 1.3 cm) equipped with a magnetic stirring bar was charged with a mixture of dipolarophile 2 (1 equiv

• , 0.150 mmol) and hydroxyimidoyl chloride 4 (1.1 equiv, 0.165 mol) in 4.5 mL of DCM and then placed in larger vial (50 mL volume, diameter 3.5 cm) containing TEA (35.85 mmol, 5 mL). The outer vial was tightly closed with a lid and the reaction mixture was stirred at room temperature for 24 h. In both