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

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• at 399 nm (Figure 5b). A broad emission was observed at 528 nm, resulting in a relatively large Stokes shift of 6100 cm−1, which can be attributed to the structural relaxation in the excited state, as inferred by the observed broad 1H NMR spectrum at room temperature. Due to the thermal energy loss

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

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• δNH2, at around 3370, 3300 and 1596 cm−1, respectively) and by the νCH2 and δCH2 vibrations (curve a) [64][65]. The broad absorption in the high frequency region is characteristic of hydrogen bonding between Si–OH and NH2 groups in functionalised silica materials. After insertion of Cu(I), small

• informative in the low frequency range, where two new broad bands are observed at 1610 and 1515 cm−1, which are compatible with the presence of –NH3+ groups (antisymmetric and symmetric bending modes, respectively) [66][67]. The study also aimed to characterise the catalyst Si-MonoAm-Cu(I) after usage in

• optimised conditions (80 °C, MW, 2 h) with both techniques (curves c in Figure 5). The fingerprints of the aminopropyl groups are still observable in the FTIR spectrum, but new bands are formed at 1660 cm−1 and below 1500 cm−1, with a minor component around 1700 cm−1, which could be related to the

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

• FWHM of 22 nm. Notably, 2b and 2c demonstrate strong chiroptical activity with |gabs| values of 6.7 × 10−3 and 1.0 × 10−2, |glum| of 2.4 × 10−3 and 7.0 × 10−3, and BCPL values of 9.1 and 95.2 M−1 cm−1, respectively. Shortly thereafter, Gong’s group further expanded the π-system by constructing a tris

• -hexabenzo[7]helicene 3 with a carbazole core, which emits at 595/628 nm (PLQY = 0.40), displays |gabs| = 2.98 × 10−3, and achieves a BCPL of 32.5 M−1 cm−1 [16]. In 2025, Babu’s group synthesized two regioisomeric π-extended azahelicenes, 4a and 4b, which differ in the position of attachment to the carbazole

• seconds. In contrast, 4b exhibits superior chiroptical properties, with |gabs| and |glum| values of 3.91 × 10−3 and 1.12 × 10−3, respectively, and an impressive BCPL of 45.77 M−1 cm−1 (Table 1). In 2021, several research groups reported structurally diverse heterohelicene systems exhibiting distinctive

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

• 125 MHz for 13C NMR in CD2Cl2 and 600 MHz for 1H NMR and 151 MHz for 13C NMR in CDCl3 and CD3CN. ATR-FTIR spectra of the compounds were recorded on a Bruker Tensor 27 FTIR spectrophotometer in the range of 4400–600 cm−1 with a resolution of 2 cm−1 at room temperature. The external reflection diamond

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• 153. The nanoribbon is soluble in common organic solvents and exhibits conductivity values up to 1.5∙10−3 S∙cm−1 when doped by TFA in the thin film state. The serendipitous synthesis of azulene-embedded [5]helicenes was reported by Usui, Suemune, and co-workers [99]. The unexpected formation of an

• coefficients (ε) of compounds 172, 22, and 104 are relatively low (below 1000 M−1 cm−1), reflecting the partially forbidden nature of the S0→S1 transitions. Incorporating strongly electron-withdrawing