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

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• Table 2). Analysis of the Huang-Rhys factors delivered that the meta-chlorinated phenyl units do indeed restrict the rotation of the donor. Moreover, the reduction of the LE character of the D1-excited state and a reduction of coupled vibrational modes in the regime from 1000–2000 cm−1 seem to decrease

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• and 150 or 100 MHz for 13C. Melting points were measured on a Meltemp apparatus in open capillary tubes and are uncorrected. IR spectra were measured on a Thermo Nicolet NEXUS 670 FT/IR spectrometer by attenuated total reflectance (ATR) and are reported in cm−1. Mass spectrometry was performed using a

• high vacuum to yield C1 as a white solid (0.3444 g, 68% yield). Mp > 300 °C; IR (ATR, cm−1): 3456 (w), 1720 (m), 1472 (m), 1378 (w), 1226 (m), 1101 (s), 1023 (m), 972 (w), 790 (w); 1H NMR (400 MHz, D2O) 6.71 (s, 4H), 5.67 (d, J = 15.4 Hz, 2H), 5.57 (d, J = 15.8 Hz, 4H), 5.46 (d, J = 8.9 Hz, 2H), 5.42

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

• (HREIMS) were measured on a MAT 711 (Varian MAT, Bremen, Germany). Electron energy for EI was set to 70 eV. Infrared spectra (IR) were measured on an ALPHA II (Bruker, Billerica, USA) spectrometer. Characteristic absorption bands are given in wave numbers (cm−1). Qualitative thin-layer chromatography (TLC

• , CDCl3) δ −56.23 (t, J = 20.7 Hz), −140.45 (dq, J = 28.6, 11.9, 11.1 Hz); ATR-FTIR (neat): 3587, 2975, 2868, 1634, 1500, 1333, 1249, 1137, 870, 820, 709 cm−1; HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C35H23Cl3F7N3NiO3, 853.9916; found, 853.9958. Ni(II)-Schiff base complex of bisTfMePhe 7: Under inert

• , 121.5, 71.2, 70.9, 63.3, 58.6, 40.7, 30.8, 23.7; 19F NMR (565 MHz, CDCl3) δ −62.57 (s); ATR-FTIR (neat): 3062, 2982, 2868, 1638, 1463, 1278, 1133, 894, 820, 705 cm−1; HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C36H26Cl3F6N3NiO3, 850.0167; found, 850.0181. Ni(II)-Schiff base complexes of (2S,4R)-TfLeu 11a

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

• for the formation of intermediates. Gao et al. studied the generation of metal acetylide A by IR spectroscopy [65]. When subsequent additions of 1 equiv FeCl3 were made in a solution of alkyne and TMG, the C–H stretch peak at 3277 cm−1 started to decrease as the temperature increased from 30 to 100 °C

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

• at 416 nm is the most red-shifted from ANTH of the listed compounds, resulting in deeper blue fluorescence. It also has the largest Stokes shift of 837 cm−1 (large Stokes shifts are attributed to attenuation of fluorescence by self-quenching processes [30]). Only ANTH obeys the mirror image rule

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

• extinction coefficient (6100 M−1 cm−1) compared to Me2B (4700 M−1 cm−1) at their λmax values of 403 nm and 394 nm in DCM, respectively [19]. This difference in light absorption is further exacerbated by the fact that the irradiation wavelength is not aligned with the λmax of Me2B. Calculating from the

• reported value, the extinction coefficient of Me2B at 405 nm is approximately 4500 M−1 cm−1. As a result, initiating the reaction in Me2B is not as efficient, and may require a shorter wavelength of higher intensity. However, as reported by Kosower et al. [18], bimanes are prone to photoreactions under UV

• crystals were then irradiated for variable periods of time using 405 nm LED (75 mW cm−2) in an Elegoo Mercury Plus Wash and Cure (turntable chamber). Samples were placed approximately 8 cm far from the light source. The average light power measured at this distance was 5 mW cm−2. During the irradiation

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• decrease to normal values of 1800–2000 cm−1, indicating a complete inhibition of the ESIPT process. These spectral transformations are usually caused by the formation of a strong N–H(O–H)···CN− (F−) hydrogen bond up to deprotonation [28]. Using the principle of “relay recognition” [29], we investigated the

• , CN) (Aldrich) were used to prepare the solutions. Spectral fluorescent experiments were performed using quartz cells (lcuvette 1.0 cm, volume V 2 mL). Stock solutions of compounds 7 or 8 (c 5.0 × 10−5 mol L−1) and tetrabutylammonium salts (c 1.0 × 10−4 mol L−1) in acetonitrile were used. The

• (6) Å, β = 102.590(3)°, V = 1821.55(9) Å3, Z = 4, ρcalc = 1.527 g cm−3, μ(Мо Кα) = 0.520 mm−1, P21/c space group. Intensities of 15441 reflections were measured in the reciprocal space (2θ ≤ 64.14°) using the ω/2θ-scanning method from a single crystal with dimensions of 0.31 × 0.25 × 0.20 mm. An

Synthesis of new condensed naphthoquinone, pyran and pyrimidine furancarboxylates

• Kirill A. Gomonov,
• Vasilii V. Pelipko,
• Igor A. Litvinov,
• Ilya A. Pilipenko,
• Anna M. Stepanova,
• Nikolai A. Lapatin,
• Ruslan I. Baichurin and
• Sergei V. Makarenko

Beilstein J. Org. Chem. 2025, 21, 340–347, doi:10.3762/bjoc.21.24

• IR spectra of compounds 5a–6d containing an alkoxyfuropyran fragment shows that in the case of methyl esters 5a, 6a, and 6c the absorption band of the alkoxycarbonyl function is shifted to a lower frequency region (1714–1721 cm−1), while ethyl esters 5b, 6b, and 6d are characterized by higher

• frequency values (1725–1731 cm−1). This observation may be due to the position of the ester fragment relative to the heterocyclic system. The analysis of the results of X-ray diffraction analysis shows that the torsion angle C(10)–C(3)–C(16)–O(17) of methyl esters 5a and 6c is −0.8(2), and 5(2)°, and of

• . In turn, in the IR spectra (KBr) of compounds 7a–f, absorption bands of the ester fragment in the region of 1714–1750 cm−1 and absorption bands of the carbonyl group of the amide fragment in the region of 1674–1688 cm−1 are observed, which suggests the existence of these compounds in the solid phase

Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity

• Abel Cárdenas,
• Zexin Jin,
• Yong Ni,
• Jishan Wu,
• Yan Xia,
• Francisco Javier Ramírez and
• Juan Casado

Beilstein J. Org. Chem. 2025, 21, 277–285, doi:10.3762/bjoc.21.20

• neutral species was measured at 1700 cm−1 and was predicted at 1730 cm−1 for m-1. This band was assigned to the symmetric CC stretching mode of the four bonds that are exocyclic to CBD, ν(CC)exo-CBD, or CBD breathing mode, as indicated by the atomic displacements shown in Figure 4. Other two strong Raman

• features were measured at 1448 and 1355 cm−1. They were predicted at 1468 and 1354 cm−1, respectively, for m-1, being assigned to CC stretching modes with slight contributions of aromatic CH bending vibrations. The complete eigenvector for these vibrations can be seen in Figure S2 in Supporting Information

• File 1. Given that former normal mode mainly involves the CBD moieties, the observed feature at 1700 cm−1 can be considered a suitable marker band of the structural and electronic changes of the antiaromatic CBD rings upon oxidation. The Raman spectra of 1, 1•+, and 12+ are shown in Figure 5. Relative

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• well-structured absorption peaks clearly showing the vibronic progressions. BPP-OiPr 3 also exhibited a small peak located at 442 nm with the molar extinction coefficient (ε) of 1800 M−1 cm−1, which was similar to the previous observations of the dark S1 states for BPP 2 and its mesityl- and tert-butyl

• (Supporting Information File 1, Table S2). The longest-wavelength absorption maximum (S0 → S1), attributed to the HOMO → LUMO transition, was calculated to be at 432 nm (f = 0.5674) for 4. Compared to the S1 states in BPP 2 (ε = 1200 M−1 cm−1) and BPP-OiPr 3 (ε = 1800 M−1 cm−1), corresponding to forbidden

• transitions as previously discussed for other BPP derivatives [21][22], the strikingly enhanced molar extinction coefficient observed for the lowest-energy band of BPP-dione 4 (ε = 17000 M−1 cm−1) indicates that the optical transition to the S1 state becomes allowed by this oxidation. BPP 2 and BPP-OiPr 3

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• obtained are summarized in Scheme 2 and Table 1. It was found that the size of the vial used to carry out the reaction significantly affected the reaction rate. Thus, in an apparatus consisting of two vials with diameters of 1.3 and 2.8 cm, the conversion of the starting compound was 37 and 31

• %, respectively, when carrying out the reaction in chloroform or methanol over two days (Table 1, entries 3 and 7). In turn, in a system of two vials with diameters of 3.7 and 7.5 cm, and with a loading of diketone 1 that was five times greater, more than two thirds of the starting compound reacted within 24 h

• (1 equiv), 0.05 mmol ʟ-proline and 2.0–5.0 mmol diene (2–5 equiv) in 3–5 mL acetonitrile was placed into a 15 mL vial (diameter 1.3 cm). This vial was then placed into a closed 50 mL vial (diameter 2.8 cm) containing 3–5 mL of formalin, and the reaction mixture was stirred at room temperature for 2

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• absorption maxima (λmax) at 299, 307, 291, 301, 307, and 369 nm, respectively. The molar absorption coefficients at λmax of N3(o), N4(o), and I1(o)–I4(o) were determined to be 12200, 12700, 47800, 22700, 12900, and 12700 M−1 cm−1, respectively. Upon irradiation with 365 nm, a new absorption band appeared in

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

• , 1255, 1163, 1053, 991, 935, 789, 690 cm–1; HREIMS m/z: [M]+ calcd for C19H14O, 258.1045; found, 258.1035. C–F bond activation through β-fluorine elimination via metalacyclopropanes. Synthesis of 2-arylbenzofurans 3 via the coupling of 1 with 2. Isolated yields are given. aNi(cod)2 (10 mol %), PCy3 (20

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

• stretch (≈1630 cm−1), which we calibrated against signals from p-xylene (≈830 cm−1). To resolve overlapping peaks, we employed curve-fitting techniques utilizing Lorentzian functional forms, facilitated by the lmfit Python package. This methodology (Figure 8) allowed us to accurately calculate conversion

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• molecular density of 1.688 g cm−3. In more details, the crystal structure reveals two short intramolecular F···H hydrogen contacts in the triphenylene core part with lengths of 2.047 Å and 2.114 Å, respectively (see Figure S33 in Supporting Information File 1). The triphenylene part of the molecule is

• values in the range of 104 and 105 L·mol−1·cm−1, respectively, as G66 possesses two triphenylene units whereas F6 only one. Both compounds, however, display substantially different photoluminescent behavior. Both F6 and G66 show a single, broad emission band with a peak maximum around 410–430 nm for F6

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• , 126.3, 123.8, 122.7, 118.3, 115.4, 43.3, 31.9, 29.5, 29.3, 27.3, 27.1, 22.7, 14.2; IR (ATR): 2959, 2929, 2856, 1661, 751 cm−1; HRMS–DART+ (m/z): [M + H]+ calcd for C24H27N2O, 359.2123; found, 359.2134. Structures of multiply fused heterocyclic compounds composed of pyridine rings. Synthesis of C–H

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

• existence of a substituted benzenoid chromophore was suggested by the UV absorption maximum at 258 nm. The presence of hydroxy and/or amino groups and a carbonyl group was indicated by IR absorptions at 3337 cm−1 and 1671 cm−1, respectively. The analysis of the HSQC spectrum, along with the 1H and 13C NMR

• cyano group in compound 1 [13][14][15]. In the IR spectrum of 1, an absorption attributed to the stretching vibration of the C≡N bond was observed at 2234 cm−1, although its intensity was very weak (Figure S8 in Supporting Information File 1). It is known that when an atom with an electron-withdrawing

• 28138) and 258 (ε 10233); IR (film/KBr) νmax: 3337, 2935, 2878, 2849, 2234 (weak), 1671, 1624, 1595, 1542, 1457, 1257, 1199, 1145, 1119, 1046, 954, 898, 738 cm−1; ECD (MeOH) λmax, nm: 211 (Δε −15.84), 239 (Δε 7.99), 281 (Δε 0.07); 1H and 13C NMR data (Table 1); HRESIMS (m/z): [M + Na]+ calcd for

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• -containing macrocycles and metalloporphyrins. Despite the impressive progress in photoredox catalysis, due to their most intensive electronic absorption band at 420 nm (Soret band, extinction coefficient of 105 M−1 cm−1), most porphyrin photocatalysts reported so far have been mainly utilized under blue

• coefficients around 104 M−1 cm−1), but they had not been used as photocatalysts in red light-induced processes until very recently. In 2022, Gryko and co-workers screened metal-free porphyrin macrocycles for various organic photochemical reactions that proceed via both oxidative and reductive quenching under

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• spectra during irradiation as upon direct irradiation, although the reaction times were significantly higher, most likely because of the much weaker molar absorption coefficient of [Ru(phen)3](PF6)2 at 520 nm (≈900 M−1 cm−1), and the fact that the photosensitization process is bimolecular (Figure 3

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• ) in tetrachloromethane (CTC) to 588 nm (orange) in formic acid. Therefore, it was found that compound 1c was characterized by a large Stokes shift upon increasing the solvent polarity, which reached 150 nm (5824 cm−1) in formic acid. This was associated with the bathochromic shift of the emission band

• highest fluorescence efficiency of 53.4% was observed for the para-methyl derivative 1b. Solutions of stilbazoles 1 in DMSO were also characterized by large Stokes shift values, reaching 207 nm (5846 cm−1) and showing nonradiative loss of excitation energy. It should be noted that stilbazoles 1, in

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

• properties of violanthrone is traced back to 1950, when Akamatu and Inokuchi measured its electrical conductivity (σ), which was found to be 3.4 × 10−4 Ω−1 cm−1 [27][28]. The chemical structure of violanthrone allows for its modification and hence the synthesis of materials with interesting spectral

• , and a λmax at 701 nm with ε of 4.69 × 104 L mol−1 cm−1 which might lead to the contribution of 3b to the photocurrent. All previous studies suggested that violanthrone and its derivatives display electronic functionality and could be potentially used in organic electronics. Nevertheless, to the best

• nm for all compounds. Compound 3a shows a slight hypsochromic shift (λmax = 741 nm) in comparison with 3b (λmax = 745 nm) and 3c (λmax = 746 nm). All compounds displayed very similar extinction coefficients between 45000 and 48000 L mol−1 cm−1. The optical gaps (Eopt) were estimated from the onset