Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

Synthesis of chiral cyclohexane-linked bisimidazolines

• Changmeng Xi,
• Qingshan Sun and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140

• bisoxazoline ligands, such as anthracene-1,8-linked bisoxazolines (AnBOX) [18][19][20] showed excellent enantioselectivities for certain substrates due to their ability to fix transition states in asymmetric reactions, realizing excellent stereoselectivities. However, they also presented some limitations to

Research progress on calixarene/pillararene-based controlled drug release systems

• Liu-Huan Yi,
• Jian Qin,
• Si-Ran Lu,
• Liu-Pan Yang,
• Li-Li Wang and
• Huan Yao

Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139

• novel multifunctional photo-responsive materials. This section will discuss drug molecule capture and release systems based on two hosts. The photo-sensitive assembly has drawn considerable interest in degradable materials, drug delivery systems, and tissue engineering. Anthracene (AnPy) derivatives are

• maintain water solubility. This assembly approach not only suppresses the fluorescence self-quenching of AnPy in the aggregated state (enhancing the yield of singlet oxygen) [115], but also boosts its photo-sensitivity – under light irradiation, the anthracene in the complex can be efficiently converted to

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• ; for example, twisted anthracene is a good CPL emitter [40][41][42][43][44][45][46][47]; the more the anthracene is twisted, the better the CPL properties [46]. As for the π-stacked cyclic oligomers, the trimers and tetramers exhibited good CPL properties, whereas the cyclic dimer consisting of curved

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

• acenes from anthracene to pentacene (57a–d) in rather low yields (16–38%). The synthetic pathway leading to the hexacene isomer 60 was more complex due to the high reactivity of intermediate pentacenes. Instead, pentacene-6,13-dione 58 was subjected to the reaction with di-n-butylacetylene (56) giving

A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• reduction of the pyrimidine ring, only a partial reduction occurs for the anthracene ring. For all other hydrogenation products 9 the coupled aromatic moiety is not affected (Scheme 6). Removal of both protecting groups is the last step in the generation of pipecolic acid derivatives (2R,6S)-5 and (2R,6S)-6

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

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

• modular synthesis, acyclic CB[n] can be easily modified synthetically [42][43][44][45][46][47][61]. Acyclic CB[n]-type receptors featuring different length glycoluril oligomers (monomer–pentamer) and different aromatic walls (e.g., naphthalene, anthracene, triptycene) have been studied [42][62][63][64][65

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

• Abstract A new deep-blue emitting and highly fluorescent anthracene (ANTH) derivative containing perfluorobenzyl (BnF) groups, 9,10-ANTH(BnF)2, was synthesized in a single step reaction of ANTH or ANTH(Br)2 with BnFI, using either a high-temperature Cu-/Na2S2O3-promoted reaction or via a room-temperature

• photostability compared to ANTH and 9,10-ANTH derivatives, and a simple synthetic access makes it an attractive material as a deep-blue OLED emitter and an efficient fluorescent probe. Keywords: anthracene; dibromoanthracene; electron poor polyaromatic systems; fluorescence; perfluoroalkylation

• ; perfluorobenzylation; photochemistry; Introduction The revolution of small organic molecules in the semiconductor industry continues to progress, replacing some silicon and metal-based electronic components. Acenes, such as anthracene (ANTH) and its higher homologues, represent some of the most studied materials that

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

• Å (5%) in the acid–acid distance (rCC) is observed along with an increase in twist by 2° (i.e. ≈ −0.1 Å/°) [39][41]. This twist can in turn be controlled by the dihedral angle of the central component of the terphenyl group (Figure 9A) – for anthracene cage 4e, an increased dihedral angle due to a

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• annihilation upconversion. This system achieves red-to-blue upconversion under red-light irradiation, rivaling the performance of traditional heavy-metal systems such as Os(II) complexes. By employing a Cr(0) photosensitizer combined with a silylacetylene-decorated anthracene annihilator, the authors have

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

• antiaromatic precursors remain challenging to study. Haley and some of us reported the oxidization of partially antiaromatic diindenoanthracene, DIAn, Figure 1, forming charged molecules stabilized by the rearomatization of the central anthracene unit [13][14]. Porphyrinoid-based molecules [15][16][17] have

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• comparable. With compound 26, no ruffling of the porphyrin ring is observed; however, with anthracene residues (27) a ruffling distortion of almost 1 Å is observed. This is not obvious at first, but differences in molecular symmetry [55] can be easily visualized using the neoplastic NSD plot [10] shown in

• Figure 3. Furthermore, the mean pyrrole ring tilt increases by 3–5° in the case of compounds 28 and 29 compared to that of compound 26. Saddle-shape distortion is reduced compared to that of biphenyl 26; this may be due to the proximity of the anthracene moiety to the β-ethyl positions, with C23–C14B

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• . Keywords: anthracene; cation; dimerization; radical; reactivity; Introduction Organic radicals have garnered significant attention in various research fields, including catalysis [1][2][3][4], chromophores [5][6][7][8], and as agents in dynamic nuclear polarization [9][10][11][12]. Recently, highly stable

• unit allows for spin localization at the 10-position of anthracene through C–C bond rotation, resulting in a tail-to-tail σ-dimer (Figure 1b). The σ-dimer exhibits an equilibrium state between the monomer radical and the σ-dimer in solution, and mechano-stimulus-induced C–C bond fission in the solid

• site, head-to-head σ-dimerization of the DAntM radical could yield 1,1,2,2-tetra(9-anthryl)ethane, which is a new anthracene embedded ethane [30] and would be a good candidate for the synthesis of overcrowded ethylene [31][32][33][34][35][36]. Herein, we report the synthesis and properties of the DAntM

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• Adam D. Bass Daniela Castellanos Xavier A. Calicdan Dennis D. Cao Chemistry Department, Macalester College, 1600 Grand Avenue, Saint Paul, Minnesota 55105, United States 10.3762/bjoc.20.155 Abstract We report the synthesis and characterization of naphthalene and anthracene scaffolds end-capped by

• been achieved as well. Other efforts have demonstrated that anthracene diimides (ADIs) can be tuned to achieve decent electron mobilities in electronic settings [13][14]. Although there have been calculations conducted that suggest 6-membered cyclic imides are more compelling than 5-membered cyclic

• imides in organic electronic materials [15], the experimental observation of similar electron mobilities across different structural isomers of naphthalene and anthracene diimide [16] confirms the need to experimentally evaluate the unstudied isomers. We became interested in the cata- (i.e. 1,2,3,4

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• square in its shape by changing anthracene in 1a to pyrene in 1b. To interpret the results of the diameter selectivity, the theoretical calculation using the semiempirical tight binding quantum chemical method GFN2-xTB was employed instead of the molecular mechanics used in our previous works, because it

• -dipyrrins, respectively. The corresponding distances in 1a are 14.13 and 18.07 Å along the anthracene and Cu-dipyrrins, respectively, as shown in Figure 2a. Meanwhile, the dihedral angles between pyrene and carbazoles in 1b are 34.2°, which is much smaller than those of anthracene (89.7°), due to less

• steric hindrance along the pyrene–carbazole bond than that along the anthracene–carbazole one. To predict the appropriate diameters of SWNTs, the spherical cavity sizes were calculated by considering van der Waals radii of all the atoms. The cavity size of Cu-nanobrackets 1b (11.83 Å) is 2.09 Å larger

Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• groups additionally provides for enhanced steric congestion at the most reactive 1,3-carbons of the furan ring (vide infra), and this could prove to be an important design strategy for large, persistent isoacenofurans. The trend continues for the entire acene series calculated, from anthracene to

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• precursors inherently limits the applicability of these reactions to the synthesis of π-CPCs containing linearly-fused benzene rings in their core scaffold (i.e., at least an anthracene pattern), or to the deprotection of peripheral benzene rings. To reach a wider variety of structures, novel synthetic

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• agent for TCNE. Anthracene-based ynamide 16 offers two potential reactive sites for TCNE, one residing at the anthracene moiety and other at the alkyne moiety, as shown in Scheme 9 [71]. As exemplified by Trolez et al., the introduction of one equivalent of TCNE to 16 at room temperature initiates a [4

• + 2] cycloaddition reaction with the anthracene moiety, yielding the DA cycloadduct 17. To achieve the conversion of the alkyne moiety of 16 into TCBD, the addition of five equivalents of TCNE to 16 or one equivalent of TCNE to 17 is required. This results in the formation of TCBD compound 18 bearing

• a derivatized anthracene moiety. Subsequently, to restore the anthracene structure of 18, the retro-DA reaction must occur efficiently. Therefore, through the addition of 1, followed by heating, the generated TCNE is effectively captured by 1. This maneuver concurrently suppresses the progression of

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• present amphiphile is originated from bent aromatic amphiphile AA [12][13], composed of two anthracene panels linked by a m-phenylene spacer with two cationic side-chains, which assembles into an aqueous ≈2 nm-sized aromatic micelle with broad host functions [14][15][16][17][18][19][20][21]. Replacement

• similar to AA [12][13], indicating self-assembly via the hydrophobic effect and π-stacking interactions (Figure 3a,b). The self-assembly in water was further supported by UV–visible analysis, displaying slight red-shifts of the anthracene absorption bands relative to the spectrum in methanol (Δλmax = +3

• below 0.1 mM (Figures S28 and S32, Supporting Information File 1), which is around 10 times lower than that of AA [12][13]. The increased stability against dilution likely arises from reduced electrostatic repulsion and increased anthracene-based π-stacking interactions due to the absence of o-alkoxy

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• % yields, respectively. When comparing compounds 25a and 25b, UV–vis and fluorescence studies (λmax = 500 nm, λem = 502 nm, Φem = 0.45 for 25a; λmax = 513 nm, λem = 517 nm, Φem = 0.26 for 25b; λmax = 442 nm, λem = 444 nm, Φem = 0.97 for 9,10-bis((triisopropylsilyl)ethynyl)anthracene – blue-colored) provide

• (triisopropylsilylethynyl)anthracene (27), which was accomplished with high yields (Scheme 6). The presence of two methyl groups in the bridge-head positions of compound 26 is crucial in these annulation reactions. These groups play a vital role in preventing undesired side reaction pathways, as their absence would lead to

• from benzene (53a), naphthalene (53b), and anthracene (53c) with compound 52, the desired target azaacenes 54a–c were successfully obtained in yields ranging from 68% to 84% (Scheme 11). As anticipated, there was a notable red shift observed from 54a to 54c, which can be attributed to the expansion of

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• layers are composed of various aromatic π-conjugated small molecules/polymers including thiophene, anthracene, carbazole, and triphenylamine [9][10][11][12][13]. Thienothiophenes are two annulated thiophene rings having four isomers, among which the most widely used isomer is thieno[3,2-b]thiophene (TT

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• of n-type semiconductors. The strategy also involved attaching triisopropylsilyl groups to the anthracene core to balance solubility and charge carrier properties. The BSPQ derivative exhibited deeper frontier orbital energy levels and enhanced electron mobility compared to the BTPQ [55]. Several

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• . The products 16 were achieved with excellent enantioselectivites which were attributed to an attractive interaction between the indole ring and the anthracene substituent of the catalyst’s framework (Scheme 5) [29]. In 2018, Piersanti and co-workers developed a phosphoric acid-catalyzed cascade