Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• yields (ΦF up to 0.69). Furthermore, enantiomeric resolution of inherent chiral MC1 was achieved using preparative chiral HPLC, enabling detailed investigation of its chiroptical behavior through circular dichroism and circularly polarized luminescence spectroscopy. Keywords: dihydroindolocarbazole

• ; inherent chirality; N-doped macrocycle; nonplanarity; regioselective cyclization; Introduction Chiral macrocycles have attracted significant research interest owing to their diverse applications in enantioselective recognition [1][2], catalysis [3][4], and circularly polarized luminescence [5][6

• through circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopy. Results and Discussion The syntheses of N-doped macrocycles MC1–3 are shown in Scheme 1. Diamines 1a and 1b were synthesized by double Pd-catalyzed C–N coupling reaction of 4,6-dichlorobenzene-1,3-diamine with phenyl

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• molecular platforms in various applications, such as circularly polarized luminescence (CPL) materials, chiral liquid crystals and asymmetric catalysis. Currently, the asymmetric catalytic synthesis of helicenes predominantly revolves around transition metal-catalyzed asymmetric annulation reactions

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

• structures, such as one-handed helical and propeller-shaped structures, can be constructed by folding the π-conjugated system using [2.2]paracyclophane as the chiral crossing unit, leading to circularly polarized luminescence (CPL) properties. Chiral cyclic dimers and trimers were synthesized using planar

• observed between the dimer and trimer, despite the same absolute configuration of the planar chiral [2.2]paracyclophane units, which was reproduced by theoretical studies. Keywords: circularly polarized luminescence; oligomer; [2.2]paracyclophane; planar chirality; Introduction Cyclophane is a general

• luminescence (CPL) [22][23][24][25] with high photoluminescence (PL) quantum efficiency (ΦPL) and anisotropy. Additionally, the π-stacked structure of [2.2]paracyclophane can be applied at a crossing point. By folding the π-conjugated system using [2.2]paracyclophane as the chiral crossing unit, optically

Wittig reaction of cyclobisbiphenylenecarbonyl

• Taito Moribe,
• Junichiro Hirano,
• Hideaki Takano,
• Hiroshi Shinokubo and
• Norihito Fukui

Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107

• . Consequently, figure-eight molecules often exhibit fascinating properties, such as unusual rearrangement reactions [9] and efficient circularly polarized luminescence (CPL) [10][11][12]. Cyclobisbiphenylenecarbonyl (CBBC) 1 is a figure-eight macrocycle, which is readily synthesized from commercially available

• peripherally modified CBBC derivatives have also been prepared and were shown to have fascinating properties [17][18][19][20][21]. For example, carbazole-substituted donor–acceptor-type CBBC derivatives exhibit both efficient circularly polarized luminescence (CPL) and thermally activated delayed fluorescence

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

• versatile scaffolds for chiral optoelectronic applications. The incorporation of nitrogen enables precise modulation of electronic structures, redox characteristics, and intermolecular interactions, thereby enhancing performance in circularly polarized luminescence (CPL), thermally activated delayed

• , emphasizing their potential as next-generation chiral optoelectronic materials and outlining future directions toward multifunctional integration and quantum technological applications. Keywords: azahelicene; chiroptical properties; circularly polarized luminescence (CPL); heteroatom containing

• in applications such as organic light-emitting diodes (OLEDs) [8], circularly polarized luminescence (CPL) [9], and chiral photocatalysis [10]. In the past decade, heteroatom-containing helicenes have attracted increasing attention due to their tunable optoelectronic properties and potential

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

• overcoming scalability challenges in quantum technologies. Despite their potential, achieving high luminescence quantum yields has largely been limited to donor-functionalized monoradicals, and a detailed understanding of the luminescent behavior of open-shell organic molecules remains elusive. This review

• delves into the photoluminescent properties and spin ground states of trityl-based mono-, di-, and multiradicals, examining the strategies employed to enhance their performance. Additionally, we review predictive methods for determining the luminescence and spin states of radicals, highlighting critical

• represent a class of stable organic radicals that exhibit luminescence. Typically, organic radicals that are luminescent exhibit poor photostability, and many representatives of the triarylmethyl family degrade upon photoexcitation [1][2][3][4]. For example, the photoluminescence of solutions containing

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• -donating strength. The development of stronger donors to enhance luminescence remains a key area of research [20][21][22]. Recently, azepine-based analogs, such as tribenzo[b,d,f]azepine (TBA, a), have been explored due to their photoluminescence properties [23][24][25][26][27]. This antiaromatic core

• , with values of 16%, 14%, and 14%, respectively. The lowest values were obtained for molecules 5a and 5b (7% and 6%, each). Remarkably, compound 5e demonstrated minimal luminescence in nearly all solvents at room temperature. This behavior has been previously reported and is believed to be due to strong

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

• furan-3-carboxylates 6c,d. It was shown that the increased number of conjugated bonds in their molecules leads to a decrease in the energy of the singlet–singlet π→π* transition and the possibility of exhibiting luminescence of the molecules under study. According to the luminescence excitation spectral

• Shimadzu UV-2401 PC spectrometer for samples in DMSO solutions in fused quartz cuvettes (optical path length 1.01 mm). Luminescence excitation spectra and luminescence spectra were recorded on a Shimadzu SF-6000 spectrofluorimeter in a 1 cm thick quartz cuvette at room temperature in a DMSO solution (c

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

• (λem = 402 nm for PH8) and 460–500 nm for G66, with absolute quantum yields of 30% and 32%, respectively. Further, their fluorescence spectra in solutions show some solvent polarity influence, with a substantial red shift as the solvent polarity is increased. In thin film, the single luminescence

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

• the E-configuration. Spectral–luminescence properties Compounds 1 form colored crystals, from pale-yellow (i.e., 1a) to almost black (i.e., 1h). They are soluble and luminescent in most common organic solvents. Solvatochromism of stilbazole 1c, containing a para-methoxy group, was studied first (see

Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• : chemosensor; hydrogen sulfide; lanthanide; luminescence; terbium; Introduction The field of luminescent lanthanide chemosensors is rapidly evolving, driven by the need for more efficient, sensitive, and versatile detection methods for environmentally and biologically relevant analytes. While significant

• for the detection of both gaseous and/or aqueous H2S are shown in Figure 1 [12][16][17]. These sensors all function via the copper sequestration mechanism, where upon addition of hydrogen sulfide to the quenched bimetallic species, luminescence modulation occurs. In our quest for highly selective

• conditions. High-resolution mass spectrometry (HRMS) analysis and the 1H NMR spectrum were consistent with formation of the Tb.1 complex (Figures S1 and S2 in Supporting Information File 1). Luminescence characterization of Tb.1 As anticipated, based on the previously reported europium complex ([Eu(triazole

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

• Kazuki Kobayashi,
• Shigeyuki Yamada,
• Motohiro Yasui and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

• and effective luminescence color-tuning method is proposed to investigate the photoluminescence behavior of two-component polymer dispersion films blended with two types of fluorinated diphenylacetylenes, namely blue- and yellow- or red-fluorescent fluorinated diphenylacetylenes. It is confirmed that

• white-light-emitting materials. Keywords: energy transfer; fluorinated diphenylacetylenes; photoluminescence; polymer-dispersed films; white luminescence; Introduction Luminescent materials in lighting and display devices have become indispensable in daily life [1][2][3]. In recent years, organic

• especially indispensable for our affluent life, is more difficult than the development of the blue-, yellow-, and red-light-emitting molecules mentioned above [24][25][26]. Therefore, to achieve white luminescence covering the entire spectral range of the visible light region, two or more colors of

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• necessary [73]. Most advantageously, this methodology tolerates many polar functional groups and allows access to pyrazole libraries from simple starting materials (alkynes, acid chlorides, hydrazines) in good to excellent yield. Notably, pyrazoles 102 and 103 demonstrate intense luminescence both in

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• potential if the arms exhibit additional properties such as luminescence, magnetism, catalysis, redox activity, or more. Such systems can also provide two orthogonal responses: the mechanical motion between the open and closed forms, and a potential new property that emerges when the arms are in spatial

• a closed “U”-shaped conformation. This type of switch was first described with the molecular tweezers 7 bearing two pyrene chromophores on the position 6 and 6” of the terpyridine, resulting in an open “W” conformation [33][34]. In this state, the system exhibits luminescence properties that are

• quenched when the tweezers are closed by the addition of a Zn2+ cation because of intramolecular π–π stacking interactions between the chromophores. The system can be reopened and its luminescence properties restored by introducing tris(2-aminoethyl)amine (TREN), which has a better affinity for Zn2+ and

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• -coupled electron transfer (PCET), forming neutral radical species 33 and the corresponding phosphate conjugate base (Scheme 8B). The hypothesis is supported by an observed increase in the luminescence quenching of *Ir(p-CF3-ppy)3 by 32 in the presence of diphenyl phosphoric acid, as quantified by the

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• , protonation, and luminescence, have recently been studied by us in sufficient detail [15], nothing is known so far about the possibility of chemical modification of this molecule. It should be emphasized that the presence of a dimethylene moiety in the peri-positions of the naphthalene system will not only

• undergo a nucleophilic substitution. Indeed, upon boiling with an excess of sodium methoxide in methanol, the crude dinitration product 10(12) gives up to 6% of a new substance with low mobility on sorbents and blue luminescence under UV light. Its spectral analysis confirmed the symmetrical structure

• (Scheme 8). In addition to the spectral data confirming the composition and asymmetric structure of compound 16, a clear sign of the emerging acenaphthylene system is its yellow-orange color, which distinguishes the UV-active (yellow-green luminescence) acenaphthylene 16 from the light-beige UV-inactive

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

• particular, Diederich et al. conducted a theoretical investigation on the photophysical properties of 1,1,2,4,4-pentacyanobuta-1,3-diene (PCBD) (63) [134]. Compound 63 and the TCBD 64 demonstrated no discernible luminescence at room temperature and 77 K (Figure 4). Transient absorption spectral measurements

• -emission (AIE)-active aggregates exhibit emissive behavior in hexane, with an emission peak at 679 nm and a shoulder at 717 nm along with a fluorescence quantum yield of 8.5%. This luminescence phenomenon can be aptly considered to be AIE, considering the pronounced constraints imposed on molecular

• processes. Analogously, the TCBDs 66 and 67, consisting of pyrene and perylene moieties, respectively, have been reported to exhibit luminescence in the NIR region in their powdered forms, with the maxima at 810 nm and 890 nm for 66 and 67, respectively, despite their nonemissive behavior in dichloromethane

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• -dicarbazolyl-3,5-dicarbonitrile. The compounds are synthesized by Sonogashira coupling reactions and characterized by steady-state and time-resolved luminescence spectroscopy. The compounds show efficient intramolecular charge transfer (ICT) from the donor to the acceptor. The photoluminescence (PL) spectra of

• steady-state luminescence spectroscopy. Meanwhile, time-resolved spectroscopy at different temperatures was used to investigate the nature of long-lived emissions of 6–9 as it was previously done for the reference compound 2,6-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)-4-(4-fluorophenyl)pyridine-3,5

• nm, further allowing us to analyze the luminescence dynamics in detail. To determine photoluminescence quantum yields (PLQY), a dedicated integrated sphere with an inner diameter of 120 mm was used in conjunction with the Edinburgh Instruments FLS980 spectrometer. This specialized setup enabled

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

• method, i.e., solution processing, was used in this study. In the previous study, the OLED of DMB-TT-TPA (8) was explained to demonstrate performance with the turn-on voltage, external quantum efficiency (EQE), and highest luminescence efficiency of 4.6 V, 0.15% and 0.40 cd/A, respectively, using a

• an external quantum efficiency (EQE) of 4.61%, along with a green emitting luminescence at 512 nm (Table 2). According to the CIE color space chromaticity diagram, the device was located at the coordinates of 0.16 and 0.51. The obtained EL results are in good agreement with the fluorescence

• a maximum luminescence efficiency of 752 cd/m2, a maximum external quantum efficiency of 4.61%, a maximum power efficiency of 6.70 lm/W, and a maximum current efficiency of 10.6 cd/A on 2.9 V turn on voltage with CIE coordinates of 0.16 and 0.51 at λEL = 512 nm. The OLED, optical and thermal

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• pharmacological activities [86][87]. Acylhydrazones can exist in either E or Z forms in solution, and they can exhibit good optical properties for applications as photoswitches, in luminescence sensing, and as metallo-assemblies [88][89]. In organic synthesis, acylhydrazones have served as stable imine

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

• , including solvatochromism and AIE enhancement. These characteristics enable tunable emission and enhanced luminescence efficiency. The potential application of tripodal derivatives in white OLEDs indicates the versatility of quinoxaline-based materials in achieving diverse emission colors [67]. Figure 7

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• orbital (HOMO) was delocalized over the Nz core and the attached carbazole moieties. There was an overlap between the HOMO and LUMO orbitals over the Nz fragment, which is likely to promote the LE component and consequently gives rise to a faster radiative decay and thus a higher luminescence efficiency

• luminescence efficiency, while a significant spatial separation between hole and particle wavefunctions considered for CT component promoting RISC process along high-lying excitation state for enhancing an exciton utilization efficiency (EUE). The photophysical properties of TPECNz were studied in solution

• performed using either a Bruker LC-Quadrupole-Time-of Flight tandem mass spectrometer or a Bruker Autoflex MALDI-TOF mass spectrometer. UV–vis spectra were recorded using a Perkin Elmer Lambda 1050 UV–vis–NIR spectrometer. Luminescence emission spectra and lifetimes were analyzed using an Edinburgh

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• benzoguanidine donor and compare it with the benchmark carbazole-based material (4CzIPN). Extended π-conjugation in 4BGIPN material results in yellow-green luminescence at 512 nm with a fast radiative rate of 5.5 × 10−5 s−1 and a photoluminescence quantum yield of 46% in methylcyclohexane solution. Such a

• exhibits a featureless yellow CT-type luminescence with λmax = 525 nm that is 44 and 25 nm red-shifted compared to 4CzIPN (λmax = 481 and 500 nm in Zeonex and MCH, respectively) [12]. The solution photoluminescent quantum yield (PLQY) of 4BGIPN is 46% under inert atmosphere and decreases down to 18% in

• aerated MCH solution. The reduction in quantum yield on exposure to oxygen is due to quenching of the triplet excited states indicating a TADF luminescence mechanism. PLQY in Zeonex films is 39% in air, which is lower than the PLQY of 87% reported for 4CzIPN [17]. The two-component excited state lifetime

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• –i, 9a, and 10a, a band with a maximum at 260–265 nm is observed, which has a shoulder at 300–305 nm. These signals seem to correspond to π–π* and n–π* transitions. In the luminescence spectra of compounds 4a–i, 9a, and 10a, there is one broadened band with an emission maximum at 409–440 nm (Figure 2