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

• , however, it leads to a poor Z–E PSS and poor resistance to fatigue. This is most likely due to internal relaxation processes prevailing over photoswitching. One interesting finding was the strong dependency of the thermal half-life on concentration in DMSO. The authors hypothesised the aggregation of 109

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

• dual modifications [69]. These derivatives have emerged as a research hotspot due to their unique combination of water solubility, biocompatibility, and host–guest encapsulation capability [47][52][70]. The aggregation behavior of amphiphilic CAs is closely related to the size of the macrocycle, the

• ) [103]. CA4-Man3-NPs achieve efficient targeted drug delivery through a unique self-assembly mechanism. This system leverages the unique polymeric characteristics of CA4, which reduces the critical aggregation concentration and enhance intermolecular orderliness to form structurally stable nanocarriers

• the aggregation behavior of aromatic or amphiphilic molecules by reducing the critical aggregation concentration, enhancing the compactness of aggregates, and modulating the orderliness within aggregates, which is referred to as calixarene-induced aggregation (CIA) [52]. Taking the SC4A-AnPy system as

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

• to be 0.65. Their PL of the cast films fabricated from the toluene solutions were also measured, and weak and inefficient luminescence were observed because of the aggregation-caused PL quenching. The PL lifetimes of (Sp)-6 and (Sp)-7 in the CHCl3 solutions were measured at each PL peak maximum; and

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• , pseudo-octahedral Ni(II) complex [44] involving the carbonyl groups of PS1 and 7a, which is further activated on aggregation of the pyridinium salt and the chromone aromatic ring through π−π stacking. Then, PC1 was submitted to Stern–Volmer quenching experiments. Whereas no interaction occurred between

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

• development of heterogeneous catalysis has faced challenges, due to uncertainties around catalytic sites, aggregation, and the leaching of active species during reactions. The use of a heterogeneous catalyst can greatly simplify the work-up process, as the catalyst can be easily removed via simple filtration

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

• incorporating dual heptagonal rings [37]. Compound 23a exhibits dynamic chirality, aggregation-induced emission (AIE), and intense CPL (|glum| = 1.7 × 10−2), whereas compound 23f, with lateral π-extension, shows enhanced thermal stability and green emission at 517 nm (Table 7). Kuehne and co-workers reported

• aggregation-caused quenching (ACQ). In 2023, Yang and co-workers reported a pair of (NBN)2-containing double and quadruple helicenes 46a–d [61] (Table 16). The neutral compounds exhibited high PLQYs of 99% and 65% in solution, and 90% and 55% in PMMA-doped films, respectively, with exceptionally narrow full

Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents

• Julius Krenzer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97

• -on of emission upon induced aggregation in alcohol–water mixtures [1]. This chromophore class has been extensively developed in recent years, even to aggregation-induced emissive (AIE) multichromophores [2] and even bichromophoric fluorimetric sensors [3][4]. The retrosynthesis of the title compounds

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• (TXA2) synthetase inhibition [10], antinociceptive [11], histone deacetylase inhibition [12], α-glucosidase inhibition [13] , tyrosinase inhibition [14], allelochemical [15], anticonvulsant [16], antioxidant [17], antiplatelet aggregation [18], anti-inflammatory [19], and UV absorption [20]. Cinnamic

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

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

• aromatic–aromatic interactions. For example, our group highlighted the influence of different fluorinated phenylalanine analogs on the aggregation rate of amyloid-forming NFGAIL peptides [14]. Amino acids 2 and 3, with their respective fluorination pattern, might be fascinating compounds in this context

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• unconjugated and “overloaded” antibodies. Unconjugated antibodies compete with antibodies containing payloads for binding, which can diminish the effectiveness of the antibody-payload materials. On the other hand, excessive loading of the antibody can lead to antibody aggregation, increased toxicity, decreased

• aggregation during photoconjugation reactions represents a major challenge for the stability and efficacy of conjugated antibodies [60]. Exposure of antibodies to light, particularly UV light, can trigger photoinduced reactions that compromise their structural stability. These phenomena include the oxidation

• disulfide bridges or Cys–Tyr bonds, further increasing the risk of aggregation. Photosensitive payloads, although essential for specific therapeutic or diagnostic applications, are particularly vulnerable to these photochemical reactions. Their light-induced modifications not only exacerbate aggregation but

Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• is a destructive stored product pest. The aggregation pheromone of this pest was prepared via a new and effective strategy. The key steps include the ring-opening reaction of chiral 2-methyloxirane, the stereospecific inversion of chiral secondary tosylate, Li2CuCl4-catalyzed coupling of tosylate

• with Grignard reagent, and oxidation with RuCl3/NaIO4. Keywords: aggregation pheromone; chiral 2-methyloxirane; red flour beetle; total synthesis; Introduction The red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), is a cosmopolitan, destructive stored product pest [1], which

• for devising a more effective and environmentally friendly strategy to control this pest [9]. Pheromone-based pest management is one of most environment benign, effective, and promising solutions [10][11]. The aggregation pheromone of T. castaneum was first reported by Ryan in 1976, secreted by the

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• enables solvent-free conditions for this transformation (Scheme 11B). Here, the aggregation state of the substrate and the reductant proved to be crucial to establish a fully operative protocol. The third reaction tested under mechanophotocatalytic conditions was the well-established decarboxylative

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

• -butyl-substituted BPP (BPP-t-Bu, PLQY: 0.47) (Figure 2b) [21][22]. Considering that two tert-butyl groups should more effectively hinder the aggregation than one isopropyl group, we tentatively attribute the enhanced PLQY of 3 to the reduced molecular symmetry, which can relax the selection rule and

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

• fluorescence emission spectroscopies reveal green photoluminescence with fluorescence quantum yields of up to 33% for the Fn derivatives. The J-aggregation for the inner fluorine-substituted dimers Gnm is energetically and stereoelectronically more favorable and G66 exhibits thin-film fluorescence with a large

• intermolecular slipped J-type aggregation, supported by S/WAXS and proposed the model of Colrec mesophase [55][56][57]. DFT computation For a deeper understanding of the electronic properties of these fluorine triphenylenes, we performed some DFT computation of F1 and G11 with the shortest methyl chain, and the

• between 410–430 nm. It is noted that G66 shows deeper red-shifted fluorescence than F6, with peaks of 610 nm and 450 nm, respectively. The J-type aggregation for G66 in thin film and liquid crystalline state is energetically favorable for the arene–perfluoroarene overlap stacking and related

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• approaches Alzheimer’s disease (AD) The pathogenesis of AD is still not clear but is marked as a multifactorial disease [24], including a good deal of hypotheses involving the cholinergic hypothesis, glutamate excitotoxicity, tau aggregation, abnormal extracellular accumulation of Aβ peptides, and oxidative

• AChE, while pyrazole scaffolds possess the ability to reduce the tau and β-amyloid dual aggregation. Benzofuran-pyrazole aldehydes were employed in the Ugi azide reaction to give the desired hybrids. From the screened compounds, 2a, 2b, 2c, 2d, 2e, and 2f demonstrated notable efficacy in regulating the

• were also remarkable, yielding a value 2-fold higher than melatonin (ORAC = 2.45 TE). Natural polyphenols have shown promising potential in inhibiting β-amyloid aggregation and also antioxidant properties, suggesting their effectiveness in preventing AD. To address this, Lambruschini et al. [36

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

• . Although meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4, 54) is an achiral molecule, the respective J-aggregates reveal supramolecular chirality caused by spontaneous mirror symmetry breaking (SMSB) during the aggregation process in an aqueous acidic solution. Using of these aggregates led to

• hypothesis that the reaction would work in acidic environment using catalysts insensitive to pH-induced aggregation. In the same aldol reaction, using of macrocycles 60 and 61 containing chiral secondary amine moieties provided not only good yields, but also good diastereoselectivities; chiral HPLC analysis

• optically active form with 16.7% ee for 63a and 11.8% ee for 63b, respectively (Table 4). The pH-induced aggregation does not only enable to control the catalytic activity, but it also allows a straightforward separation and recovery of the catalyst from the reaction mixture by acidification and

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• nature of the rotaxane framework, CD-based polyrotaxane is known to form an aggregation structure by the formation of hydrogen bonds among the CD units [89][90][91][92][93]. Owing to the inclusion structure on the polyrotaxane, it is likely to form a hexagonal packing-type crystalline structure, which is

• different from that of a single CD molecule. Such an aggregation behavior of polyrotaxane induces the increase of the mechanical strength of the material or the construction of a nanosheet, which is beneficial for material application. Meanwhile, CD-based polyrotaxane requires various synthetic demands, as

• discussed in the previous sections, resulting in the limited applicability of this aggregate formation. To solve this issue, we used a CD-based [3]rotaxane unit as an aggregation unit instead of a CD-based polyrotaxane. As described above, the [3]rotaxane unit can be flexibly designed and integrated with

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

• modification of dihydroxyviolanthrone where the effect of three alkoxy substituents on the 16,17-bis(2-ethylhexyloxy)anthra[9,1,2-cde]benzo[rst]pentaphene-5,10-dione, on aggregation and photovoltaic properties was studied [30]. It was found that derivatives with the shortest linear alkyl chain (n-hexyl

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

• luminescent materials, particularly after the 2001 discovery of aggregation-induced emission. This study focuses on fluorinated diphenylacetylene-based luminescent molecules, revealing that specific molecular modifications can enhance fluorescence and achieve a wide range of photoluminescence colors. A simple

• has been severely delayed [4][5][6]. However, since Tang et al. first reported the aggregation-induced emission phenomenon in 2001 [7], the development of solid-state light-emitting materials has accelerated significantly [8][9][10]. Many photoluminescent materials that emit blue, green, and yellow

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• . This is problematic for gels in particular, as gels are mostly solvent by composition, it is to be expected that the drying procedures required may lead to a change in morphology due to effectively concentrating the sample, leading to more aggregation, any salts present in the solution could also

• the mechanism of aggregation is further exemplified by Jones et al. [44]. It was shown that SEM could directly observe structural defects, resulting in the collapse of helically braided structures into their constituent fibrils which can interact with other fibres (Figure 10). The branching density

• [69][70]. We have previously used the power of contrast matching to investigate self-assembly by selectively deuterating 2NapFF to identify the molecular packing structure in D2O solutions (Figure 15) [68]. SANS allowed the surfactant-like aggregation of 2NapFF to be elucidated which provides the

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• aggregation, attracting interest for the treatment of Alzheimer’s disease [240], was a selective agonist of the farnesoid X receptor FXR (EC50: 3.2 µM) [241], and displayed remarkable neuroprotective effects against oxidative injuries by acting as potent activator of nuclear factor erythroid-derived 2-like 2

Finding the most potent compounds using active learning on molecular pairs

• Zachary Fralish and
• Daniel Reker

Beilstein J. Org. Chem. 2024, 20, 2152–2162, doi:10.3762/bjoc.20.185

• default parameters and aggregation = ‘sum’ using the PyTorch deep learning framework. For the single-molecule Chemprop implementation, number_of_molecules = 1 while for the ActiveDelta implementation number_of_molecules = 2 to allow for processing of multiple inputs as described previously [29]. We

Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• (version 0.94.11) [34]. The first 50 data points were removed due to aggregation effects in some samples. A linear, horizontal background was set to an appropriate value. The data were fitted to either: ellipsoidal cylindrical core-shell, ellipsoidal core-shell or spherical core-shell structures, with a

• (black lines) indicate that a spherical-to-ellipsoidal transition occurs in H2O but not in D2O. Note that the grey circles indicate the native, E-isomer state, and the slope of −3 at low Q values (b) indicates the presence of larger-scale aggregation. The dimensional changes to the ellipsoidal and