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

• triad (red) was hoped to activate the benzyl alcohol nucleophile, but it does not activate (polarize) the electrophile (substrate ester group). (B) One of Rebek’s “clefts” [108][109]. The rigidly organized carboxylic acids both bind the substrate and the transition state for hydrolysis of an acetal. (A

Unraveling aromaticity: the dual worlds of pyrazole, pyrazoline, and 3D carborane

• Zahra Noori,
• Miquel Solà,
• Clara Viñas,
• Francesc Teixidor and
• Jordi Poater

Beilstein J. Org. Chem. 2025, 21, 412–420, doi:10.3762/bjoc.21.29

• -electron contributions) for a perpendicular magnetic field over a plane 1 a.u. above the molecular plane of the pyrazole ring of the o-carborane-fused pyrazoles. Red/blue arrows when the component parallel/antiparallel to B is greater than 30% of the vector modulus. Diatropic/paratropic circulations are

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• experimental (black) and simulated Boltzmann-averaged (red: (2’S,3’S,12S)-1; green: (2’S,3’S,12R)-1) ECD spectra of compound 1. A plausible biosynthetic pathway of 1–3. Biofilm inhibition and eradication assessment via CV staining assay. A) S. aureus biofilm inhibition by farinosone D (1) and farinosone A (2

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

• Picardie Jules Verne UR 7378, 10 rue Baudelocque, 80000 Amiens, France Institute of Physics and Chemistry of Materials of Strasbourg (IPCMS), University of Strasbourg UMR 7504, 23 rue du Loess, BP 43, 67034 Strasbourg CEDEX 2, France 10.3762/bjoc.21.22 Abstract Red-light-activated photocatalysis has

• become a powerful approach for achieving sustainable chemical transformations, combining high efficiency with energy-saving, mild conditions. By harnessing the deeper penetration and selectivity of red and near-infrared light, this method minimizes the side reactions typical of higher-energy sources

• , making it particularly suited for large-scale applications. Recent advances highlight the unique advantages of both metal-based and metal-free catalysts under red-light irradiation, broadening the range of possible reactions, from selective oxidations to complex polymerizations. In biological contexts

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• triphenylphosphine with MBH nitriles of isatins in acetonitrile at room temperature quickly gave red solid products 6a–d in high yields (Scheme 3). In this reaction, triphenylphosphine acted as a nucleophile to finish an allylic SN2 reaction. The obtained triphenylphosphaneylidenes are stable, which can be isolated

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

• , Me: methyl). Cyclic voltammograms of 1 and 2. UV–vis–NIR electronic absorption spectra of 1 (top) and 2 (bottom) during the electrochemical oxidation in 0.1 M n-Bu4N·PF6 in CH2Cl2 at room temperature. The traces are black lines for neutral, blue lines for radical cation, and red lines for dication

• theoretical Raman band at 1730 cm−1. FT-Raman spectra in CH2Cl2 (approx. 10−2 to 10−3 M) of: top) 1 (black), 1•+ (blue), and 12+ (red). Bottom) 2 (black), 2•+ (blue), and 22+ (red). Oxidations are carried out by stepwise addition of NOBF4 in CH2Cl2. Force constants for the CC stretching vibrational

• coordinates of the neutral (black), radical cation (red) and dication (blue) of m-1 and m-2 compared with those obtained, under the same level or theory, for neutral naphthalene (NAP) and cyclobutadiene (CBD). NICS-XY scans, at the (U)B3LYP/6-311G(d,p) level, for neutral m-1 and m-2 (black) and for their

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

• -substituted derivatives [21][22]. In comparison to the absorption spectrum of BPP 2, this lowest-energy absorption band of BPP-OiPr 3 was red-shifted by ≈26 nm, which marked the inductive and resonance effects of the electron-donating isopropyloxy group with lone pairs of electrons, raising the HOMO level

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

• -withdrawing substituents on the N-aryl moieties enhanced the thermal stability of the Z-isomers while maintaining the advantageous photoswitching properties upon irradiation with red light [52]. The effect of substituents on the thermal cis–trans isomerization of azobenzenes has also been widely studied, and

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• 298 K. The 1H NMR signals of the CF2H group are indicated in red. C) Determination of the dissociation constant (Kd) of the n-Bu3PO···2b HB complex by fitting the data to a single-site binding model. Hydrogen bond donation ability of various donors as quantified by the dissociation constant (Kd) of

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• promising potential for designing stimuli-responsive and smart polymers in the future. ESIMS spectrum of an equimolar mixture of G1 and H1 in CHCl3/CH3CN (1:1, v/v), including calculated (blue) and experimental (red) isotopic distribution for [H12 + G12 − 2PF6−]2+. Calculated and found m/z = 2444.3373 and

• and G1. The brown dotted lines show the hydrogen bond distance between H2 and the positively charged region of G1 (d[C–H···O] = 2.2–3.5 Å). The red dotted lines show the hydrogen bond distance between H2 and the proton of the phenyl group of G1 (d[C–H···O] = 2.7–2.9 Å). c) Dimeric structure showing

Hot shape transformation: the role of PSar dehydration in stomatocyte morphogenesis

• Remi Peters,
• Levy A. Charleston,
• Karinan van Eck,
• Teun van Berlo and
• Daniela A. Wilson

Beilstein J. Org. Chem. 2025, 21, 47–54, doi:10.3762/bjoc.21.5

• , which results in more rigid domains. The anomalous shapes observed, with bending starting from seemingly random positions, support this hypothesis (Supporting Information File 1, Figure S36). These irregular shapes are reminiscent of some anomalous shapes observed in red blood cells [25]. It was also

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

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• clarification). Structure of (M,P,M)-3 in the crystal of 3·CH2Cl2 (carbon and oxygen atoms are shown as grey and red ellipsoid at the level of 50% probability, and hexyl groups and hydrogen atoms are removed for clarity). UV–vis absorption spectrum (black line) and emission spectrum (blue line, excited at 400

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

• red-shift of the emission peak. Keywords: arene–perfluoroarene interaction; decafluorobiphenyl; fluorinated triphenylene; fluoroarene nucleophilic substitution; organolithium; Introduction Non-covalent arene–fluoroarene intermolecular interactions [1][2] are drawing increasing attention due to their

• (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

• maximum is shifted to 450 nm (518 nm) and 610 nm for F6 (PH8) and G66, respectively. The thin film emission of G66 is red-shifted by about 120 nm compared with its solution, while the one of F6 is red-shifted only by 30 nm. This huge difference in thin film emission can be explained via their

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

• inhibitors, and their effects were investigated using the Amplex-Red® kit in C. elegans. Individuals exposed to compounds 2a, 2b, 2c, 2d, 2e, and 2f at a concentration of 1 mM were analyzed for AChE activity in their extracts. The results revealed significant inhibition of AChE levels, with compound 2e

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

• light irradiation. There are a few reports on red light-mediated transformations using other pyrrolic macrocycles, such as thiaporphyrin [94], phthalocyanine [95], and subphthalocyanine [96]. Porphyrin macrocycles can also absorb red light (Q bands at 518, 553, 592, and 648 nm with extinction

• 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

• red light irradiation [97]. Firstly, they evaluated the photoreductant role of metal-free macrocycles, H2TPP (18) and PPIX 78, in the red light-induced C–H arylation of different substrates such as furan, coumarin, thiol, pivalamide, aryl thiaether and the selenium equivalents. Use of both macrocycles

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

• is necessary to accomplish a reasonable balance between the MOST parameters. Hence, to increase the energy density and to induce a decent red shift of the absorption, two, three or even more norbornadiene units may be combined in one integral molecule by attachment to a shared, linking arene unit

• UV range [30]. Therefore, we aimed at further modification of the core structure of bis-and tris-norbornadienes, which may lead to a more pronounced red shift of the absorption while maintaining the high energy density. As this has been shown in other cases already [34], we anticipated that the

• substitution patterns, the compounds 1h–l,n showed the characteristic long-wavelength bands with maxima between 310 nm (1k) and 345 nm (1n) and low-energy zero onsets from 345 nm (1k) to 420 nm (1n). Hence, the red shift of the absorption bands correlates with the size of the respective π-system of the

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• , the A domain (gray rectangles in a) is responsible for activating the substrate BB to be incorporated, and the substrate BB specificity is dictated by the nonribosomal code (the 10 residues that defines its binding pocket, small red circles). Algorithms for A domain substrate prediction were trained

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

• dimethylamino group, were studied (Table 1 and Figure 3). It was found that in most solvents, compound 1i was characterized by a single pronounced absorption maximum in the range of 503–525 nm that red-shifted upon increasing the solvent polarity. In formic acid, due to the protonation of the dimethylamino

• visible region of the spectrum (from blue to red, Figure 3B and Figure 4). Acidic solutions were the most blue-shifted due to the formation of the protonated form 1iH+ (Scheme 2). Two emission maxima were observed in acetic acid and associated with the corresponding absorption maxima. The first, located

• color from blue to orange (Figure 7, top). The most blue-shifted emission was observed for stilbazole 1a without additional substituents. The introduction of an electron-donating group led to a red shift of the emission in accordance with increasing donor strength and number of substituents. Stilbazoles

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• their activity against various types of cancer. N-Glycosides of indigo, indirubin, and isoindigo, blue, red, and yellow sugars, turned out to be of special interest because of their high cancerostatic activity and structural novelty. The present article provides an account on the synthesis and

• myelocytic leukemia [5][6][7]. Indirubin, a red isomer of indigo, is an ingredient of indigo naturalis active against various cancers. Since the 1990s, we are witnessing a renaissance of the chemistry of indirubins because of their activity as potent inhibitors of several kinases, such as GSK-3β and CDK’s [8

• , indirubin, and isoindigo which can be regarded as blue, red, and yellow sugars, respectively. Review Indigo-N-glycosides (blue sugars) In 2002, Laatsch and Maskey reported the isolation of the akashins A, B and C, indigo-N-glycosides, from terrestric Streptomyces (Scheme 2) [17][18]. These natural products

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

• equation; LoD = yB + 3sB. yB is the signal associated with the blank and sB corresponds to the standard deviation of the blank [22][23]. LoD: [Tb.1·3Cu]3+ 0.63 μM, λem = 544 nm. Previously reported lanthanide complexes [12][16][17]. Absorption (red line), excitation (yellow line, λem = 615 nm), and

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• the formation of a coordination bond; the benzene moiety is located in a hydrophobic pocket. bThe conformations of compounds 4a–e are identical, whereas the position of compound 5e (red) is significantly different. Reaction of 2-aminoimidazole (1) with N-substituted maleimides (2) and N

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• dependency on the amount of PyBA added. The absorption spectra of catC60-lip and C60-lip were compared in PBS(–) (Figure 3). At two different concentrations, no significant change was observed in catC60-lip, whereas broadening and a red shift were observed in C60-lip at higher concentrations (10 mol equiv

• (–) and DMSO under irradiation for 30 min by blue LED lamp. In the ESR spectra, signals corresponding to the adducts are indicated with red (4-oxo-TEMPO in a), blue (DMPO-OH in b), and green (DEPMPO-CH3 in c) arrows. Acknowledgements The authors thank Dr. Ebert from ETH Zurich for his support on ESR

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

• photoluminescence (PL) have been developed, whereas red PL with PL wavelengths in the long wavelength region is considered difficult to achieve owing to the energy gap law [11][12][13]. Over the past few decades, our group has been vigorously pursuing the exploration of functional molecules with a linear

• suppresses the formation of the twisted ICT state, resulting in red fluorescence even in the solid state (Figure 2) [23]. The precise tuning of molecular and electronic structures has made it possible to produce a wide range of PL colors. However, the development of white-light-emitting materials, which are

Computational design for enantioselective CO₂ capture: asymmetric frustrated Lewis pairs in epoxide transformations

• Maxime Ferrer,
• Iñigo Iribarren,
• Tim Renningholtz,
• Ibon Alkorta and
• Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

• by a red sphere. (B) Schematic representation of the two possible ring-opening reactions of PO in the presence of activated CO2. Symmetric FLP scaffolds considered in the first study. X denotes N or P. Subset of FLP scaffolds considered in the catalyst optimisation study. Substituents and labels are