Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• variations in the switching properties. However, it is important to note that altering one property typically impacts other characteristics as well [21][22]. In this regard, both the substitution of the NBD periphery to produce push–pull derivatives and the variation of the central scaffold itself have been

• considering the carbon-based scaffold as superior regarding their properties, while also highlighting some unique properties exhibited by heterocyclic derivatives [21]. C7-substituted NBD species have been scarcely investigated in terms of their switching behavior but have been employed as synthetic

• little attention in the literature, with investigations largely limited to forward conversions [35]. Here, we present 2,3-heteroatom-incorporated NBD derivatives and compare their properties with those of previously published isocyclic derivatives. By utilizing push–pull functionalization and

Carbon-rich materials: from polyaromatic molecules to fullerenes and other carbon allotropes

• Hiroko Yamada and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2025, 21, 798–799, doi:10.3762/bjoc.21.62

• their unique electronic and photophysical properties, research in the area of carbon-rich molecules and polyaromatic molecules became explosive in their activity and a numerous new studies and directions have emerged. Because of dramatic expansion and development of these research areas, these molecules

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• presence of air, no product was formed. This finding indicates that iodide salt plays a crucial role in driving the reaction and acts as a catalyst in the reaction process. The electronic properties of the substituents on the compounds influenced the reaction yield. Phenol with the –OMe group produced a

• were obtained using platinum electrodes as the anode and cathode (Scheme 25). Studies showed that CH₃CN performed better than CH₃OH due to its wider electrochemical window and better solubility. The results indicated that the electronic properties of substituents had no significant effect on the yield

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• –inhibition assay. The measured results were systematically contextualized employing new reference compounds such as the respective homobivalent Man/Man glycocluster. An in-depth study comprising the analysis of the photochromic properties and the potential as inhibitors of bacterial adhesion of the synthetic

• scaffold molecules, respectively [14][15], – differing inhibitory properties in carbohydrate-specific bacterial adhesion resulted. To further investigate the effect of relative ligand orientation in carbohydrate recognition, we and others have utilized photoswitchable glycoconjugates [16][17][18][19

• states of the bis-azobenzene glycocluster 6βGlc3αMan 1 representing different relative Man/Glc orientations. In order to put the biological properties of the previously described photoswitchable heterobivalent cluster glycoside 6βGlc3αMan 1 [24] into perspective, several relevant analogs were synthesized

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• , however, there was no complementary RNA-based tool with comparable live-cell-imaging properties. Based on the autocatalytically generated fluorophore 4-(p-hydroxybenzylidene)imidazolidin-5-one (HBI) in GFP, in vitro selection on derivatives of HBI led to the discovery of the first fluorogen-activating

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

• supramolecular chemistry involves the synthesis of macrocyclic hosts and studies of their molecular recognition properties. The most widely studied macrocyclic host systems include those created entirely by covalent bonds (crown ethers, cyclodextrins, calixarenes, cyclophanes, pillararenes, cucurbit[n]urils (CB

• sulfate). In this paper, we present the synthesis and molecular recognition properties of a new acyclic CB[n]-type receptor C1 which allows us to disentangle these two effects. Results and Discussion This results and discussion section is organized as follows: First, we present the design, synthesis, and

• spectroscopic characterization of C1 along with determination of its inherent aqueous solubility and self-association properties. Next, we present the X-ray crystal structure of C1 as its C1·Me6CHDA complex. Subsequently, we describe a qualitative investigation of C1·guest and M1·guest complexation by 1H NMR

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

• stereoelectronic effects such as hyperconjugation and electrostatic attraction/repulsion. These fluorine-derived conformational effects have been exploited to control the shapes, and thereby enhance the properties, of a wide variety of functional molecules including pharmaceutical agents, liquid crystals

• upon whether the 1,2-difluoro stereochemistry is threo or erythro. For example, the diastereoisomeric difluorinated stearic acids 14 and 15 (Figure 3) are found to have very different physical properties [28]. When deposited into a monolayer above a water phase, the threo-isomer 14 occupies a small

• attached to every carbon of an alkyl chain (e.g., II, Figure 4), then a structure results that is conceptually intermediate between alkanes and perfluoroalkanes. Such structures, dubbed “multivicinal fluoroalkanes”, have interesting conformational properties that are dependent upon the stereochemistry [39

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• significantly affects their electronic features as well as molecular and crystalline structures [30][31][32]. For example, the fluorination of oligoacene frameworks manipulates their electronic properties as well as their solid-state packing motifs [33][34][35][36]. The most pronounced example is that pentacene

• - and 13-fluoropicene, formed dimeric structures through intermolecular F∙∙∙H contacts and behaved as p-channel semiconductors. By contrast, little information is available about the effects of polyfluorination on the physical properties and structures of phenacenes. It is expected that polyfluorination

• under examination. Theoretical analyses Quantum chemical studies were performed to understand the electronic spectral behavior of the F8-phenacenes. The calculation level at B3LYP/6-31+G(d,p) [52] was chosen because the B3LYP functional qualitatively reproduced the experimental properties of some fused

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

• modify a series of peptide and protein-related properties such as stability, specificity, and folding. In this regard, fluorinated amino acids are particularly important. Incorporation of fluorinated groups into the sequence of peptides and proteins can, for instance, regulate the respective

• hydrophobicity, alter the folding properties, and improve cell permeability [3][4][5]. Despite the evidence that unnatural amino acids play a significant role in the mentioned areas, synthesizing these building blocks can still be a major challenge [6]. A potent strategy in this regard is the utilization of

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• attention due to their unique properties in stereoselective allylic substitution. This review highlights recent advances in copper-catalyzed asymmetric allylic substitution reactions with chiral secondary alkylcopper species, encompassing several key strategies for their generation: stereospecific

• generating configurationally unstable organocopper species with secondary carbon–metal bonds, their unique properties, and related mechanistic insights. This review also aims to outline future research directions and prospects, contributing to the development of more efficient and selective copper-catalyzed

• styrenes with diverse electronic properties as well as those containing sensitive functional groups such as esters, amides, and vinyl halides, to yield the desired β-chiral olefins in high enantioselectivity. Notably, the methodology could even be applied to vinylferrocene and vinylsilane derivatives

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

• specifically recognizes and binds to surface antigens present on tumor or other targeted cells. (2) Linker: the linker connects the antibody to the payload. The nature of the moiety linking the drug/radiolabel/imaging agent to the antibody plays a crucial role in the pharmacokinetic properties [4][5

• antibodies [11]. In the case of ADCs, conjugation of the linker/payload to the antibody must not drastically alter the pharmacokinetics or physicochemical properties of the antibody [12][13]. Typically, zero to eight payloads are attached to the antibody. Heterogeneous ADCs may thus be a mix of both

• additionally generate an undesirable new stereocenter [26][27]. Few methods have been developed for the functionalization of tyrosine (Tyr) and tryptophan (Trp). With a low abundance (≈3%) in proteins, Tyr modifications are widely recognized for their ability to profoundly impact protein properties and

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• then elucidated as massarilactone D 4,7-di-O-crotonyl. Cytotoxic and nematicidal activities The antiproliferative properties of massarilactone D and the newly synthesized analogues were evaluated against the murine fibroblasts L929, human cervix carcinoma KB3-1, human lung carcinoma A549, human

• , as indicated by structure–activity relationship analysis. Conclusion In the present study, the use of various acylating reagents to modify massarilactone D introduces distinct functional groups, each with unique chemical properties. This approach led to the synthesis of seven previously undescribed

Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions

• Xiao-Yang Bi,
• Xiao-Shuai Yang,
• Shan-Shan Chen,
• Jia-Jun Sui,
• Zhao-Nan Cai,
• Yong-Ming Chuan and
• Hong-Bo Qin

Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47

• route. Keywords: acidic dearomazation; benzofuran; (±)-simonsol C; total synthesis; Introduction Star anise, derived from Illicium species cultivated in southeastern China [1] possesses significant economic, culinary, and medicinal value [2]. Particularly noteworthy are its medicinal properties

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• accessibility of these bioactive compounds for pharmaceutical applications. Keywords: amino acids; hydantoin; microwave-assisted; one-pot reaction; Urech synthesis; Introduction The hydantoin moiety is a scaffold found in many biologically active compounds exhibiting a diverse range of properties, including

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

• the oxazinane skeleton is an interesting scaffold for the design of synthetic routes for drug targets. The reaction works very well with a broad range of aromatic disulfides. Ortho, meta, and para-substituents with different electronic properties afford moderate to excellent yields. The reaction fails

Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• and allomaltol derivatives have the wide variety of biological activity [12][13][14][15][16]. This means that designing such hybrid products can significantly alter the pharmacological properties. Results and Discussion The starting compounds 1 were prepared from allomaltol employing a previously

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• properties along a C=C double bond [1]. This effect has been established to be very advantageous to expand the range of reactions of different functional groups that can be coupled efficiently through a conjugated π-system. In this context, the addition reaction of vinylogous nucleophiles to carbonyl

• for the synthesis of tertiary trifluoromethyl carbinols [6][7]. In this context, trifluoromethyl carbinols constitute a key structural motif present in a wide range of molecules with important biological activities (Figure 1) [8][9][10], on account of the distinctive properties of organofluorine

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

• have promising applications in optoelectronics. For example, investigation of the photophysical and electronic properties of ANTH began in the 1960s [1][2][3], and since then many new ANTH derivatives have been synthesized and explored for their use as fluorescent probes, organic semiconductors, and

• , respectively. In this work, we explored the effects of the bulky and electron-withdrawing substituent perfluorobenzyl (BnF) on the photophysical properties and on the air- and photostability of ANTH for the first time. We hypothesized that the steric bulk of BnF and the flexibility of the –CF2– moiety between

• ANTH and the –C6F5 group might provide the desired spatial isolation of the ANTH (and other PAH) cores, and result in enhanced photoluminescence by disrupting close π–π stacking in the solid state. In addition, air- and photostability might also be improved due to the steric and electronic properties

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

• light irradiation, undergoing rearrangement and photodegradation, so there may be a risk of degradation if irradiation using UV light is tried. Alternatively, the lack of a [2 + 2] cycloaddition of Me2B, may be due to its photophysical properties not allowing for a reaction to occur, rather than the

• )bimane (DMOCDO10) and syn-(Me,Me)bimane (DXABIM10) [26], a room temperature structure of Me4B (TNZBCO10) [27], and a planar syn-(H,ethynyl)bimane (WAYHEJ) [28]. Optical properties The optical properties of the three bimanes were measured to investigate differences in their excited state properties, as

• shown in Table 2. These properties help to explain the variation in photoreactivity. Quantum yields were measured using Me2B as an internal reference, with a value of 33% in acetonitrile, as initially determined by Kosower [19]. While tentative, the low fluorescence quantum yields of these compounds may

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• Abstract Diazocines are photoswitches derived from azobenzenes by bridging the two phenyl rings in ortho position with a CH2CH2 group forming an eight membered (diazocine) ring. Diazocine is superior to most azobenzenes in almost all photophysical properties (switching efficiency, quantum yield

• photoswitches with superior photophysical properties. The parent ethylene-bridged diazocine shows excellent switching photoconversion between the Z and the E configurations (Γ(Z → E)385nm = 92% and Γ(E → Z)520nm > 99% in n-hexane) due to well-separated n–π*-transitions in the visible part of the electromagnetic

• accumulation in the environment after excretion [1][6][7]. These superior properties of diazocines have been exploited in several applications such as the control of protein folding by implementation as cross-linkers between protein side chains [8] or in peptide backbones [9], as photoswitchable

Synthesis of electrophile-tethered preQ₁ analogs for covalent attachment to preQ₁ RNA

• Laurin Flemmich and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

• antibiotic properties, others expand the chemical diversity and thus the functional sophistication of ribonucleic acids, as in the case of Q [3]. In most bacteria, Q biosynthesis is tightly regulated by riboswitches, which are highly structured RNA elements located mostly in the 5’-leader of messenger RNA

• nucleoside queuosine (Q) occurring as natural tRNA modifications. Purine ring numbering is indicated in grey. The synthetic targets of this study are highlighted in grey: Natural riboswitch ligand pre-queuosine 1 (preQ1), a novel preQ1 analog with altered base-pairing properties (2,6-diamino-pre-queuosine 2

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• separated using chiral resolution. This involves separating the two enantiomers by converting the racemic mixture into a pair of diastereoisomers with the help of a chiral compound. The resulting diastereoisomers can be separated based on their physical properties using crystallization, distillation, or

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

• light and promote mass transfer. As understanding of the methodology advances, the development of more complex synthetic strategies, including C–H, C–C, and C–heteroatom-bond formation, is expected [79]. Moreover, we anticipate that the difference in photophysical properties between organic molecules in

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• to 2.88 V) and unsuccessful substrates 4i–m, S9a, S9b (from 1.73 V to 2.54 V) (Table S2 in Supporting Information File 1) span similar potential regimes suggesting that the success of the anodic oxidation likely depends on the structural rather than the electrochemical properties of the starting 2,2

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

• zeolites [28][29][30][31][32]. Undoubtedly property changes can occur in cavities, but those properties not covered by organization must be explicable: I would argue (for typical ground-state reactions) they are covered by the concept of polarization. Modern descriptions of enzyme active sites speak of

• a size-selective space [105][126][129][130][132][134]. A key advantage is that these capsules have been made on multi-hundred-gram scales and can be recycled [132]. Additionally, control of structural or bound water by the capsule [105] and properties such as a lowered pKa inside [125] demonstrate a

• instance, the window[1]resorcin[3]arene capsule type [135] demonstrates that the symmetry and properties of traditional symmetric capsules can be modulated, although precise control over the assembly remains difficult. Finally, we must mention the recently reported cavitand capsules of Gibb, who has