Get a better glimpse on sequential photoreactions of trisnorbornadienes with ¹⁹F NMR spectroscopy

• Julian Felix Maria Hebborn,
• Ben Eric Merten,
• Thomas Paululat and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 527–534, doi:10.3762/bjoc.22.38

• exemplarily with a trifluorinated trisnorbornadienylbenzene that 19F NMR spectroscopy may be applied as a useful complementary method for the investigation of sequential photoreactions. The trisnorbornadiene core structure was used as it figures as promising scaffold for molecular solar thermal (MOST) energy

• thermal energy storage; photochemistry; photochromism; quadricyclanes; Introduction Photochromic compounds, which change their physical and chemical properties reversibly upon irradiation, figure as a versatile basis for the development of functional materials, whose performance can be switched or

• controlled by light [1][2][3][4]. To add to that, the photochromic reaction allows to convert the energy of the applied light into chemical energy, which can thus be stored and eventually released on demand as heat in the back reaction. Therefore, photochromic reactions constitute the centerpiece of the

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• Lebanese Atomic Energy Commission, National Council for Scientific Research CNRS –L, P.O. Box: 11-8281, Riad el soleh, 1107 2260, Beirut, Lebanon 10.3762/bjoc.22.36 Abstract The contamination of water by uranium poses a serious threat to ecosystems and human health, creating a need for efficient and

• extraction by PCP HA. Supporting Information Supporting Information File 6: Experimental part. Acknowledgements The authors express their gratitude to the Lebanese Atomic Energy Commission- LAEC and the Unité de Chimie Environnementale et Interactions sur le Vivant- UCEIV for their support of this work

Recent advances in the stereoselective synthesis of distal biaxially chiral molecules

• Fanxing Zhou,
• Chen Zhang,
• Lingyu Sun,
• Yiyun Fang,
• Siming Zheng,
• Lina Hu,
• Mengyang Shen,
• Zhen Zhao,
• Wei Xu,
• Yunqiang Sun and
• Zi-Qiang Rong

Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34

• "-ternaphthalene compounds [35]. This work significantly advanced the development of bi- and multiaxial chirality. The synthesis of multiaxial chiral molecules requires appropriate steric hindrance to elevate the rotational energy barrier of each chiral axis [36], and the spatial interactions between axes are

• prioritizing the construction of axially chiral diastereomers with the highest energy barriers to reduce the venture of subsequent epimerization. At the same time, the higher barrier diastereomer served as a chiral template for building the stereoconfiguration of axial chiral bonds. Remarkably, this strategy

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• oxidatively deaminated to the TCA cycle intermediate α-ketoglutarate for energy production and additional biosynthetic pathways. There are two glutaminase isozymes in humans: KGA is encoded by the GLS1 gene and is expressed mainly in the kidney and brain and LGA encoded by the GLS2 gene is expressed mainly in

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• solid state structure of the compound 7. All the above-mentioned non-bonded interaction distances are shorter than the sum of the van der Waals radii of the respective elements in contact [55]. Computational analysis To further evaluate the energy-minimised structures useful for molecular

• energy gap, which are key parameters for understanding the compound's chemical reactivity and stability. In both compounds, the HOMO is mainly localised on the tert-butyl-substituted phenyl ring, while the LUMO is localised on the naphthalimide moiety. For both structures, the estimated energy gaps are

• around 3 eV. Compound 7 has an energy gap of 3.098 eV, having HOMO and LUMO energies of −5.6153 eV and −2.5170 eV, respectively (Figure 4a). Compound 8 has an energy gap of 3.049 eV with HOMO and LUMO energies of −5.6036 eV and −2.5546 eV, respectively (Figure 4b). These values indicate that compounds 7

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• the case where the entire group is formed by sixteen signals of the same intensity. In support of this, the energy-minimized structures of two regioisomeric capsules, 492 isomer 1 and 492 isomer 2, each containing a chloroform molecule (Figure 4a, PBE0/def2-SVP, gCP, D4, SMD (chloroform), ORCA 6.0.1

• . Molecular structures of partially nitrated calixarene 16 (a) and exhaustively nitrated calixarene 15 (b). Two projections shown in each case and thermal ellipsoids are drawn at a 50% probability level. Planar and energy-minimized structures (with CHCl3 molecule included and triazole groups highlighted) of

Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)

• Tin Zar Aye,
• Rubal Sharma,
• Muthu Karuppasamy,
• Daiya Suzuki,
• Haruka Nakajima,
• Yoshitane Imai,
• Mitsuhiro Arisawa,
• Mohamed S. H. Salem and
• Shinobu Takizawa

Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25

• lowest energy excited state (S1) and TD-DFT calculated transitions at MN15/6-311G(2d,p)/SMD=chloroform level of theory. Chiroptical properties of oxaza[n]helicenes: (A) CD spectra measured in chloroform (1 × 10−5 M); CPL spectra measured in chloroform (1 × 10−3 M). Solid lines for (M)-configuration and

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• valuable features, amide derivatives are ubiquitous across the pharmaceutical, agrochemical, dye, polymer, and renewable-energy industries [6][7][8][9][10][11]. Accordingly, the development of efficient methods for both amide-bond formation and the selective transformation of amide functionalities remains

• , thereby lowering the energy barriers associated with both nucleophilic attack by n-butanol and subsequent C–N bond cleavage. As a result, the overall esterification process is significantly accelerated. In 2021, Ma et al. developed an elegant method for the transamidation of tertiary amides catalyzed by

• ) Metal-free photoredox catalysis for cleavage of N-PMB anilide. Funding This study was supported by the Korea institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean Government (MCEE) (RS-2022-KP002707, Jeonbuk, regional Energy Cluster Training of Human resources) and

Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls

• Mark M. Gulman,
• Yuliya F. Polienko,
• Sofia Yu. Trakhininа,
• Yuri V. Gatilov,
• Tatyana V. Rybalova,
• Sergey A. Dobrynin and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22

• components of many high-tech materials, such as energy storage and organoelectronics devices [1][2][3][4][5][6][7][8], catalysts [9][10], bioactive coatings and nanoparticles [11][12], organic radical contrast agents (ORCAs) for magnetic resonance imaging (MRI) [13][14], etc. For these applications, numerous

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

• with oxygen via 2 the ketal structure 3 can decarboxylate [50], generating another high-energy ferryl-oxo species 4 (bound with succinate) which can lead to hydroxylation or carbocation chemistry [51]. Finally, other classes of tailoring enzymes can also act as electrophiles and lead to ring-size

• single, concerted step. This concerted mechanism allows the reaction to bypass a high-energy, non-stabilised secondary carbocation intermediate that would result from a stepwise migration. This pathway is facilitated by the enzyme's active site, where aromatic residues (e.g., Tyr564) are proposed to

Spirobarbiturates with a pyrrolizidine moiety: synthesis, structure and biological evaluation

• Arthur A. Puzyrkov,
• Andrew S. Drachuk,
• Ekaterina A. Popova,
• Alexander V. Stepakov and
• Vitali M. Boitsov

Beilstein J. Org. Chem. 2026, 22, 274–288, doi:10.3762/bjoc.22.20

• and nucleotide, DNaze I-binding). The structure of the 8DNH protein was retrieved from the protein data bank and the Molegro Virtual Docker 6.0 software was used to prepare it for the docking study [66][67]. The pose organizer and the ligand energy inspector tool were used to examine the docking

Conformational analysis of difluoromethylornithine: factors influencing its gas-phase and bioactive conformations

• Matheus P. Freitas

Beilstein J. Org. Chem. 2026, 22, 237–243, doi:10.3762/bjoc.22.17

• preference arises primarily from hyperconjugative stabilization, particularly the σCH → σ*CN interaction, while steric effects modulate the relative stability among low-energy conformers. The gauche effect is intensified in the zwitterionic form due to electrostatic interactions. In contrast, the

• this framework, DFMO is expected to display the gauche effect when type-I structures dominate, because the polar C–N bond forms two gauche interactions with the polar C–F bonds. High-level DLPNO-CCSD(T)/CBS calculations support this expectation: the four lowest-energy structures are type I and together

• -energy structures (1–4) differ mainly by rotations about the C–COOH, C–NH2, and C–C(NH2) bonds. As a result, their relative energies are governed primarily by the local environments of these groups rather than by the orientation of the difluoromethyl unit. Steric analysis based on exchange energies

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• analysis indicate that the HOMO and LUMO are localized on the carbazole and phthalimide fragments, respectively, affording a small singlet–triplet energy gap. In the solid state, compound 1 exhibits pronounced phase dependence: powder samples display room-temperature delayed emission with principal bands

• -resolved biological imaging [6], chemical and biological sensing [7], as well as energy transfer and upconversion processes [8]. The unique characteristics of organic materials, including their solubility, ease of processing, molecular structure programmability, and the tunability of their emission color

• polymer hosts. In contrast, TADF relies on the reduction of the singlet–triplet energy gap (ΔEST), facilitating thermally activated reverse intersystem crossing (RISC) from the triplet state to the singlet excited state, where the excitation energy is released via delayed fluorescence [29]. Common

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• phosphate rocks, a practice that has evoked concerns due to the natural resource depletion through a refining process called the Wöhler process [34]. It incurs extremely high energy costs of approximately 12.5–14 MWh per 1 t (1 metric ton = 1000 kg) of white phosphorus [34]. In recent years, synthetic

• methods for phosphorus chemicals that do not depend on white phosphorus or phosphorus chloride have been developed to reduce energy consumption and environmental hazards. For example, Montchamp’s group and Yang’s group have focused on using sodium phosphinate as an alternative to PCl3, and various halogen

• chloride obtained from phosphate rock using white phosphorus as a raw material; this is accompanied by a large electric energy consumption and emission of large amounts of corrosive gases. In our work, the reaction time and temperature can be further improved; however, the obtained results suggest a novel

A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts

• Holly Helmers,
• Mark Horton,
• Julie Concepcion,
• Jeffrey Bjorklund and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10

• unable to purchase nitric acid of this grade from a commercial source. While 3 was produced as a mixture with its regioisomer 7, this approach yielded the desired intermediate in a single step without the need for the high-energy diazonium intermediate used in other syntheses [6][7][8][9]. After having

Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• blue-shifted by 38 nm, and the shorter-wavelength emission peak (408 nm) was blue-shifted by 19 nm. These blue shifts are attributed to the hydrophobic environment in the PMMA matrix. In such low‐polarity surroundings, the excited state is less stabilized, resulting in a higher excited‐state energy and

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• indicative of a high NLO response in a typical organic NLO chromophore. Apart from the existence of donor (D) and acceptor (A) groups linked by a π-conjugation path, the NLO response is also influenced by the strength of the D and A groups in the structure. For high NLO responses, a small energy gap between

• the HOMO and the LUMO (ΔE), resulting from the presence of the strong D/A groups, is an important indicator. Based on the EFISH results, the calculations show that 2a and 2b have a small energy gap and a high β value because they have a stronger electron-donor group than 2c. Additionally, 2a and 2b

• solvents with different polarity and the calculated absorption spectra dataa. The absorption maxima (λabs), oscillator strength (f) and transitions for 2a–c and 2a–c+CN−. Experimental and calculated NLO properties and energy gap (ΔE) values for 2a–c. Td values of the dyes. Supporting Information

Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure

• Ilia A. Pilipenko,
• Mikhail V. Grigoriev,
• Olga Yu. Ozerova,
• Igor A. Litvinov,
• Darya V. Spiridonova,
• Aleksander V. Vasilyev and
• Sergey V. Makarenko

Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5

• (electron) pair – the π-system of the nitro group, and bonds of the Cl···O, Cl···N, C–H···X (X = Cl, O, N) are realized, which are shown in Figures S47–S57 in Supporting Information File 1. The energy of such interactions can be comparable with the energy of “classical” hydrogen bonds [47]. Conclusion In

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• bond dissociation energy (BDE). Although zirconium shares many characteristics with titanium as a group-congener transition metal, it is known to form stronger bonds in several cases. For example, the Ti–O BDE is reported as 115 kcal·mol−1, whereas the Zr–O BDE is 132 kcal·mol−1 [4]; likewise, Ti–Br

• transfer (XAT) mediated by zirconocene bistosylate (Scheme 7A) [22]. Alkyl chlorides are inexpensive and readily available feedstocks; however, their chemical transformation has been challenging due to the high bond dissociation energy of the C–Cl bond compared to the C–Br and C–I bonds [12]. Motivated by

• transformations of monofluoroalkyl groups have been considered difficult due to their negative reduction potentials. In contrast, the authors focused on the comparatively small bond dissociation energy (BDE) of C(sp³)–F bonds. Based on the hypothesis that this property could enable C–F bond functionalization via

Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene

• Dmitry N. Platonov,
• Alexander Yu. Belyy,
• Rinat F. Salikov,
• Kirill S. Erokhin and
• Yury V. Tomilov

Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2

• the set of conformations of anion 2 and found that conformer 2', with an allyl-anionic fragment shifted to form a nucleophilic CH fragment (Figure 3), is only 9.6 kcal/mol less stable than the main conformer 2 (the energy values of other conformers are given in Supporting Information File 1). Note

• chlorine is associated with an increase in energy of the lowest unoccupied molecular orbital of halogen molecules and a decrease in their electrophilicity. Therefore, if an electrophilic mechanism takes place, iodine apparently reacts with the main conformer faster than a transition to conformer 2' may

• negative free energy changes for all the stages of this reaction. A chlorination experiment with 2,2,6,6-tetramethylpiperidinyloxyl revealed a trace amount of a trap product detected by high-resolution mass spectrometry to support the radical mechanism. However, this does not exclude the possibility of a

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• most detail and attract continuing attention as perspective high-energy materials [76][77][78][79][80][81][82][83][84][85][86] and physiologically active substances [87]. At the same time, aliphatic compounds containing the nitro-NNO-azoxy group are practically unknown, with the exception of a few

• estimated, as this step requires the change in spin-state. However, unexpectedly we found that addition of higher energy singlet nitrene C-s to A is not barrierless (ΔG≠ 10.9 kcal/mol). Moreover, according to our calculations C-s can easily (ΔG≠ 5.7 kcal/mol) undergo unimolecular rearrangement to the dimer

• of 0.1 V/s at 298 K. Free energy diagram of possible interaction pathways between 1a and dinitramide-derived radical A according to ωB97X-3c [94]/CPCM(MeCN) level of theory. Free energies ΔG and activation free energies ΔG≠ are given in kcal/mol. Dashed lines correspond to spin-state-changing

Mechanistic insights into hydroxy(tosyloxy)iodobenzene-mediated ditosyloxylation of chalcones: a DFT study

• Jai Parkash,
• Sangeeta Saini,
• Vaishali Saini,
• Omkar Bains and
• Raj Kamal

Beilstein J. Org. Chem. 2025, 21, 2703–2715, doi:10.3762/bjoc.21.208

• , the detailed calculated reaction mechanism differs. Scheme 2 and Scheme 3 depicts the reaction mechanism for these two possible cases, i.e., when X is electron-donating and electron-withdrawing, respectively. Figure 1 depicts the free energy reaction profile for the chalcone with X = -SCH3. The

• corresponding reaction profile for X = -OCH3 has been discussed in our earlier study [34]. Figure 2 and Figure 3 present the free energy reaction profiles for chalcones with X = -Cl and X = -NO2, respectively. Table 1 lists the free energy and potential energy for various intermediates and transition states for

• chalcones with different substituents, X = -SCH3, -Cl, -NO2 including the data for X = -OCH3. The difference between free energies for consecutive reaction species are shown over arrows in Figures 1, 2 and 3 for substituents X = -SCH3, -Cl and -NO2, respectively. Table 1 also reports these free energy

Tandem hydrothiocyanation/cyclization of CF₃-iminopropargyl alcohols with NaSCN in the presence of AcOH

• Ruslan S. Shulgin,
• Ol’ga G. Volostnykh,
• Anton V. Stepanov,
• Igor’ A. Ushakov,
• Alexander V. Vashchenko and
• Olesya A. Shemyakina

Beilstein J. Org. Chem. 2025, 21, 2694–2702, doi:10.3762/bjoc.21.207

• , electron ionization, electron energy: 70 eV, ion source temperature 200 °C; mass range 34–650 Da. The solvent was chloroform or acetone. Column chromatography was performed on silica gel 60 (70–230 mesh, particle size 0.063–0.200 mm or 230–400 mesh, particle size 0.040–0.063 mm, Merck). Commercially

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• , protonation of these compounds resulted in a lowering of the HOMO energy level, leading to an increase in the HOMO–LUMO gap and, consequently, greater molecular stability. In contrast, deprotonation led to an increase in the LUMO energy level, with little influence on the HOMO energy. Notably, the neutral

• operation: −x + 2, −y + 1, −z + 1. Molecular energy as a function of the torsion angle obtained from a relaxed dihedral scan at the M06-2X/def2-TZVPP level of theory. Identification of the carbon atoms used in the theoretical study of chemical shifts. In red, easily identifiable carbon atoms in the

Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds

• Vasudevan Dhayalan

Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200

• ]. The use of visible light as an energy source has significantly expanded the scope of organic molecule activation and its application in organic synthesis or medicinal chemistry [12], thereby driving the fast development of various photocatalytic transformations. Among these advances, dual catalysis

• , and advanced optical and energy materials. Review Visible-light-driven NHC/4CzIPN-catalyzed reactions Recently, Shu and co-workers developed a direct and innovative preparation of highly functionalized aryl amide derivatives 3 from aryl aldehydes 1 and substituted imines 2 under mild conditions in the