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

• products were detected under the optimized conditions (Scheme 2). Based on our previous reports [48][56], DFT calculations, and cyclic voltammetry (CV) analyses (Figure 1), anodic single-electron transfer (SET) is expected to occur first from 3, generating the electrophilic radical cation [3]·+ as 3 (Eox

• attributed to the increased deviation from planarity, particularly in the more extended helicenes, consistent with previous studies [60]. To gain further insight, we performed anisotropy of the induced current density (AICD) calculations for 5a and 5b at the B3LYP/6-311G(d,p) level in the gas phase [61]. The

• [8]helicenes 5a and 5b, we performed DFT calculations to locate the transition states with the highest Gibbs free energies. In both cases, the transition states correspond to conformations in which the terminal rings adopt a face-to-face arrangement along the helical axis (Figure 3). The calculated

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

• restored after recalcination prior to reuse. Based on DFT calculations, the authors proposed that octanol is deprotonated and coordinated to Ce, while the amide substrate is simultaneously activated electrophilically through coordination to the Ce center (A). This dual activation enables the lattice oxygen

• transition-metal-catalyzed asymmetric C–H activation reactions as a directing group, thus necessitating an efficient method for the cleavage of 8-aminoquinoline-derived amides. The role of Me2SO4 in this transformation was elucidated through DFT calculations. Methylation of the carbonyl oxygen by Me2SO4

• bioactive compounds underwent smooth esterification with TFE to give the corresponding 2,2,2-trifluoroethyl esters 82–85 in high yields. To elucidate the reaction mechanism, cyclic voltammetry experiments, control reactions, and DFT calculations were conducted. At the anode, bromide ions are oxidized to

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

• found in pseudolaric acid B (14) biosynthesis [64][65]. In this case, the linear precursor 12 is first cyclised to give intermediate 14a akin to the α-terpinyl cation (see Scheme 3). From here, quantum chemical calculations indicate that the subsequent 1,2-alkyl shift and olefin cyclisation occur in a

• operational intermediates, as calculations showed instead a concerted rearrangement towards the tertiary cation 23c to be more likely. From here, ent-kaurene (24) is obtained directly after elimination. The formation of ent-atiserene (25) involves a more dramatic rearrangement to reach the tertiary

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

• formation of azomethine ylide from alloxan (1) and ʟ-proline (2) was previously studied using DFT calculations [43]. Based on the calculated data, it was assumed that the 1,3-dipole is formed as a result of a multistage sequence: initial generation of a zwitterionic imine intermediate from 1 and 2, followed

• barbiturate moieties of paired enantiomers (see Supporting Information File 1, Tables S2 and S3). The Hirshfeld surface (HS) analysis provides a robust tool for visualizing and characterizing intermolecular interactions in organic crystal lattices. The calculations of the HS were performed using

• allowed unambiguous determination of the absolute configuration of the spirobarbiturate adducts. Additionally, a detailed analysis of intermolecular interactions in the crystal structure was performed using Hirshfeld surface calculations, providing valuable insights into the packing arrangements of these

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• represent thermodynamically favored, more stable products formed upon prolonged heating. To support the hypothesis that the carbonyl carbon atom in pyranoquinoline exhibits higher electrophilicity than in the open-chain ester, quantum chemical calculations were performed to evaluate their electrophilic

• properties (see Supporting Information File 1, pages S3 and S50–S51). The methyl ester was selected as the model open-chain compound. Calculations revealed that the initial atomic charge on the carbonyl carbon in the lactone was +0.234, whereas in the methyl ester it was slightly lower at +0.225. Further

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

• conformational stability. High-level DLPNO-CCSD(T)/CBS calculations revealed that type-I conformers – those maximizing gauche interactions between C–F and C–N bonds – dominate the equilibrium population, confirming the presence of the fluorine gauche effect. natural bond orbital (NBO) analysis showed that this

• 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

• with two additional structures – one with the COOH group (II) and another with the C2H4NH2 group (III) positioned between the two C–F bonds – were subsequently optimized at the B3LYP-GD3BJ/6-311++G(d,p) level [28][29][30][31] of density functional theory. Frequency calculations confirmed that all

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

• Abstract A twisted D–π–A molecule, PI-Cz 1, was designed and synthesized using phthalimide as the acceptor, carbazole as the donor, and a phenylene bridge. Single-crystal X-ray diffraction revealed a markedly non-coplanar skeleton. Calculations based on the crystallographic geometry and frontier-orbital

• -containing acceptor and potential intermolecular interactions, providing conditions for enhanced SOC and RTP manifestation in crystalline or partially crystalline states. By combining single-crystal structural analysis, quantum calculations, and steady-state/time-resolved/temperature-dependent spectroscopy

• influencing the electronic properties and excited-state dynamics of 1. Building on the crystallographic data, quantum-chemical calculations were performed using the Gaussian 09 software at the B3LYP level of theory. The calculations revealed that the highest occupied molecular orbital (HOMO) is primarily

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• ) Å, b = 9.3243(5) Å, c = 10.1072 (4) Å, β = 102.480(4)°, V = 776.19(7) Å3, Z = 2, μ(Mo Kα) = 0.217 mm−1, Dcalc = 1.345 g/cm3, 4252 reflections measured (7.378° ≤ 2Θ ≤ 61°), 4252 unique (Rint = 0.0407, Rsigma = 0.0545) which were used in all calculations. The final R1 = 0.0596, wR2 = 0.1470 (I >= 2σ(I

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• be partially responsible for its high membrane permeability. To investigate if an IMHB is indeed present in 1, we combined DFT calculations with NMR spectroscopy titrations. For a system containing an IMHB, it would be expected that replacing the proton (O–H) with a deuteron (O–D) would lead to an

• isotope effect observable as changes in the 13C NMR chemical shift [18][19]. DFT calculations were based on a truncated model (Figure 6a) containing the essential elements for intramolecular hydrogen bonding. The structure was considered both in vacuum as well as with DMSO or water as implicit solvents

• and 0.1% phosphoric acid in the ratios 35:65 and 25:75, v/v for the distribution coefficient and stability experiments, respectively. The ChemStation software (Version B.04.03, Agilent Technologies) was used for instrument control and data collection. Computational chemistry DFT calculations were

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

• chiral platinum(II) complex was synthesized via Sonogashira coupling and subsequent coordination of a pincer ligand to a precursor. The complex exhibited a broad absorption band ranging from 250 to 550 nm in the UV–vis spectrum, with TD-DFT calculations indicating mixed ligand-to-ligand charge transfer

• behavior, through a combination of experimental measurements and density functional theory (DFT) calculations. The experimental UV–vis spectrum was in good agreement with the DFT calculations, revealing that the electronic transitions originate from both ligand-to-ligand charge transfer (LL’CT) and metal

• spectroscopy, as well as high-resolution mass spectrometry (HRMS). Due to its low solubility, single crystals suitable for X-ray crystallographic analysis could not be obtained. Spectroscopic analysis and DFT calculations To elucidate the electronic structure of the platinum(II) complex, UV–vis absorption

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

• cyanide and the chemosensor is determined by a 1H NMR study and explained by DFT calculations. Keywords: chemosensor; DFT calculations; donor–π–acceptor–π–donor based organic dyes; indan-2-one; NLO; Introduction Over the past decades, the functional heterocyclic push–pull dyes have attracted significant

• functional theory (DFT) and time-dependent DFT (TD-DFT) calculations, which were consistent with experimental results. NLO properties of the compounds were experimentally determined using the EFISH method and calculated using theoretical methods. Additionally, the thermal decomposition temperatures, an

• spectrometry methods (Figures S1–S10 in Supporting Information File 1). Optical properties of dyes Photophysical properties of dyes 2a–c were assessed in four different organic solvents with various polarities (DMSO, acetone, chloroform, and THF) via absorption spectra and DFT calculations (Table 2). Figure 2a

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

• (Rigaku OD, 2021) software package. All of the structures were solved by direct methods using the SHELXT program [48] and refined by the full-matrix least squares method over F2 using the SHELXL program [49]. All of the calculations were performed in the WinGX software package [49], the calculation of the

• −3, μ(Mo Kα) 8.393 mm−1, F(000) = 504, 9545 reflections measured (6.762° ≤ 2Θ ≤ 139.896°), 3676 unique (Rint° = 0.0391, Rsigma° = 0.0425) which were used in all calculations. Flack parameter 0.299(14), crystal is a racemic twin, and final refinement of this structure was completed as racemic twin

• , F(000) = 576.0, 3763 reflections measured (8.352° ≤ 2Θ ≤ 139.956°), 2056 unique (Rint = 0.0223, Rsigma = 0.0260) which were used in all calculations. The final R1 was 0.0321 (I > 2σ(I)) and wR2 was 0.0844 (all data). Crystal of 9а, C13H10Cl3N3O3, M = 362.60, monoclinic, space group P21/n, at 100(2

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

• for the success of the reaction. DFT calculations suggested that in the transition state (TS1), a Cl–π interaction between the chlorine atom on the zirconocene catalyst and the aromatic ring of the substrate facilitated rapid halogen atom transfer (XAT), generating a radical at the C3 position of

• potential and stabilizing the radical pathway. The DFT calculations are shown in Scheme 13A. The activation barrier for the XAT process was calculated to be ΔG‡ = 8.0 kcal/mol, indicating that this process can proceed spontaneously around room temperature. Moreover, the transition state (TS1) suggested the

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

• possibility of i-halogenation via a chain radical mechanism (Scheme 3). The initiation stage includes an oxidation of anion 2 into the corresponding radical 13 which in turn reacts with halogens to form products 4a,b and a halogen atom which can also oxidize the anion. Quantum chemical calculations revealed

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

• calculations were performed [93] on ωB97X-3c [94] /CPCM(MeCN) level of theory (Figure 3). Based on cyclic voltammetry data, control experiments, and our previous study, the mechanism of the electrochemical synthesis of nitro-NNO-azoxy compounds 2 was proposed (Figure 3, Scheme 5). The reaction starts from

• end of the reaction), which is sufficient to oxidize ADN. According to the performed calculations, competitive oxidation of 1a does not occur, which is confirmed by the obtained CV-data (see Figure 1 and Figure 2). According to DFT calculations, the reaction of N-radical A with 2-nitro-2

• 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

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

• computationally. The results obtained for chalcones are in qualitative agreement with results reported for substituted styrenes [31]. Computational Methodology Quantum chemical calculations were carried out using Gaussian 09 package [37]. The hybrid exchange-correlation functional B3LYP-D3 (including dispersion

• . The solvent considered for the present study was dichloromethane (CH2Cl2). Frequency calculations were performed for all optimized structures to confirm the stationary point and transition state. Intrinsic reaction coordinate (IRC) calculations were carried out to validate the transition states. The

Recent advancements in the synthesis of Veratrum alkaloids

• Morwenna Mögel,
• David Berger and
• Philipp Heretsch

Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206

• -NOESY and DFT calculations. The tertiary amine was masked as the hydrochloride salt with concomitant ketal deprotection, which was followed by hydrogenation to remove the benzyl protecting group to obtain (±)-4-methylenegermine hydrochloride (17·HCl) in 31 steps (LLS from commercial materials) and an

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

• compounds 3n and 4n was carried out using torsion angle analysis and 13C NMR chemical shift calculations to evaluate the absence of expected signals in the NMR spectra of these compounds. Their photophysical properties were also assessed, confirming a preference for a fluorescence mechanism via an ICT

• efficient synthesis of eight novel imidazo[1,2-a]pyridine–thiazolidinone hybrids in high yields (up to 99%). A spectroscopic analysis of selected compounds was carried out, including torsion angle evaluation and 13C NMR chemical shift calculations, justifying the absence of expected signals in some cases

• Information File 1 (Tables S4 and S5). B97-D/def2-TZVPP calculations confirmed the hypothesis that the carbons labeled as 10, 11, 13, and 14 could be split in four peaks (Table 3) with chemical shift differences of ≈1 ppm and ≈8 ppm for the ortho and meta carbon atoms, respectively, with respect to the N

Recent advances in total synthesis of illisimonin A

• Juan Huang and
• Ming Yang

Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199

• . However, subsequent density functional theory (DFT) calculations by the Tantillo group on rearrangements of potential biosynthetic precursors revealed that structure 10 corresponds to a transition state rather than a stable intermediate of the 1,2-alkyl migration [27]. Their study further indicated that

Isoorotamide-based peptide nucleic acid nucleobases with extended linkers aimed at distal base recognition of adenosine in double helical RNA

• Grant D. Walby,
• Brandon R. Tessier,
• Tristan L. Mabee,
• Jennah M. Hoke,
• Hallie M. Bleam,
• Angelina Giglio-Tos,
• Emily E. Harding,
• Vladislavs Baskevics,
• Martins Katkevics,
• Eriks Rozners and
• James A. MacKay

Beilstein J. Org. Chem. 2025, 21, 2513–2523, doi:10.3762/bjoc.21.193

• phenomenon was observed previously with V and this design element was intentionally incorporated with an expectation toward aiding in triplex stability [33]. For Db1, calculations reveal that the intended H-bond between the cationic –NH2+– moiety did in fact form (ca. 2.1 Å, Figure 7A). However, the distal

Synthesis of the tetracyclic skeleton of Aspidosperma alkaloids via PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction

• Ru-Dong Liu,
• Jian-Yu Long,
• Zhi-Lin Song,
• Zhen Yang and
• Zhong-Chao Zhang

Beilstein J. Org. Chem. 2025, 21, 2470–2478, doi:10.3762/bjoc.21.189

• of new reactions and strategies. In this work, a PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction of N-substituted cyclobutenone provided a facile approach to the direct construction of the ABCE tetracyclic framework of Aspidosperma alkaloids. DFT calculations showed

The intramolecular stabilizing effects of O-benzoyl substituents as a driving force of the acid-promoted pyranoside-into-furanoside rearrangement

• Alexey G. Gerbst,
• Sofya P. Nikogosova,
• Darya A. Rastrepaeva,
• Dmitry A. Argunov,
• Vadim B. Krylov and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2025, 21, 2456–2464, doi:10.3762/bjoc.21.187

• in this case, a computational study was carried out. Herein, we report the obtained results. Computational Details All the calculations were performed using the ORCA 5.0.4 software package [32]. DFT B3LYP functional with the third order Grimme’s correction (D3) [33] and def2-TZVP [34] basis set were

• employed. CPCM model [35] with the default parameters for methylene chloride was used to account for bulk solvent effects. Such choice of computational parameters for protected carbohydrate molecules was validated in our previous investigation [36]. The defgrid3 option was used throughout the calculations

• . The optimized structures were subjected to hessian calculations and the resulting Gibbs free energies were used for the analysis in this work. For DLPNO-CCSD(T) calculations CC-pVTZ basis set was used. The Altona-Sundaralingam parameters [37][38] for furanoside rings were calculated using the online

Catalytic enantioselective synthesis of selenium-containing atropisomers via C–Se bond formations

• Qi-Sen Gao,
• Zheng-Wei Wei and
• Zhi-Min Chen

Beilstein J. Org. Chem. 2025, 21, 2447–2455, doi:10.3762/bjoc.21.186

• excellent conversion rates (up to 95% yield) and high enantioselectivity (up to 96% ee). Notably, isoquinoline derivatives containing polycyclic naphthalene moieties or ortho-substituted phenyl groups also demonstrated good reactivity and compatibility. DFT calculations indicated that the C–Se bond

• products demonstrated complete E-stereoselectivity (E/Z ratio >20:1). Notably, under the same reaction conditions, aliphatic selenols remained unreactive. Density functional theory (DFT) calculations revealed that the rate-determining step involves the nucleophilic attack of the selenium anion in

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• given in Supporting Information File 1, Figure S1). In addition to the calculations already outlined, a series of toxicity properties of methyl laurate were calculated using ADMETLab 3.0 in comparison with common organic solvents and some green solvents. The obtained results were visualized with a

Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs

• Guang-Wei Zhang,
• Yong Zhang,
• Le Shi,
• Chuang Gao,
• Hong-Yu Li and
• Lei Xue

Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181

• . This further corroborates the decisive role of the macrocyclic architecture in the anion recognition process. Quantum chemical calculations were performed with the ORCA 5.0.3 software [29]. The geometry optimization was performed by using B3LYP with the def2-SVP basis set. As illustrated in the