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

• molecular design approaches for TADF include twisted donor–acceptor structures (for example, carbazole or phenoxazine as donors and triazine, nitrile, or carbonyl groups as acceptors) as well as B/N multiresonance frameworks [30][31][32]. These strategies have been successful in achieving efficient triplet

• , 478.1682. a) Single-crystal structure of 1, b) HOMO distribution calculated on the crystallographic geometry, and c) LUMO distribution calculated on the crystallographic geometry. Photophysical properties of 1 in solvents of varying polarity: a) UV–vis absorption spectra and b) fluorescence emission

• spectra (excitation wavelength: 365 nm). Fluorescence and phosphorescence spectra of 1 in THF (excitation wavelength: 365 nm). a) Steady-state and delayed emission spectra of 1, b) room-temperature emission lifetimes monitored at 550 nm and 600 nm, c) time-resolved emission spectra, d) temperature

Screwing the helical chirality through terminal peri-functionalization

• Devesh Chandra,
• Sachin and
• Upendra Sharma

Beilstein J. Org. Chem. 2026, 22, 205–212, doi:10.3762/bjoc.22.14

• method for the generation of helical chirality primarily involves cycloaddition and central/axial to helical chirality transfer reactions [31] (Figure 1A and B). In addition to this, a parallel strategy also offers a promising approach to achieving configurationally stable helicenes via terminal peri

• induction of helical chirality which majorly relies on the π extension of organic scaffolds via annulation/cycloaddition and B) central/axial to helical chirality conversion. C) Induction of helical chirality in [4]helicene via terminal peri-functionalization. D) Induction of helical chirality in [5

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

• , Leuven B-3001, Belgium 10.3762/bjoc.22.13 Abstract Solvent-dependent transformations of polysubstituted 2-acetyl-2,5-dihydrothiophenes to the corresponding 2-hydroxy- or deacetylated derivatives are described. The treatment of a methanolic solution of the dihydrothiophene substrates with sodium

• phenols [25]. Hocking has described the oxidation of o-hydroxyacetophenone and some benzophenones with an aqueous alkaline hydrogen peroxide solution [26]. The key steps of oxidation of ketones into phenols include: a) nucleophilic addition of the hydroperoxide anion to the carbonyl carbon; b) [1,2]-aryl

• (retention time 6.905‒6.961). One of these peaks can be assigned to the product 2a, while the other peak showed that the deacylated product 3a is formed during the transformation with subsequent oxidation by sulfur in the oxidation/reduction step to form 2,5-dihydrothiophene 1-oxide 2a′ (Figure 1, a and b

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• -resistant enterococci (VRE), two new meroterpenoids, streptoquinolines A (1) and B (2), were isolated from a culture of terrestrial Streptomyces sp. TMPU-A0679. The structures of 1 and 2 were elucidated based on spectroscopic analyses, including NMR and MS, and were found to consist of a drimane-type

• B (2) (Figure 1). Compounds 1 and 2 possessed a unique skeleton consisting of a drimane-type sesquiterpene fused with a quinoline moiety and both exhibited potent antibacterial activity against Gram-positive bacteria. This study describes the production, isolation, structural elucidation, and

• preparative HPLC, yielding streptoquinolines A (1, 7.50 mg) and B (2, 8.05 mg). The physicochemical properties of 1 and 2 are summarized in Table 1. Compounds 1 and 2 showed characteristic absorption maxima at 200–202, 214, 231–234, 312, and 349–350 nm in UV spectra. Common IR absorption bands at 3414–3427

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

• 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

• 1.0 Hz before Fourier transformation. Spectra were processed with MestReNova. Synthesis of 25CN-NBOH·HCl (1·HCl). a) 2C-CN is available in 4 steps from 2C-H [12]: 1) TFAA, TEA, DCM; 2) TiCl4, dichloromethyl methyl ether, DCM; 3) NH2OH, HCl, EtOH, then Ac2O; 4) NaBH4, EtOH, then HCl. b) Salicylaldehyde

• , oxygen atoms red, and chloride ion green. b) The crystal packing reveals alternating layers, a polar layer with hydrogen bonds (black dashed lines), and a hydrophobic layer with π–π-stacking (grey dashed lines). SCXRD and XRPD spectra of different preparations of 1·HCl. Blue: SCXRD spectrum of 1·HCl. Red

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

• , thereby creating water-soluble derivatives of this ancient dye. A) UV–vis spectra of 6,6’-dibromo-5,5’,7-indigotrisulfonic acid trisodium salt (10) (10 μM) in aqueous solution at different pH values. B) UV–vis spectra of 6,6’-dibromo-5,5’-indigodisulfonic acid disodium salt (9) (10 μM) in aqueous solution

• at different pH values. A) Generalized synthetic scheme for several previous syntheses of 6,6’-dibromoindigo. B) The synthetic scheme for 6,6’-dibromoindigo described in this work. Synthetic scheme for the preparation of 6,6’-dibromoindigo from p-bromotoluene (5). Nitration of p-bromotoluene (5

• ) yields a mixture of regioisomers 3 and 7. Benzylic bromination of 4-bromo-2-nitrotoluene (3). A) Treatment of 4-bromo-2-nitrobenzyl bromide (6) with DMSO did not yield the alkoxysulfonium ion intermediate 8. B) Silver nitrate-mediated Kornblum oxidation yields 4-bromo-2-nitrobenzaldehyde (4) in fair

Asymmetric Mannich reaction of aromatic imines with malonates in the presence of multifunctional catalysts

• Kadri Kriis,
• Harry Martõnov,
• Annette Miller,
• Mia Peterson,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2026, 22, 151–157, doi:10.3762/bjoc.22.8

• ). This suggests that possibly the halogen bond plays a role in the emergence of the stereoselectivity of the reaction. The reaction with the similar quinidine derivative with reduced double bond (catalyst B) was slower and less selective affording the opposite enantiomer in low enantiomeric purity (14

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

• calculation. (b) Optimized structure of R-Pt by DFT calculation. Emission spectrum of 1 wt % PMMA matrix (R-Pt) (λex = 300 nm). (a) CD spectra of S/R-Pt in 1.0 × 10−5 M dichloromethane solution. (b) CPL spectra of 1 wt % PMMA film (λex = 300 nm). Synthesis of the binaphthyl-based ligand and the platinum(II

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

• 436 nm, 461 nm and 403 nm, respectively, and the peak at the longer wavelength seen before interaction with CN− disappeared. The peaks for 2a–b+CN− arise from the HOMO−1→LUMO transitions, while for 2c+CN− are contributed from the HOMO−2→LUMO transitions, with the contributions ≈94–99%. Considering the

• dyes 2a (a), 2b (b), and 2c (c); Photographs of dyes in the given solvents of different polarities under ambient light (d) c = 10 μM. Absorption spectra of dyes 2a (a), 2b (b), and 2c (c) upon addition of 20 equiv of anions in DMSO; photographs of dyes with/without addition of anions under ambient

• light (d) (c = 10 μM). Absorption spectra of titrated dyes (2a–c) with up to 50 equiv of CN− (a) 6:4, (b) 7:3, and (c) 4:6 in DMSO/H2O (v/v) (c = 30 μM). Partial 1H NMR spectral change of 2b (c = 10 mM) after up to 2 equiv of TBACN (c = 1 M) in DMSO-d6. Optimized geometries of 2a–c and 2a–c+CN− obtained

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

• geometrically calculated positions and included in the refinement in the “riding” model. Crystal of 2, C6H2Cl3N3O2, M = 254.46, monoclinic, space group P21, at 100.4(5) K: a = 11.6233(2), b = 6.39530(10), c = 13.1586(2) Å, β = 96.5730(10), V = 971.71(3) Å3, Z = 4 (two independent molecules), Dcalc = 1.739 g·cm

• . The final R1 was 0.0260 (I > 2σ(I)) and wR2 was 0.0655 (all data). Crystal of 3, C7H5Cl3N2O4, M = 287.48, monoclinic, space group P21/n, at 100.00(10) K: a = 8.3468(3), b = 6.1819(2), c = 21.2056(6) Å, α = 90, β = 93.234(3), γ = 90o, V = 1092.45(6) Å3, Z = 4, Dcalc = 1.748 g·cm−3, μ(MoKα) 7.658 mm−1

• ) K: a = 11.4834(6), b = 11.0564(5), c = 23.7834(10) Å, α = 90, β = 91.057(4), γ = 90o, V = 3019.1(2) Å3, Z = 8 (two independent molecules), Dcalc = 1.595 g·cm−3, μ(Mo Kα) 5.651 mm−1, F(000) = 1485.2, 21310 reflections measured (7.44° ≤ 2Θ ≤ 139.94°), 5708 unique (Rint° = 0.0984, Rsigma° = 0.0556

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• other functionalities. The following sections highlight representative examples of both modes in complex molecule synthesis. Total synthesis of (±)-keramaphidin B by Baldwin, 1996 Although the methodologies for aromatic ring hydrogenations have only recently flourished, the reduction of aromatic rings

• to obtain saturated aliphatic or heterocyclic rings and their subsequent application in the total synthesis of natural products has a long history. A brilliant early work is Baldwin's total synthesis of the macrocyclic diamine natural product (±)-keramaphidin B in the year of 1996 (Scheme 9) [71][72

• 81 was prepared via a Polonovski–Polish reaction and isomerization, which, when adopting the proper conformation, spontaneously underwent an intramolecular [4 + 2] cycloaddition to construct the unsaturated bridged ring of (±)-keramaphidin B in a single transformation. Subsequently, the iminium ion

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

• suggested that the developed reaction would be applicable to halichondrin synthesis. The Zr/Ni-mediated ketone synthesis was then applied to the total synthesis of homohalichondrin B (58, Scheme 11B). Using a fragment corresponding to homohalichondrin B, the coupling reaction furnished ketone 57 in 82

• synthesis of homohalichondrin B (58). This synthetic strategy proved broadly applicable to multiple members of the halichondrin family, enabling the efficient synthesis of nine natural products: halichondrins A–C, norhalichondrins A–C, and homohalichondrins A–C. The Zr/Ni-mediated one-pot ketone synthesis

• group achieved the first total synthesis of cyctetryptomycins A and B by employing a zirconium catalyst (Scheme 12) [5]. The synthesis commenced with the dimerization of 3-bromotryptophan derivative 59. As an initial step, the authors sought to develop a mild and scalable method for the dimerization of

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

• -hydroxyisoquinolones [36][37]. Additionally, the analyses of both HOMO and Fukui f– function shows little or no nucleophilicity at this position (Figure 2). Therefore, the formation of products 4a,b and 10k could proceed through the intermediary formation of the corresponding compounds 5 and their subsequent

• with the formation of 4a,b, as well as the formation of hydrazone product 10k exclusively in the case of the most sterically hindered diazonium electrophile leads to the conclusion that the direct electrophilic attack onto the i-position could take place in all these cases. To clarify this, we analyzed

• 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

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• products 28–35, 38 and 39 [56]). The yields varied considerably depending on the substrate, leading to the following conclusions: (a) unhindered ketones lacking functional groups generally react in high yields; (b) sterically hindered ketones provide products 33, 36, and 39 with low yields; (c) electron

• chlorides was also utilized in the total synthesis of (S)-jamaicamide C and laingolide B (not shown) [121][122]. Schwartz’s work on alkenylzirconium complexes revealed high-yielding, stereoretentive transformations under similar conditions (Scheme 29H) [123]. In a complementary study, Srebnik showed that

• with SOCl2, and treatment with base (Scheme 38; yields refer to the transformation of B → C) [139]. A reaction which includes a fluorine–chlorine exchange and subsequent elimination of HCl was reported by Shibata and co-workers (Scheme 39) [140]. In this reaction the AlEt2Cl has a dual role of fluorine

One-pot synthesis of ethylmaltol from maltol

• Immanuel Plangger,
• Marcel Jenny,
• Gregor Plangger and
• Thomas Magauer

Beilstein J. Org. Chem. 2025, 21, 2755–2760, doi:10.3762/bjoc.21.212

• to ethylmaltol (1) combined with the rather harsh deprotection conditions, led us to investigate other masking groups. Next, we turned towards silyl protecting groups as they offered (a) facile tuning of stability and (b) the opportunity for acid-mediated deprotection during aqueous work-up

• ethylmaltol (1) is the use of maltol (2) as the starting material, which is readily available from tree barks. Importance and synthetic approaches to ethylmaltol (1). (a) Ethylmaltol (1) is widely used as a flavor enhancer. (b) Reported syntheses. (c) One-step synthesis from naturally occurring maltol (2

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

• 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 Vladimir A. Tartakovsky N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow

• -nitrosopropane (1a) is expected to be barrierless with the formation of N-oxyl radical B. The radical B undergoes very low-barrier (ΔG≠ 5.5 kcal/mol) fragmentation with the release of NO2 molecule and formation of the final product 2a. An alternative pathway for the formation of 2a is a direct NO2 extrusion from

• ]/CPCM(MeCN) level of theory (in the case of >15 conformers, 15 most stable according to GFN2-xTB were analyzed). CV-curves of 0.01 M solutions of a) 1a (blue), b) 1f (azure), c) 1c (pink), d) 1i (yellow), e) S4 (red), f) S3 (green), g) S2 (brown), and h) S1 (orange) in 0.1 M n-Bu4NBF4 solution in MeCN

Total synthesis of asperdinones B, C, D, E and terezine D

• Ravi Devarajappa and
• Stephen Hanessian

Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210

• members of prenylated indole alkaloids exhibiting α-glucosidase activity is described. Asperdinones B, C, D, and E are characterized by the presence of a (3R)-3-indolylmethylbenzodiazepine-2,5-dione unit at C-3 of C4–C7 prenylated indoles. Methods of direct and indirect prenylation of indole and

• -indolylmethylbenzodiazepine-2,5-diones known as asperdinones B, C, D, and E (1–4) exhibiting moderate α-glucosidase inhibitory activity was recently isolated from cultures of Aspergillus spinosus WHUF0344 (Figure 1) [14]. The putative biogenetic precursor, (3R)-3-indolylmethylbenzodiazepine-2,5-dione 5 was also isolated as a

• )-configured asperdinones as new members of this small subfamily of 7-prenyltryptophans with appended benzodiazepine-2,5-dione and diketopiperazine units piqued our interest. Herein, we report our efforts toward the total synthesis of asperdinones B, D, C, and E (1–4) and terezine D (6). Considering their

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• hetero- and carbocycles. To date, we have proposed new protocols for the synthesis of 2-pyridones [20], imidazo[1,2-a]pyridones and pyrido[1,2-a]pyrimidinones [21][22][23][24], pyrido[2,1-b]oxazinones and oxazolo[3,2-a]pyridones [25] using ammonia, 1,2- and 1,3-diamines or 1,2- and 1,3-amino alcohols

• octahydrocyclopenta[b]oxazolo[3,2-a]pyridin-5-ones in the reactions of 3-oxo ester 1 and cycloketones with amino alcohols [26]. However, these attempts turned out to be unsuccessful because of the increased occurrence of side processes (56%); however, an increase in the proportion of the cis,trans

• at the acyl moiety with the amino group of diamino alcohol 3 to generate a three-component intermediate B (Scheme 4). The latter undergoes intramolecular cyclization involving the C=N bond in two equally probable directions: by adding a free amino group to form a hexahydropyrimidine ring of

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

• -mediated ditosyloxylation of α,β-unsaturated carbonyl compounds (chalcones) bearing an aryl group at β-position (compound A) leading to formation of two possible products, that are: α-arylated β,β-ditosyloxy-substituted carbonyl compound (compound B – geminal product) and β-arylated α,β-ditosyloxy

• free energy profile for HTIB-mediated ditosyloxylation of chalcone with X = -NO2 leading to the formation of the α,β-ditosyloxy ketone. Free energies are reported in kcal/mol. Bond lengths are reported in Å. Structure of reactant (chalcone, compound A), geminal product (compound B), vicinal product

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

• dihydrofurans 3d,e remained comparable to those of 3a,b. Perhaps the yields of salts 2d,e were affected by steric factors hindering the intramolecular cyclization or their stability under the reaction conditions. Using TMS-protected secondary and primary iminopropargyl alcohols 1f,g (due to their instability

• and 3a appeared immediately upon mixing the starting reagents (Figure 1a and b). This indicated that the cyclization occurred almost immediately. Moreover, in the NMR spectra of the 1g/NaSCN/AcOH reaction mixture in MeCN we detected signals assigned to isothiozolium salt 2g (1H NMR: δ 8.30 s (CH

• stirring. The reaction mixture was heated in a glycerol bath at 80 °C for 10 h. The solvent was evaporated and the residue was purified by column chromatography (eluting with hexane/acetone 1:1) to obtain the mixture of products 4 and 5. 1H and 19F NMR monitoring of 1a/NaSCN/AcOH (a, b) and 1g/NaSCN/AcOH

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

• metathesis for closing the D-ring (Scheme 7). For the left-hand fragment including the A-, B-, and C-ring, the synthesis started from commercially available (S)-Wieland–Miescher ketone (34), which can also be synthesized via a three-step sequence (Scheme 8). To access 35, several protecting group

• butenolide moiety, selective α-methylation, formation of a lactam, reduction of the former to an amine, and installation of two different protecting groups. Aryl bromide 53 (fragment B) was then ready for coupling. Lithium–halogen exchange in fragment B 53 and subsequent 1,2-addition to fragment A 47

• (12), only one synthesis is reported [14]. The Masamune group disclosed this synthesis in 1968, starting with a sequential ring construction of the C, B and A-ring from Hagemann’s ester (61) to C-nor-D-homo steroid precursor 62 (Scheme 13). The piperidine F-ring was then coupled after D-ring

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• , 95%; ii) method A: MeI, K2CO3, DMF, rt, 22 h, crude: 99%; iii) method B: methyl N-methylanthranilate, pyridine, 0–5 °C, 2 h, rt, 17 h, 71%; iv) NaOH, MeOH/H2O, reflux, 1 h, crude: 95%; v) 1. SOCl2, DCM, reflux, 8.5 h; 2. AlCl3, 0–5 °C, 1.5 h, reflux, 3 h, 26%; vi) NaBH4, DMF/EtOH, rt, 2 h, 93%; vii

Chemoenzymatic synthesis of the cardenolide rhodexin A and its aglycone sarmentogenin

• Fuzhen Song,
• Mengmeng Zheng,
• Dongkai Wang,
• Xudong Qu and
• Qianghui Zhou

Beilstein J. Org. Chem. 2025, 21, 2637–2644, doi:10.3762/bjoc.21.204

• – sarmentogenin and ʟ-rhamnose connected by the C3–O bond. In the steroidal skeleton, both the A/B and C/D rings are cis fused, which is different from common steroids. Besides, the steroidal skeleton is moderately oxidized at the C3, C11, and C14 positions. The introduction of the hydroxy groups and the

• C14 β-OH group. The revised synthetic route is described in Scheme 2. At first, 4 was subjected to a Pd/C-catalyzed hydrogenation to afford the desired A/B-cis fused intermediate 7 along with its C5 epimer as a 2:1 separable mixture in a quantitative yield. By treating 7 with the Bestmann ylide

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

• ], tetrahydrobenzo[b]pyrans [68], and pyrrolo[3,4-c]quinolinediones [69]. EDDA favors the enol formation of the thiazolidinone (2) through hydrogen donation from the protonated amino group, thus facilitating its removal and formation of enol ii (Scheme 4). This enol adds to the carbonyl group of the aromatic

• : a) 1H NMR spectra (600 MHz, DMSO-d6) with expansions, and b) 13C NMR spectra (151 MHz, DMSO-d6) with expansions. a) Molecular structure of 3n with crystallographic labeling (50% probability displacement). b) Perspective views of intermolecular hydrogen bonds (dotted lines) of 3n. (‘) symmetry

• experimental spectrum. In blue, suppressed or absent carbon atoms bound to hydrogen atoms. a) Visual impressions of the solvatochromic study in various solvents (10−5 M) after excitation with a natural light. b) UV–vis absorption spectra of 3n in different solvents (10−5 M) at room temperature. c) Normalized

Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

• Liangyu Liu,
• Wanqiu Lu,
• Quanping Guo and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

• , culminating in cyclization mediated by N,N'-dicyclohexylcarbodiimide (DCC)/N-methylmorpholine (NMM) at 0 °C for 7 days [18]. This method, however, is lengthy, operationally complex, difficult for product isolation, and carries a significant risk of racemization. Wong and Jolliffe synthesized segetalins B (2

• -tail cyclization step proved challenging. Initial attempts using common coupling reagents such as 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU), HBTU, or HOBt alone in DMF failed to produce any detectable cyclized product [24][25][26]. Ultimately