Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• Duesseldorf, Germany Integrative Taxonomy of Plants, Friedrich-Schiller-University Jena, 07743 Jena, Germany Senckenberg Institute for Plant Form and Function (SIP) Jena, 07743 Jena, Germany National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, HI 96741, USA 10.3762/bjoc.22.39 Abstract In addition

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

• spectroscopy. The extraction performance was systematically evaluated as a function of pH and ligand-to-metal molar ratio to study the effect of these two key parameters on the extraction process. In doing so, this work aligns with current research dedicated to the design of functional supramolecular materials

Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• complex and diminishing its deacetylase function. However, the maximal HDAC inhibition by Au–NH2 was considerably less compared to Au–(CI-994) and CI-994, suggesting Au–(CI-994), is inhibiting HDAC enzymatic activity by direct competition for the HDAC active site. We next determined the IC50 of Au–(CI-994

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

• optimisation. In this study, we report the in-silico modelling and anticancer activity of two 1,8-napthalimide (NAP) derivatives containing organyl selanyl groups. The organylselanyl function n-octylselanyl (n-OctSe) or phenylselanyl (PhSe) was introduced at the 6-position of a naphthalimide structure having a

• conserved 3-(4-(tert-butyl)phenoxy)propyl function at the imide nitrogen. The resultant naphthalimide–organylselanyl conjugates, NAP-SePh and NAP-Se(n-Oct), were characterised using various spectroscopic techniques, including FTIR, ¹H, ¹³C, ⁷⁷Se NMR and high-resolution mass spectrometry (HRMS). NAP-SePh was

• secondary amino functions strongly suppress acetylation and the embedded sulfur function contributes to the apoptosis induction [40][41].The third modification route centres on functional group engineering, in which small amine substituents are replaced with polyamines or long aliphatic chains, thereby

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

• the pKa of [3]·+ radical cation and spin density of neutral radical intermediate Int-I (optimized at the UB3LYP/6-31G+(d,p) level of theory with IEPCM model as solvation of DCM. Grimme’s dispersion with the original D3 damping function was applied as empirical dispersion correction to the optimized

Non-central chirality in organic chemistry

• Ken Tanaka and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2026, 22, 370–371, doi:10.3762/bjoc.22.24

• . Collectively, the articles in this Thematic Issue should not be viewed as an exhaustive account of non-central chirality but rather as representative snapshots of an evolving landscape. They capture the current state of the field, where structure, reactivity, dynamics, and function increasingly intersect under

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

• substrate scope, mechanistic features, and unique advantages or limitations, with the goal of providing a comprehensive overview of current strategies and future opportunities for amide-bond manipulation. Review Transition-metal catalysis Various transition metals that function as Lewis acids have been

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

• crokonoid B (67) by oxidation, carbocation formation and 1,2-alkyl shift in a semi-pinacol rearrangement [127]. The authors of the isolation report proposed an epoxide 67a as initiating species, but a diol could also serve in this function (see Scheme 21B). Upon formation of the secondary carbocation 67b, a

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

• asymmetric synthesis, where they serve as chiral ligands and organocatalysts, delivering high enantioselectivities [17][18]. Their tunable HOMO–LUMO gaps and controlled π–π interactions, is key to the use of helicenes in molecular electronics and organic semiconductors as well. Helicenes function as active

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

• coefficients (absorbance), as a function of the wavelength (185–750 nm) and pH in the interval 2.0–12.0, were determined at 30.8 °C. A stock solution (5.0 mM) of 1·HCl in N-methyl-2-pyrrolidone (NMP) was added to 36 mL of an ionic strength-adjusted buffer solution (I = 0.172 M) containing acetate, phosphate

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

• ), revealing two emission bands centered at approximately 427 nm and 596 nm (Figure 2). The corresponding emission decays were well fitted by a three-exponential function, yielding fluorescence components of 3.6 ns (62%), 8.0 ns (20%), and 0.39 ns (18%) at 427 nm, and phosphorescence components of 0.11 μs (64

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

• carboxylic acids [4]. The trichloromethyl group is a convenient precursor of the carboxylic function, which determines their use in the synthesis of α-amino acids [5]. A number of natural trichloromethyl-containing compounds are metabolites of symbionts of marine sponges – cyanobacteria [6][7][8] – and have

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

• isomer of anion 2 we analyzed the structure of its highest occupied molecular orbital (HOMO) and the distribution of the electrophilic Fukui function (f–) [28] – the difference in electron density between the anion and the derived radical by abstraction of one electron (Figure 2). Both approaches

• revealed that the α-position is most nucleophilic. Notably, anion 1 demonstrated similar HOMO and Fukui function distribution (see Supporting Information File 1), however, all positions would lead to the very same products. The potassium salt of anion 2 was generated in an acetonitrile solution from hexa

• -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

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

• frequencies of the carbonyl function (ν 1633–1593 cm−1) and N–H, O–H groups (ν 3435–3126 cm−1), which indicates their participation in the hydrogen bond formation [67]. On the other hand, the IR spectra of hexahydrooxazolo[3,2-a]pyridones 5a–c contain intense absorption bands of the C=O function at ν 1652

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

• , thioethers, disulfides, phosphonothioates, and trifluoromethyl sulfides. Additionally, due to the presence of two electrophilic sites (the sulfur atom and the carbon of the nitrile function), thiocyanates can readily undergo domino-type intramolecular cyclization reactions to form heterocycles. So, if a

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

• 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

• emission spectra of 3n in different solvents (10−5 M) at room temperature. d) Lippert–Mataga plot showing Stokes shift as a function of solvent orientation polarizability (Δf) for compound 3n. Photophysical study in aqueous solution under different pH values for compound 3n (10−5 M) at room temperature. a

Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies

• Zhi-Qi Cao,
• Jin-Bao Qiao and
• Yu-Ming Zhao

Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198

• function as an engine, consistently pushing the boundaries of the discipline. From the early synthesis of simple molecules to the current precise assembly of complex natural products and functional materials, the iteration of methods and optimization of strategies have always been key to breaking through

• atmosphere significantly suppressed side reactions, yielding the cyclized product in excellent yield and selectivity. This indicates that N-formylsaccharin, beyond acting as a CO-releasing agent, may function as a ligand in the catalytic cycle to regulate the palladium catalyst’s activity and stability

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

• Giuseppe Granata,
• Loredana Ferreri,
• Claudia Giovanna Leotta,
• Giovanni Mario Pitari and
• Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

• temperature, η is the solvent viscosity, and R is the solute radius. The zeta potential (Z) was calculated by using Henry’s equation where UE is the electrophoretic mobility, ζ is the dielectric constant, f(Ka) is the Henry’s function, and η is the viscosity. Biological assays: Cell viability was measured by

Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

• Udyogi N. K. Conthagamage,
• Lilia Lopez,
• Zuliah A. Abdulsalam and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

• proteins that are responsible for essential cellular functions [1]. As a result, the function and properties of lipid membranes are significantly influenced by their lipid composition, which varies across various domains of life, including mammalian, prokaryotic, and plant cells, and even between

• bacteria or malignant cells like cancer) [5][6], or to influence membrane protein function and thereby control cellular behavior [7][8]. One promising approach is the development of light-activated molecules that can modulate membrane properties upon irradiation, enabling remote activation with high

• spatiotemporal precision [9]. Rotaxanes have emerged as promising tools for performing various functions in lipid membranes, owing to their multiple sites for derivatization, which allow fine-tuning of their structure and function in membranes. For instance, they have been used to transport ions across lipid

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

• reactivity of this double bond can pose significant challenges, particularly in cycloadditions or other organic transformations that necessitate extended cycloaddition processes and elevated temperatures. With a boiling point in excess of 260 °C, methyl laurate has the potential to function as a green

• optimized [3 + 2] cycloaddition conditions. The primary strategy for the selection of these compounds as catalysts is predicated on their capacity to function as H-bond acceptors and/or H-bond donors. As has been documented in previous research, imine-based templates or [2]rotaxane that possess an amide

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

• Elizaveta V. Gradova,
• Nikita A. Ozhegov,
• Roman O. Shcherbakov,
• Alexander G. Tkachenko,
• Larisa Y. Nesterova,
• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

• bioactive molecules (Figure 1). This scaffold exhibits a broad range of pharmacological activities, including significant in vitro antimycobacterial properties [4], potent antitumor effects against melanoma cell lines [5], and antagonism of TH2 lymphocyte function [6]. Due to their wide-ranging biological

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• photoswitchable units directly into the macrocycle remain relatively underexplored compared to their axle-based counterparts. This likely stems from the long-standing focus on the shuttling motion of the macrocycle as the hallmark of rotaxane function, which naturally led to early designs positioning

Comparative analysis of complanadine A total syntheses

• Reem Al-Ahmad and
• Mingji Dai

Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178

• finding highlights the importance of complanadine A’s pseudo-dimeric structural motif for its biological function. The Sarpong total synthesis – 2010 In the same year (2010), Sarpong and co-workers reported their total synthesis of complanadine A (Scheme 3). Their synthesis features a biomimetic cascade

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• -hydroxy-β-lactams or 2-hydroxycyclobutanones can function either as inherent structural motifs in target natural products or as strained reactive intermediates, facilitating C–H functionalization via four-membered ring opening [6][7][8][9][10][11]. Quinones display distinct photochemical reactivities

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• direct π–π interactions with each other. Overall, the X-ray crystal structures of G2W1 and G2W3 demonstrate that the incorporated OMe groups are deleterious for their function as solid state sequestrants because they serve to: 1) fill their own cavity, and 2) promote the non-planarity of the triphenylene

• elements that are capable of cavity self-inclusion. Improved function of acyclic CB[n] as solid state sequestrants should be possible by their incorporation into porous polymeric materials. Experimental General experimental details Starting materials and reagents were purchased from commercial suppliers

• at 25 °C as determined by UV–vis. Experiments were performed in triplicate (n = 3). The error bars represent the standard deviation of the three trials. a) Plot of removal efficiency of methylene blue (240 μM, 1 mL) from water as a function of time after incubating with H2 (5.0 mg) at 25 °C as