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

• Supporting Information File 16: Synthesis of compounds, copies of NMR, HRMS and UV–vis spectra and DFT results. Acknowledgements The numerical calculations reported in this paper were fully performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources). This study constitutes

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

• group; X-ray; Introduction Trichloromethyl groups containing compounds are widely used in the organic synthesis of practically significant substances [1][2]. Based on them, methods have been developed for the synthesis of hard-to-access 5-aminoisoxazoles [3], α- and γ-heterosubstituted unsaturated

• 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

• nitro group upon breaking the C–C bond [16][17]. Substituted nitrocyclopropanes in reactions with various nucleophiles form linear precursors for the synthesis of γ-substituted α-aminobutyric acids [18][19], cyclic nitropyrrolines [20] and isoxazoline N-oxides [18]. The nitrocyclopropane fragment is a

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

• synthesis of complex natural products and pharmaceutical agents. This review highlights recent advances in catalytic (hetero)arene hydrogenation, with a focus on its application in natural product synthesis. Keywords: aromatic rings; dearomatization; hydrogenation; natural products; total synthesis

• ; Introduction For decades, a principal objective in natural product synthesis has been the development and utilization of efficient methods to access molecular frameworks with defined stereochemical complexity [1]. Natural products, such as taxol [2], strychnine [3][4][5], and tetrodotoxin [6][7][8], which

• contain complex three-dimensional structures, make total synthesis challenging. The retrosynthetic analysis [9], alongside the evolution of methodologies such as “two-phase synthesis” [10], “biomimetic synthesis” [11], or “protecting-group-free synthesis” [12], has progressively streamlined synthetic

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

• where organic synthesis plays a central role, including pharmaceuticals, agrochemicals, materials chemistry, organic semiconductors, and organic thin-film solar cells. These areas are intimately linked to human life; thus, advances in organic synthesis are essential for improving human well-being

• . Nearly two centuries after the seminal 1828 synthesis of urea from inorganic precursors – often regarded as the birth of organic synthesis – the field continues to evolve rapidly and to exert profound impact on society. A retrospective of almost 200 years of organic synthesis shows that the development

• for future development. Keywords: halogen atom transfer; photoredox; radical; total synthesis; zirconium; Introduction Zirconium, a transition metal in the same group as titanium, has been employed across research fields and in medical applications owing to its distinctive physical and chemical

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

• prepared in 1868 by Charles Friedel – best known for the Friedel–Crafts reaction – via the reaction of ketones with phosphorus pentachloride, these compounds have steadily gained attention over the decades. In recent years, their distinct reactivity and potential in organic synthesis have been increasingly

• recognized. This review provides a comprehensive overview of the synthesis and application of alkenyl chlorides, with a focus on developments over the past four decades. By organizing this growing body of work, I aim to highlight key advances and help guide the design of new transformations involving this

• ], and pesticides [7] (Figure 2). Throughout this review, the term “alkenyl chloride” refers broadly to chloroalkenes beyond vinyl chloride (CH2=CHCl), the monomer used in polyvinyl chloride (PVC) production. Before detailing the synthesis and applications of alkenyl chlorides, we wish to acknowledge

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

• synthesis of ethylmaltol from a renewable precursor. Keywords: ethylmaltol; flavor enhancer; maltol; methylation; 4-pyrones; Introduction In 1969, a Pfizer patent first disclosed ethylmaltol (1) as a powerful, purely synthetic flavor and aroma enhancer (Scheme 1a) [1]. It has been found to have a 6-times

• 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

• , Russian Federation 10.3762/bjoc.21.211 Abstract An atom- and step-economical electrochemical method for the synthesis of aliphatic nitro-NNO-azoxy compounds from the corresponding nitroso compounds was developed employing ammonium dinitramide, a prospective green oxidant for aerospace propulsion

• applications in organic synthesis as precursors for free radicals in selective transformations [5][6][7][8][9][10][11] and polymerization initiators [12], energetic materials [13][14][15], NO donors [16][17], and organic light-emitting diodes (OLEDs) [18]. Despite the wide diversity of their applications

• , electroorganic synthesis has become a powerful and reliable strategy for the functionalization of organic compounds under green and mild reaction conditions [36][37][38][39]. The control of selectivity through the variation of parameters such as current, voltage, electrolyte, electrodes, and the type of

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

• Ravi Devarajappa Stephen Hanessian Department of Chemistry, Université de Montréal, Station Centre-Ville, C.P. 6128, Montreal, QC, H3C 3J7, Canada Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697, USA 10.3762/bjoc.21.210 Abstract The total synthesis of new

• their architecturally intricate structures [8]. For these reasons, and considering the structural and stereochemical complexities of some members, indole alkaloids have been prime compounds of interest for total synthesis with spectacular successes [2][9][10]. A subset of simple indole alkaloids

• activity [20]. A related metabolite lacking the C7 prenyl group had been isolated from the cultures of Aspergillus chevalieri in 1976 [21]. The structure and absolute stereochemistry were confirmed by synthesis from tryptophan and ʟ-alanine [22]. The isolation of terezine D (6) and more recently, the (3R

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

• Svetlana O. Kushch Marina V. Goryaeva Yanina V. Burgart Marina A. Ezhikova Mikhail I. Kodess Pavel A. Slepukhin Alexandrina S. Volobueva Vladimir V. Zarubaev Victor I. Saloutin Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences, S. Kovalevskoy St. 22/20

• -trifluoroacetoacetate and methyl ketones enables the synthesis to be carried out for octahydropyrido[1,2-a]pyrimidin-6-ones and hexahydrooxazolo[3,2-a]pyridin-5-ones, the preferential formation of which depends on the substituent in the methyl ketone component. Dual acid–base catalysis of the reactions with alkyl

• methyl ketones increases the regioselectivity in the synthesis of octahydropyrido[1,2-a]pyrimidinones. The cyclization with acetophenone is characterized by the regiospecific generation of these bicycles. The presence of three chiral centers in the synthesized bicycles, depending on the alkyl substituent

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

• Ruslan S. Shulgin Ol'ga G. Volostnykh Anton V. Stepanov Igor' A. Ushakov Alexander V. Vashchenko Olesya A. Shemyakina A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Science, 1 Favorsky Str., 664033 Irkutsk, Russia 10.3762/bjoc.21.207 Abstract The synthesis of

• from chemists as it is one of the most expedient and direct methods for the formation of a new C–S bond [9][10][11]. Thiocyanates represent a valuable class of molecules serving as versatile intermediates [12][13][14][15] in the synthesis of a broad range of organosulfur compounds, including thiols

• medicinal chemistry [33][34] and organic synthesis [35]. For example, they have been found to exhibit inhibitory activity against human leukocyte elastase (HLE) [35] and anti-HIV-1-activity [36]. Hydroperoxy sultams can also act as oxidants [37]. Conclusion In summary, we have developed a simple route to

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

• dense stereochemistry and, thus, have stood long as benchmarks in chemical synthesis. Recently, these steroid alkaloids gained popularity as challenging targets in total synthesis, with a clear shift toward convergent strategies. Not only do these syntheses feature rapid assembly of their challenging

• functionalization for rapid access to these exceptional alkaloids, while also showcasing the evolution of the art of synthesis and its ability in meeting the demands posed by molecular complexity. Keywords: alkaloid synthesis; convergent synthesis; total synthesis; Veratrum alkaloids; Introduction Veratrum

• alkaloids belong to the class of steroid alkaloids and are pseudoalkaloids, as they emerge biogenetically from steroidal biosynthesis via cholesterol and not, as usual for alkaloids, from amino acids [1]. For synthetic chemists, this combines challenges for steroid and alkaloid total synthesis and poses

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

• ; Friedel–Crafts reaction; heterocycles; new ring systems; Introduction In our prior report [1] we disclosed the synthesis of new fused ring derivatives of the dibenzo[c,f][1,2]thiazepine skeleton (1, Figure 1) shown by general structure 2. In recent publications we have also reported the synthesis of new

• have been also prepared. The synthesis of key intermediates 6 and 7 is presented in Scheme 1. The reaction of sulfonyl chloride 9 with 1,3-benzodioxol-5-amine or 2,3-dihydro-1,4-benzodioxin-6-amine gave sulfonamides 10 or 11, respectively. N-Methylation with methyl iodide via compounds 12 and 13

• , respectively (Scheme 2). The structure of compounds 20e and 21g was also confirmed by single-crystal X-ray diffraction (Figure 3). We demonstrated the potential utility of the synthesized new ring systems in the field of medicinal chemistry by the synthesis of tetracyclic analogues 20b and 21b of tianeptine

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

• Sciences and Biotechnology, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai, 200240, China 10.3762/bjoc.21.204 Abstract Herein, we report a concise chemoenzymatic synthesis of the cardenolide rhodexin A in 9 steps and the first protecting-group-free synthesis of its

• aglycone sarmentogenin in 7 steps from 17-deoxycortisone. The synthesis features a scalable enzymatic C14–H α-hydroxylation, a Bestmann ylide-enabled one-step construction of the butenolide motif, a late stage Mukaiyama hydration, and a stereoselective C11 carbonyl reduction. Keywords: cardiac glycosides

• ; C–H hydroxylation; chemoenzymatic synthesis; Mukaiyama hydration; protecting-group-free synthesis; Introduction Cardiac glycosides (CGs) are widely distributed natural products, generated by plants and amphibians [1]. Structurally, they are composed of an aglycone-steroidal moiety, an unsaturated

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

• different products were obtained), delivers excellent yields (up to 99%), and requires low catalyst loading (10 mol %). This new approach was successfully applied to the synthesis of eight novel imidazo[1,2-a]pyridine–thiazolidinone hybrids in good to excellent yields (66–99%). A spectroscopic study of

• ], antioxidant [34], cytotoxic [35], and antiproliferative [36]. The structures of these compounds allow the synthesis of a large collection of bioactive molecules due to their nucleophilic and electrophilic properties [37]. One of the forms of modifications is at the methylene group, particularly in the 5

• explored. One notable approach is the use of microwave irradiation. Microwave-assisted synthesis has proven effective in reducing reaction times and improving yields [59][60][61][62]. Herein, we report the synthesis of 5-arylidene derivatives from rhodanine or thiazolidine-2,4-dione via the Knoevenagel

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

• strategy for the total synthesis of segetalins A–H, J and K (1–10), bioactive cyclopeptides isolated from Vaccaria segetalis. Linear precursors were assembled on cost-effective 2-chlorotrityl chloride resin via Fmoc-SPPS, followed by PyBOP-mediated head-to-tail cyclization in DMF (10−3 M). After RP-HPLC

• scalable methodology overcomes limitations of prior syntheses, enabling biological evaluation. Keywords: Fmoc-solid-phase peptide synthesis (Fmoc-SPPS); head-to-tail cyclization; plant cyclopeptides; Vaccaria segetalis; Introduction Cyclopeptides have garnered significant research interest owing to their

• synthetic approaches have encountered significant challenges. Sonnet et al. reported the first total synthesis of segetalin A (1) via Sasrin resin-based SPPS, followed by cyclization under highly dilute conditions (10−4 M) with diphenylphosphoryl azide (DPPA) [17]. While successful, this approach suffers

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• to SG not only by electrostatic interactions but also covalently, the BU1 synthesis is straightforward lacking difficult and time-consuming purification, and it is obtained in relatively high yield over 60%. Once BU1 was prepared, its covalent attachment on the surface of SG was achieved in two steps

• solution (10 mM) for 1 h or 3 × 15 min; experiments were done using 50 mg of SG-NHCO-BU1. Synthesis of SG-NHCO-BU1 and SG-BU1 materials based on covalently and non-covalently attached BU1 on the SG surface. Supporting Information Supporting Information File 4: Characterization of materials and additional

• experiments regarding anion uptake. Acknowledgements We thank Dr. Zdeněk Moravec for the TGA measurements and Dr. Arico Del Mauro for assistance with the BU1 synthesis. Funding The authors thank the RECETOX Research Infrastructure (LM2023069) financed by the Ministry of Education, Youth, and Sports, and 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

• ; NHC; organic photocatalyst; radicals; visible-light; Introduction Over the last ten years, NHC-catalyzed visible-light-promoted radical chemistry has been extensively developed for the cost-effective and practical synthesis of bioactive intermediates, pharmaceuticals, drugs, and natural products [1

• ]. 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

• carbenes (NHCs) with photocatalysts. The review encompasses transition-metal-based photocatalytic reactions for C–C and C–HA cross-coupling reactions involving various acyl fluorides, amides, aldehydes, carboxylic acids, and esters, highlighting their broad applications in organic synthesis and medicinal

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

• , illisimonin A has garnered significant interest from the synthetic chemistry community. To date, five research groups have accomplished the total synthesis of illisimonin A. This review offers a comprehensive overview of its isolation, proposed biosynthetic pathway and the synthetic strategies employed in its

• total synthesis. Keywords: bioinspired synthesis; biosynthetic pathway; Illicium sesquiterpene; illisimonin A; total synthesis; Introduction The genus Illicium, the sole member of the family Illiciaceae, is a rich source of sesquiterpenoid natural products. To date, a wide variety of sesquiterpenes

• considerable interest from synthetic chemists. Although the intricate structures of this family have posed significant challenges to chemical synthesis, more than 30 total syntheses of Illicium sesquiterpenes have been reported until now [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22

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

• primary driving forces behind the advancement of organic synthetic chemistry. With rapidly evolving organic synthesis technologies, a diverse array of novel methods and sophisticated strategies continues to emerge. These approaches not only complement and synergize with one another but also significantly

• enhance synthetic efficiency, reduce costs, and provide robust solutions to challenges encountered in the synthesis of complex molecular architectures. Ryania diterpenes are natural products characterized by intricate structures and high oxidation states. Biological studies have revealed that the family

• focuses on reviewing the efficient application of ring-construction methods and synthetic strategies in the total synthesis of highly oxidized Ryania diterpenoid natural products, emphasizing the pivotal role of novel synthetic methods and strategic innovations. Keywords: natural products; Ryania

Ni-promoted reductive cyclization cascade enables a total synthesis of (+)-aglacin B

• Si-Chen Yao,
• Jing-Si Cao,
• Jian Xiao,
• Ya-Wen Wang and
• Yu Peng

Beilstein J. Org. Chem. 2025, 21, 2548–2552, doi:10.3762/bjoc.21.197

• Abstract The total synthesis of bioactive (+)-aglacin B was achieved. The key steps include an asymmetric conjugate addition reaction induced by a chiral auxiliary and a nickel-promoted reductive tandem cyclization of the elaborated β-bromo acetal, which led to the efficient construction of the

• the tropical rain forests of the Kalimantan region (Indonesia) [1][2]. These cyclic ether natural products belong to the typical aryltetralin lignans, which have already attracted broad attention from the synthetic community [3][4][5]. Zhu and co-workers disclosed a concise synthesis of (±)-aglacins B

• (2) and C (3), featuring a visible light-catalyzed radical cation cascade for the formation of the C8–C8′ and C2–C7′ bonds [6]. Subsequently, they improved the reaction conditions to achieve the racemic synthesis of aglacins A (1) and E (4) as well [7]. In 2021, the Gao group described the total

Rapid access to the core of malayamycin A by intramolecular dipolar cycloaddition

• Yilin Liu,
• Yuchen Yang,
• Chen Yang,
• Sha-Hua Huang,
• Jian Jin and
• Ran Hong

Beilstein J. Org. Chem. 2025, 21, 2542–2547, doi:10.3762/bjoc.21.196

• synthesis and structural determination of malaymycin A (1) as well as the subsequent design of structural analogues for biological evaluation [16][17][18][19][20]. Preliminary structure–activity relationship (SAR) studies revealed that fungicidal activity is highly dependent on the nature and

• target-oriented synthesis toward malayamycins remains to be complished and several steps need to be improved, the current strategy provides a reliable platform to access various uracil nucleosides and derivatives for developing potent fungicides. Selected natural uracil-containing nucleosides (the key

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

• , and low toxicity make calixarene derivatives valuable drug candidates against cancer. The aim of the present study was the synthesis and characterization of a calix[4]arene derivative in which known anticancer isothiouronium groups were clustered on a calix[4]arene scaffold bearing long C12 alkyl

• anticancer activity. The synthesis and structural characterization of compound 3 were carried out, and its self-assembly behavior in aqueous medium was investigated using dynamic light scattering (DLS) and electrophoretic light scattering (ELS). The anticancer potential of compound 3 was assessed in human

• renal carcinoma cells (786O) and normal human fibroblasts (SW1), and the tumor cells selectivity was evaluated. To elucidate the role of the isothiouronium groups, antiproliferative effects were also estimated on calix[4]arene precursor 1 lacking these functional groups. Results and Discussion Synthesis

Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

• Kaylen D. Lathrum,
• Emily M. Hanneken,
• Katelyn R. Grzelak and
• James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

• control compounds 37–42 (blue lines) in acetonitrile solvent. Synthesis of pentacyclic aromatic heterocycles from varying alkynes.a Synthesis of pentacyclic aromatic heterocycles from varying azides.a Summary of UV–vis absorbance/emission signals. Minimum inhibitory concentration assay results.a

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

• Department of Chemistry, Ohio Wesleyan University, Delaware, OH, 43015, USA Department of Chemistry, Binghamton University, 4400 Vestal Parkway East, Binghamton, NY 13902, USA Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia 10.3762/bjoc.21.193 Abstract Non-coding ribonucleic

• regions of RNA. We herein report the synthesis and binding studies of new isoorotamide-based PNA monomers that target uridine–adenosine base pairs via a distal base recognition strategy. Monomers were designed with an arylisoorotamide core attached to a linker aimed at bypassing the uridine in a U–A pair

• , and it is easily prepared using well established peptide synthesis protocols, allowing for accessible incorporation of synthetic nucleobases [17][18]. With these advantages in mind, Rozners’ lab first demonstrated in 2010 that PNA not only binds favorably and quickly to RNA, but that it binds more

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• Roman A. Irgashev Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, 620137, Russia 10.3762/bjoc.21.191 Abstract A versatile synthetic route to thieno[3,2-b]thiophenes was elaborated from dimethyl 3-nitrothiophene-2,5-dicarboxylate

• organic synthesis. A widely adopted strategy for building the TT scaffold involves the annulation of a second thiophene ring onto a suitably functionalized thiophene precursor. Most commonly, this approach starts from halogenated thiophenes such as 3-bromo- or 3-chlorothiophenes, which undergo subsequent

• -alkylation and base-promoted cyclization to form the 3-hydroxy-TT molecules (Scheme 2). Results and Discussion We began our study by investigating the reaction of dimethyl 3-nitrothiophene-2,5-dicarboxylate (1) with Na2S, inspired by Beck’s reported synthesis of 2-substituted-3-aminobenzo[b]thiophenes via