Heterologous biosynthesis of cotylenol and concise synthesis of fusicoccane diterpenoids

• Ye Yuan,
• Zhenhua Guan,
• Xue-Jie Zhang,
• Nanyu Yao,
• Wenling Yuan,
• Yonghui Zhang,
• Ying Ye and
• Zheng Xiang

Beilstein J. Org. Chem. 2025, 21, 1489–1495, doi:10.3762/bjoc.21.111

• enzymatic terpene cyclization and chemical synthesis [30][31][32][33]. Briefly, the carbon scaffolds are forged by terpene cyclases, followed by concise chemical transformations to yield the desired natural products. Here, we describe heterologous biosynthesis of cotylenol by engineering the biosynthetic

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• -amination of benzoxazoles by transition-metal-catalysed reactions that traditionally involve aryl halide scaffolds [11][12][13][14]. However, these procedures entail disadvantages that need to be overcome if green chemistry criteria are to be met; high temperatures, long reaction times, the need for ligands

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• versatile scaffolds for chiral optoelectronic applications. The incorporation of nitrogen enables precise modulation of electronic structures, redox characteristics, and intermolecular interactions, thereby enhancing performance in circularly polarized luminescence (CPL), thermally activated delayed

• (MR-TADF) emitters to date. In 2023, the same group introduced the first deep-blue chiral MR-TADF emitters based on heterohelicene scaffolds 41a–c [56]. These compounds exhibited sharp emissions at 440–444 nm in solution and 445–449 nm in doped films, with emission bandwidths as narrow as 23 nm and

• [5]helicene (compound 57b) by coupling two 12H-benzo[b]phenoxazine (BPO) units and systematically compared it to its N,N-analogue (compound 57a) derived from 13H-dibenzo[b,i]phenoxazine (DBPO) scaffolds [72] (Table 19). Compound 57b was obtained in significantly higher yield and, like compound 57a

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• conducting polymers or scaffolds for drug synthesis. Among them, 1,3-dihydrobenzimidazoles are widely found in many materials, drug candidates, and catalysts. For instance, they can be used in organic light-emitting diodes (OLEDs) [38], as water-soluble antitrypanosomatid agents [39], or in the synthesis of

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• design beyond all-hexagon polycyclic aromatic hydrocarbons (PAHs). Among these, π-conjugated scaffolds featuring embedded azulene units have gained considerable attention due to their unique optical and electronic properties. This review provides an overview of representative azulene-embedded

• gap, aromaticity of azulene subunit and anti-Kasha’s emission from higher excited states. In such cases, the azulene unit merely acts as a linker within a more complex benzenoid framework. This review covers all types of azulene-embedded molecular scaffolds, regardless of whether they contain a

• scaffolds of this type. Given the rapid progress in this field, with nearly half of the cited works published since 2020, this review focuses primarily on purely hydrocarbon structures, with less emphasis on heteroatom-containing molecules. Typically, only the final synthetic steps leading to the fused

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• difunctionalization of N-arylacrylamides has emerged as a powerful strategy for the construction of diverse nitrogen-containing heterocycles, particularly oxindoles and related scaffolds. This review provides a comprehensive summary of recent advances in oxidative radical difunctionalization of N-arylacrylamides with

A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

• Ashutosh Nath,
• John Mark Awad and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

• modifications of MCRs could generate novel and complex molecular scaffolds [1][2][3][4][5][6][7][8]. Some MCR adducts generated from Ugi, Passerini, Gewald, Biginelli, and Groebke–Blackburn–Bienaymé (GBB) reactions have been modified to form chemically diverse heterocyclic scaffolds with potential biological

• activities [9][10]. Imidazo[1,2-a]pyridine and isoquinolinone-kind scaffolds are privileged rings which can be found in drug molecules such as zolimidine [11], zolpidem [12], alpidem and antiemetic drug 5-HT3A antagonist palonosetron [13] (Figure 1). Imidazopyridine-fused isoquinolinones have been developed

• group on the imidazopyridine moiety have direct electronic impact on the IMDA reaction. This integrated reaction process provided a new avenue for the preparation of heterocyclic scaffolds with potential biological activity. Experimental General procedure for the synthesis of intermediates 4 and 6 The

Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• (MMV) [3]. OSM’s aim is to “find a drug for malaria as quickly as possible” [3]. In the past, OSM synthesised and screened various derivatives of three related parent scaffolds (series 1–3) provided by GlaxoSmithKline (GSK) in non-commercial antimalarial screening datasets [4]. The group’s current

• et al. for 5-position halogenated scaffolds [10]. Several different triazolopyrazine compounds bearing chlorine, bromine or iodine at the 5-position, gave no ipso-substituted (5-substituted) products when refluxed in toluene with phenethylamine, with all major products being substituted at the 8

• -position (tele-substituted; Figure 1), distant from the halogen leaving group at position 5 [10]. A plausible reaction mechanism was proposed by Korsik et al. [10]. The antimalarial activity of series 4 triazolopyrazine scaffolds is generally reduced by substitution of an amine functionality at the 8

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• the past five years is presented, particularly emphasizing the active scaffolds of bioactive cinnamic acid derivatives. The review provides a strategic overview of alternative synthetic routes and highlights the latest innovations, including more efficient, highly selective, and environmentally

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• diverse scaffolds have been reported in the literature, the identification and use of novel PCs with tunable and diverse optical and redox properties can pave the way to uncharted reactivity. In this context, sulfur-based cores, widely used as acceptors in photoelectric materials [9][10][11][12][13][14

• : diphenyl sulfone (4), dibenzo[b,d]thiophene 5,5-dioxide (5), and 9,9-dimethyl-9H-thioxanthene 10,10-dioxide (6). The selection of these scaffolds was aimed at investigating the effect of conjugation and rigidity/flexibility on the presence of the same donor (TBA, a). In the case of the D–A compounds 4a and

• transfer (CT) character in scaffolds 4a and 6a can be attributed to the absence of a complete conjugated system. On the other hand, the fluorescence profile showed more differences in the analysis of the three members of the D–A family. Again, 5a revealed a bathochromic effect compared with the less

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• . A preliminary investigation revealed that krishnolide A (7) exhibited unique anti-human immunodeficiency virus (HIV) activity, representing the first report of anti-HIV activity in khayanolide-type limonoids. However, the highly oxygenated and polycyclic scaffolds pose substantial challenges toward

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• ) triflate-catalyzed post-Ugi assembly of novel pyrazolo[1,5-a][1,4]diazepine scaffolds is reported offering high yields (up to 98%) under mild conditions. The synthetic sequence involves the Ugi four-component reaction (U4CR) of pyrazole-3-carbaldehydes, primary amines, 3-substituted propiolic acids, and

• ; pyrazolodiazepines; silver catalysis; Ugi reaction; Introduction Synthetic chemists are continuously involved in the development of methodologies for accessing new heterocyclic scaffolds that resemble naturally occurring products and biologically active molecules [1][2]. Nitrogen heterocycles draw particular

• privileged scaffolds [4][5][6] and are well-known for their use as anxiolytics, hypnotics, and muscle relaxants (Figure 1) [7][8]. Diazepam, sold under the brand name Valium, is among the first marketed medications of the benzodiazepine family [9]. Alprazolam, sold under the brand name Xanax, is a fast

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• utilizing in situ-generated π-allylpalladium complexes to capture strained cyclic allene intermediates (Scheme 4) [22]. By modulating the ligands in the reaction system, two distinct polycyclic scaffolds, 13 or 14, could be synthesized with high selectivity. Mechanistically, the Pd(0) catalyst coordinates

Cu–Bpin-mediated dimerization of 4,4-dichloro-2-butenoic acid derivatives enables the synthesis of densely functionalized cyclopropanes

• Patricia Gómez-Roibás,
• Andrea Chaves-Pouso and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2025, 21, 877–883, doi:10.3762/bjoc.21.71

• platform for the synthetic diversification on these important scaffolds. Surprisingly, when the TBAF-mediated cyclization was attempted on bisamide 9 the corresponding cyclopropane 18 was not formed (Table 2, entry 6). The use of other mild bases at different temperatures also resulted unproductive

• functionalized cyclopropane scaffolds depending on the nature of the carboxylic acid derivative. Chemodivergent reactivity observed in copper-catalyzed borylative couplings of allylic gem-dichlorides. Cu-Bpin-mediated dimerization of 4,4-dichoro-2-butenoic acid derivatives. Control experiments. Proposed

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

• + 2] cycloaddition established, the scope and pivotal properties of the core structure was assessed (Scheme 1). Single point modifications of the tethered backbone were tolerated, enabling access to small 3D bicyclic scaffolds 4b, 4c, and 4d containing both a boron and ester handle. Consciously aware

• . Access to vicinal boron scaffolds 4f and 4g provided conclusive evidence that sensitization of alkenylboronic esters is achievable using xanthone, with in situ oxidation enabling direct access to otherwise challenging to synthesize cyclobutyldiols. The lower observed diastereoselectivity may reflect

• strategies for cyclobutyl scaffolds [53][54][55], products 6 and 7 could be synthesized via mild conditions [68]. Inspired by recent advances by Nolan and co-workers demonstrating the synthetic power of gold catalysts in EnT catalysis [31][69][70][71][72], we probed the reactivity of [Au(SIPr)(Cbz)] in our

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• hydrogen bonding with Cys200. These results underscore the potential of 4-(1-methylamino)ethylidenepyrrolidine-2,3-diones, especially compound 5e, as promising scaffolds for the development of anti-inflammatory agents targeting iNOS-related pathologies. Keywords: anti-inflammatory pyrrolidine-2,3-dione

• -disubstituted pyrrolidine-2,3-diones as scaffolds for the development of anti-inflammatory agents targeting iNOS-related pathologies. Results and Discussion Synthesis of 4-(1-methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones 5a–e The reaction between 4-acetyl-3-hydroxy-1,5-disubstituted-3

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• report the copper-catalyzed synthesis of tetrahydroquinoline derivatives via a domino reaction of aniline with cyclobutanone oxime. This method demonstrates a selective approach for generating bioactive tetrahydroquinoline scaffolds, which have broad applications in pharmaceutical chemistry. The reaction

• stereocontrol (Scheme 1b) [24]. In 2023, Zeng et al. reported the first example of a chromium-catalyzed spirocyclization between anilines and cyclobutanones, providing direct access to medicinally relevant cyclobutane-annulated and structurally constrained spirotetrahydroquinoline (STHQ) scaffolds [25]. Given

• -catalyzed method for the synthesis of spirotetrahydroquinoline (STHQ) derivatives via the reaction of anilines with cyclobutanone oxime. This protocol offers a straightforward approach to constructing structurally diverse STHQ scaffolds under mild conditions, with broad substrate scope and high functional

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• scaffolds – alkanes – then we will progress to ethers, alcohols, sugars, amines (and their derivatives), carbonyl compounds, peptides, and finally sulfur-containing compounds. By arranging the material in this way, we hope that newcomers to the field might be able to readily envisage ways to apply these

• concepts to their own scaffolds of interest. Review 1 Alkanes The simplest organic scaffolds are the alkanes. In such molecules, C–C bond rotations often have low energy barriers, and they often deliver conformers that are similar in energy, and this means that many alkanes have considerable conformational

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• the MCR product is possible thus increasing the versatility of these reactions in terms of structural diversity and molecular complexity. In this context, a wide variety of heterocycles and macrocycles as important biological scaffolds have been synthesized [6]. One of the most important components

• . Synthesis of heteroaromatic systems One of the most powerful applications of MCRs is the synthesis of heterocyclic compounds and several reports in recent years showed the advantages of using this tool as a synthetic strategy to generate complex molecular scaffolds with medicinal relevance [25][26][27]. In

• the cyclization process producing various highly diverse nitrogen-containing heterocycles, which are valuable scaffolds in medicinal chemistry [46]. Synthesis of non-aromatic heterocycles As stated above, DMSO can also hydrolytically decompose to formaldehyde. There are many examples of reactions in

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• , Chiba 263-8522, Japan 10.3762/bjoc.21.43 Abstract β-Amino cyanoesters are important scaffolds because they can be transformed into useful chiral amines, amino acids, and amino alcohols. Halogen bonding, which can be formed between halogen atoms and electron-rich chemical species, is attractive because

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• tetracyclic steroid scaffolds such as 17β-estradiol [18], where the diazocine core mimics the framework of the bioactive compound (Figure 1a). The other option is to attach the diazocine photoswitch as a substituent (appendix) to the biologically active molecule (Figure 1b) [6][10][19][20][21]. The art of

• switching properties even in an aqueous environment and are therefore promising switches in photopharmacological applications. a) Structural similarity of N-acetyl diazocine 1 with known 17βHSD3-inhibitor tetrahydrodibenzazocine (THB) [17] and parent diazocine with steroid scaffolds [18]. b) Parent

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• environmentally friendly synthetic strategies, especially one-pot multicomponent and tandem reactions, are key to modern organic and medicinal chemistry [1][2][3][4][5][6][7] and have proven to be successful in generating diverse heterocyclic scaffolds, as highlighted in a recent book [8]. Multicomponent

Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• ]. Chemists thus turned toward scaffolds that were easier to access [36][111]. Self-assembled containers, capsules, nanoreactors In the 1990s, Rebek popularized “softball”/”tennis ball” reactors [112][113][114]. These “capsules” [115][116][117] are two or more molecules that self-assemble via hydrogen bonds

• formation possible in metal–ligand bonding provides chemists with a shortcut to access 3D scaffolds. When well-designed linkers and metals are combined, discrete cages emerge as the thermodynamic product (Figure 5A) [22][142][143][144]. Typically, rigid linkers are required to enforce geometry, although a

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• prepared scaffolds are valuable additions to the class of pyrazolo-1,2-benzothiazine antibiotics with selective antistaphylococcal activity. Keywords: acetamides; antibiotics; antimicrobial; benzothiazines; Staphylococcus aureus; Introduction The global crisis of antibiotic resistance has been

• resistance [2]. Innovative scaffolds for novel antibiotic drug candidates are required to create new methods for safe and effective treatments. Chemically designed drug leads can complement naturally found antibiotics and may engage multiple modes of action and might have a longer lifetime before resistance

• evolves [3]. Complex chemical scaffolds with more than one protein-engaging functionality in a single molecule are advantageous for selectivity. This concept of synergistic compounds and complex chemical interactions helps to boost biological activity and prolongs the emergence of resistance in pathogens