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

• 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

• ) Visual impressions of the aqueous solution at various pH after excitation with a natural light. b) UV–vis absorption spectra. c) Normalized emission spectra. Molecular fragments associated with intramolecular charge transfer states. Frontier molecular orbitals of compounds 3n and 4n in three different

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

• Vasudevan Dhayalan Department of Chemistry, National Institute of Technology Puducherry, Karaikal-609609, Puducherry, India 10.3762/bjoc.21.200 Abstract Over the past two decades, organocatalyzed visible-light-mediated radical chemistry has significantly influenced modern synthetic organic

• ; 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

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

• (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

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

• chains at the lower rim. The resulting amphiphilic calix[4]arene derivative 3 spontaneously self-assembled into nanoscale aggregates in aqueous medium, as demonstrated by dynamic light scattering analysis. The cytotoxicity of compound 3 towards cancer cells was assessed using human renal carcinoma cells

• ][26]. A variety of calixarene-based nanoconstructs have been reported, including nanosystems with light-triggered anticancer activity [27], potential anticancer vaccine candidates [28], and nanocarriers for anticancer drug delivery [29][30][31][32][33]. Numerous bioactive groups have been introduced

• 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

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

• first minutes of rotaxane insertion. Likewise, azobenzene photoswitching did not induce permeabilization in the more rigid and thicker EYPC/Chol 6:4 bilayers, which showed minimal release (5%). Furthermore, we discovered that when the unthreaded axle is irradiated with light, an unknown, irreversible

• photochemical process occurs, which triggers the release from only the vesicles containing EYPC. These findings underscore the significance of both the physical and chemical properties of the bilayer in enabling effective light-triggered cargo release through rotaxane activation. Keywords: lipid membrane

• 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

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

• , the use of TT frameworks for semiconductors has led to significant progress in organic field-effect transistors (OFETs), organic photovoltaics, organic light-emitting diodes, and chemical sensors [1][2][3]. For instance, TT-containing copolymers have shown high hole mobility, strong absorption in the

• notable DNA intercalation and antiproliferative effects [16][17], while TT–BODIPY derivatives were shown to efficiently generate singlet oxygen and demonstrate light-induced cytotoxicity, highlighting their promise as photodynamic therapeutic agents [18]. Near-infrared TT–DPP-based dyes have also been

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

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

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

• catalysts that could promote the proposed PET reaction of 9a on the basis of our previous results [15]. The reaction was performed in MeCN in the presence of photocatalysts under blue light-emitting diode (LED) irradiation at 30 °C. The results are listed in Table 1. Catalysts I [28], II [29], and III [30

• concerted nor stepwise. These findings shed light on the mechanistic innovation of a PET-initiated radical-derived reaction that was driven by the ring-strain release. Synthetic plan. a) General model of cyclobutenone bond cleavage; b) our previously reported method; c) plan for indole Aspidosperma alkaloid

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• simple building blocks [72]. The main feature of light-induced transformations is the involvement of electronically excited states that occur during photon absorption, leading to the formation of reactive intermediates causing significant changes in chemical compound reactivity. As a result, light energy

• compounds [78][79][80][81][82]. The work of Davis, Derksen and co-workers [83] presents interesting results on the use of UV light to study the reactivity of bicyclic divinyl ketones and the dependence of photochemical reaction products on wavelength. Under anhydrous conditions, irradiation of divinyl

• ketone 154 with UV-C (200–280 nm) light yielded approximately equal amounts of products 155 and 156 (1.25:1 after 85% conversion). In the presence of water (CH3CN/H2O 10:1), a crystalline cyclooctene compound 157 was obtained by irradiation of 154. However, compound 156 was not detected. When irradiating

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

• for precise control over their structural, dynamic, and functional properties. By harnessing light as a non-invasive stimulus with high spatial and temporal resolution, these photoswitches allow for the modulation of the rotaxanes’ intra- and intermolecular interactions, optoelectronic properties, and

• resulting influence on rotaxane operation. Due to their architectural versatility and precise light control, photoswitchable rotaxanes hold promise for a broad range of applications, including light-responsive molecular machines, smart materials, and biofunctional systems. However, emerging applications

• increasingly require rethinking and developing new structural designs that incorporate more efficient and advanced photoswitches to fully realize their potential. Keywords: macrocycle; photoisomerization; photoswitches; rotaxanes; shuttling; Introduction Harnessing light energy to control intra- and

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

• separable regioisomers: gracilisoid F (54) in 42% yield and gracilisoid H (56) in 40% yield, respectively (Scheme 8). Here, light triggered a regiodivergent Norrish–Yang cyclization, while the acidic nature of silica gel sufficiently promoted an α-hydroxy ketone rearrangement. This type of rearrangement was

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

• toxic, mutagenic, or carcinogenic and their presence, even in trace amounts, can cause issues with the kidneys, liver, brain, and central nervous system. Moreover, dyes can obstruct light penetration, affecting the photosynthetic processes in water bodies and disrupting the balance of aquatic ecosystems

• methyl substituents (H2). Fortunately, the X-ray crystal structures of G2W1 and G2W3 reported below shed further light on their poor performance as solid state sequestrants. X-ray crystal structure of G2W1 and G2W3 Eventually, we were able to grow single crystals of G2W3 (CCDC 2466611) and solve their

Enantioselective radical chemistry: a bright future ahead

• Anna C. Renner,
• Sagar S. Thorat,
• Hariharaputhiran Subramanian and
• Mukund P. Sibi

Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174

• catalysts. The drawbacks of chiral Lewis acids have been overcome to an extent using organocatalysis. The use of photochemistry to generate radicals by light-induced electron transfer has resulted in elegant enantioselective radical transformations. Several transition-metal photocatalysts [9] and organo

• . A mechanistically distinct way of achieving enantioselective radical transformations is the use of metalloradical catalysis [54]. A metalloradical is a persistent metal-centered radical species that can homolytically activate substrates without other initiators, light, or electricity. Several

Pd-catalyzed dehydrogenative arylation of arylhydrazines to access non-symmetric azobenzenes, including tetra-ortho derivatives

• Loris Geminiani,
• Kathrin Junge,
• Matthias Beller and
• Jean-François Soulé

Beilstein J. Org. Chem. 2025, 21, 2234–2242, doi:10.3762/bjoc.21.170

• Paris, France 10.3762/bjoc.21.170 Abstract Azobenzenes are photoresponsive compounds widely used in molecular switches, light-controlled materials, and sensors, but despite extensive studies on symmetric derivatives, efficient methods for synthesizing non-symmetric analogues remain scarce due to

• of applications, including molecular switches, sensors, and light-controlled materials [1][2][3][4][5][6][7][8]. The photoswitching behavior arises from the reversible photoisomerization between the E- and Z-forms of the azobenzene chromophore, driven by the isomerization of the N–N double bond. This

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• F and cryptotrione have fused and spiro five-membered rings, respectively [25][26]. Strepsesquitriol bearing bridged five-membered rings was firstly synthesized by Li in 2024 [27]. The green fluorescent protein (GFP) core chromophore (o-LHBDI) displayed a potential application in organic light

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

•  15) [74][75][76]. Tang et al. recently reported the environmentally friendly production of glyceraldehyde and dihydroxyacetone from using glycerol through photocatalytic oxidation under visible light using a Cuδ+-decorated WO3 photocatalyst in the presence of hydrogen peroxide (H2O2) [77]. The

• aqueous-phase reforming (APR) technology for the production of light hydrocarbons and hydrogen in a single step from aqueous organic phases [97] containing 1-hydroxypropan-2-one (acetol), ethanol, benzene-1,2-diol (catechol), acetic acid or mixtures thereof. The process was conducted over various Ni-based

• simulated solar light and molecular O2 as the oxidant, and mesoporous carbon nitride (SGCN) as the photocatalyst. The latter showed excellent photoconversion (>95%) of furfural with 33% and 42% selectivity of HFO and MAN, respectively (Scheme 35). Xiao et al. developed this method and suggested that the

Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• visible light. How to design a bioinspired approach may be most attractive to synthetic chemists. Recently, Tang [16] and Jia [17] independently reviewed their remarkable bioinspired total syntheses as accounts. Tang documented their longtime carrier of learning from nature aiming to achieve better

• invented. Moreover, bioinspired total synthesis involving visible light and enzymes are new significant trends in this field, and these techniques have demonstrated great power in achieving unprecedented selectivity and reactivity. Since nature still prevails in rapid generating molecular complexity and

Solar thermal fuels: azobenzene as a cyclic photon–heat transduction platform

• Jie Yan,
• Shaodong Sun,
• Minghao Wang and
• Si Wu

Beilstein J. Org. Chem. 2025, 21, 2036–2047, doi:10.3762/bjoc.21.159

• thermal fuels have undergone significant advancements over the past four decades, emerging as a promising technology for light-to-thermal energy conversion. While these materials exhibit considerable development potential, critical challenges remain that hinder their practical implementation. In this

• ) through structural or bond rearrangements, thereby enabling solar energy storage. This reversible process is termed "energy charging", while the subsequent transformation of high-energy photoisomers back to their ground state – triggered by external stimuli such as light, heat, or catalysts – releases

• light-harvesting carbazole units with photoresponsive azobenzene units in a unique macromolecular architecture (Figure 4c) [48]. The resulting cross-linked polycarbazole structure led to a high solar thermal storage capacity of 179.9 J/g and an extended half-life at 60 °C, increasing from 7 min for the

Understanding the origin of stereoselectivity in the photochemical denitrogenation of 2,3-diazabicyclo[2.2.1]heptene and its derivatives with non-adiabatic molecular dynamics

• Leticia A. Gomes and
• Steven A. Lopez

Beilstein J. Org. Chem. 2025, 21, 2007–2020, doi:10.3762/bjoc.21.156

• ; stereoselectivity; Introduction Photochemical reactions utilize light as a sustainable energy source and are considered to be ‘green’ reactions [1][2]. Organic chromophores absorb light, accessing higher-lying excited state(s) that exhibit distinct reactivities, leading to bond breaking and formation, irreversibly

• are closer to the range of irradiation wavelengths of the experimentally used light source (333–364 nm). For 1, this peak is closer to experimental absorbance, λmax = 338 nm [80]. The remaining peaks, shown in blue and green for S2 and S3, respectively, absorb at higher energy than the experimental

• light source. Electronic transitions to these excited states are impossible in the experiment and thus will not be considered for this photochemical mechanistic study. DBH photodenitrogenation mechanism We then turned our attention to the photochemical reaction mechanisms leading to the formation of

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• 22, 14195 Berlin, Germany School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, UK 10.3762/bjoc.21.153 Abstract Light-mediated methodologies for the reduction of acylazolium species generated during N-heterocyclic carbene (NHC)-catalyzed

• reactions have been developed. Employing the simple amine, DIPEA, as the terminal reductant, products resulting from overall 2-electron or 4-electron-reduction processes could be obtained using either a photocatalytic approach under blue light irradiation or directly under UV-A light irradiation without an

• additional photocatalyst. Moreover, under the same photocatalyst-free conditions, UV-A-light-mediated reduction could be achieved using triethylsilane as the only reductant with subsequent desilylation and NHC elimination with fluoride delivering the corresponding aldehyde product. Keywords: carbenes

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

• Miao Xiao,
• Liuyang Pu,
• Qiaoli Shang,
• Lei Zhu and
• Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

• , C11, and C12 contiguous stereogenic centers, provided important insights that influenced the design of our second-generation total synthesis. Compared with the Snider-type radical cyclization using stoichiometric amounts of metal oxidants, visible-light-induced photoredox-catalyzed radical cyclization

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• of each reaction was thus 200 μL, with final concentrations of 100 mM (for substrates), 500 mM (for co-substrates) and 1 mM (for catalysts). After 48 h, the outcome of the reactions was determined by analytical UPLC–MS with, additionally, evaporative light-scattering detection [22][23] to enable

• subsequently used. Panel B: yields, estimated by evaporative light scattering detection, of reactions involving combinations of substrates, co-substrates and catalysts (dash: <2% estimated yield). Highlighted combinations (green boxes) were selected for mass-directed purification. aMultiple intermolecular

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• (c) MC3. (d) Molecular arrangements of MC3. Hydrogen atoms are omitted for clarity. (a) Absorptions and (b) emissions of compounds 3a, 3b, MC1, MC2, and MC3 measured in dichloromethane at room temperature. The inset shows the photographs under UV light at 365 nm. The concentration is 10 μM

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• photochemical and electrochemical methods, have been explored. Over the past two decades a variety of light-promoted imino-pinacol coupling reactions have been developed, involving the use of catalytic transition-metal complexes [35][36], organic dyes [37][38][39], and polyaromatic compounds [40][41] as

• purified through flash column chromatography on silica gel to give the isolated pure product. X-ray determined structure of chiral piperazine 2b. Synthesis of vicinal diamines via imino-pinacol coupling in the presence of metal-based reductants. Light-promoted imino-pinacol coupling for the synthesis of

• on a 0.1 mmol scale. Proposed reaction mechanism. Cyclic voltammetry investigation. Cyclic voltammetry of a 0.325 M solution of Et4NBF4 in DMF (light-blue line). Cyclic voltammetry of diimine 1a (10 mM) recorded in a 0.325 M solution of Et4NBF4 in DMF (dark-blue line). Cyclic voltammetry of diimine

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• ). Shining light will bring the molecule to a generic excited state (which is different for different photoswitch classes and substitution patterns and will not be treated in detail), which can then relax back to the ground state in either of the two wells. In cases where the two absorption spectra of the

• absence of light. Apart from some special cases where more competing mechanisms are operating [5], the thermal isomerisation typically is a first-order decay: Where I is the monitored signal at the time t, I0 the initial signal, and k the kinetic constant. Once k is known, the thermal half-life t1/2 can

• picoseconds to several years. The presence of heteroatoms also introduces H-bond donors and acceptors and metal coordination sites [11]. Like azobenzenes, E–Z isomerisation of azoheteroarenes can be triggered by light irradiation, while Z–E isomerisation proceeds through irradiation with a different

Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp²)–C(sp²) bond scission of styrenes

• Prafull A. Jagtap,
• Manish M. Petkar,
• Vaishnavi R. Sawant and
• Bhalchandra M. Bhanage

Beilstein J. Org. Chem. 2025, 21, 1799–1807, doi:10.3762/bjoc.21.142

• , antibacterial, and anti-inflammatory activities [10][11][12][13]. In the field of optoelectronics, especially with 2,4-diarylquinoline derivatives, extensive studies have highlighted their applicability in organic light-emitting diode (OLED) systems as functional materials [14][15] and cutting-edge fluorescent

• light of climate change and the ongoing energy crisis, there is an urgent need to reform energy and chemical production by prioritizing environmentally sustainable methods that are both practical and broadly implementable. Styrenes are industrially important bulk chemicals [39], with an estimated global