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

• can be used to synthesize complex and unique compounds that cannot be produced by thermal reactions, making photochemical transformations preferable to classical ones, especially when considering the concept of «green chemistry» [73]. Therefore, photochemical rearrangements have great theoretical and

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

• , toxicity, pesticide similarity, and biodegradability of methyl laurate in comparison with a series of conventional organic solvents, water, some fatty acids and their derivatives. The findings of this investigation revealed that methyl laurate exhibited better green solvent properties when evaluated

• , have deleterious effects on human and environmental health [1][2][3]. There is an ongoing and intensive research effort to identify new biocompatible alternatives to replace these existing solvents and many of the criteria that a solvent must meet to be considered green have been well defined in

• different sources [4][5]. In order to fulfil this requirement, a considerable number of green solvents of various classes have been developed for a range of applications, including the extraction of natural compounds [6][7][8][9], food analysis [10][11][12], pharmacology [13][14][15], and organic synthesis

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

• the naphthalimide. Specifically, red fluorescence was observed when the merocyanine formed, and green fluorescence when the spiropyran was generated. Notably, this rotaxane was employed for the detection of sulfite, where the addition of sulfite led to the deactivation of FRET. This occurs due to a

• Michael addition taking place at the active site (C=C−C=N+) in the merocyanine unit in the presence of sulfite ions, resulting in color changes from red to green. This work represents a substantial advancement in the development of rotaxane-based fluorescent probes, providing highly sensitive and

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

• green solution was heated and refluxed in an oil bath set at 95 °C for 3.5 h under N2. The reaction mixture was poured into a flask containing MeOH (280 mL) and stirred overnight at rt. The heterogenous mixture was centrifuged (7500 rpm, 5 min) portionwise, and the supernatant was removed. The crude

• , green; H-bonds, yellow-red striped. Cross-eyed stereoview of: a) a molecule of G2W1 in the crystal, b) the packing of G2W1 along the xz-diagonal in the crystal. Color code: C, grey; H, white; N, blue; O, red. a) Plot of removal efficiency of methylene blue (240 μM, 1 mL) from water after incubating with

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• of alkenyl halides 7a and 7b with the green oxidant H2O2 gave trace conversion after 3 days; however, the reaction using m-CPBA catalyzed with p-TSA was complete in 24 hours and afforded the halogenated lactones 8a and 8b in 33% and 34% yield, respectively (Scheme 1). We have recently reported the C3

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

• ) should enable the development of methodologies that expand radical transformations to a larger number of substrates in green and sustainable ways. Nickel is an earth-abundant transition metal that has been used in several organic transformations [49][50][51][52]. Chiral nickel catalysts have been

• quenching, in some cases involving radical–polar crossover processes. The photoredox catalysts used in most of the synergistic catalysis are Ir and Ru-based systems that are expensive and less readily available. This limitation can be overcome by developing green and sustainable organophotoredox systems

• green alternative to solution-phase chemistry [91]. Mechanical grinding or milling also provides a means to generate radicals via piezocatalysis [91], an emerging strategy that warrants investigation in the context of enantioselective radical reactions. Future research holds the key to addressing

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• rapid molecular diversification, offering transformative potential for green chemistry and pharmaceutical applications. By unifying mechanistic insights with practical synthetic design, this review provides valuable guidance for future innovations in precision organic synthesis. Keywords: economical

• platform, as exemplified by recent breakthroughs in polycyclic skeleton construction and stereo-divergent cyclization. The implementation of pathway economy fosters significant advancements in green chemistry by minimizing synthetic steps, reducing waste generation, and enhancing atom economy. Notably

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• estimated closer to the structurally similar compound 7b in silico, however, according to the logk value, it should be in the lower right corner also supported by its permeability value (green category). Derivative 10b is clearly an extremity among these compounds, being the only molecule containing 6 rings

Synthesis of triazolo- and tetrazolo-fused 1,4-benzodiazepines via one-pot Ugi–azide and Cu-free click reactions

• Xiaoming Ma,
• Zijie Gao,
• Jiawei Niu,
• Wentao Shao,
• Shenghu Yan,
• Sai Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 2202–2210, doi:10.3762/bjoc.21.167

• Xiaoming Ma Zijie Gao Jiawei Niu Wentao Shao Shenghu Yan Sai Zhang Wei Zhang School of Pharmacy, Changzhou University, 1 Gehu Road, Changzhou 213164, China Department of Chemistry and Center for Green Chemistry, University of Massachusetts Boston, 100 Morrissey Blvd, Boston, MA 02125, USA 10.3762

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

• transformations far from thermodynamic equilibria have emerged abundantly with the consideration of green chemistry [89][90][91][92]. Redox-active organic compounds, transition metal coordinating compounds and even an electrode surface were commonly employed as catalysts in the electrochemical transformations [93

• indole 5 and a Ru(0) species F that was oxidized on the RVC anode to regenerate A. This electrochemical formation of indole, using easily available reactants and proceeding successfully under aqueous solution with simple undivided cell, was a green and convenient route towards indole. A series of

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

• : aldehydes; biobased chemistry; biomass; carbonyl; fine chemicals; ketones; multicomponent; platforms; sustainability; Introduction Shifting towards sustainable practices in the chemical industry relies on continued advancement of green chemistry sciences which aim to minimize the global environmental

• impact while maintaining the efficiency of the chemical processes [1]. Green Chemistry principles outlined by Anastas and Warner in their work “Green Chemistry: Theory and Practice (2000)” [2] notably highlight atom economy, waste minimization and the use of renewable feedstock as pillars of sustainable

• % (Scheme 10b) [39]. This strategy offers a green and efficient approach to synthesize PA from biomass resources. The synthesis of PA was also achieved in a two-step process from cellulose (Scheme 10c) [40]. The use of biobased monomers is receiving tremendous attention in the field of bioplastic materials

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

• Zhengyi Qin Yuting Yang Nuran Yan Xinyu Liang Zhiyu Zhang Yaxuan Duan Huilin Li Xuegong She State Key Laboratory of Natural Product Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China State Key Laboratory of Green Pesticide, Guizhou University

• Technology Major Program of Gansu Province of China (24ZD13FA017, 23ZDFA015 and 22ZD6FA006), the State Key Laboratory of Green Pesticide and Guizhou University (GPLKF202505), and the Fundamental Research Funds for the Central Universities (FRFCU, lzujbky-2025-it46).

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

• charged solar thermal fuels for deicing tests [74], showing effective ice removal capability under green light irradiation (Figure 7a). Wang et al. developed a photostimulated self-heating wristband [94] that elevates surface temperature from 29 °C to 44 °C upon blue light irradiation, protecting users

• Society. This content is not subject to CC BY 4.0. (e) Molecular structure of the trisazobenzenophane. Figure 6e was adapted with permission from [82] Copyright © 2013 American Chemical Society. This content is not subject to CC BY 4.0. (a) Deicing test of charged solar thermal fuels under green light

α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

• Vladyslav O. Honcharov,
• Yana I. Sakhno,
• Olena H. Shvets,
• Vyacheslav E. Saraev,
• Svitlana V. Shishkina,
• Tetyana V. Shcherbakova and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157

• reactions, widely used as a green alternative for the synthesis of active pharmaceutical ingredients [7] and opens up the possibility of creating new compounds from the class of peptidomimetics [8][9][10], which often exhibit diverse biological effects [11] including antidiabetic [12], antiviral [13

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

• ), S2 (blue), and S3 (green) states. Relevant structures (S0 and S1 minima and endpoints of the MEP calculation) are shown below the plots. The C–N and N=N bond lengths are in angstroms on the structures shown. S1 energy is shown on the plot with a red star. (a) The bond lengths we calculated are

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

• 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

• products observed by analytical HPLC. Structures and structure elucidation of intermolecular reaction products. The relevant reactivity modes are indicated by colour: O–H insertion (green); N–H insertion (blue); formal C–H insertion (yellow); and cyclopropanation (pink). Synthesis of α-diazoamide

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

• , these macrocycles show blue to green emissions with high fluorescence quantum yields (ΦF up to 0.69). Owing to the existence of inherent chirality, two enantiomers of N-doped macrocycle MC1 were successfully isolated by chiral resolution, enabling detailed investigation of its chiroptical properties

• eV for MC1, 2.61 eV for MC2, and 2.68 eV for MC3, respectively, based on the onset absorptions. MC2 and MC3 display strong blue emissions at 487 nm and 458 nm, respectively, while MC1 exhibits green photoluminescence at 516 nm. To better understand the electronic structures of these N-doped

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• ), diglycidyl methylphosphate (2, blue), and triglycidyl phosphate (3, green) for 48 hours. Cell viability was determined using the MTT assay. Data represent mean ± standard deviation (n = 3). The y-axis shows relative cell viability (%) compared to untreated control, and the x-axis indicates the logarithmic

• concentration of each compound. The dashed line marks the 50% viability threshold (IC50). Linear sweep voltammograms of 1 × 10−4 М HSA (black) and HSA mixed with each of the three alkylating agents; 1 (red), 2 (green), and 3 (blue). Conditions: supporting electrolyte: 0.1 M Et4NBF4, working electrode: glassy

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

• applications in the preparation of chiral ligands. Keywords: chiral piperazines; electrosynthesis; flow chemistry; green chemistry; imino-pinacol coupling; Introduction Vicinal diamines represent a highly valuable class of compounds that, over the past decades, have found widespread application in natural

• 1a (10 mM) in presence of 1 equiv of methanesulfonic acid (10 mM) recorded in a 0.325 M solution of Et4NBF4 in DMF (green line). Cyclic voltammetry of diimine 1a (10 mM) in presence of 2 equiv of methanesulfonic acid (20 mM) recorded in a 0.325 M solution of Et4NBF4 in DMF (dark-red line). Cyclic

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• ; nitrogen – blue; carbon – grey; hydrogen – pale green). Proposed synthetic approach. Preparation of the aldehyde 4. Cycloaddition with N-methylmaleimide. Cycloaddition with N-phenylmaleimide. Cycloaddition with dimethyl fumarate and dimethyl maleate. Supporting Information Supporting Information File 30

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

• series of compounds 34a–c (Scheme 9) which melt upon irradiation with UV light in the solid phase. Upon irradiation with green light, the compounds isomerise back to the solid phase. The large depth of light penetration of these compounds (>1400 µm for both UV and vis light) and the high capacity for

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

• features of this protocol include the use of O2 as an ideal, green oxidant, operational simplicity and scalability, high atom- and step-economy, and cost-effectiveness, collectively enabling the single-step synthesis of two medicinally relevant N-heterocycles in excellent combined yields. Keywords: C–C

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• potential in advancing the green transformation of the chemical industry while enhancing inherent process safety. Safety, cost-effectiveness, and operational efficiency serve as pivotal drivers for advancing flow chemistry in nitration processes. This review provides a comprehensive analysis of the

Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

• Natalia Lebedeva,
• Fedor Kliuev,
• Olesya Zvereva,
• Klim Biriukov,
• Evgeniya Podyacheva,
• Maria Godovikova,
• Oleg I. Afanasyev and
• Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

• , usage of classical reducing agents – H2 on Pd/C or NaBH4 did not show similar chemoselectivity [26]. Additionally, the NaH2PO2 usability is engaging due to fine green chemistry metrics, e.g., an E-factor less than 1 was reached, moreover the main wastes of this process were safe and useful as

On the aromaticity and photophysics of 1-arylbenzo[a]imidazo[5,1,2-cd]indolizines as bicolor fluorescent molecules for barium tagging in the study of double-beta decay of ¹³⁶Xe

• Eric Iván Velazco-Cabral,
• Fernando Auria-Luna,
• Juan Molina-Canteras,
• Miguel A. Vázquez,
• Iván Rivilla and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2025, 21, 1627–1638, doi:10.3762/bjoc.21.126

• show that, in the absence of barium, compound 18 exhibits almost coplanar components, so both systems form a combined fluorophore highlighted in green in Figure 5. The correlation between energy and this dihedral angle by means of a Karplus-like [31] equation up to the fourth degree in the form shows

• (⟨RBa0⟩)n denote the average Ba–O bond distances (in Å) for the different crown ethers. Distances between Ba2+ and the ring points of electron density of benzene (in green) are also gathered in (B). ΔGiso and ΔGrxn terms stand for the Gibbs energies (in kcal/mol) described in Scheme 2 and have been

• points at z = 1 are shown in light green. Calculateda absorption (λabs, in nm) and emission (λem, in nm) wavelengths of compound 19 at the free and barium perchlorate bound states, using different DFT functionals. Supporting Information Supporting Information File 51: Energies, calculated absorption and