Copper catalysis: a constantly evolving field

• Elena Fernández and
• Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

• -workers demonstrates that the efficient and green direct C–H amination of benzoxazoles can be catalyzed by copper chloride salts in acetonitrile in the absence of any acidic, basic, or oxidizing additives [8]. Both CuCl and CuCl2 were found to be extremely efficient in promoting the reactions, which

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

• offers wide-ranging potential for substrate expansion and the functionalisation of bioactive compounds. This study presents a green and efficient C–H amination, catalysed by CuCl and CuCl2, in acetonitrile without acidic, basic or oxidant additives that is accelerated by microwave (MW) irradiation and is

• -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

• reported in numerous green protocols, offer significant advantages over the use of conventional heating. The goal was to utilise selective, volumetric dielectric heating to save time and energy, enable selective catalysis and generally achieve higher selectivity and yields [53][55][56]. Building on the

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

• incorporating dual heptagonal rings [37]. Compound 23a exhibits dynamic chirality, aggregation-induced emission (AIE), and intense CPL (|glum| = 1.7 × 10−2), whereas compound 23f, with lateral π-extension, shows enhanced thermal stability and green emission at 517 nm (Table 7). Kuehne and co-workers reported

• excellent PLQYs – 99% and 90% in solution, and 80% and 77% in PMMA-doped films, respectively. In 2024, Wang’s group developed a B,N-embedded hetero[8]helicene 47, exhibiting narrow green emission at 531 nm (FWHM = 36 nm), a high PLQY of 93%, and outstanding CP-OLED performance (EQE = 32.0%; |gEL| = 7.74

• -containing derivatives showed red-shifted emission, broader FWHM, lower PLQYs, and diminished BCPL values, indicating a trade-off between extended conjugation and emissive efficiency. Yin’s group introduced 1,4-BN motifs into compounds 51a and 51b, which emitted blue-green light at 474 and 465 nm

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• corresponding state. The Franck–Condon states of the tautomers, existing in solution, are given in green. Changes of the absorbance of compound 1 at 465 nm in toluene upon turning on and off the irradiation source (365 nm). a) Change of ΔE(K-E) in kcal/mol as a function of the substitution on different

• -acceptor sites are given in red and blue, respectively. The axle of intramolecular rotation is given in green. The twisting angles α and β are indicated in magenta. Perspective switching compounds, generated by the computational quantum chemistry calculations. Relative stability (M06-2X/TZVP) and spectral

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

• reactions were carried out at ambient pressure (control) and under HHP (up to 3.8 kbar) conditions. These representative reactions provided higher yields for the products and HHP enabled truly green processes that are catalyst- and solvent-free, to occur with high yields and producing only non-toxic by

• are one of the major driving forces in green synthesis [1][2]. High hydrostatic pressure (HHP) activation, one of such methods, is based on mechanical compression force. The typical pressure range is 2–20 kbar that is orders of magnitude greater than the conditions traditionally employed in chemistry

• protocol was even applied in the elegant syntheses of platencin [30], and steroid derivatives [31]. Despite these encouraging applications, there is a broad area to be developed for the advancement of green synthesis efforts. Continuing our program on developing environmentally benign synthetic methods [32

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• and the relatively green chemistry of generating amidyl radicals. Amidyl radicals offer several advantages that enhance their applicability in organic synthesis: 1) The BDE of amidyl N–H bond is more than 105 kcal/mol, relative to the bond (C–H, Si–H, B–H, and Ge–H) which BDE is lower than 100 kcal

• modified. In recent years, photocatalysis has been widely adopted due to its green and efficient nature [45][46][47][48][49][50][51]. The generation of amidyl radical is implemented by HRP. Six different methods (Figure 2c), which have been developed for visible-light mediated reactions, could generate

• the research of direct functionalization via HAT processes and the development of green chemistry in photocatalysis, this review will focus on the generation of amidyl radicals and reaction mechanisms and highlight the photocatalyzed reaction characteristics. This review aims to provide researchers

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

• or green colours of 157–159 and azulene-like weak absorption due to S0→S1 transition. Strong chiroptical responses were revealed by ECD spectra, with the maximum |gabs| values reaching 0.022 (at 421 nm) and 0.021 (at 427 nm) for 158, and 159, respectively. These values are among the highest |gabs

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

• radical C, which adds to the N-arylacrylamide, followed by intramolecular cyclization and deprotonation to form the final products 19. To further expand the radical difunctionalization toolbox, electrochemical approaches have emerged as a green and efficient alternative, offering precise redox control

• from N-cyanamide alkenes (Scheme 27) [16]. This approach is notable for its alignment with the principles of green chemistry, utilizing the metal-free photocatalyst 4CzIPN under visible light conditions. In this system, N-cyanamide alkene 54 and BrCF2CO2Et 55 were used as model substrates, with 4CzIPN

Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents

• Julius Krenzer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97

• . This can be obtained from renewable biomass and is therefore considered to be a "green" solvent. In 2-MeTHF (conditions (C)), product 1f was isolated with a yield of 95% and derivative 1h with a yield of 91%. This shows that the sustainable solvent is a potent alternative to 1,4-dioxane. With the new

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• (open circles) isotherms of [3.3.3]_oligo (dark red), [3.3.3]_linear (red), [3.3.3]_branch (orange), [4.3.3]_oligo (purple), [4.3.3]_linear (blue), and [4.3.3]_branch (green). a) CO2 at 298 K and b) N2 at 77 K. Formylation of naphthalene-fused propellanes. Properties of methylene-alternating

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• predict the experimentally observed reaction site with 78% accuracy over the whole dataset when using no energy threshold, meaning that only the reaction site corresponding to the lowest-energy complex is predicted to be the reaction centre. In Figure 9A, the predictions, correct (green) or wrong (red

• with the experimentally observed reaction site in green and the predicted reaction site marked by a blue circle. For molecule 1, we can see in the original paper from Yeung et al. [26] that the reaction preceding the C–H activation is an intramolecular cyclization between the C atom marked in green and

• single-point calculations did not result in better agreement with experimental observations. The ten molecules with their experimentally observed main reaction site in green and all predicted reaction sites within a 1 kcal·mol−1 threshold as a blue circle are shown in Figure 11. Using the previously

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

• –Bienaymé (GBB); imidazopyridine; intramolecular Diels–Alder (IMDA); isoquinolinone; multicomponent reaction (MCR); re-aromatization; Introduction Multicomponent reactions (MCRs) have intrinsic green chemistry advantages of synthetic efficiency and operational simplicity. Performing post-condensational

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• the electrophilic core highlighted by a smaller area of red color surrounded by green color of 1. Electron-rich periphery oxygens (formerly the carbonyl of benzoic acid) are highlighted by a greater area of red color. 1H NMR titration experiment of 1 with LiBArF20 at an incremental equivalency in

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

• excellent yield (Scheme 2) [32]. The formed anhydride 3 was smoothly converted to the amide at room temperature. This method provides a green approach by allowing cinnamic acid derivatization in water as a benign solvent. Similarly, Rajendran and Rajan (2023) reported a one-pot transamidation of cinnamamide

• situ formation of an active enol ester 26. The phenol was formed in situ during the second step from phenylboronic acid oxidation utilizing H2O2 (30%) as green oxidant (Scheme 8B) [40]. Sureshbabu and co-workers (2023) activated the carboxyl group of 4-hydroxycinnamic acid (1) by selectively reacting

• /N-acylation reactions, metal catalysts, particularly precious transition metals, are considered less sustainable due to their limited availability. Therefore, metal-free catalysis methods have emerged as an alternative to respond to the green chemistry agenda. For instance, Huy and Mbouhom (2019

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

• Gomberg (see TTM and PTM in Figure 1a) [31]. Gomberg’s radical emits light in the green region of the visible spectrum, which is shifted bathochromically by substituting the ortho- and para-positions of the trityl phenyl rings with halogens. However, all symmetrical halo-trityl radicals exhibit low ϕ

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

• Jilei Cao Leiyang Bai Xuefeng Jiang Hainan Institute of East China Normal University, State Key Laboratory of Petroleum Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

• Zhihua Liu,
• Ya-Zhi Chen,
• Ji Wang,
• Qingling Nie,
• Wei Zhao and
• Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

• colors: green or grey = C, white = H, blue = N, red = O, orange = S, and purple = Cs. For the crystal structure, the overall stoichiometry of Cs+, PO43−, 18-crown-6 and anion receptor is 3:1:3:1. Phosphate anion is encapsulated inside the hexaurea cavity and stabilized by 12 × N–H···O hydrogen bonds

Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• belonging to the scaffold of O-QC1 arise. Further, the singlet signal corresponding to the CH3 group of the tosyl moiety shifts from 2.45 ppm to 2.47 ppm. A spectrum containing approximately a 45:55 ratio of O-NBD1/O-QC1 can be found after 140 minutes of irradiation (Figure 2b, green). A different behavior

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• Babak Kaboudin Milad Behroozi Sepideh Sadighi Fatemeh Asgharzadeh Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Gava Zang, Zanjan 45137-66731, Iran 10.3762/bjoc.21.61 Abstract In this review, we describe recent advances in electrochemical green methods for the

• electrosynthesis as a green, precise, and low-cost method to prepare phosphorous structures. Keywords: electrosynthesis; green synthesis; organophosphorus compounds; P–C bond formation; P–heteroatom bond formation; Introduction The electrochemical synthesis is a valuable and beneficial method for the preparation

• recent years on developing new methods for synthesizing organophosphorus compounds [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Developing sustainable and green methods for synthesizing organophosphorus materials is a growing field. Methods based on photocatalysis [36], flow-based

New advances in asymmetric organocatalysis II

• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60

• from a brief Web of Science analysis of the 6,700 articles, published within the past 25 years, retrieved through a search of the keywords “asymmetric organocatalysis”. Organocatalysis is now part of various areas of chemistry, spanning as far as polymer, materials, as well as green and sustainable

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

• the desired product. Keywords: copper catalysis; cyclobutane-fused tetrahydroquinolines; domino cyclization reaction; green synthesis; Introduction Tetrahydroquinolines (THQs) represent a privileged scaffold in medicinal chemistry, exhibiting a broad spectrum of biological activities and serving as

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• protocol [41], the fluorescent GFP (green fluorescent protein)-expressing strain PKL1162 was applied to mannan-coated microtiter plates. In this assay, fluorescence intensity correlates with the number of adhered bacterial cells. The photoswitches 1–5 (cf. Figure 1) were used as inhibitors of bacterial

• to the O-azobenzene (AB) photoswitch. (Orthogonal) photoswitching alters the relative spatial orientation of the two sugar units. Glucose (Glc) moieties are colored in blue and mannose (Man) in green according to the symbol nomenclature for carbohydrates (SNFG) [29][30]. A: Wavelength-selective

• ) is depicted as ribbon diagram and the ligands are displayed as stick models (glycoclusters 1 and 2: EE: blue; ZZ: violet; EZ: green; ZE: red). Superposition of the isomers shows the similarity of the binding of the terminal mannoside antenna within the FimH CRD and the different orientations of the

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• )cyanophenylacetonitrile) fluorophores for easy access, which will contribute to the rapid dissemination of the RNA imaging approaches associated therewith. Keywords: covalent RNA labeling; FLAP; fluorophore synthesis; HBC530; self-alkylating ribozymes; Introduction The discovery of fluorescent reporters, such as green

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

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• exceptional functional group tolerance, accommodating phenyl, aliphatic, phenol, alcohol, heterocyclic, and sulfide groups. This scalable, rapid, and eco-friendly strategy offers a promising avenue for the efficient synthesis of hydantoins, aligning with green chemistry principles and expanding the

• advantages over conventional heating, such as enhanced reaction rates and yields [17]. Microwave irradiation is also aligned with our group’s sustainability goals of adhering to the principles of green chemistry [18]. Following our previous works in the synthesis and evaluation of biologically active

• ” aspect of the protocol under microwave irradiation conditions, which enables rapid conversion of the starting materials to the products in water – a green solvent – in less than two hours makes this protocol an expedient and environmentally benign synthesis of hydantoins from amino acids. The scalability