Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• epoxide-opening cyclisation for the oxetane formation (Scheme 11b) [45]. The highest yield was obtained for the PhSH/I2 10:1 activator under unusually mild conditions – the authors believed it is due to the oxa-bridge which facilitates the Lewis acid coordination. In 2001, Rousseau and colleagues reported

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

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

• directing group facilitates this step as it stabilizes the complex through coordination to the Pd atom, thereby lowering the reaction barrier. A depiction of the CMD step is shown in Figure 1. Upon C–H bond breaking, the Pd atom moves into the plane of the aromatic ring, forming a palladacycle intermediate

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• organometallics guests, albeit less common, are also observed. These form a variety of structures from supramolecular second-sphere coordination adducts to pseudorotaxanes [35][36]. With highly charged metal ions, electrostatic interactions and first-sphere coordination bonds are dominant, while second-sphere

• coordination with inorganic and organometallic complexes involves hydrophobic interactions and van der Waals forces (mainly with the organic parts of these guests). Several forces are at play in the formation of supramolecular assemblies with gold in the form of haloaurate ions, as detailed in the forthcoming

• cations, the geometry is different from that observed in {α-CD·[K(OH2)6]+[AuBr4]−}n, because coordination of Rb+ and Cs+ takes place both at OH groups and at the O atoms of the glucopyranosyl ring in the CD tori (Figure 2, right). This strong coordination, in cooperation with the geometrically favourable

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

• are presented. Keywords: hypervalent iodine; macrocycle; metal coordination; supramolecular; Introduction Supramolecular chemistry is emerging as a pivotal area of research in both medicinal and materials chemistry that opens the avenue for new functionalized materials for their use in medical

• Information File 1. Single crystals with quality suitable for XRD analysis were obtained in both cases (Figure 5). Unlike the previous assumption of metal coordination at the macrocycle core [17], the crystal structures reveal complexation of both cations at the periphery of the macrocycle. Both 1/LiBArF20

• in this HIM system, the 1H NMR titration data was used to determine the association constants for metal coordination. Two stock solutions were prepared with one containing a concentration of 2.83 mM of the macrocycle (HIM) in a mixture of deuterated chloroform and acetone 1:2. The second stock

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

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

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

• studied silver(I)-catalyzed intramolecular heteroannulation reaction is depicted in Scheme 5. The process begins with the π-coordination of the silver catalyst to the triple bond in the Ugi-adduct 15a generating intermediate A. This is followed by a nucleophilic attack by the pyrazole nitrogen on the

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

• , enabling programmable access to structurally distinct molecular architectures from identical substrate precursors through precise manipulation of metal coordination [16][17][18]. This sophisticated approach capitalizes on the stereoelectronic tunability of ancillary ligands to dictate reaction pathways

• , tetrabutylammonium iodide (TBAI), and water significantly accelerated aryne generation, thereby increasing its local concentration. This favored aryne coordination to the palladium center, followed by CO insertion and reductive elimination to furnish phenanthridinones. In contrast, when dppm was introduced

• , oxidative addition of the C–I bond to palladium formed the four-membered aryl–palladium complex Int-5. Steric hindrance from the bulky dppm ligand, combined with slower aryne release (using KF as the fluoride source), attenuated aryne coordination. Under these electron-deficient conditions, CO

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

• mechanism for the copper-catalyzed diastereoselective dimerization of 4,4-dichoro-2-butenoic acid derivatives (Scheme 4). Initially, the LCu–pin complex generated through reaction between LCu–Ot-Bu and B2pin2 undergoes coordination and regioselective insertion into 1 giving rise to β-borylated organocopper

• addition to a second molecule of 1. Given the negative results observed for other crotonate derivatives (Scheme 3c), coordination between the Li cation and the two chlorine atoms via proposed transition state D may be crucial not only for diastereoselective control but also for the viability of this step

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

• L as an anion receptor to extract cesium salts (chloride, nitrate, carbonate, sulfate, and phosphate) from the solid phase into chloroform. Remarkably, Cs3PO4 exhibits the highest extraction efficiency, driven by strong cooperative interactions involving ion-dipole coordination between Cs+ and

Substituent effects in N-acetylated phenylazopyrazole photoswitches

• Radek Tovtik,
• Dennis Marzin,
• Pia Weigel,
• Stefano Crespi and
• Nadja A. Simeth

Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66

• classical azobenzenes. Heterocyclic rings offer, for example, enhanced polarity, electron pairs for metal coordination [27], better water-solubility, and variable pKa [28][29]. Special attention has been given to 5-membered N-heterocyclic azobenzenes, which not only maintain the azobenzenes properties but

Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• . Trimethylsilyl cyanide (TMSCN) has been used as a sacrificial cyanide source. We found that isocyanide (rather than cyanide) is a preferred coordination to calcium during the catalytic cycle, while the active catalyst prefers a side-on coordination of cyanide. The configuration-determining step is a

• conditions. The product was isolated as colorless crystals in good yield of 81% (Scheme 1). Complex 4 crystallizes as a C2-symmetric chiral mononuclear complex in which Ca is bound to two monodentate phosphate ligands (Figure 1). Four MeOH ligands complete the slightly distorted octahedral coordination

• sphere. The phosphate ligands are in cis-position with respect to each other. The structure of 4 shows similarities to that of a BINOL-derived calcium phosphate complex that also crystallizes with four methanol ligands, creating an octahedral coordination sphere with phosphate ligands in cis-position [52

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• interactions and enhanced electronic stabilization through lithium coordination. This explains the critical role of lithium in achieving a high enantioselectivity. Isotope-labeling experiments using 10B-enriched 1,1-diborylalkanes (S)-49 further supported this mechanism, showing a stereoinvertive

• energy compared to (S,S)-TS9. Both transition states demonstrated a lithium center's coordination involving bromide, benzoate, and ligand oxygen atoms. The (S,R)-TS8 transition state exhibited a significantly shorter Li–Br interaction distance (2.81 Å compared to 3.74 Å in (S,S)-TS9), offering

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

• reacts with the enolate of the ketone, which is stabilized by coordination with Fe(III), resulting in the formation of the C–C bond. A further oxidative aromatization process affords compound I. Compared to the protocol developed by Zhang et al. [24], the reaction is less regioselective, as Troger’s base

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• zinc cations to align 1.1 through the formation of hydrogen-bonded coordination complexes. Thus, when a single crystal of the [Zn(bpe)2(H2O)4](NO3)2·8/3H2O·2/3bpe complex was exposed to UV irradiation (dark blue phosphor lamps, λ = 350 nm) for 25 h, only 46% conversion to 1.2 was observed via 1H NMR

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• starts with a single-electron oxidation of 4a on the electrode surface to form cation radical A, in which Br(II) is chelation-stabilized by the carboxyl group [21] and the neighbouring Br substituent [24]. Intermediate A rapidly undergoes irreversible chemical reaction by HFIP coordination to transient

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

• proximal electrostatic potential, even when the charges are flexibly arranged, remote, and solvated in water. Metal-organic cages The exploration of metal-organic cages (MOCs), also known as supramolecular coordination cages (SCCs), as catalysts is thriving [22][36][138][139][140][141]. The reversible bond

• typically not possible for imine [314] or metal-coordination cages [156][202][365]. Further, the robust amide cages could withstand harsh conditions such as ester hydrolysis, allowing access to the key acid-functionalized cages [38] that mimic aspartyl proteases and glycoside hydrolases. Otte has employed

• between a simple, highly symmetrical, often hydrophobic pocket of a typical coordination cage host system and the complex, highly unsymmetrical and largely polar environment of an enzyme active site is a moot point… [since]… the mechanisms which an enzyme utilizes to accelerate chemical reactions are in

Synthesis of new condensed naphthoquinone, pyran and pyrimidine furancarboxylates

• Kirill A. Gomonov,
• Vasilii V. Pelipko,
• Igor A. Litvinov,
• Ilya A. Pilipenko,
• Anna M. Stepanova,
• Nikolai A. Lapatin,
• Ruslan I. Baichurin and
• Sergei V. Makarenko

Beilstein J. Org. Chem. 2025, 21, 340–347, doi:10.3762/bjoc.21.24

• compounds 5a, 5b, 6b, 6c, and 7a. Acknowledgements The physicochemical studies were performed on the equipment of Center for Collective Use ''Physical and chemical methods for the study of nitro compounds, coordination, biologically active substances and nanostructured materials'' at the Interdisciplinary

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• %. Beyond their coordination with transition metals, phthalocyanin ligands also exhibit remarkable photoreactivity in supporting non-metallic central elements. Recent work by Amara et al. highlights the efficiency of silicon-based phthalocyanin complexes in red-light-driven photooxidation processes, marking

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• depicted in Figure 2. The reaction is initiated by formation of the five-membered copper-containing intermediate INT-5 through coordination of Cu(OAc)2 with the N-iminoquinolinium ylide species 5. This process is followed by decarboxylative N–O bond insertion into 4, yielding the N-acyl copper(III

• slightly diminished reactivity (23c and 23d). In addition, poor reactivity was observed with dioxazolones bearing thiophene, implying that the undesired coordination of sulfur to copper reduces the reactivity (23e). Despite the reduced reactivity, excellent enantioselectivity was still maintained. Moreover

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• cooperative intermolecular forces. Zinc ion-induced coordination with the macrocycle and a terpyridinium derivative enabled orthogonal polymerization, as revealed by 1H NMR, DLS, and TEM techniques. In addition, viscosity measurements showed a transition from oligomers to polymers at the critical

• ., metal coordination interactions and hydrogen bonding), providing access to various multiresponsive orthogonal self-assemblies or smart supramolecular polymers [24][25]. For example, the discovery of cucurbit[8]uril complexation in a 1:2 and 2:2 host–guest stoichiometry leads to a wide spectrum of

• coordinating metal ions. In such supramolecular polymers, orthogonal host–guest and coordination interactions are responsible for polymerization. Host–guest complexation and zinc coordination When forming supramolecular polymers, an AB-type monomer, i.e., the guest G2, is supposed to interact with the

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• of analogous substrates demonstrates that a bidentate nitrogen structure and a free N–H group are essential for this transformation. The catalytic cycle begins with the coordination of 8-aminoquinoline 71 to Cu(II) catalyst 74, providing an arylcopper complex 76 (Figure 13). This is followed by a

• enantioselectivity is the introduction of serine-derived bisoxazoline ligands L8 (sBOX). Upon coordination with a copper catalyst, these ligands present second-sphere ester groups, which facilitate the additional stabilization of noncovalent interactions at the penta-coordinated Cu(III) intermediate 82 in the

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• dual activity as a metal catalyst as well as a Lewis acid [8][9][10][11]. However, in many cases, the role of copper is not clear and both activities often work synergistically. In all other cases, copper’s activity is due to the coordination/complexation with unsaturated systems, but it is rarely

• begins with a nucleophilic attack of hydrazine on the aldehyde, activated by the copper salt, to give the corresponding hydrazone XXVIII. Subsequently, the formation of a Mannich-type intermediate XXIX was hypothesized by interaction between the hydrazone and the alkene mediated by Cu(OTf)2 coordination

• , which favors the approach of the reaction centers. It is again a metal coordination that activates the C–C double bond towards an intramolecular reaction to give the tetrahydropyrazole XXX via formation of a C–N bond. The final oxidation in air gives the 4,5-dihydropyrazole 31. Cu(OTf)2 is also capable

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

• Merve Yence,
• Dilgam Ahmadli,
• Damla Surmeli,
• Umut Mert Karacaoğlu,
• Sujit Pal and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

• from certain plant species (Figure 1) [12]. The acenaphthylene-fused thiophene-based heteroarene 3 is another heterocyclic fluoranthene analogue, which was used as an organic semiconductor in transistors [13]. The synthesis and coordination complexes of the acenaphthylene-fused N-heterocyclic (NHC