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

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• firstly through the coordination of an alkene by the HVI reagent, which activates it toward intramolecular attack by an internal nucleophile. Following this, substitution of the iodane(III) can occur from the nucleophilic halide in solution to reveal the halo-cyclised product (Figure 2). In this review

• ) whereby AgBF4 first activates the fluoroiodane 12 for alkene coordination. Intramolecular nucleophilic attack of oxygen on the more substituted carbon forms the cyclised intermediate A and eliminates fluoride. Phenonium intermediate B is formed with elimination of the iodoarene and subsequent attack of

• activated after coordination to PhI(OAc)2, then intramolecular nucleophilic attack from oxygen and nucleophilic attack by bromide forms the final product. NMR studies of PIDA and the substrate indicated that there was no interaction between them, thereby discounting this second pathway and thereby providing

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• batteries, due to the ease of their structural modification, rich redox chemistry, and robust coordination M–N4 environment [100][101][102][103][104][105]. The key processes employed in energy transfer and storage are the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• such stimuli. When the rotaxane motif contains cyclophane or a crown ether, stimuli induced by a transition metal or an electrostatic interaction have been widely used. These interactions are easily controlled, and they induce relatively strong coordination interactions among the components, making

Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

• David Ocklenburg and
• David Van Craen

Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250

• positively charged or charge-neutral, is their metal-driven self-assembly. Unfortunately, this can also be their Achilles' heel, as the underlying coordination bonds are fragile compared to covalent bonds. For example, metallocages can easily break apart by the addition of competitive anions which are highly

• ligand resulted in no clean formation of a charge-neutral metallocontainer with zinc(II) acetate. We believe that the modification with benzoyl chloride does not only alter the solubility but also shields the secondary amine which might act as additional coordination site. Binding of monocarboxylate

• ] receptor because the modification seems to decrease the zinc–zinc distance and the cavity size substantially enough to prevent coordination of monocarboxylates to both zinc centers due to their sterical demand. Average binding constants of log K = 3.44 for acetate and log K = 3.33 for benzoate were

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• method of controlling fungal infections. The mechanism of inhibition of azoles and their derivatives is based on the formation of a coordination bond between their heterocyclic nitrogen atom, which carries an unshared electron pair, and the haem iron atom. The formation of this bond leads to inhibition

• compounds 4a–e and 5a–e to CYP51 and to evaluate which of these molecules could act as inhibitors of the enzyme. As mentioned above, CYP51 inhibitors contain a heterocyclic nitrogen atom that forms a coordination bond with haem iron. Therefore, only those compounds that could form such a bond according to

• fingerprints (IFP) between the docking ligands and the protein shows that, similar to the reference ligand voriconazole, the compounds interact with the protein through hydrophobic interactions with hydrophobic residues of the protein and the formation of coordination bonds with the haem iron (Table 3). At the

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• , even with Ni(II) metalation. There are many other methods available to achieve different desired atropisomeric ratios. These include thermal enrichment [67][68], photoracemization [69][70], axial-ligand coordination [71], precise separation techniques [50] or a combination of the procedures mentioned

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

• Stiliyana Pereva,
• Stefan Dobrev,
• Tsveta Sarafska,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

• -CD–nH2O (n = 2–7) constructs. Similar results had been obtained for the positioning of the first water molecule hosted by the smaller α- and β-CD counterparts [13][14]. The calculations indicate that water coordination to the narrow rim results in creating two new H-bonds between the CD host and the

• guest water molecule at the expense of destroying one hydrogen bond from the initial γ-CD structure. It should be noted that coordination of water to the wide rim (construct d) creates two new H-bonds between the CD host and the guest water molecule and one H-bond between secondary OH-groups of γ-CD

• sequential coordination of the water guests. The resulting supramolecular architecture, composed of CD and interconnected water molecules, is stabilized by hydrogen bonds between the water molecules and CDs. The pattern previously observed for α- and β-CD hydration is fully relevant for γ-CD: the hotspot of

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• ][19][20]. The catalytic activity of metallophthalocyanines originates from their planar, cyclic structure with a developed π-conjugation system. This makes the fifth and sixth coordination sites of the central metal ion available for coordination with the reactant molecules of the catalytic reaction