Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• spectra [1]. Moreover, the ethylene bridge creates a cyclic 8-membered core, inverting the thermodynamically stability in favor of the Z boat conformation compared to parent azobenzene, which has a stable E configuration [1][2][3][4]. Preceding studies including azobenzene-based photopharmacophores showed

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

• (CS) conformation consistent with C5 (Figure 8A) [39]. This low-symmetry cage 3e was designed by taking advantage of the geometric rules discovered studying cage 1. We have introduced the term conformational autodesymmetrization to describe this rational approach to accessing low-symmetry cavities [39

• low-symmetry conformation of cage 3 in solution [39]. Due to their stability, we can typically reclaim our cages up to quantitatively after binding or catalysis experiments, often just via a work-up and precipitation. This breadth of available data opens considerable opportunities in computational and

• (increased flexibility) (Figure 9B) [41]. The ability to tune catalytic activity by tuning the cage rigidity, conformation, or dynamics is certainly an advantage rather than a liability [395][398][399][400][401][402]. It is perhaps unsurprising that the balance of rigidity and flexibility [403][404

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• in the subsequent nucleophilic attack by the acceptor [137]. This α-glycosyl triflate was readily converted to its skew-boat conformation 62 which led to the attack of the glycosyl acceptor 64 from the β-face of the sugar pyranoside ring exclusively to form the 1,2-trans glycoside 65. Thus, the N

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

• crystal of 5b (Z’ = 3), contains 3 independent molecules, the crystals of 6c and 7a (Z’ = 2) contain 2 independent molecules, with all independent molecules having similar conformation and equivalent geometric parameters within the experimental error limits. The crystallographic data of the structure are

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• analysis oversimplified the system by neglecting to account for potential contributions from different conformers possibly involved in HB interactions. To rectify this problem, we searched for two possible structures for each Me3PO–HB donor pair, where the HB donor adopts a different conformation in each

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

• adopted a nonplanar conformation, with one aromatic residue protruding out of the macrocyclic skeleton plane. Adopting such a conformation rendered it possible for the π-electron-rich phenyl ring to interact strongly with π-electron-deficient guest molecules G1 by means of charge–transfer interactions and

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• yellow crystals from the same solution. X-ray crystallography reveals that in the colorless crystal [27], compound 1 adopts a conformation with approximate Cs symmetry, with the plane of symmetry (σ) shown in the top view in Figure 2a. The structure of Cs-1 in this crystal is essentially the same as that

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

• Radell Echemendía,
• Carlee A. Montgomery,
• Fabio Cuzzucoli,
• Antonio C. B. Burtoloso and
• Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

• analysis. The geometries of starting materials 1a and 2a’ were pre-optimized in the solvated phase using Gaussian 16 at the PBE0/def2-TZVP/def2-TZVPD level of theory, after a conformation search using Crest [43][44][45][46][47][48][49]. Next, the electrostatic potential map of the iodonium ion 2a’ was

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• intramolecular Michael addition. Preliminary conformational studies on tripeptides including this scaffold in the central position show an extended conformation in solution (NMR) and in the solid state (X-ray). Keywords: fluoroalkyl groups; heterocycles; hydrazino acids; peptides; tetrahydropyridazines

• strategy, the control of the stereoselectivity of the intramolecular aza-Michael addition could be envisaged with various chiral catalysts in further studies. These heterocyclic hydrazino acids, when incorporated into the peptidic structure, appear to confer an extended conformation. These interesting

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

• adopts a 1,3-alternate conformation and binds simultaneously to the epoxide O-atom and iodide anion via (NH···O and NH···I) hydrogen-bonding interactions. The TBA countercation is bound to the O-atom of the epoxide ring with hydrogen bonds and is situated away from the I− anion. This crucial transition

• ]pyrroles, and at the same time their conformation is rigid due to the presence of sp2-hybridized carbon bridges between the pyrrole units and alkyl groups on two of the inner N atoms of the macrocycle [64][65][66]. Among the OxP derivatives tested for organocatalysis (48a–i and 49a–i), only N-dialkylated

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• and acceptor groups arranged in a specific sequence, such as in D–π–A chromophores. This creates the conditions for efficient intramolecular charge transfer (ICT), which plays a key role in the DSE phenomenon. Also, additional substituents can affect the geometry and conformation of the molecule

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• -fluorinated analogs [38]. It is anticipated that the introduction of a CF2 could eventually stabilize the conformation of the six-membered ring via stereolectronic interactions of the CF σ* orbitals with the neighboring CH σ orbital [40]. The 180° FCCH dihedral would rigidify the six-membered ring. We present

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• single-crystal X-ray analysis were obtained by slow evaporation of a dichloromethane/isopropanol solution of 3b. The crystal structure of 3b, displayed in Figure 4, shows a very similar twisted conformation of the core of the molecule to that of the related methoxy-substituted structure obtained from

• dihydroxyviolanthrone. Chemical structures of 2b and 3b. Optimised ground state geometries of compounds 2 and 3 calculated using B3LYP/6-311G(d,p) in the gas phase. Views of the crystal structure of 3b (left, shows displacement ellipsoids drawn at 50% probability level, right showing the twisted conformation

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• (4a) initially resulted in the glycosylation of the oxygen atom to give intermediate A (−20 °C, 1.5 h). Extension of the reaction time (20 °C, 12 h) afforded N-indigoglycoside 5a which was isolated in 35% yield. The product contained an α-rhamnosyl moiety with 4C1 conformation. The formation of the

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

• inhibitor conformation found by docking is energetically unfavorable and therefore the expected activity of compound 5e will be much lower than that of compounds 4a–e. Molecular docking data can therefore be used to infer the structure–activity relationship. The substituent on the C-5 atom of

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

• were determined. All structures were investigated using the NSD method [8][9], which allows a quantification and visualization of distortion modes. It can be observed from the crystal structures that the porphyrins’ rings all exhibit the typical saddle-shaped conformation. Interestingly, substitution

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

• (Figure 1): (1) facing inward into the cavity, which creates a belt of hydrogen bonds (the so-called “head–tail” arrangement, “closed” conformation). Notably, in this way, the size of the cavity vestibule is significantly reduced and in the second way (2) they are directed outside the cavity, thus

• G09 package. The PyMOL software was used to create molecular graphics images [32]. Chemical structure of γ-CD (A); M062X/6-31G(d,p) optimized conformers of nonhydrated γ-CD in two projections – side view (B) and top view from O6 side of the truncated cone (C). The "closed" conformation is with

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• -shaped conformation it precipitates out of solution acting as a thermodynamic sink [5][6]. Shortly after, Cram et al. recognized the potential of resorcin[n]arenes as compounds large enough to encapsulate other simple molecules or ions and group them with other known macrocyclic arene compounds, e.g

• , chlorinated species 1h and 1i, and carboxylic acid-containing 1s, developed high quality crystals from standing solutions in dimethyl sulfoxide for 1h and 1i, and methanol for 1s. Their molecular crystal structures were determined and are shown in Figure 1b displaying the classic cone conformation for both

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• and nonbonding interactions for the halogen at C4. Finally, density functional theory (DFT) calculations corroborate the preference of talose analogues to adopt a 4C1-like conformation and a natural bonding orbital (NBO) analysis demonstrates the effects of hyperconjugation from C–F antibonding

• orbitals. Keywords: organofluorine; pyran inter-halide; solid-state conformation; solution-state conformation; Introduction Polyfluorinated pyran analogues of carbohydrates have attracted attention over the years. This class of glycomimetics has great biological potential with useful applications [1][2

• ][25][26][27][28][29][30], such as the solution-state conformation of diastereomeric polyfluorohexitols [31]. Herein, we report the synthesis of pyran inter-halide analogues of ᴅ-talopyranose 6, integrating also the 2,3-cis, 3,4-cis relationship for the halogens, from known intermediate 5 (Figure 1b

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• ], electronic effects [17][18], and conformation [19][20][21]. Some trifluoromethoxylated molecules can be used as drugs in the treatment of various pathologies (Figure 1) [22][23][24][25][26][27][28][29]. On the other hand, despite its toxicity at higher doses, selenium is also an essential trace element in

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• -methylcrotylsilane (product 52) and disubstituted cyclic silanes (such as the silane, leading to 53), locked in syn-conformation. For the 2,3-disubstituted allylation products such as 52 and 53, the diastereomeric ratio spanned across 18:1 to >50:1. Notably, all 2,3-disubstituted silanes required an increased

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• catalyst closer to the support, impacting electronic properties and ligand conformation. With large catalyst molecules, the pores of an ordered mesoporous material being similar in size to the catalyst can create significant diffusion barriers as the catalyst attempts to enter the pores. As a result, the

• covalent bonding. These adsorptive interactions can alter the electronic properties and conformation of the supported organocatalyst, thereby influencing its catalytic activity compared to its homogeneous counterpart. For instance, Fotaras et al. showed that the incorporation of a tripeptide-like

Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

• , depending on the values adopted by the torsional angles around the glycosidic linkages [10]. The high variability of linkages type, branching, stoichiometry, anomeric configuration (alpha and beta), and conformation contributes to the intricate nature of glycans. The complexity of the glycome is even higher

• only by their chemical composition but also by their conformation. As mentioned above, glycans are characterised by a huge conformational diversity (see Figure 1): even individual furanoid or pyranoid monosaccharides can assume various shapes and in longer glycans the relative orientation of the

• design and discovery providing access to physics-based molecular modelling tools and machine learning technologies from a single modelling environment, however, it is not free-accessible. Further valuable insights into the structure and conformation of saccharides, determined by experiment and simulation

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• ) that contains mostly Z isomers. This can be reversed using blue light or heat in a process that is stable over many cycles [7]. Isomerisation of azobenzene leads to a change in its conformation and polarity which, when combined into a surfactant molecule, modifies the resulting molecular geometry and

• . It should be noted that a lag between the time taken to reach the PSS and the time for the new micelle morphology to form is expected. This is due to the additional time that is required for diffusion and reassembly of the AzoTAB in the Z conformation into the new equilibrium structure [22]. The

• , Supporting Information File 1). This morphology change can be attributed to two changes in the AAPTAB on E–Z isomerisation [19]. Firstly, the shape change of the AAPTAB to the bent, “T-shape” conformation prevents the π–π stacking which was previously possible in the more planar, E isomers that were arranged