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

• found. We thus suspect that the substituents play a crucial role in in the population of the respective exited state and we can at this state not rule out a contribution also from the triplet state. Moreover, we could not find a quantitative correlation between the R-substituents and ΦE→Z, however, some

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

• as the cathode and changed the anode electrode to find the best efficiency. The platinum plate electrode is more suitable than felt due to its larger contact surface, and using graphite electrodes in the form of a rod had good efficiency. The best results were obtained using a RVC electrode as the

• functional groups and can help to find new drug candidates. The reaction was carried out in an undivided cell where the anode was platinum, and the cathode was graphite at a constant current of 5 mA. The mechanistic study showed that a radical process might be involved in the reaction, and the role of

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• according to the results of 1H NMR dilution experiments. The molecular recognition behavior of the hosts C1 and M1 toward a panel of seven ammonium ions was explored by 1H NMR spectroscopy and isothermal titration calorimetry (ITC). We find that C1 generally binds slightly more tightly than M1 toward a

• out the effect of chain length by a comparison of Me6PDA with Me6HDA. We find that the longer and more hydrophobic Me6HDA guest binds 1.92-fold stronger to C1; similarly, Me6HDA binds 2.25-fold stronger to M1. These differences are likely due to the increased hydrophobicity of the additional CH2 group

• . Finally, we can compare the binding of the primary ammonium versus the corresponding quaternary ammonium ion guest toward C1 and separately M1. We find that C1 binds the quaternary ammoniums somewhat stronger: Me6PXDA vs PXDA (1.72-fold), Me6CHDA vs CHDA (2.42-fold), Me3AdA vs AdA (4.59-fold). A similar

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• directly to target cells via the antibody without affecting normal, healthy tissue. Importantly, the use of antibodies in modern medicine is not restricted solely to ADCs and cancer therapy. For example, mABs now find routine use in the context of radionuclide (PET) imaging agents, informing therapeutic

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

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

• of the biological activity and to find biomedical applications, different releasing systems of this anion are developed. The peroxynitrite anion is formed by coupling of nitric oxide (NO) and the superoxide (O2•−). An efficient system has been developed to realize this reaction (Scheme 16) [74]. In a

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• investigated nucleophilic substitution reactions of various N- and P-containing nucleophiles to MBH carbonates of isatins. It is interesting to find that diverse functionalized 3-substituted oxindole derivatives were successfully prepared in satisfactory yields and with high diastereoselectivity. In addition

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• prediction of thermal back reactivity. Moreover, we attempt to find the optimal functional for achieving a high correlation with experimental values by DFT calculation. Results and Discussion Photochromic properties in n-hexane Compounds N1–N3 were synthesized according to the procedures described in the

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

• Yujun Pang,
• Jinglan Yan,
• Nawaf Al-Maharik,
• Qian Zhang,
• Zeguo Fang and
• Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

• aryldifluoromethylation/cyclization reaction (for details about optimization conditions, please see Supporting Information File 1). We were delighted to find that when 2-fluorophenylacetic acid was employed as the fluorine source, a wide range of benzimidazole substrates were also compatible with this reaction. For

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• , the optimization of chemical reactions has been performed by manual experimentation guided by human intuition and through the design of experiments where reaction variables are modified one at a time to find the optimal conditions for a specific reaction outcome. Recently, a paradigm change in

• stirred tank reactor (CSTR) cascade. The platform allowed to showcase the autonomous optimization to find the ideal reaction conditions for Suzuki–Miyaura and photoredox-catalyzed coupling reactions. A plug-and-play, continuous-flow chemical synthesis system (Figure 6a) was intelligently designed by

• been performed based on DOE methodologies, with the objective of maximizing the yield of the reaction product. However, these techniques are not well suited to find the global optimal conditions and scale exponentially with the number of variables. Computational approaches that rely on optimization

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

• with porphyrins, the direct linkage between their pyrrole units leads to a more contracted cavity compared to that of porphyrins. Similar to calix[4]pyrroles, synthetic metallo- and free-base (metal-free) porphyrins find various applications in the fields of medicine, energy, catalysis, molecular

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• for nutrient and space, and that “chemical weapons” of this sort are widespread in nature. Waksman used the BGF workflow to find more than 20 new antibiotics throughout his career, wherein microbial culture extracts were fractionated and then tested for antimicrobial activity. The active fractions

• definition) identical; they must act on the same cellular target and display the same bioactivity. It is not necessarily the case the other way around for bioactivity. However, bioactivity has long been used as a proxy to help find new natural products, whose chemical structure is typically determined after

• progress is in fact due to our inability to interpret the corresponding genetically encoded biosynthetic instructions. While scientists will undoubtedly find more applications of AI, its strongest suit is arguably to help humans find hidden patterns in bulk data, such as the many bits and pieces of

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

• qualitative comparison of the guest binding tendency was accomplished by 1H NMR competition experiments to find out about the selectivity of the new receptor and to circumvent the drawback that no binding constants for longer dicarboxylates could be determined. Therefore, the behavior of [L2Zn2] with

• fashion with an included lever to control the selectivity by an external stimulus. Additionally, the clear take home messages from recent conferences paired with the latest insights from working with such charge-neutral hosts in the laboratory show that one major task is to find a solution for the so far

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• mentioned above, spanning diverse areas of modern synthesis and catalysis. We hope that you will find them beneficial, enlightening, and stimulating. The 6th International Symposium on Synthesis and Catalysis (ISySyCat2025) will take place at the University of Coimbra from September 2–5, 2025 (https

Computational design for enantioselective CO₂ capture: asymmetric frustrated Lewis pairs in epoxide transformations

• Maxime Ferrer,
• Iñigo Iribarren,
• Tim Renningholtz,
• Ibon Alkorta and
• Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

• find the most efficient catalyst for a given reaction [26][57]. They are a valuable tool for the in silico design of catalysts [27][58]. Volcano plot analysis requires a set of reactions that follow the same mechanism but whose stationary points possess different energies. Generally, the larger the

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• very weak estrogenic activity [8]. Although a detailed SAR is still warranted, the initial reports prompted us to find a suitable synthetic method for 5-substituted 2-hydroxybenzopheneones, and to evaluate their UV-absorbing properties. Various methods for the synthesis of benzophenones have been

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

• cavity is quite full with 7 water molecules incorporated into it. It can be assumed that the number of H-bonds is optimal in γ-CD–7H2O (the complex with seven water molecules) and that when further water molecules are added, not all of them find a suitable position to form a hydrogen bond with the host

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• as sun light, as a greener approach and easily available biomass-derived furfuryl alcohols as starting materials. The flow platform with the developed protocol was utilized successfully to make several dihyropyranones that may find wide applications in medicinal and materials chemistry and natural

Machine learning-guided strategies for reaction conditions design and optimization

• Lung-Yi Chen and
• Yi-Pei Li

Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212

• previously reported conditions for the same or similar reaction types and conduct several experimental trials to evaluate the resulting reaction yields. However, this empirical approach is unlikely to find the optimal conditions, since the reaction outcome depends on a large and complex combination of

• optimization of general reaction conditions as a multi-armed bandit problem, where each set of reaction conditions is a slot machine, and each experiment is a round of playing on one of these machines. The challenge is to find the slot machine with the highest win rate using a limited number of rounds. For

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

• tetracarboxylic acid head group and short-to-long aliphatic tails from ethyl to n-undecyl may find applications in the development of novel materials, e.g., as ligands in nanoparticle synthesis. We were surprised to find out that 2-iodoresorcinol did not produce the desired resorcin[n]arene. Repeated experiments

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

• , ECPM, Strasbourg, France CPE Lyon, Lyon, France 10.3762/bjoc.20.207 Abstract Trifluoromethoxylated molecules and selenylated compounds find a wide range of interesting applications, but separately. In order to combine the potential of these two motifs and to propose a new class of compounds, we have

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• indicated DMSO as the best for the attainment of high yields and diastereoselectivity (entries 1–5 vs 6 in Table 4), we further examined bases in this solvent to find out that t-BuOK behaved nicely, and the reaction of 2b with 2.0 equiv of diethyl malonate for 0.5 h at room temperature furnished 93% yield

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• pharmacological properties and may find application in the design of new promising medications. Herein, we present a convenient synthetic approach for the preparation of previously unknown [1,2,5]oxadiazolo[3,4-d][1,2,3]triazin-7(6H)-one heterocyclic systems containing both a furoxan/furazan fragment condensed to

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• identification rates and may help to identify otherwise difficult to find interactions between active compounds and proteins, which may result from unperturbed conditions, and thus are of high physiological relevance. Keywords: chemical proteomics; diagnostic ions; mass spectrometry; target identification

• spectrometry-based chemical proteomics represents a robust method for the identification of NP protein targets, in some cases, the synthetic effort associated with the above-described SAR study to find a functional NP probe might outweigh the advantages of this approach. Considering a complementary strategy

• -improving search algorithms to find a new features and probe–protein interactions. Automatization of chemical proteomics workflows The increased throughput and less hands-on time during the chemical proteomics workflows led recently to a number of protocols, which either multiplicate the sample preparation