Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• structures can improve physicochemical and biological properties [19][20][21][22][23][24][25][26][27]. Among these groups, the difluoromethyl moiety has gained considerable attention [28][29][30]. Commonly, it is synthesized by the reaction of a nucleophile with difluorocarbene. However, the generation of

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• amides in moderate three-step yields. Keywords: amine; chirality transfer; [1,3]-proton shift reaction; tetrafluoroethylene fragment; Introduction A fluorine atom has quite peculiar chemical and physical properties compared to others, and hence changes in molecular properties resulting from the

• with a tetrafluoroethylene fragment exhibit significantly different molecular properties compared to monofluorinated, difluorinated, or trifluoromethylated molecules [8][9]. Therefore, more and more tetrafluoroethylenated molecules having a variety of applications, such as bioactive substances (Figure

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• ester was also a suitable substrate for the reaction (Scheme 20, 20p). In addition, the presence of substituents such as hydroxy or chlorine groups on the anthrones had no impact on the reaction (Scheme 20, 20q–t). Chiral coumarins, renowned for their bioactive properties, form the cornerstone of

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• and Suzuki–Miyaura cross-coupling reactions followed by Brønsted acid-mediated cycloisomerisation. The developed methodology tolerates various functional groups and leads to moderate up to quantitative yields of the final products. The impact of different functional groups on the optical properties

• reactions (Figure 1). Polycondensed heterocycles containing a uracil moiety have also been studied in recent years. For example, compound A exhibits antitumor and antimicrobial properties (Figure 2) [66][67]. Compounds A and B are used as starting materials for the synthesis of polyaromatic derivatives of

• other compounds with medicinal or photophysical properties [52][53][54][55]. Compounds A are related to the class of natural products known as coumestans, while B resembles flavins. While the medical potential of coumestans is still the subject of current research, interesting photocatalytic properties

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

• ) derivatives, which possess recognized pharmacological properties [12]. They used sequential reactions catalyzed by palladium and copper. The process involves an initial amination, which can be carried out via either the Buchwald–Hartwig or the Chan–Lam reaction, followed by a palladium-catalyzed

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• parent compounds. Furthermore, fluoroalkenes can be utilized as feedstock for fluoropolymers. Teflon, which is a well-known fluoropolymer with excellent water-repellent and oleophobic properties, is synthesized by polymerizing a monomer called tetrafluoroethylene. As a consequence, convenient and diverse

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

• Kazuki Kobayashi,
• Shigeyuki Yamada,
• Motohiro Yasui and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

• fluorophore 1a and yellow fluorophore 1f Based on our investigation of the PL behavior of PMMA dispersion films containing a mixture of 1a and 1c, we investigated the PL properties of PMMA dispersion films containing a mixture of blue fluorophore 1a and yellow fluorophore 1f (Figure 5). The collected

• 80:20 ratio was also consistent with the corresponding absorption spectrum of 1a (Figure S2h in Supporting Information File 1). This result clearly indicates an energy transfer from 1a to 1f. Next, we evaluated the PL properties of the PMMA film blended in a 95:5 ratio, which had a higher weight

• diphenylacetylene libraries with excellent solid-state luminescent properties, the PMMA dispersion film containing a methoxy-substituted fluorinated diphenylacetylene exhibited dark blue PL, the PMMA film containing a diphenylamino-substituted fluorinated diphenylacetylene exhibited green–yellow PL, and the PMMA

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

• centres are indicative of the FLP’s reactivity [45][46]. Thus, substituents must be selected to ensure a broad spectrum of acidity and basicity of the LA and LB. Different methods for determining these properties have been described in the literature. Because of their easy computation, the proton affinity

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

• -absorbing as well as photo-antioxidant properties via an intramolecular hydrogen transfer [5]. The structure–activity relationship between the substituents of 2-hydroxybenzophenones and their UV-absorption properties has been reported previously [6]. It was concluded that the ability to absorb UV light and

• 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

• earlier, 5-substituted-2-hydroxybenzophenones showed a better photoantioxidant ability, and can be an alternative to the commercially used UV-absorbers. Towards this, the UV absorption properties of the synthesized compounds were evaluated (Figure 6 and Figure S30 in Supporting Information File 1). UV

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

• properties of γ-CD (the largest of the three most abundant native CDs), the main experimental methods applied in this study were differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). By coupling these techniques with density functional theory (DFT) calculations we try to shed some

• ]. Comparison between the CDs: γ-CD vs α- and β-CD Analysis of the binding properties of CDs reveals that these very similar molecules, members of the CD family with six to eight glucose monomers in a ring (α-, β-, and γ-CD) have some common characteristics, but also differ in others. Below we list some

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

• -assembly across many length scales (Figure 1), allowing for the control of properties through not only chemical modifications on the monomer, but also changes to the gelation process [2]. Whilst this tunability is advantageous in that it allows for a wide range of functionality and applications, this also

• gives rise to difficulties in understanding and predicting gel structure and properties [2]. In order to understand the supramolecular structure, a robust characterisation regime is required. A comprehensive work edited by Weiss and Térech discussed in detail the plethora of chemical systems

• use of fluorescence probes should be used in tandem with CLSM. For example, Raeburn et al. showed that the addition of molecular rotors and fluorescent dyes affects the bulk network of self-assembled materials using rheology. The co-packing was observed to alter rheological properties of the materials

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

• as 6-methyluracil (MU), 1,3,6-trimethyluracil (TMU), and pyridine (Py), and the results of the experiments are presented in this article. The hydroxy derivatives of MU and Py, obtained through oxidation followed by acid hydrolysis, possess compelling biological properties, rendering them practically

• spectral properties of HPy (9) are in agreement with those reported in the literature [29]. The most effective catalyst for the pyridine oxidation was found to be РсСо. Its addition to the reaction in the amount of 0.1–0.3 wt % increased the yield of pyridin-2-yl ammonium sulfate (8) up to 78–81% (Table 2

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• was isolated in unchanged form. It should be mentioned that the key step of the studied recyclization is an intramolecular nucleophilic addition of a nitrogen atom at the double bond of the pyranone ring. Comparing the chemical properties of the considered amides and hydrazides it can be assumed that

• . Finally, neutralization of intermediate E by HClconc leads to target product 4. It is interesting to note that chemical properties of the synthesized furanones differ from previously described 3-acetyltetronic acids 2 obtained from the corresponding hydrazides 1. As it was shown in a prior paper compounds

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• electronic and electrooptical properties, various derivatives have been synthesized via peripheral modifications of the triangulenium cations. In particular, various functional units can be introduced at the N-positions of azatriangulenium cations. For example, N-alkyl-substituted triazatriangulenium (TATA

• cations [21]. Moreover, ion-pairing assemblies of 1a+ and the π-electronic receptor–anion complexes as pseudo-π-electronic anions exhibited electric conductive properties [22][23][24][25]. The structures and electronic states of ions directly affect the arrangement of constituent ions in the assemblies

• and resulting properties. Thus, the design and synthesis of ion pairs are important for preparing functional ion-pairing assemblies. In contrast to N-alkyl-substituted TATA+ cations, only a few N-aryl-substituted TATA+ cations have been reported to date [26][27][28][29]. This is probably because the

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

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

• scarcity and diversity, as they need to cover a vast reaction space [26][27]. However, collecting data relevant to chemical reactions represents a significant challenge. While specific molecular properties can be precisely computed using existing simulation methods like quantum chemical calculations

• ]. Most of the existing methods were originally designed for predicting reaction properties (such as activation energy, reaction enthalpy, etc.) or classifying reactions, but they can be potentially adapted for reaction conditions prediction by modifying the output layer of the model. Both global reaction

• of molecules using density functional theory (DFT) calculations, which are computationally expensive and time-consuming [62]. To overcome this challenge, some studies have proposed to pre-generate QM properties datasets and train ML models to serve as fast feature generators for new molecules [16

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• ][41][42][43]. The inhibitory activity of β-lactamases is exhibited by those congeners with a (3R,5R)-configuration, such as clavulanic acid (1), whereas clavams with other configurations are not lactamase inhibitors, although some of these have antifungal or antibacterial properties [35]. In the

• ) dyes commonly employed nowadays in photoredox catalysis [47], was tested in our reaction. This dye was chosen due to its oxidizing properties, and it ranks among the most oxidizing agents within this class of compounds (E1/2[*PC/PC•−] = +1.56 V vs SCE) [48], but it proved ineffective in our reaction

• , enhances charge transfer by stabilizing the mesityl moiety. Conversely, the introduction of tert-butyl groups increases the life time of the excited state [52][53][54][55][56]. As a consequence, the PC IV is a strong oxidant in the excited state and displays unique oxidizing properties (E1/2[*PC+/PC

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

• -tetrahalohexanediols. Conformational analysis and lipophilicities of the latter compounds were determined and trihalogenated alkanes were incorporated into piperidines of pitolisant [23]. This work was an extension of our synthetic routes to multivicinal organofluorines to unveil some of their unique properties [24

• order to decipher the key physical properties of complex pyran inter-halides, we performed 19F NMR analysis of halogenated talose analogues 12–15 (Figure 2). First, all analogues adopt standard 4C1-like conformations. Comparison of the vicinal and geminal coupling constants for each organohalogen

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

• specific properties of the fluorine atom [1][2][3], fluorinated compounds are now present in a wide range of applications, from materials to life sciences [4][5][6][7][8][9][10][11]. In order to propose new molecules with specific properties for targeted applications, the development of new fluorinated

• moieties is an active research field [12]. Among these emerging fluorinated groups, the association of the CF3 moiety with chalcogens is an interesting approach. In particular, the trifluoromethoxy group (CF3O) possesses valuable properties such as electronegativity [13][14], lipophilicity [15][16

• human physiology [30][31]. Moreover, several selenylated molecules have found applications in various fields such as materials or bioactive compounds [32][33][34][35][36][37][38][39][40][41][42][43]. Some selenylated compounds exhibit fascinating biological properties. Despite these separate converging

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• antioxidant properties were determined using the reaction with synthetic radicals, the cupric reducing antioxidant capacity assay, the inhibition process of superoxide radical anion formation by xanthine oxidase, and the process of lipid peroxidation of rat liver (Wistar) homogenates in vitro. Keywords

• neuroprotective, antihypoxic effects, act as antiparkinsonian agents [3][4][5], exhibit antitumor and antibacterial activity [6][7][8], possess antioxidant properties for regulating free radical processes [9][10][11]. The functionalization of polyphenolic compounds by introducing various substituents or

• properties [28]. Anti-tuberculosis activity was identified for 5-substituted 2-mercapto-1,3,4-oxadiazoles [29], 5-substituted-2-[(3,5-dinitrobenzyl)-sulfanyl]-1,3,4-oxadiazoles and 1,3,4-thiadiazoles [30]. Some derivatives of 5-(4-tert-butylphenyl)-1,3,4-oxadiazole-2(3H)-thione showed antiproliferative

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

• ; rearrangement; Introduction Nitrogen-containing organic compounds (sometimes referred to as alkaloids due to their basic properties) are of critical importance in medicinal chemistry because of their unique binding properties to biomolecules [1]. Out of 55 drug candidates, approved by the FDA in 2023, 28 (51

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

• , anticancer, non-steroidal anti-inflammatory, antihypertensive, antipsychotic, anxiolytic and in other pharmaceuticals [3][4][5]. Therefore, considering the diversity of biological properties, development of reliable approaches for the synthesis of new nitrogen heterocyclic systems is a highly urgent goal

• high-energy materials [8][9][10][11][12][13]. Moreover, furazan derivatives possess antiproliferative, antibacterial, antiparasitic and antiviral activity [14][15][16]. On the other hand, furoxans referred to as unique heterocyclic compounds that exhibit NO-releasing properties under physiological

• various diseases [17][18][19][20]. Therefore, due to their NO-releasing abilities, furoxan derivatives also demonstrate anticancer, antiplatelet, antiviral and antiparasitic properties [21][22][23][24][25][26][27][28][29][30][31][32]. Another valuable nitrogen heterocyclic scaffold in medicinal chemistry

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

• discuss the properties and applications of different chemical proteomics linkers with special focus on their fragmentation releasing diagnostic ions and how these may improve the confidence in identified active compound–peptide conjugates. The application of advanced search options improves the

• , the linkers were proposed and designed to mainly facilitate the enrichment of the probe–protein or probe–peptide conjugates and their selective release after enrichment. In this review we would like to highlight the fragmentation properties of the different linkers and resulting ions as the valuable

• , the physicochemical properties are highly similar as well as the mass of the conjugate leading to coelution from LC and cofragmentation during MS/MS. The case study of the adamantane-based probe revealed at least five probe-derived diagnostic ions from labile search, which are summarized in Figure 11B

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• energies of relevant species either via force field or quantum chemical methods to assess the properties of a reaction such as activation energies or selectivity. Irrespective of the degree of automation, in silico calculations are often less time-sensitive than wet-lab experiments and can be used to

• by observing the influence of substituents on a reaction outcome. However, Hammett parameters have shown to not fully describe observed trends. Therefore, complementary representations capturing other properties of a molecule have been derived (vide infra) [28]. While traditional linear free energy

• properties and thus makes it suited towards the accelerated design of chemicals and materials, including organocatalysts [29]. Due to this potential, an increasing number of research groups have used ML to predict and develop new organocatalytic reactions. This review aims to provide a critical overview of

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu₄NBF₄ or electrogenerated acid

• Mizuki Yamaguchi,
• Hiroki Shimao,
• Kengo Hamasaki,
• Keiji Nishiwaki,
• Shigenori Kashimura and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

• Organofluorine compounds have attracted great attention in various fields, such as organic materials and pharmaceuticals [1][2][3], because fluorinated compounds sometimes show specific properties [4]. So far, several methods have been developed for the synthesis of fluorinated compounds. Using nucleophilic

• also been proposed [19][20]. Thus, the synthesis of fluorinated compounds is an active research field. Among these compounds, skeletons bearing CF2 units are important [21][22][23][24], because such molecules can change the physical properties and biological activity. They can also serve as building