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Search for "properties" in Full Text gives 2249 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

  • Cristina Martini,
  • Muhammad Idham Darussalam Mardjan and
  • Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

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  • achieved during the last five years, and classifies them into five categories: synthetic methods, building blocks, scaffolds, biological activities and physical properties. Keywords: Groebke–Blackburn–Bienaymé reaction; multicomponent reactions; heterocycles; imidazo[1,2-a]pyridines; isocyanides
  • on biological activities or photophysical properties (i.e., fluorescence) of GBB adducts. Another advantage is that, by replacing the amidine component (classically 2-aminopyridines) with other heterocycles, different scaffolds are obtained, and this is extremely efficient in diversity-oriented
  • generation of new scaffolds by coupling the GBB reaction with other transformations; d) the study of the biological and pharmacological properties of these fused heterocycles; e) the study of the photophysical properties of the GBB adducts. At the end of this overview, conclusions will be drawn about the
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Published 01 Aug 2024

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

  • Ivana Weisheitelová,
  • Radek Cibulka,
  • Marek Sikorski and
  • Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

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  • artificial systems. Additionally, 5-deazaflavins have emerged as prospective antitumor agents [9][10]. Surprisingly, among the broad family of flavin derivatives, 5-deazaalloxazines have received less attention regarding their photophysical properties, despite their close similarity to the above-mentioned 5
  • -dimethyldichloromethyleniminium chloride and the Vilsmeier reagent, or condensations between o-aminobenzaldehydes and barbituric acid [20][21][23][24][25][26][27]. Neither of these methods allows for the introduction of an aryl substituent into C(5), which confers unique chemical and physical properties on 5-aryldeazaalloxazines
  • of photocatalysts by tuning their redox and photophysical properties. Thus, we successfully developed a one-pot, three-component synthetic method with those substituents in 5-aryldeazaflavins 1 on the deazaisoalloxazine core or on the phenyl ring by condensation of N-substituted anilines, aromatic
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Published 31 Jul 2024

Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

  • Sabyasachi Chakraborty,
  • Eduardo Mayo Yanes and
  • Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

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  • on a range of electronic molecular properties of PASs. Keywords: computational chemistry; database; dataset; π-conjugated; polycyclic aromatic hydrocarbons; polycyclic aromatic systems; Introduction Polycyclic aromatic systems (PASs) – molecules made up of fused aromatic rings – are among the most
  • a PAS’s rings and its various molecular properties remain elusive. Revealing these relationships can deepen our understanding of these systems, as well as pave the way toward efficient and effective design of new functional PASs. Given its breadth and complexity, a natural approach to exploring the
  • PASs and their molecular properties. The first installment, COMPAS-1 [6], contains ~35k cata-condensed polybenzenoid hydrocarbons (cc-PBHs) and has already enabled various directions of investigation, including by training of both interpretable machine [7] and deep learning methods [8], which led to
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Published 31 Jul 2024

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

  • Moisés Alejandro Alejo Hernandez,
  • Katia Pamela Villavicencio Sánchez,
  • Rosendo Sánchez Morales,
  • Karla Georgina Hernández-Magro Gil,
  • David Silverio Moreno-Gutiérrez,
  • Eddie Guillermo Sanchez-Rueda,
  • Yanet Teresa-Cruz,
  • Brian Choi,
  • Armando Hernández Garcia,
  • Alba Romero-Rodríguez,
  • Oscar Juárez,
  • Siseth Martínez-Caballero,
  • Mario Figueroa and
  • Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

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  • Acinetobacter baumannii [26], as supported by the current study. In addition, some lanthipeptides have been shown to have anticancer and immunomodulatory properties [11][27]. A low development of resistance to lanthipeptides has been observed, with nisin being the most well-known case in the food industry
  • properties against S. epidermidis and P. aeruginosa resistant strains and failed to exhibit the same effects against E. coli and C. difficile. As a result, we present the discovery of two new lantibiotics that have demonstrated efficacy in combating both Gram-positive and Gram-negative pathogens. Methodology
  • needed for the biosynthesis of a mature peptide were manually selected. The core peptide sequences of the lanthipeptides were then analyzed using the ProtParam and RiPPMiner tools [5] to calculate their physicochemical properties, such as molecular weight, isoelectric point, and GRAVY score (Table S2 in
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Published 30 Jul 2024

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

  • Samuel M. G. Dearman,
  • Xiang Li,
  • Yang Li,
  • Kuldip Singh and
  • Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

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  • ; fluorobenziodoxoles; halogen bonding; hypervalent iodine; Selectfluor; Introduction An important strategy in the drug discovery process is the incorporation of fluorine into biologically active molecules because fluorine can improve bioactivity and pharmacokinetic properties [1]. Consequently, 22% of all small
  • properties of hypervalent iodine(V) fluorides with hypervalent iodine(III) fluorides 2 and 19a. Supporting Information Crystallographic data (excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre and allocated the
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Published 29 Jul 2024

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

  • Alexander V. Tsygankov,
  • Vladyslav O. Vereshchak,
  • Tetiana O. Savluk,
  • Serhiy M. Desenko,
  • Valeriia V. Ananieva,
  • Oleksandr V. Buravov,
  • Yana I. Sakhno,
  • Svitlana V. Shishkina and
  • Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

Graphical Abstract
  • -4CR proceeds through the formation of an azomethine (Schiff base) in the first stage [39][40]. Therefore, considering the results of our previous work [39] on the nature and properties of azomethines based on β-chlorovinylaldehyde 1 (Figure 1), we decided to study the possibility of using the three
  • Ukraine "Directed synthesis, chemical transformations and properties of new nitrogen-containing heterocyclic compounds" (0122U001857).
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Published 26 Jul 2024

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

  • Adam D. Bass,
  • Daniela Castellanos,
  • Xavier A. Calicdan and
  • Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

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  • cyclic imides. The solid-state structures of the N-phenyl derivatives, determined by X-ray crystallography, reveal changes in packing preference based on the number of aromatic rings in the core. The optical and electronic properties of the title compounds compare favorably with other previously
  • 1,2,5,6- [9][10] and 2,3,6,7-naphthalene diimides (NDIs) have been produced and utilized in electronically active polymers (Figure 1). The linear extension of 1,4,5,8-naphthalene diimide to produce tetracene [11] and hexacene [12] diimides, some with interesting properties such as near-IR absorption, has
  • physical properties. Results and Discussion Synthesis The synthesis of the title compounds is shown in Scheme 1. To obtain a naphthalene core with the requisite 1,2,3,4-tetracarbonyl derivatization pattern, we leveraged the cycloaddition of 1 equiv of aryne percursor 1 with 2 equiv of dimethyl
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Published 25 Jul 2024

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

  • Javier Gómez-Ayuso,
  • Pablo Pertejo,
  • Tomás Hermosilla,
  • Israel Carreira-Barral,
  • Roberto Quesada and
  • María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

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  • piperazinoquinazoline derivatives, a core found in fungal metabolites [25][26], systems with promising antitumour activity [27], as well as dipyrrolopiperazinone derivatives, substructure found in some alkaloids such as dibromophakellin or the palau’amine [28], which possess immunosuppressive and cytotoxic properties
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Published 25 Jul 2024

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

  • Hiwot M. Tiruye,
  • Solon Economopoulos and
  • Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

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  • properties make them privileged structures in medicinal chemistry [2]. Benzoquinone and naphthoquinone can exist as ortho-quinone and para-quinone, with the latter considered more stable [5]. Additionally, p- and o-quinones are formed in metabolism of drugs [6] as well as polycyclic aromatic hydrocarbons
  • their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels can be derived via the oxidation onset potentials as shown in the literature [51]. The electrochemical properties of all products are summarized in Table 5. Individual CVs, with onset potentials
  • indicated, are given in Supporting Information File 1. The optical properties of the PAPs were investigated by UV–vis absorption spectroscopy in 10−5 M solutions in CH2Cl2, as depicted in Figure 1. The UV–vis spectra of these compounds exhibited strong absorption in the region of 250–370 nm. These
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Published 24 Jul 2024

Syntheses and medicinal chemistry of spiro heterocyclic steroids

  • Laura L. Romero-Hernández,
  • Ana Isabel Ahuja-Casarín,
  • Penélope Merino-Montiel,
  • Sara Montiel-Smith,
  • José Luis Vega-Báez and
  • Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

Graphical Abstract
  • is compelling evidence that incorporating a heterocyclic moiety into a steroid can alter its pharmacological and pharmacokinetic properties, driving intense interest in the synthesis of such hybrids among research groups. In this review, we present an overview of recent synthetic methodologies
  • perspective, the incorporation of a spiro fragment significantly impacts the properties of the drug candidate. Introducing a spirocyclic moiety often leads to increased potency and selectivity, as observed in comparisons between spirocycles and their non-spiro counterparts. Furthermore, several examples
  • illustrate that a spirocycle can alter the stability, physicochemical, and pharmacokinetic properties of the structure [9]. In this review, we summarize recent synthetic procedures reported between 2000 and 2023 for synthesizing steroidal spiro heterocycles. The review categorizes the procedures based on the
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Published 24 Jul 2024

A fiber-optic spectroscopic setup for isomerization quantum yield determination

  • Anouk Volker,
  • Jorn D. Steen and
  • Stefano Crespi

Beilstein J. Org. Chem. 2024, 20, 1684–1692, doi:10.3762/bjoc.20.150

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  • εtrans/εcis is the highest, results in the formation of >95% cis-azobenzene [17]. The quantum yields (Φ) of isomerization of this process have been determined using different irradiation wavelengths, solvents, and methods [18][19][20][21][22][23][24]. One of the most interesting properties of azobenzene
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Published 22 Jul 2024

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

  • Maria-Paula Schröder,
  • Isabel P.-M. Pfeiffer and
  • Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

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  • the founding member of this RiPP class. It is biosynthesised by Omphalotus olearius and has nematocidal properties. In types I through III of borosins, the precursor peptide is fused to the MT domain; OphMA designates the fused precursor-MT from the omphalotin A BGC (Figure 7). After auto-modifying
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Published 18 Jul 2024

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

  • Fátima C. Teixeira,
  • António P. S. Teixeira and
  • C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

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  • -triazinephosphonate (TPs) derivatives. The evaluation of the proton conduction properties of the new membranes and relative humidity (RH) conditions and at 60 °C, showed that they present higher proton conductivities than the prepared Nafion membrane and similar or better proton conductivities than commercial Nafion
  • structural properties of the membranes restrain their stability and durability, their humidity and temperature application conditions, and their efficiency and consequently, the performance of fuel cells or eletrolysers [18][19]. Many organic polymers with acidic functional groups have been developed as
  • conduction properties of new membranes were evaluated by electrochemical impedance spectroscopy (EIS) at 60 °C at different relative humidity (RH) conditions. The results showed higher proton conductivities than recast Nafion membrane and similar or better proton conductivities than commercial Nafion N115
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Published 17 Jul 2024

pKalculator: A pKa predictor for C–H bonds

  • Rasmus M. Borup,
  • Nicolai Ree and
  • Jan H. Jensen

Beilstein J. Org. Chem. 2024, 20, 1614–1622, doi:10.3762/bjoc.20.144

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  • combination with an ML model to predict a variety of properties. These properties encompass the site of metabolism [31][33], the strengths of hydrogen bond donors and acceptors [34][35][36], and the regioselectivity of electrophilic aromatic substitution reactions [14]. Building on the methodology from
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Published 16 Jul 2024

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

  • Evgen V. Govor,
  • Vasyl Naumchyk,
  • Ihor Nestorak,
  • Dmytro S. Radchenko,
  • Dmytro Dudenko,
  • Yurii S. Moroz,
  • Olexiy D. Kachkovsky and
  • Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

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  • performance in the parallel GBB reaction. (Hetero)aromatic aldehydes 2{1–6} illustrating electronic and steric effects on the parallel GBB reaction. Physicochemical properties of the chemical space of 271 Mln. members obtained by virtual GBB reaction (MW – molecular weight; HAcc/HDon – H-bond acceptor/donor
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Published 16 Jul 2024

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

  • Ka-Lung Hung,
  • Leong-Hung Cheung,
  • Yikun Ren,
  • Ming-Hin Chau,
  • Yan-Yi Lam,
  • Takashi Kajitani and
  • Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

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  • are available. UV-light-driven supramolecular transformations on a macroscopic length scale were pioneered by Leung and Feringa [42][43]. Besides, we recently reported the first indigo amphiphiles in fabrication of macroscopic soft scaffolds with photoshrinking properties as a smart functional cell
  • , Figures S13–S33. Photochemical properties of DAn in organic medium The photochemical properties of DAn were first studied in organic solvent by UV–vis absorption spectroscopy. The synthesized DA11 in THF solution (20 µM) showed a strong absorption band at 470–685 nm in the UV–vis absorption spectrum
  • reversibility of the other compounds, DAn with shorter alkyl linkers were also examined in THF solvent by UV–vis absorption spectroscopy, where they showed photochemical properties similar to those of DA11 (Figure 1a and Figure 1b). THF solutions of DA7 and DA6 showed a strong absorption band at 470–685 nm
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Published 15 Jul 2024

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

  • Ana Flávia Candida Silva,
  • Francisco A. Martins and
  • Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

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  • pervade biochemistry in peptides and proteins. The chemical and biological properties of substituted pyrrolidine derivatives, along with many other compounds, hinge on the relative stereochemistry. It is well established that the presence of fluorine in an organic molecule can significantly influence the
  • stereochemical behavior. Consequently, various molecular properties, such as polarity, viscosity, and intra- and intermolecular interactions, are impacted by the C‒F bond. These features underlie the important role of selective fluorination in pharmaceuticals and agrochemicals development [1]. For instance
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Published 12 Jul 2024

Benzylic C(sp3)–H fluorination

  • Alexander P. Atkins,
  • Alice C. Dean and
  • Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

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  • driven largely by the beneficial effects of including fluorine into bioactive molecules. These advantages include the modulation of potency, bioavailability and physical properties of drug and agrochemical compounds [1][2][3]. The significance of fluorination is reflected in the fact that a large number
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Published 10 Jul 2024

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

  • Yukang Wang,
  • Yan Yao and
  • Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

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  • , the incorporation of pyridyl groups that are commonly found in pharmaceutically active compounds are also possible (8). In general, the catalytic efficiency of this new electrophotochemical protocol was found to be relatively independent of the electronic properties of the aryl substituents and the
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Published 03 Jul 2024

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

  • Yu Fan,
  • Ahmed El Rhaz,
  • Stéphane Maisonneuve,
  • Emilie Gillon,
  • Maha Fatthalla,
  • Franck Le Bideau,
  • Guillaume Laurent,
  • Samir Messaoudi,
  • Anne Imberty and
  • Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

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  • possess excellent photophysical properties and strong affinity for targeted LecA with Kd values in the micromolar range. Analysis of the thermodynamic contribution indicates that the Z-azobenzene isomers have a systematically stronger favorable enthalpy contribution than the corresponding E-isomers, but
  • photomodulating chemical, biological or pharmacological activities or properties [11][12]. Light is generally noninvasive and orthogonal toward most elements of living systems. It can be easily and precisely controlled in time, location, wavelength, and intensity, thus enabling the precise activation and
  • deactivation of biological function. It also offers the potential to change the properties of defined molecules in biological systems with minimal disturbance to the rest of the system. Photoswitchable ligands, i.e., the incorporation of light-responsive moieties into a drug-like molecular structure, allow
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Published 03 Jul 2024

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

  • Lu Li,
  • Na Li,
  • Xiao-Tian Mo,
  • Ming-Wei Yuan,
  • Lin Jiang and
  • Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

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  • good yields. The electronic properties of the substituents, irrespective of their positions on benzylamines, displayed no substantial disparity on the reaction outcomes, leading to the formation of 4ab–ap in 50–80% yields. Both the heteroarylmethylamines and sterically hindered α-methylbenzylamine
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Published 02 Jul 2024

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl2 and NH4SCN/KSeCN

  • Jialiang Wu,
  • Haofeng Shi,
  • Xuemin Li,
  • Jiaxin He,
  • Chen Zhang,
  • Fengxia Sun and
  • Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

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  • ; thiocyanation; thiocyanogen chloride; Introduction Pyrazoles and their derivatives are an important class of five-membered heterocyclic compounds [1][2][3][4][5] that have drawn increasing attention from organic chemists, due to their potential biological and pharmaceutical properties including anti
  • -ranging biological activities. Specifically, representative examples include fasicularin (IV, Figure 1), which possesses cytotoxic properties [21] and psammaplin B (V, Figure 1), which shows antimicrobial and mild tyrosine kinase inhibition activities [22]. In addition, Se-aspirin (VI, Figure 1) has been
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Published 28 Jun 2024

Predicting bond dissociation energies of cyclic hypervalent halogen reagents using DFT calculations and graph attention network model

  • Yingbo Shao,
  • Zhiyuan Ren,
  • Zhihui Han,
  • Li Chen,
  • Yao Li and
  • Xiao-Song Xue

Beilstein J. Org. Chem. 2024, 20, 1444–1452, doi:10.3762/bjoc.20.127

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  • DFT calculations for predicting key properties of organic molecules such as BDE, nucleophilicity, and electrophilicity [48][49][50][51][52][53][54][55][56][57][58][59][60]. Recently, applications of the Elastic Net model with Avalon fingerprints [55] and the deployment of artificial neural network
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Published 28 Jun 2024

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

  • Nicole Javaly,
  • Theresa M. McCormick and
  • David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

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  • attention from periodic trends in XB length to periodic trends in XB strength. The σ-bond oriented 180° relative to the halogen bond plays a central role in tuning the halogen bond properties [1][2][3][4]. Indeed, it impacts the size of the σ-hole (Vs,max), and the energy of the σ* orbital has been shown be
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Published 27 Jun 2024

Challenge N- versus O-six-membered annulation: FeCl3-catalyzed synthesis of heterocyclic N,O-aminals

  • Giacomo Mari,
  • Lucia De Crescentini,
  • Gianfranco Favi,
  • Fabio Mantellini,
  • Diego Olivieri and
  • Stefania Santeusanio

Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123

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  • imidazole and pyrazine pharmacophores, are well represented in the area of medicinal chemistry since they possess pharmacological properties as mammalian target of rapamycin (mTOR) inhibitors [7], adenosine triphosphate (ATP) competitive inhibitors of the insuline-like growth factor 1 (IGF-1) receptor
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Published 26 Jun 2024
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