jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ana G. Neo | José Luis Ramiro | María García‐Valverde | Jesús Dı́az | Carlos F. Marcos
Source: Molecular Diversity (review, 2023-04-12)
Field: Chemistry — Organic Chemistry

Stefano Marcaccini: a pioneer in isocyanide chemistry Stefano Marcaccini was one of the pioneers in the use of isocyanide-based multicomponent reactions in organic synthesis. Throughout his career at the University of Florence he explored many different faces of isocyanide chemistry, especially those geared towards the synthesis of biologically relevant heterocycles. His work inspired many researchers who contributed to other important developments in the field of multicomponent reactions and created a school of synthetic chemists that continues today. In this manuscript we intend to review the articles on isocyanide multicomponent reactions published by Dr. Marcaccini and analyse their influence on the following works by other researchers. With this, we hope to highlight the immense contribution of Stefano Marcaccini to the development of isocyanide chemistry and modern organic synthesis as well as the influence of his research on future generations. We believe that this review will not only be a well-deserved tribute to the figure of Stefano Marcaccini, but will also serve as a useful inspiration for chemists working in this field. Isocyanide ; Tribute ; Chemistry ; Nanotechnology ; Organic chemistry ; Political science ; Materials science ; Law Multicomponent Synthesis of Heterocycles ; Synthesis and biological activity ; Bioactive Compounds and Antitumor Agents
Authors: Lin-Qiang Li | Jian‐Qiang Zhao | Yanping Zhang | Yong You | Zhen‐Hua Wang | Zhen-Zhen Ge | Ming‐Qiang Zhou | Wei‐Cheng Yuan
Source: Molecules (article, 2023-07-13)
Field: Chemistry — Organic Chemistry

Diastereoselective Formal 1,3-Dipolar Cycloaddition of Trifluoroethyl Amine-Derived Ketimines Enables the Desymmetrization of Cyclopentenediones In this research, a metal-free diastereoselective formal 1,3-dipolar cycloaddition of <i>N</i>-2,2,2-trifluoroethylisatin ketimines and cyclopentene-1,3-diones which can efficiently lead to the desymmetrization of cyclopentene-1,3-diones is developed. With the developed protocol, a series of tetracyclic spirooxindoles containing pyrrolidine and cyclopentane subunits can be smoothly obtained with good results (up to 99% yield and 91:9 dr). Furthermore, the methodology can be extended to trifluoromethyl-substituted iminomalonate, and the corresponding formal [3+2] cycloaddition reaction affords bicyclic heterocycles containing fused pyrrolidine and cyclopentane moieties in moderate yields with >20:1 dr. The synthetic potential of the methodology is demonstrated by the scale-up experiment and by versatile transformations of the products. Desymmetrization ; Cycloaddition ; Cyclopentene ; Pyrrolidine ; Chemistry ; Cyclopentane ; Yield (engineering) ; 1,3-Dipolar cycloaddition ; Bicyclic molecule ; Stereochemistry ; Formal synthesis ; Combinatorial chemistry ; Organic chemistry ; Enantioselective synthesis ; Catalysis ; Materials science Asymmetric Synthesis and Catalysis ; Fluorine in Organic Chemistry ; Synthesis and Catalytic Reactions
Authors: Walaa A. Bedewy | Mosaad S. Mohamed | Ahmed M. Abdelhameed | Mohamed A. Elsawy | Mohammed Al-Muhur | Noriyuki Ashida | Ashraf N. Abdalla | Tamer A. Elwaie | Tomohisa Nagamatsu | Hamed I. Ali
Source: Journal of Enzyme Inhibition and Medicinal Chemistry (article, 2023-06-21)
Field: Chemistry — Organic Chemistry

Design, synthesis, and antitumor efficacy of novel 5-deazaflavin derivatives backed by kinase screening, docking, and ADME studies Novel 5-deazaflavins were designed as potential anticancer candidates. Compounds <b>4j, 4k, 5b, 5i,</b> and <b>9f</b> demonstrated high cytotoxicity against MCF-7 cell line with IC<sub>50</sub> of 0.5-190nM. Compounds <b>8c</b> and <b>9g</b> showed preferential activity against Hela cells (IC<sub>50</sub>: 1.69 and 1.52 μM respectively). However, compound <b>5d</b> showed notable potency against MCF-7 and Hela cell lines of 0.1 nM and 1.26 μM respectively. Kinase profiling for <b>4e</b> showed the highest inhibition against a 20 kinase panel. Additionally, ADME prediction studies exhibited that compounds <b>4j</b>, <b>5d, 5f,</b> and <b>9f</b> have drug-likeness criteria to be considered promising antitumor agents deserving of further investigation. SAR study showed that substitutions with 2-benzylidene hydra zino have a better fitting into PTK with enhanced antiproliferative potency. Noteworthy, the incorporation of hydrazino or ethanolamine moieties at position 2 along with small alkyl or phenyl at N-10, respectively revealed an extraordinary potency against MCF-7 cells with IC<sub>50</sub> values in the nanomolar range. ADME ; HeLa ; Potency ; IC50 ; Chemistry ; Docking (animal) ; Kinase ; Cytotoxicity ; Stereochemistry ; Cell culture ; Biochemistry ; Pharmacology ; Combinatorial chemistry ; In vitro ; Biology ; Medicine Synthesis and biological activity ; Plant Gene Expression Analysis ; Synthesis of Organic Compounds
Authors: Zhenwei Lv | Yan Li | Erik V. Van der Eycken | Lingchao Cai | Liangliang Song
Source: Organic Chemistry Frontiers (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

6-<i>Exo-dig</i> cyclization/dearomatization cascade towards N–O fused spiro polyheterocycles A hypervalent iodine-mediated cascade cyclization of alkyne-tethered N -alkoxybenzamides for the construction of structurally novel N–O fused spiro polyheterocycles was developed. Hypervalent molecule ; Chemistry ; Dig ; Cascade ; Alkyne ; Stereochemistry ; Iodine ; Combinatorial chemistry ; Organic chemistry ; Computer science ; Catalysis ; World Wide Web Oxidative Organic Chemistry Reactions ; Catalytic C–H Functionalization Methods ; Catalytic Alkyne Reactions
Authors: Karim Jarmoni | K. Misbahi | Vincent Ferrières
Source: Current Medicinal Chemistry (review, 2023-04-27)
Field: Chemistry — Organic Chemistry

Imidazo[4,5-b]Pyridines: From Kinase Inhibitors to more DiversifiedBiological Properties Imidazo[4,5-b</i>]pyridines are amongst the oldest known heteroaromatic derivatives. Their structural similarity with purine basis has however aroused the curiosity of biologists and resulted in the developments of innovative bioactive compounds. This review thus firstly describes the main synthetic ways currently used to produce imidazo[ 4,5-b</i>]pyridine derivatives, and secondly gives examples of their potential, especially focusing on protein inhibition abilities, thus opening the way to applications as anti-cancer or antimicrobial agents. Chemistry ; Kinase ; Biological activity ; Pharmacology ; Computational biology ; Combinatorial chemistry ; Biochemistry ; Biology ; In vitro Synthesis and biological activity ; Cancer Mechanisms and Therapy ; Phosphodiesterase function and regulation
Authors: Mackenzi Steczkowski | Dmitry Kurouski
Source: Journal of Forensic Sciences (article, 2023-03-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Elucidation of the effect of heat exposure on hair colored by permanent and semipermanent colorants using surface‐enhanced Raman spectroscopy Confirmatory identification of hair colorants can be used to establish a connection between a suspect and the crime science or demonstrate the absence of such connections. A growing body of evidence shows that surface-enhanced Raman spectroscopy (SERS) could be a confirmatory, minimally destructive, and fully noninvasive analysis of hair colorants. In SERS, a signal that provide the information about the chemical structure of both permanent and semipermanent dyes present on hair is enhanced by a million-fold using noble metal nanostructures. However, it is unclear whether the information of hair colorants can be revealed if hair was contaminated or exposed to harsh environments such as sunlight and heat. In this work, we determine the effect of a short- and long-term heat exposure on SERS-based analysis of hair colored with blue and red permanent and semipermanent dyes. We found that short and especially long-term heat exposure at 220°C could alter chemical structure, and consequently SERS spectra, of permanent and semipermanent colorants. This thermal degradation of permanent dyes complicates their direct identification using SERS. We also found that partial least squares discriminant analysis can be used to overcome this issue allowing for highly accurate identification of both permanent and semipermanent dyes on colored hair that was exposed to 220°C for 6-12 min. These results show that heat exposure of colored hair should be strongly considered upon their SERS-based examination to avoid both false positive or false negative identification of chemical dyes. Colored ; Raman spectroscopy ; Surface-enhanced Raman spectroscopy ; Chemistry ; Materials science ; Optics ; Raman scattering ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Identification and Quantification in Food ; melanin and skin pigmentation
Authors: М. Н. Горбунова | Darya D. Zagumennova | Л. М. Лемкина
Source: Polymers for Advanced Technologies (article, 2023-06-07)
Field: Chemistry — Organic Chemistry

Novel biocidal polyampholytes with guanidinium and carboxy groups Abstract Polyampholytes are a promising class of multifunctional polymers containing both cationic and anionic groups. By varying the total charge of the copolymers, it is possible to significantly change the properties of the target macromolecule, such as molecular weight, solubility, reactivity, etc. In an attempt to create new polyampholytes, here the radical copolymerization of 2,2‐diallyl‐1,1,3,3‐tetraethylguanidinium chloride (AGC) with acrylic (AA), methacrylic (MAA), vinylacetic (VAA), and crotonic (CA) acids in bulk and in organic solvents has been studied and described. The relative reactivity of the unsaturated acids in the radical copolymerization with AGC in bulk appears to be MAA &gt; AA &gt; CA &gt; VAA. It is shown that both AGC double bonds participate in copolymerization with unsaturated acids, forming a cyclolinear polymer chain including cis/trans‐stereoisomeric pyrrolidinium subunits. The kinetics of this polymerization has been studied. The possibility and prospects of chemical modifications of copolymers by drugs bearing an amino group are considered. Moreover, the copolymers under study, including the guanidinium moiety, are effective against Gram‐positive and Gram‐negative bacteria. Copolymer ; Moiety ; Cationic polymerization ; Reactivity (psychology) ; Polymer chemistry ; Polymer ; Polymerization ; Macromolecule ; Solubility ; Chemistry ; Side chain ; Guanidinium chloride ; Materials science ; Organic chemistry Antimicrobial agents and applications ; Advanced Polymer Synthesis and Characterization ; Synthesis and properties of polymers
Authors: Raed H. Althomali | Ebraheem Abdu Musad Saleh | Riyadh Hasan Mohammed Ali | Ikromjon Mamadoliev | Montather F. Ramadan | Ashwaq Talib Kareem | Saurabh Aggarwal | Salema K. Hadrawi
Source: Nanoscale Advances (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Synthesis of a bistriazolyl-phenanthroline–Cu(<scp>ii</scp>) complex immobilized on nanomagnetic iron oxide as a novel green catalyst for synthesis of imidazoles <i>via</i> annulation reactions We designed and prepared a novel <i>N</i>-heterocycle-based nanocatalyst by a post synthetic method, namely the [Fe<sub>3</sub>O<sub>4</sub>@DAA-BTrzPhen-Cu(ii)] composite. In this method, bistriazolyl-phenanthroline groups were stepwise synthesized on an Fe<sub>3</sub>O<sub>4</sub> substrate and used as a tetradentate nitrogenous ligand for coordinating to copper ions. The obtained nanocomposite was well characterized using FT-IR, PXRD, TGA, EDAX, ICP-OES, EDX-mapping, SEM, TEM, VSM and BET analyses, which confirm the formation of a thermostable crystalline spherical particle morphology with the particle size in the range of 17 nm to 25 nm and a magnetization value of 42 emu g<sup>-1</sup>. Also, the catalytic activity of [Fe<sub>3</sub>O<sub>4</sub>@DAA-BTrzPhen-Cu(ii)] as a novel and magnetically separable heterogeneous nanocatalyst was evaluated in preparing various tetrasubstituted imidazole derivatives from one-pot four-component condensation of anilines, aldehydes, 1,2-diketones and ammonium acetate, and favorable products were produced with excellent yields. The stability, low Cu leaching, and heterogenous nature of the nanocatalyst were confirmed by hot-filtration and leaching tests. The copper based nanocatalyst could be easily recovered by magnetic field separation and recycled at least 8 times in a row without noticeable loss in its catalytic activity. Annulation ; Phenanthroline ; Catalysis ; Chemistry ; Lewis acids and bases ; Combinatorial chemistry ; Organic chemistry Multicomponent Synthesis of Heterocycles ; Chemical Synthesis and Reactions ; Synthesis and Biological Evaluation
Authors: Enrico Marcantonio | Debora Guazzetti | Kelly Bugatti | Lucia Battistini | Andrea Sartori | Giorgio Pelosi | Claudio Curti | Franca Zanardi
Source: Chemistry - A European Journal (article, 2023-05-19)
Field: Chemistry — Organic Chemistry

Turning the Imidazole Core into Three‐Dimensional Ring Systems: Mild Organocatalytic Entry to Enantiopure 6,7‐Dihydrobenzimidazoles Organocatalytic asymmetric transformation of common aromatic heterocycles via in situ formation of highly reactive dearomatized ortho-quinodimethane diene species and subsequent [4+2] cycloaddition with suitable dienophiles has become a powerful tool to enter cyclohexane-fused heterocycles. Most of these reactions were previously applied to benzo-fused heterocycles or poorly aromatic rings. Herein, we disclose how previously intractable aromatic imidazole rings, equipped with removable methylidene malononitrile activating handle, could be involved as competent cycloaddends with β-aryl enals in efficient eliminative [4+2] cycloadditions under mild organocatalytic conditions. This method allowed the efficient and direct preparation of scantly represented 6,7-dihydrobenzo[d]imidazoles with optimal enantio- and regioselectivities. Post-cycloaddition chemical editing provided imidazole-based ring systems with diverse oxidation state and functional groups. Enantiopure drug ; Cycloaddition ; Imidazole ; Ring (chemistry) ; Chemistry ; Malononitrile ; Combinatorial chemistry ; Diene ; Organocatalysis ; Aryl ; Cyclohexane ; Organic chemistry ; Stereochemistry ; Enantioselective synthesis ; Catalysis Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions ; Asymmetric Synthesis and Catalysis
Authors: Xinwei Zhang | Yaoyao Lu | Zhen Wang | Mengting Chen | Shuizhen Lin | Xiaolei Huang
Source: ACS Omega (article, 2023-12-19)
Field: Chemistry — Organic Chemistry

Palladium-Catalyzed C2-Selective Direct Arylation of Benzo[<i>b</i>]thiophene 1,1-Dioxides with Arylboronic Acids A novel oxidative cross-coupling of benzo[<i>b</i>]thiophene 1,1-dioxides with arylboronic acids was reported. The efficient reaction occurred at the C2-position via C-H activation, followed by Pd(II)-catalyzed arylation. Furthermore, a series of C2-arylated products with significant photoluminescence properties have been synthesized and characterized, which illustrates the potential applications of our method in the aggregation-induced emission field. Thiophene ; Catalysis ; Chemistry ; Palladium ; Oxidative phosphorylation ; Medicinal chemistry ; Combinatorial chemistry ; Organic chemistry ; Biochemistry Catalytic C–H Functionalization Methods ; Sulfur-Based Synthesis Techniques ; Catalytic Cross-Coupling Reactions
Authors: Stefania-Claudia Jitaru | Andrei Neamțu | Gabi Drochioiu | Laura Darie‐Ion | Iuliana Stoica | Brîndușa Alina Petre | Vasile Robert Grădinaru
Source: Pharmaceutics (article, 2023-01-21)
Field: Materials Science — Biomaterials

A Diphenylalanine Based Pentapeptide with Fibrillating Self-Assembling Properties Peptides and their related compounds can self-assemble into diverse nanostructures of different shapes and sizes in response to various stimuli such as pH, temperature or ionic strength. Here we report the synthesis and characterization of a lysozyme derived pentapeptide and its ability to build well-defined fibrillar structures. Lysozyme FESNF peptide fragment was synthesized by solid phase peptide synthesis using the Fmoc/t-Bu strategy, purified by analytical high-performance liquid chromatography (HPLC) and its molecular weight was confirmed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Spectroscopic features of this pentapeptide were investigated by UV-visible spectroscopy and fluorimetry showing the pattern of marginal phenylalanine residues within the peptide sequence. Self-assembling properties were determined using atomic force microscopy (AFM), aggregation index and thioflavin T assay (ThT). FESNF generating fibrillar structures observed by AFM and aggregation propensity were primarily influenced by pH conditions. Moreover, the experimental data were confirmed by molecular dynamics simulation studies. The obtained fibrils will be used next to explore their potential to act as support material for medical and cosmetic application. Pentapeptide repeat ; Thioflavin ; Lysozyme ; Chemistry ; Peptide ; Mass spectrometry ; Self-assembly ; Circular dichroism ; Chromatography ; Combinatorial chemistry ; Crystallography ; Biophysics ; Organic chemistry ; Biochemistry Supramolecular Self-Assembly in Materials ; Antimicrobial Peptides and Activities ; Chemical Synthesis and Analysis
Authors: Devalina Ray | Suman Majee | Ram Naresh Yadav | Bimal Krishna Banik
Source: Molecules (review, 2023-04-17)
Field: Chemistry — Inorganic Chemistry

Asymmetric Reactions of N-Phosphonyl/Phosphoryl Imines The asymmetric reactions of imines continued to attract the attention of the scientific community for decades. However, the stereoselective reactions of <i>N</i>-phosphonyl/phosphoryl imines remained less explored as compared to other <i>N</i>-substituted imines. The chiral auxiliary-based asymmetric-induction strategy with <i>N</i>-phosphonyl imines could effectively generate enantio- and diastereomeric amine, <i>α</i>,<i>β</i>-diamine, and other products through various reactions. On the other hand, the asymmetric approach for the generation of chirality through the utilization of optically active ligands, along with metal catalysts, could be successfully implemented on <i>N</i>-phosphonyl/phosphoryl imines to access numerous synthetically challenging chiral amine scaffolds. The current review critically summarizes and reveals the literature precedence of more than a decade to highlight the major achievements existing to date that can display a clear picture of advancement as well drawbacks in this area. Diastereomer ; Chirality (physics) ; Stereoselectivity ; Chemistry ; Amine gas treating ; Optically active ; Combinatorial chemistry ; Imine ; Asymmetric induction ; Diamine ; Catalysis ; Enantioselective synthesis ; Stereochemistry ; Organic chemistry ; Physics Asymmetric Hydrogenation and Catalysis ; Chemical Synthesis and Analysis ; Asymmetric Synthesis and Catalysis
Authors: Shanshan Liu | Xianying Zhou | Lin‐Yu Jiao | Chao Li | Zheng Wang
Source: Chemistry - A European Journal (article, 2023-04-17)
Field: Chemistry — Inorganic Chemistry

Sunlight Induced and Alternative Sc(OTf)<sub>3</sub> Catalyzed Remote C−H Halogenation of Indoles A mild and catalyst-free sunlight induced protocol for the remote meta bromination of electron-deficient indoles is described for the first time. Herein, N-bromosaccharin is activated by sunlight irradiation. Alternately, a synergistic activation model (Sc(OTf)<sub>3</sub> /HFIP) has also been developed for the activation of haloniums, complementary to the light induced strategy. In addition, the cascade C6-H bromination and benzylic C-H oxidation under photocatalytic conditions was also discussed. High regio-and chem-selectivity, mild reaction conditions, and scalability demonstrate great potential of the developed methods in practical applications and further functionalization. Halogenation ; Catalysis ; Sunlight ; Selectivity ; Chemistry ; Photocatalysis ; Surface modification ; Cascade ; Combinatorial chemistry ; Irradiation ; Photochemistry ; Medicinal chemistry ; Organic chemistry ; Physical chemistry ; Physics Vanadium and Halogenation Chemistry ; Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions
Authors: Yingwei Zhang | Chunhua Wang | Yong Yi | Wenzhi Wang | Jun Yang
Source: Polymers (article, 2023-06-25)
Field: Materials Science — Polymers and Plastics

Synthesis and Properties of Polyamide 6 Random Copolymers Containing an Aromatic Imide Structure In order to adjust the properties of polyamide 6 (PA6) and expand its application, a new strategy of introducing an aromatic imide structure into the PA6 chain through the random copolymerization method is reported. The diimide diacid monomer was first synthesized by the dehydration and cyclization of pyromellitic dianhydride and 6-aminocaproic acid before it reacted with 1,6-hexamethylene diamine to form poly(amide imide) (PAI) salt, and finally synthesized PA6/PAI random copolymers containing an aromatic imide structure by the random copolymerization of ε-caprolactam and PAI salt. The introduction of an aromatic imide structural unit into the PA6 chain could have a great influence on its properties. As the content of PAI increases, the crystallinity (<i>X</i><sub>c</sub>) and melting temperature (<i>T</i><sub>m</sub>) of the PA6/PAI random copolymer gradually decrease, but its glass transition temperature (<i>T</i><sub>g</sub>) increases obviously. When the PAI content is 20 wt%, the copolymer PA6/PAI-20 has the best comprehensive performance and not only has high thermal stabilities but also excellent mechanical properties (high strength, high modulus, and good toughness) and dielectric properties (low dielectric constant and dielectric loss). Moreover, these properties are significantly superior to those of PA6. Such high-performance PA6 random copolymers can provide great promise for the wider applications of PA6 materials. Copolymer ; Imide ; Materials science ; Polymer chemistry ; Condensation polymer ; Glass transition ; Polyamide ; Pyromellitic dianhydride ; Crystallinity ; Polymer ; Polyimide ; Composite material Synthesis and properties of polymers ; Dielectric materials and actuators ; Flame retardant materials and properties