Refernces
10.1016/j.tet.2016.07.018
The study presents a novel and efficient copper-catalyzed vinylic Finkelstein reaction for the synthesis of various halogenated alkenes, which are important structural elements in pharmaceuticals, agrochemicals, and natural products. The researchers developed a method to convert alkenyl iodides and bromides into their chlorinated and brominated counterparts with high yields and full retention of double bond geometry. This method's broad applicability and mild reaction conditions make it suitable for a range of functionalized substrates. The study demonstrates the potential of this reaction in total synthesis and medicinal chemistry by using it to synthesize the C1–C9 fragment of laingolide B and for the late-stage modification of drug-like molecules. The researchers also explored the extension of this halogen exchange to acetylenic and allenic Finkelstein reactions.
10.1021/ja1084749
The study conducted by Roland Appel, Nicolai Hartmann, and Herbert Mayr from the Department of Chemistry at Ludwig-Maximilians-Universit?t München, investigates the cyclopropanation reactions using sulfur ylides. It focuses on the rates of reactions between stabilized and semistabilized sulfur ylides with benzhydrylium ions and Michael acceptors, measured using UV-vis spectroscopy in DMSO at 20°C. The research establishes a correlation between the second-order rate constants (log k2) and the electrophilicity parameters (E) of the electrophiles, which aids in calculating the nucleophile-specific parameters (N and s) for the sulfur ylides. The findings indicate that the rate constants for cyclopropanation reactions with Michael acceptors align with those for carbocations, suggesting a stepwise mechanism with the initial nucleophilic attack being rate-determining. This study provides a quantitative approach to understanding sulfur ylide reactivity, which is crucial for predicting the scope and limitations of cyclopropanation reactions in organic synthesis.
10.3906/kim-1711-97
The study focuses on the synthesis, solvatochromism, and biological activity of novel azo dyes that incorporate 2-pyridone and benzimidazole moieties. The azo dyes were synthesized through the diazotization of 4-(1H-benzo[d]imidazol-2-yl)aniline and subsequent coupling with substituted 3-cyano-2-pyridones. The dyes were characterized using UV-Vis, FT-IR, and NMR spectroscopy, as well as elemental analysis. The study explored the solvatochromism of the dyes across various solvents and investigated their tautomeric forms. Biological tests, including MTT assays, revealed that the dyes exhibit good biocompatibility and antiproliferative activity against tumor cell lines MDA-MB-231 and HCT-116, suggesting potential applications in cancer treatment.
10.1016/j.jorganchem.2011.12.014
The research focuses on the synthesis and characterization of novel platinum(II) complexes with pyrimidine-functionalized N-heterocyclic carbene (NHC) ligands, aiming to merge successful systems for the activation and functionalization of methane. The study involves the preparation of platinum(II) complexes with aryl and alkyl substituents through transmetalation using corresponding silver complexes. The reactants include imidazolium salts, Ag2O, and [(COD)PtCl2], with the synthesis carried out in dichloromethane or DMSO under specific conditions. The characterization of the complexes was performed using 1H and 13C-NMR spectroscopy, elemental analysis, and X-ray single crystal structures for five compounds. The complexes were tested for catalytic activity in methane activation but showed no significant catalytic activity under the tested conditions. The detailed analyses include melting points determination, NMR spectroscopy, and X-ray crystallography, with results indicating stable complexes under strong acidic conditions but without catalytic activity in methane oxidation.
10.1016/j.bmcl.2009.11.037
The research presents the synthesis and biological evaluation of novel 5-styryl and 5-phenethyl-substituted 2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoles, which are analogs of the drug dimebolin. The study focuses on the synthesis of these compounds and their activity against therapeutically relevant targets, such as serotonergic, adrenergic, histamine, and other receptors. The experiments involved the reaction of aryl acetylenes with tetrahydro-1H-c-carbolines in a biphasic system using DMSO, KOH, and a phase-transfer catalyst, leading to the formation of (Z)- and (E)-isomers of 2-methyl-5-styryl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoles. Further hydrogenation yielded the desired 5-phenethyl derivatives. The structures of the compounds were confirmed using LC–MS and 1H NMR spectroscopy, with specific attention to the chemical shifts and coupling constants indicative of the (Z)- and (E)-isomers. The biological activities were assessed through cell-based assays, measuring the compounds' abilities to inhibit serotonin-induced responses, block histamine H1 receptors, and their affinities to various receptors, which were determined by displacement of radio-labeled ligands. The most potent compounds were further profiled against a panel of 31 therapeutic targets to determine their specificity.
10.1021/jo502621a
The research focuses on developing a solvent- and metal-free methodology for the alkoxy-chalcogenylation of styrenes using molecular iodine (I2) as a catalyst and dimethyl sulfoxide (DMSO) as a stoichiometric oxidant, under microwave irradiation. The purpose of this study was to create an environmentally friendly approach for the functionalization of olefins with sulfur and selenium, achieving good to excellent yields of the desired products in just 10 minutes. The findings concluded that this method not only enhances reaction efficiency but also minimizes undesirable side reactions typically associated with halide nucleophiles. Various nucleophiles, including methanol, ethanol, and acetic acid, were successfully employed, demonstrating the versatility of the protocol in synthesizing β-substituted aryl selenides and sulfides.
10.1016/S0022-328X(99)00709-3
The study in the Journal of Organometallic Chemistry focuses on the direct nucleophilic displacement of halides (chlorine or iodine) in compounds with the formula (Me3Si)3CSiRRX, where R and R represent various organic groups. The researchers investigated the reactions of these compounds with nucleophiles such as KOCN, KSCN, KCN, or NaN3 in different solvents like CH3CN, MeOH, and DMSO, or CH3CN mixed with H2O. The study explores the influence of steric hindrance on the reactivity of silicon centers bearing the bulky trisyl group (Tsi). It was found that by reducing the steric hindrance or using linear nucleophiles, direct bimolecular displacement reactions occur without the observation of rearrangement. The study also successfully synthesized new compounds with different groups and examined their reactivity with the mentioned nucleophiles, providing insights into the ease of reactions on silicon centers bearing the bulky trisyl group.
10.1021/ja046965q
The study presents a novel synthetic strategy for the creation of dendronized protein polymers (DPPs), which are cylindrical macromolecules with well-defined lengths and diameters. The researchers combined biological and chemical methods to achieve this precision. They expressed a monodisperse, R-helical polypeptide backbone in bacteria using a DNA template, which determined the length and overall rod shape of the DPP. Subsequently, synthetic dendrons were grafted onto the polypeptide backbone's reactive amino acid side chains, creating a dendritic shell that controlled the thickness. The resulting DPPs self-assembled into highly ordered liquid crystalline structures due to their uniform shape and size. The research demonstrated that these DPPs could be tailored in terms of size and chemical functionality, and their self-assembly was driven by excluded volume interactions, leading to long-range order in their liquid crystalline phases. This approach opens up new possibilities for the design of materials with predictable properties at the nanoscale.
10.1021/jm201332p
The study focuses on the design of inhibitors for β-amyloid (Aβ) aggregation, a key process in Alzheimer's disease (AD). Researchers developed a substituted peptide, [Nle35, D-Pro37]Aβ42, using molecular dynamics simulations to stabilize Aβ structures suitable for NMR analysis. This peptide was found to stabilize Aβ trimers, prevent mature fibril and β-sheet formation, and reduce aggregation when mixed with wild-type Aβ42. Furthermore, a small molecule lead compound was identified through ligand-based drug design, showing similar inhibitory effects to the peptide. The study demonstrates the potential of using molecular dynamics simulation to guide experiments aimed at understanding AD and developing therapeutics.
10.1002/cmdc.201200311
The study focuses on the synthesis and evaluation of asymmetric 4-aryl-1,4-dihydropyridines (DHPs) as potential potentiators of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), which is a protein affected by mutations causing cystic fibrosis (CF). The researchers synthesized a set of asymmetric DHPs and tested them on cells expressing different CFTR mutations, including G1349D, DF508, and G551D. The study aimed to identify compounds that could improve the function of the CFTR protein, particularly for class III mutations that impair channel gating. The most active racemates were then subjected to chiral separation to assess if a single enantiomer was responsible for the observed activity. The results showed that several DHPs had potentiating effects at nanomolar concentrations, but the chiral separation did not reveal significant differences in potency between the individual enantiomers, suggesting that the asymmetric nature of the DHPs was not critical for their activity as CFTR potentiators.
10.1039/c7cc07366f
The research focuses on the development of an atom-economic and environmentally friendly method for synthesizing benzothiazoles and naphtho[2,1-d]yhiazoles from N-substituted arylamines and elemental sulfur under metal-free conditions. The study involves a series of experiments where various N-substituted arylamines react with elemental sulfur in the presence of DMSO as both a solvent and an oxidant at 140°C under a nitrogen atmosphere, leading to the formation of double C-S bonds through C-H bond functionalization. The reaction conditions were optimized to achieve high yields, and the scope of the reaction was explored with different substituted arylamines. Control experiments and GC-MS analysis were conducted to propose a reaction mechanism involving the formation of an imine intermediate and subsequent cyclization. The research also demonstrates the synthesis of extended π-conjugated systems and the compatibility of the method with a wide range of functional groups, highlighting the advantages of readily available starting materials and tolerance to various substituents.
Xi
Xi:Irritant;
