Refernces
10.1021/om034385g
The study investigates the reactions of 3-(pentafluorophenyl)indene and (pentafluorophenyl)cyclopentadiene with tetrakis(dimethylamido)titanium(IV), resulting in the formation of products where one or both ortho fluorines of the C6F5 group are replaced by dimethylamino groups. This suggests a titanium-mediated, intramolecular nucleophilic aromatic substitution mechanism. The research led to the isolation of organic products and the conversion of substituted cyclopentadiene to a ferrocene derivative. The study provides insights into the selective activation of polyfluorinated organic compounds, a significant challenge in synthetic chemistry, and contributes to the understanding of transition metal complex mechanisms for C-F activation.
10.1055/s-2004-831166
The research focuses on the stereoselective preparation of (E)-α-bromoacrylates from mixtures of brominated Ando phosphonates. The main objective was to synthesize phosphonates containing phenoxy substituents, a CO2Et group, and bromine atoms at the interspersed methylene group. The experiments involved deprotonating mixtures of these reagents with NaH and adding various aldehydes at 0 °C to yield unsaturated α-bromoesters with high E-selectivity. The reactants included phosphonates 6b and 7b, aldehydes, and NaH, while the analyses used to characterize the products and monitor the reactions included NMR spectroscopy, mass spectrometry, and optical rotation measurements. The study also explored the conversion of these α-bromoacrylates into other compounds, such as 1,3-dienes and natural products, and discussed the challenges and optimizations in the synthesis process.
10.1021/jo702023s
The research focuses on the copper(I)-catalyzed [3+2] cycloaddition of nucleosides and nucleotides to synthesize oligonucleotide dimers and conjugates with near-quantitative yield. The experiments involved the preparation of 2′-azide or 2′-acetylene modified adenosines as building blocks for the mild and efficient synthesis of oligonucleotide hetero- and homoconjugates. Reactants included adenosine, sodium hydride, alkyl chlorides, and various azides and acetylenes, which were subjected to cycloaddition reactions under different conditions to optimize the process. The analyses used to characterize the synthesized compounds included 1H and 13C NMR spectroscopy, high-resolution mass spectrometry (HRMS), and MALDI-TOF mass spectrometry, as well as high-performance liquid chromatography (HPLC) to monitor the reaction progress and confirm the formation of the desired triazole-linked conjugates.
10.1039/c3dt32983f
This study aims to investigate the mechanism of hydrosilylation of styryl alcohols initiated by N-heterocyclic carbenes (NHC) in the presence of dihydrosilane. Tetrabutylammonium fluoride (TBAF) is used to quench the reaction, terminating the hydrosilylation process by reacting with any remaining silicon derivatives. It is a quaternary ammonium salt with four n-butyl groups attached to a nitrogen atom and a fluoride ion. TBAF is an effective scavenger of silicon-containing species and is commonly used in organic synthesis to terminate reactions involving silicon reagents. Sodium hydride (NaH) has been tested as an alternative base to NHC to initiate hydrosilylation reactions. It is known for its strong basicity and ability to deprotonate alcohols. It consists of a sodium cation and a hydride ion. NaH can generate alkoxides by deprotonating alcohols, which can then react with dihydrosilane to form high-valent silicon complexes.
10.1016/j.tet.2018.03.048
The study focuses on the selective synthesis of 1,4,5-trisubstituted imidazoles from α-imino ketones, which are prepared through N-heterocyclic-carbene (NHC)-catalyzed aroylation of imidoyl chlorides with aromatic aldehydes. The research outlines a straightforward methodology that involves NHC-catalyzed aroylation, followed by chemoselective reduction of the imino group, and subsequent annulation with formamide to form the imidazole ring. This approach allows the rapid and regioselective synthesis of imidazole derivatives with potential applications in pharmaceuticals and agrochemicals. The study demonstrates the substrate scope and optimization of reaction conditions, highlighting the importance of this method in creating chemical libraries for further application.
10.1016/j.ejmech.2016.06.014
The research focuses on the synthesis and antimicrobial activity of a novel class of mono and bis heterocycles, including styryl, pyrrolyl, and pyrazolyl sulfonylmethyl-1,3,4-oxadiazolyl/thiadiazolyl amines. The study utilizes Z-styrylsulfonylacetic acid as a synthetic intermediate and employs various synthetic methodologies to prepare these compounds. The antimicrobial activity of these synthesized compounds was then evaluated against different bacterial and fungal strains. The reactants used in the synthesis encompass semicarbazide, thiosemicarbazide, POCl3, tosylmethyl isocyanide, sodium hydride, diazomethane, and chloranil, among others. The synthesized compounds were characterized using techniques like infrared (IR) spectroscopy, nuclear magnetic resonance (NMR), high-resolution mass spectrometry, and elemental analysis. The antimicrobial activity was assessed using the agar well diffusion method and broth dilution test to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC). The findings revealed that mono heterocyclic compounds, particularly 5-(4-chlorostyrylsulfonylmethyl)-1,3,4-thiadiazol-2-amine (5c), exhibited superior antimicrobial activity against certain bacteria and fungi compared to the bis heterocyclic systems.