Refernces
10.1055/s-2007-990869
The research presents a study on the Chlorotrimethylsilane-Mediated Friedl?nder Synthesis of 2-(a-Chloroalkyl)quinoline Derivatives, which are significant in medicinal chemistry for their use in synthesizing potential analgesics, anti-inflammatories, and other pharmaceuticals. The researchers explored a novel approach using chlorotrimethylsilane (TMSCl) as a catalyst and water scavenger in the Friedl?nder reaction, extending the scope of the reaction to include a-chloroketones. The study involved the condensation of 2-aminoacetophenone and 2-aminobenzophenone with ethyl 4-chloro-3-oxobutanoate, as well as reactions with 1,3-dichloroacetone and 2-chlorocyclohexanone under controlled conditions. The products were analyzed using 1H and 13C NMR spectroscopy, and the yields were compared to those from traditional procedures, showing significant improvements. The simplicity and high yield of the method make it a valuable tool for the synthesis of these important compounds.
10.1016/j.tetlet.2006.04.097
The research focuses on the synthesis of substituted 3-furan-2(5H)-ones, which are structural motifs found in numerous bioactive natural products. The methodology involves a Diels–Alder sequence using anthracene and maleic anhydride to form a lactone, which upon deprotonation and electrophilic quenching, yields α-substituted lactones. Key reactants include anthracene, maleic anhydride, sodium borohydride, and various electrophiles such as methyl iodide, allyl iodide, butenyl bromide, benzyl bromide, tributyltin chloride, diethyl chlorophosphate, and chlorotrimethylsilane. The experiments utilize techniques like flash vacuum pyrolysis (FVP) to convert alkylated lactones into 3-substituted furan-2(5H)-ones. The study also explores the challenges and limitations of using cyclopentadiene in such reactions and proposes an alternative route to overcome these issues. Analytical techniques such as 13C NMR and IR spectroscopy were employed to confirm the structure and successful functionalization of the synthesized compounds.
10.1016/S0022-328X(00)00181-9
This study focused on the synthesis of acylsilanes, a class of compounds with unique chemical properties that are widely used in various synthetic methods. The researchers used an oxidative hydrolysis method to generate acylsilanes in high yields in a short reaction time using N-bromosuccinimide (NBS) as a medium for the hydrolysis of 2-silyl-1,3-dithianes. This study aimed to find an alternative to the traditional mercuric chloride hydrolysis method, which is time-consuming and toxic. The chemicals used in the study included aldehydes, 1,3-propanedithiol, BF3·OEt2, n-BuLi, trimethylsilyl chloride, and various bases such as Et3N, Ba(OH)2, and imidazole. These chemicals were used to convert aldehydes into 1,3-dithianes, which were then converted into 2-silyl-1,3-dithianes, and finally hydrolyzed to generate acylsilanes. The use of NBS was intended to improve the efficiency and safety of the hydrolysis process and avoid the formation of undesirable byproducts such as carboxylic acids due to the oxidation of aromatic acylsilanes.
10.1002/adsc.200900905
The study presents a novel protocol for the direct sulfonylation of benzylic, allylic, and homoallylic alcohols using sodium arenesulfinates, catalyzed by iron(III) chloride and with chlorotrimethylsilane as an additive. This method bypasses the need for preactivation of alcohols and offers a more atom-economical and environmentally benign approach compared to previous methods that required stoichiometric amounts of base and/or metal salts. The sulfonyl group, known for stabilizing carbanions and acting as radical stabilizers and cationic synthons, is introduced into intermediate molecules to facilitate the construction of C-C bonds and other transformations. The study explores the efficiency of this method with various alcohols and sulfinate salts, providing useful building blocks for organic synthesis and expanding the scope of reactions involving unactivated double bonds.
10.4067/S0717-97072012000200014
The study explores a convenient method for synthesizing substituted benzimidazoles using Trimethylsilyl Chloride (TMSCl) as a catalyst in a microwave-induced two-phase system. The chemicals involved include o-phenylenediamine and various carboxylic acids as starting materials, TMSCl as the catalyst, and solvents such as DMF and water. The TMSCl catalyzes the cyclization of o-phenylenediamine with carboxylic acids to form benzimidazoles. The microwave conditions significantly reduce reaction time and enhance yield compared to conventional heating methods. The synthesized compounds were evaluated for their in vitro antibacterial and antifungal activities against several pathogenic strains, revealing that certain compounds, such as 3e, 3f, 3g, 3k, 3m, 3n, and 3o, demonstrated antimicrobial activity comparable to standard drugs like ampicillin and itraconazole, with the most effective compounds showing activity at a MIC of 6.25 μg/mL. The study concludes that the presence of a substituted phenyl ring at position 2 of the benzimidazole structure might be responsible for the enhanced antimicrobial activity.
10.1021/jo00388a017
The study explores the synthesis and reactivity of silyl-substituted cyanoamines as reagents for heterocyclic synthesis. Key chemicals involved include (dialkylamino)acetonitriles, chlorotrimethylsilane, lithium diisopropylamide (LDA), and silver fluoride. The researchers attempted to silylate the anion derived from several (dialkylamino)acetonitriles but encountered self-condensation issues. They successfully synthesized a-silylated cyanoamines by slowly adding chlorotrimethylsilane to (benzylmethylamino)acetonitrile and treating the resulting ammonium salt with LDA. These silyl-substituted cyanoamines were then treated with silver fluoride to produce desilylated cyanoamines, which were expected to generate aminocarbenes but instead led to 1,3-dipolar cycloadducts via cyano-substituted azomethine ylide intermediates. The study also investigated the cycloaddition behavior of [benzyl[(trimethylsilyl)methyl]amino]malononitrile, finding that it undergoes smooth dipolar cycloaddition with various dipolarophiles in the presence of silver fluoride, potentially serving as a convenient nitrile ylide precursor. The research highlights the potential of these compounds in heterocyclic synthesis and the challenges in generating and trapping aminocarbenes.
10.1039/c39760000371
The study investigates the flash thermolysis of trimethylsilyl 2-oxobicyclo[3.3.1]nonane-1-carboxylate (1), which leads to the formation of enol ethers (3) and (5). The primary focus is on the transient existence of a strained bridgehead enol ether (2) as an intermediate. The ester (1) is prepared by reacting the corresponding acid with trimethylsilyl chloride in the presence of pyridine. Thermolysis is conducted at various temperatures, and products are isolated based on their volatility using the 'sandwich technique' for slightly volatile compounds and direct distillation for volatile ones. The main products identified are enol ethers (3) and (5), along with their hydrolysis products, ketones (4) and (6). The study also observes the formation of butadiene and enol ether (7) at higher temperatures, suggesting they are secondary products derived from compound (5). The structures of the products are confirmed through spectroscopic data and chemical analysis. The presence of enol ethers (3) and (5) supports the formation of the strained bridgehead enol ether (2), which can undergo a [1,3] hydrogen shift to form (3) or a retro-Diels-Alder reaction to form (5).
10.1007/BF00764628
The study focuses on the synthesis and biological activity of the trimethylsilyl ether of Vitamin D2, a compound of interest due to its potential to increase the stability of antirachitic preparations. The researchers synthesized Vitamin D2 trimethylsilyl ether (I) using a reaction involving hexamethyldisilazane and trimethylsilyl chloride, and then assessed its biological activity through various tests including calcium and phosphorus levels in blood, alkaline phosphatase activity, and the presence of a specific calcium-binding protein in the duodenal mucosa of Leghorn chicks. The results showed that the biological activity of the etherified Vitamin D2 was comparable to the non-etherified form, with some differences attributed to molecular mass and equimolar amounts. The study also examined the stability of the preparation over a six-month storage period, finding that the etherified form demonstrated greater stability, which was hypothesized to be due to the protective effects of the trimethylsilyl group against oxidation and degradation. The findings suggest that the use of silylated derivatives could reduce the loss of Vitamin D2 during storage, thereby increasing its economic value.
10.1039/DT9850002191
The research focuses on the synthesis of organofunctional siloxanes containing metal-ligating side-chains. The purpose of this study was to develop a range of tri-, tetra-, and penta-siloxanes that could potentially be used to attach transition-metal species to solid supports, thereby creating catalysts that combine the versatility and selectivity of homogeneous catalysts with the separation advantages of heterogeneous systems. The researchers synthesized these siloxanes from commercially available dichlorosilanes using three different procedures, resulting in air-stable oils, except for those functionalized with pyridine and phosphine, which were prone to oxidation. The study concluded that these organofunctional siloxanes could serve as models for future syntheses and investigations of long-chain organofunctional polysiloxanes. Key chemicals used in the process included various dichlorosilanes, such as SiMeCl2H, SiMeCl2(CH=CH2), and SiMeCl2(CH2CH=CH2), as well as reagents like chlorotrimethylsilane, benzene, and lithium compounds for the introduction of functional groups.
10.1016/S0022-328X(96)06482-0
The research focuses on the synthesis and reactivity of P-ferrocenylalkylidenephosphanes and related iminophosphanes and diphosphenes. The purpose of this study was to investigate the interaction between an electrophilic center and a ferrocenyl substituent, which has been shown to exhibit interesting physical and chemical properties in previously reported compounds. The researchers synthesized and characterized P-ferrocenyl-substituted alkylidenephosphanes and explored their conversion to acylphosphanes and 1,2-diacyldiphosphanes, as well as a new type of phosphirene synthesis. They also examined the stabilization of iminophosphanes and diphosphenes through transition metal complexation. Key chemicals used in the process included ferrocenylbis(trimethylsilyl)phosphane, acylchlorides, alcohols, n-butyllithium, trimethylchlorosilane, and iodine, among others. The conclusions drawn from the study highlighted the successful synthesis of the target compounds and their potential complexation behavior with metal cations, with the X-ray structures of certain compounds providing insights into their molecular configurations and bond lengths.
10.1134/S1070428009070100
The study investigates the synthesis and reactions of pyrazole-4-carbaldehydes. The researchers converted 1-, 3-, and 5-alkylpyrazoles, as well as linearly bridged bis-pyrazoles, into the corresponding 4-formyl derivatives using the Vilsmeier–Haak reaction under standard conditions and microwave activation in DMF. They found that 5-chloro-1,3-dialkyl-1H-pyrazoles did not undergo formylation under these conditions. The study also explored the reaction of 1,1′-bridged bis-3,5-dimethyl-1H-pyrazoles with 2-sulfanylethanol in the presence of chloro(trimethyl)silane to produce bridged bis-4-(1,4,6-oxadithiocan-5-yl)-1H-pyrazoles. The compounds synthesized in this study have potential applications in medicinal chemistry due to the significance of pyrazole rings in many modern drugs.
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