10.1016/j.tetlet.2008.06.123
The study focuses on the synthesis of substituted 2-azabicyclo[3.2.1]octadienes, which are significant in the creation of natural products and biologically active compounds, through the ring expansion of substituted norbornadienes using toluenesulfonyl azide. The researchers explored the regioselectivity of the cycloaddition/rearrangement process with various mono- and disubstituted norbornadienes, finding that both types could be converted into the bicyclooctadiene ring system with high regiocontrol and in moderate to excellent yields. The study also investigated the impact of different substituent groups on the reaction's outcome, noting that electron-withdrawing groups resulted in little to no product, while hydroxymethyl derivatives provided a moderate yield of a single regioisomer. The synthesized 2-azabicyclo[3.2.1]octadienes can be further modified to yield highly substituted derivatives of the 2-azabicyclo[3.2.1]octane ring system, which is prevalent in natural products and pharmacologically active molecules, thus providing a valuable route for the synthesis of these complex structures.
10.1016/j.ejmech.2013.11.020
The research focuses on the design and synthesis of thiazole derivatives as potent FabH inhibitors with antibacterial activity. The study aimed to develop new antibacterial agents by targeting the fatty acid biosynthetic pathway, specifically the enzyme FabH. Two series of compounds, A (4ae4g) and B (5ae5g), were synthesized by forming an amine bond between aromatic acids and 4-phenylthiazol-2-amine or 4-(4-bromophenyl)thiazol-2-amine. These thiazole derivatives were evaluated for their antibacterial activity against four bacterial strains using the MTT assay, with minimum inhibitory concentration (MIC) values ranging from 1.56 mg/mL to 100 mg/mL. The compounds also showed FabH inhibition ability with IC50 values ranging from 5.8 mM to 48.1 mM. The research involved the synthesis of key intermediates, the formation of amide bonds, and the evaluation of antibacterial activity. Docking simulations and 3D-QSAR studies were conducted to understand the binding mode and structure-activity relationships. The analyses included elemental analysis, NMR, MS, and enzyme assays to determine the IC50 values. The experiments used various reagents, such as aluminum chloride, bromine, thiourea, and acetyl chloride, and involved techniques like thin-layer chromatography, melting point determination, and ESI mass spectrometry. The study concluded that compound 5f exhibited the best antibacterial and E. coli FabH inhibitory activity, suggesting its potential as an antibacterial agent.
10.1016/S0040-4039(00)96887-4
The research aimed to explore the preparation and reactivity of simple 5,6-dihydropyridinium salts, specifically focusing on the simplest member of this class, 2 (R1 = alkyl, R2 = H), as new synthons for the synthesis of functionalized piperidine systems. The study commenced with the preparation of the starting N-methyl A2-piperidone 1, which was then reacted with acetyl chloride to form the dihydropyridinium salt 2. This salt was found to be sensitive to temperature but could be efficiently reacted with a series of Grignard reagents at -50°C, leading to the formation of C-2 substituted enol acetates 6a-f with yields ranging from 50-93%. The research concluded that these reactions were reproducible on both small and large scales, provided attention was paid to experimental details. The study also demonstrated a synthetic application of synthon 1 by converting the Grignard addition product to benzomorphan 12 in three steps, showcasing a method for double substitution at the C-4 position of the piperidine ring. Key chemicals used in the process included acetyl chloride, Grignard reagents, and various piperidone derivatives.
10.1021/ja805541u
The research focuses on the development of novel nucleophilic catalysts, AcOLeDMAP and BnOLeDMAP, for the enantioselective rearrangement of indolyl acetates and carbonates to form chiral quaternary carbon-containing oxindoles. The study addresses the challenge of achieving high enantioselectivity and reactivity in this transformation. Key experiments involved the synthesis of various catalysts, substrates, and the evaluation of their performance in the rearrangement reactions. Reactants included N-protected oxindoles, acetyl chloride, and different electrophiles for substrate preparation. The catalysts were designed with specific side chain conformations to enhance reactivity and selectivity. Analyses utilized techniques such as NMR/MS for catalyst assessment, X-ray crystallography for stereochemical confirmation, and chiral HPLC for enantiomeric excess determination. The results demonstrated that the new catalysts significantly improved both the reactivity and enantioselectivity of the rearrangement reactions, with AcOLeDMAP proving particularly effective.
10.1039/b508972g
The research focuses on the development of a novel and efficient method for generating o-quinone methide intermediates, which are crucial in the biomimetic synthesis of complex benzopyran derived natural products, specifically (±)-lucidene and (±)-alboatrin. The study provides experimental evidence supporting the hypothesis that the biogenesis of these natural products may involve a hetero Diels–Alder cycloaddition between an o-quinone methide intermediate and a simple or activated tri-substituted olefin. The researchers successfully synthesized (±)-lucidene and (±)-alboatrin using this new method, which involves the preparation of o-quinone methide precursors 6a and 6b. The experiments utilized various reactants, including 2-hydroxybenzyl alcohol, acetyl chloride, and different dienophiles, and were conducted under controlled conditions such as specific temperatures and the use of inert atmospheres. Analytical techniques employed in the study included NMR spectroscopy, mass spectrometry, infrared spectroscopy, and X-ray crystallography, which were used to characterize the intermediates and final products, confirming their structures and evaluating the efficiency of the newly developed synthetic method.
10.1039/b408677e
The study presents a novel method for converting S-tert-butyl groups into acetyl-protected thiols, which are crucial for self-assembly processes, particularly in the field of nanotechnology and molecular electronics. The reaction is catalyzed by bromine in the presence of acetyl chloride and acetic acid, offering a mild and efficient alternative to existing methods that rely on harsher conditions. The chemicals used include tert-butyl thiols, acetyl chloride, bromine, and acetic acid. The purpose of these chemicals is to facilitate the transformation of the robust tert-butyl protecting groups into more versatile and labile acetyl-protected thiols, which can be hydrolyzed in situ to free thiols, thereby enabling the integration of molecular systems into nanostructures and electronic circuits for studying their properties.
10.1016/j.ejmech.2007.02.019
The research focused on synthesizing a series of 12 new Mannich bases derived from 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones, aimed at evaluating their potential as antineoplastic agents. The study utilized chemicals such as acetyl chloride, aluminum chloride, dimethylformamide (DMF), formaldehyde, and various secondary amines in the synthesis process. The cytotoxicity of the synthesized compounds was assessed using the MTT assay on human pre-B-cell leukemia cell line BV-173 and chronic myeloid leukemia cell line K-562. The results indicated that the Mannich bases exhibited concentration-dependent cytotoxic effects, with some compounds inducing programmed cell death at low micromolar concentrations. The findings suggest that these heterocyclic chalcones represent a promising class of cytotoxic agents, warranting further pharmacological evaluation to elucidate their mechanisms of action and structure-activity relationships.
10.1021/ja994209s
The research focuses on the development of a new method for constructing ortho ring-alkylated phenols, which are prevalent in natural products and have applications as antioxidants, anticorrosives, and anticancer agents. The purpose of this study was to devise a procedure that could synthesize a variety of these phenols in a single operation, overcoming the limitations of previous methods such as rearrangement, electrophilic substitution, lithiation, and halogenation. The researchers aimed to achieve this by utilizing the reduction of ortho O-acylated phenones to produce phenols with ortho saturated alkyl substituents. The chemicals used in this process include NaBH4 as a reducing agent, organomagnesium reagents (Grignard reagents), and organolithium reagents to initiate the cascade reaction. The researchers also used acetyl chloride and ethyl vinyl ether (EVE) in their experiments. The study provides a detailed table (Table 1) that outlines the scope of the procedure, showcasing various nucleophiles and reaction conditions that lead to different products. The research concludes with a summary of the procedure's salient features, including the use of o-OBOC substituted aryl ketones and aldehydes, and the role of metal or its corresponding salt in the conversion of intermediate C to D.
F, 
C
F:Flammable;
