Refernces
10.1039/c8nj01223g
The research focuses on the green synthesis of gold (Au), silver (Ag), platinum (Pt), and palladium (Pd) nanoparticles using sodium rhodizonate as a bifunctional reducing and stabilizing agent. The study involves the preparation of these nanoparticles in water through a single-step process and evaluates their catalytic efficiency in reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using sodium borohydride (NaBH4) and in the dual-catalytic oxidation of formic acid followed by the reduction of methyl orange (MO). The synthesized nanoparticles were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, and zeta potential measurements to determine their size, morphology, crystallinity, elemental composition, and surface charge. The catalytic activities of the nanoparticles were assessed through UV-Vis spectrophotometer monitoring of the absorbance changes at specific wavelengths, corresponding to the reactants and products in the reduction reactions.
10.1039/c001465f
The research focuses on the development of new synthetic strategies for the synthesis of highly functional erythrina, oxindole, and pyrrolidinoindoline skeletons, which are structural motifs found in bioactive alkaloids. The experiments involve the use of 4-aminophenol-derived amides as building blocks for these complex alkaloid structures. Key reactants include 4-aminophenol, homoveratroyl chloride, lithium aluminium hydride, and ethyl 3-chloro-3oxopropanoate, among others. The oxidative dearomatization process is central to the synthesis, utilizing iodobenzene diacetate (IBD) in methanol to form cyclohexenone intermediates, which are then further reacted with allyl bromide and potassium carbonate to yield oxindoles. The study also reports an unprecedented rearrangement leading to the formation of 3-hydroxyoxindole and the synthesis of a mimic of the natural alkaloid CPC-1. Analytical techniques such as 1H NMR and 13C NMR spectroscopy were employed to characterize key intermediates and final products, confirming the success of the synthetic routes and the structural diversity of the synthesized compounds.
10.1080/00397911.2015.1041048
The research details the convergent versus divergent three-step synthesis of the first (4-aminophenoxy)alkanoic acid-based tripodal melamines. The study aimed to develop novel tripodal N-substituted melamines as s-triazine derivatives, which have potential applications in the construction of luminescent enantiomorphic three-dimensional metal-organic frameworks. The researchers compared two synthetic routes, starting from either N-(4-hydroxyphenyl)acetamide (Paracetamol) for the convergent approach or cyanuric chloride with 4-aminophenol for the divergent approach. Key chemicals used in the process included Paracetamol, cyanuric chloride, 4-aminophenol, ethyl bromoacetate, and various reagents for the hydrolysis and etherification steps. The conclusions highlighted that N-(4-hydroxyphenyl)acetamide was a promising starting material for the convergent synthesis of the novel tripodal melamines with overall yields of 76% for (4-aminophenoxy)acetic acid and 47% for 4-(4-aminophenoxy)butyric acid derivatives. The divergent approach yielded similar compounds with overall yields ranging between 36 and 48%. The crucial steps in both strategies were the Williamson etherification of N-masked forms of 4-aminophenol and the acidic hydrolysis of the (4-aminophenoxy)alkanoic segments during their N-, O-chemoselective deprotection.
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