10.1016/j.jorganchem.2007.12.033
The research focuses on the synthesis, structure, and reactions of novel j3S,C,S-pincer palladium complexes containing a 3,5-pyridinediyl unit. The cyclopalladation of 3,5-bis(diphenylphosphinothioyl)pyridine led to the formation of new j3S,C,S-pincer palladium complexes with a p-bond between Pd and the 4C of the centered 3,5-pyridinediyl unit. The study utilized the quaternization and complexation ability of the pyridine imine nitrogen (Npy) atom to synthesize various new pincer-type complexes, including hetero-binuclear complexes. The experiments involved Pd-catalyzed aryl phosphination of 3,5-dibromopyridine with diphenylphosphine, followed by sulfurization to obtain the ligand. Further reactions with PdCl2(PhCN)2 and sodium acetate yielded the pincer palladium complex, which was then subjected to quaternization and complexation reactions. The chemical structures were confirmed using NMR, FAB-mass spectroscopy, elemental analysis, and X-ray crystallography. The study also investigated the UV–Vis absorption spectra of the complexes.
10.1016/S0040-4020(98)01046-1
The research involves the synthesis and reactivity of bis(arylcarbamoyl)-N-arylphenacylamine oximes, which are precursors to N-unsubstituted O-arylcarbamoylhydroxylamines and 1,3-dihydroimidazol-2-ones. The study aimed to explore the Beckmann fragmentation and intramolecular cyclization of these compounds to form imidazol-2-ones. The researchers found that the expected Beckmann fragmentation did not occur under the tested conditions, and instead, the compounds underwent intramolecular nucleophilic addition, leading to the formation of imidazolidinones. The synthesis involved the use of N-arylphenacylamines, hydroxylamine hydrochloride, sodium acetate, aryl isocyanates, and TsOH.H2O (p-toluenesulfonic acid monohydrate), among other reagents. The conclusions of the research were that bis(arylcarbamoyl)-N-arylphenacylamine oximes are excellent precursors for the synthesis of the target compounds, and the reactions provided high yields of the desired products, with the process being confirmed through various analytical techniques including NMR, IR, and mass spectrometry.
10.1021/om801029k
The research investigates the reaction of Rhodium(III) porphyrins (specifically Rh(ttp)Cl) with methanol in the presence of inorganic bases at high temperatures (150 °C) to produce rhodium porphyrin methyls (Rh(ttp)CH3) with high yields (up to 87%). The study aims to understand the carbon-hydrogen bond activation chemistry of rhodium porphyrins and to explore the conditions under which methanol can react with these complexes to aid in the design of catalysts for catalytic methane oxidation. The key findings suggest that Rh(ttp)H is the key intermediate for carbon-oxygen bond cleavage, and the role of bases is to facilitate the formation of reactive intermediates and enhance reaction rates. The research concludes that to achieve efficient rhodium porphyrin-based methane oxidation, it would be necessary to either continuously remove methanol or carry out the reaction at lower conversions. The key chemicals used in the research include Rh(ttp)Cl (rhodium(III) tetrakistolylporphyrinato chloride), methanol, various inorganic bases (such as KOH, NaOH, K2CO3, Na2CO3, Potassium bicarbonate (KHCO3), K3PO4, Potassium acetate (KOAc), and Sodium acetate (NaOAc)), and other rhodium porphyrin complexes like Rh(tpp)Cl, Rh(tmp)Cl, and Rh2(ttp)2.
10.1021/ja01334a060
The study explores the synthesis and properties of various naphthyl derivatives of barbituric acid. The research focuses on creating compounds where the naphthyl group is either directly attached to the 5-carbon atom or connected via methylene groups. The chemicals involved include a-naphthylmethyl bromide and a-naphthylethyl bromide, which were used for alkylation to introduce naphthylmethyl and naphthylethyl groups into barbituric acids. The study also utilized alkyl barbituric acids, sodium acetate, and urea in the synthesis processes. The goal was to investigate the potential therapeutic properties of these derivatives as sedatives and hypnotics, similar to known compounds like barbital and amytal. The study reports the successful synthesis of several derivatives, including 5,5-ethyl-a-naphthylmethylbarbituric acid, 5,5-n-butyl-a-naphthylmethylbarbituric acid, and 5,5-allyl-a-naphthylmethylbarbituric acid, among others. However, none of the synthesized compounds exhibited desirable physiological effects comparable to barbital or amytal. The study also details the preparation methods and the physical and analytical data of the synthesized compounds.
10.1246/bcsj.48.1249
The research explores two methods for synthesizing naphtho[1,8-bc]furans (VIa-VId). The first method involves decarboxylation of compounds IIa-IId, which were prepared from tetralone derivatives (Ia-Id) and ethyl bromoacetate. The yields of IIa-IId from Ia-Id were 45%, 43%, 49%, and 46% respectively. The second method involves heating compounds Va-Vd with acetic anhydride and sodium acetate, yielding VIa-VId at 34%, 46%, 46%, and 70% respectively. The study concludes that the presence of propionic acid residues in the starting materials may inhibit the free rotation of carbonyl groups, leading to lower yields. Additionally, the formation of lactones was observed as a side product in some reactions, which may also contribute to the lower yields of the desired furan compounds. The research highlights the challenges in synthesizing naphtho[1,8-bc]furans and suggests that further investigation into synthetic methods and reaction conditions is needed to improve yields and understand the underlying mechanisms.
10.1080/00397911.2010.527421
The research aims to develop a novel and efficient method for synthesizing γ-lactone, keto-d-lactone, and butenolide derivatives through the Baeyer–Villiger rearrangement of cyclobutanones. These compounds are significant due to their widespread presence in nature and potential biological activities, making them valuable as intermediates in the synthesis of complex natural products. The study explores the Baeyer–Villiger rearrangement conditions using various cyclobutanones, identifying that freshly prepared peracetic acid with sodium acetate in refluxing CHCl3 provides excellent conversion and good yields. The researchers also developed a one-pot synthesis of keto-d-lactone from the rearrangement products using p-TsOH in refluxing benzene. Additionally, they synthesized butenolide derivatives through a series of reactions involving lithium diisopropylamide (LDA) and PhSeCl, followed by hydrogen peroxide treatment. The study concludes that this method offers a facile and efficient route for the synthesis of these important chemical structures, with potential applications in the total synthesis of natural products like stryllactone. Key chemicals used in the research include cyclobutanone derivatives, peracetic acid, sodium acetate, p-TsOH, NaBH4, LDA, PhSeCl, and hydrogen peroxide.
10.1021/acs.orglett.0c03025
The study introduces a novel method for synthesizing cyano-tetrazoles, a unique class of compounds with four nitrogen atoms in a five-membered ring. Historically, the synthesis of cyano-tetrazoles has been challenging due to the scarcity of practical synthetic methods. The researchers developed a straightforward cycloaddition process using readily accessible aryl diazonium salts and diazoacetonitrile as the key reactants. The reaction is catalyzed by silver acetate and sodium acetate, with the metal cation controlling the formation of two distinct regioisomers of disubstituted tetrazoles. The study demonstrates remarkable functional group compatibility and high yields, making it a versatile approach for synthesizing a wide range of cyano-tetrazole derivatives. Additionally, the researchers conducted density functional theory (DFT) calculations to elucidate the mechanism, revealing that the regioselectivity is governed by the metal cations used in the reaction. This method not only fills a long-standing gap in heterocyclic chemistry but also has potential applications in organic synthesis, medicinal chemistry, and materials science.
