10.1016/S0040-4020(01)92361-0
The research focuses on the amidinoethylation of amino compounds, a new reaction that involves the addition of amines to the C=C double bond of various N,N'-substituted-propenamidines. The purpose of this study was to explore the synthesis of 3-amino-substituted-N,N'-substituted-propanamidines, which are not easily accessible through classical synthetic methods. The researchers found that the most nucleophilic amines, such as piperidine, morpholine, and pyrrolidine, added under mild conditions, while aliphatic and aromatic amines required more drastic conditions. The conclusions drawn from the study illustrate the activation of the C=C double bond of propenamidines by the conjugated amidine function, providing a new class of Michael acceptors for amino compounds. The chemicals used in the process include a variety of amines, such as piperidine, morpholine, pyrrolidine, cyclohexylamine, diisopropylamine, and aromatic amines, as well as solvents like acetonitrile, dimethylformamide, and ethylene glycol dimethylether, and catalysts such as acetic acid and SnCl4.
10.1016/S0040-4020(01)87786-3
The research focuses on the indirect electrochemical α-methoxylation of aliphatic ethers and acetals, a process that is technologically significant for the formation of mixed acetals, aldehydes, or ortho-esters. The study utilizes tris(2,4-dibromophenyl)amine as a redox catalyst in methanol solution, which allows the reaction to occur at low potentials with an undivided cell, leading to higher regioselectivity compared to direct electrolysis without a catalyst. The method is particularly valuable for the regioselective methoxylation of secondary carbon atoms in the presence of primary or tertiary ones and for the acetal carbon in 1,3-dioxolanes. The redox catalyst's stability under reaction conditions enables more than a thousand turnovers. The conclusions highlight the superiority of the indirect electrochemical method in terms of regioselectivity and the potential for large-scale applications, as demonstrated by the successful large-scale electrolysis of 1,2-dimethoxy ethane.
10.1016/S0040-4039(00)76198-3
The research focuses on the synthesis and structural analysis of octakis(aryloxy)naphthalenes, a novel class of molecules with oxygen atoms attached to each available position of the aromatic binuclear skeleton. The purpose of the study was to prepare these compounds from octafluoronaphthalene using DMEU-promoted complete nucleophilic substitution, a method previously employed for benzene-based systems. The reactions were carried out at approximately 90°C over several weeks, yielding products with varying efficiencies ranging from 55-85%. The chemicals used in the process include octafluoronaphthalene, sodium phenoxide, and DMEU (dimethoxyethane) as the promoter. The conclusions drawn from the study include the successful synthesis of the parent compound with an 85% yield and the characterization of its properties, as well as the discovery of a unique empty-cage clathrate structure for octakis(m-tolylthio)naphthalene and the elucidation of the host-guest packing in the acetone inclusion compound of octakis(β-naphthyloxy)naphthalene.
10.1002/(SICI)1521-3749(199911)625:11<1897::AID-ZAAC1897>3.0.CO;2-9
The study investigates the synthesis and crystal structures of two samarium complexes, [SmI2(DME)3] (1) and [Sm2I(NPPh3)5(DME)] (2), formed by reacting samarium metal with N-iodine-triphenylphosphaneimine in 1,2-dimethoxyethane (DME) under ultrasound treatment. Complex 1 is obtained as two different crystallographic forms, brownish-black crystals (1a) and violet-black crystals (1b), while complex 2 forms colorless, moisture-sensitive crystals containing two DME molecules per formula unit. The crystal structures reveal that in 1a and 1b, the samarium atoms have a coordination number of eight, with different I-Sm-I bond angles distinguishing the two forms. In complex 2, the two samarium atoms are linked via μ-N atoms of two phosphoraneiminato ligands to form a planar Sm2N2 four-membered ring, with one samarium atom achieving a distorted tetrahedral environment and the other a distorted octahedral environment through coordination with various ligands.
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