نتایج جستجو برای: amines
تعداد نتایج: 20593 فیلتر نتایج به سال:
The first iron-catalyzed guanylation of amines is reported. Commercially available Fe(OAc)2 acts as an excellent catalyst for the addition of amines to carbodiimides. The reaction is broadly applicable to a variety of primary, secondary, and heterocyclic amines, and tolerates a wide range of functionalities allowing the easy preparation of a large family of guanidines. The low price and low tox...
C,N-coupling reactions of aryl chlorides and aryl amines catalyzed by a nickel catalyst are reported. 17 new amines are synthesized in yields of 57-99%. 2,6-Dichloro substituted imines can be selectively aminated. Both mono- and di-aminated products are obtained. Different substrates and amines are tested to look into the influence of electronic effects and steric hindrance to the reaction. An ...
The rhodium-catalyzed regioselective amination of tertiary allylic trichloroacetimidates with unactivated aromatic amines is a direct and efficient approach to the preparation of α,α-disubstituted allylic aryl amines in good yield and with excellent regioselectivity. This method is applicable to a variety of unactivated primary and secondary amines and allows for the preparation of reverse pren...
109 Biogenic amines are a group of organic nitrogenous compounds formed and degraded by the metabolisms of living organisms (microorganisms, plants and animals). The main biogenic amines associated with wine are putrescine, histamine, tyramine and cadaverine, followed by phenylethylamine, spermidine, spermine, agmatine and tryptamine. Biogenic amines in wine can be formed by various microorgani...
Aromatic amines are important intermediates in industrial manufacturing. N-Oxidation to N-hydroxyarylamines is a key step in determining the genotoxic properties of aromatic amines. N-Hydroxyarylamines can form adducts with DNA, with tissue proteins, and with the blood proteins albumin and hemoglobin in a dose-dependent manner. The determination of hemoglobin adducts is a useful tool for biomon...
Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vascula...
The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, chiral to their N-Boc-protected derivatives solvent-free c...
Aliphatic amines, such as n-hexylamine (primary), di-n-hexylamine (secondary) and tri-n-hexylamine (tertiary amine), react with tetrabromophenolphthalein ethyl ester molecules (TBPEH) to form reddish or red-violet charge-transfer complexes (CT complexes) in 1,2-dichloroethane (DCE). The absorption maxima of the CT complexes with all primary amines occur at around 560 nm, with secondary amines a...
The determination of biogenic amines in alcoholic beverages is important to assess the potential risks associated with the consumption of high concentrations of these compounds. In addition, product storage conditions and the length of storage can cause the formation of biogenic amines that reduce product quality. We report a new method using cation-exchange chromatography with either suppresse...
Aliphatic amines were determined in sediments and sediment pore waters from several contrasting sites in Chesapeake Bay. The aliphatic amines diethylamine, set-butylamine, n-propylamine, and i-propylamine were detected in a limited number of pore-water samples at concentrations generally less than 0.6 /IM. The occurrence of these amines showed no obvious correlation to other sediment geochemica...
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