نتایج جستجو برای: vinyltriphenylphosphonium salts
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Aryl(alkynyl)iodonium salts have been demonstrated to be valuable precursors to a diverse range of heteroaromatic ring systems including aryl[1,2-a]imidazopyridines. Successful application, using the recently described aryl(alkynyl)iodonium trifluoroacetate salts, is described, highlighting for the first time that the regioselectivity of this process is both counter-ion and concentration depend...
The binding of conjugated bile salts to pancreatic colipase and lipase has been studied by equilibrium dialysis and gel filtration. The results indicate that at physiological ionic strength and pH, conjugated bile salts bind as micelles to colipase: 12-15 moles/mole of colipase for the dihydroxy conjugates and 2-4 for the trihydroxy conjugates. No binding of bile salt takes place from monomeric...
Benzalkonium salts are widely used as disinfectants, biocides and detergents,among a variety of other applications. The cationic surface-activity of these salts determines their potential to act as a biocide on both target and non-target organisms. In this study, a quick synthesis of a complete set of the benzalkonium salts differing in the length of an alkylating chain (from C(2) to C(20)) is ...
Chrysiasis is the phenomenon of bluish to slategray skin pigmentation induced by prolonged treatment with gold salts. The most common etiology is the administration of gold salts to patients with rheumatoid arthritis. Although parental gold salt administration is now uncommon because of the availability of biologic agents and disease-modifying antirheumatic drugs, chrysiasis may still be seen b...
Bile from patients with mixed gallstones and controls without gallstones was analysed for relative concentrations of bile salts, phospholipids and cholesterol. A significant difference was found in the concentration of bile salts in normal controls and patients with cholelithiasis. The mean values for total bile salts, phospholipids and cholesterol in patients' bile were Mean + S.E. 84.34 + 15....
The hydroamination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. Heterogeneous intermolecular hydroamination reactions of alkynes with aromatic amines using different inexpensive copper salts of hetropolyacid catalysts were investigated. Among heteropoly salts, copper salts of silicotungstic acid showed highest a...
Manganese and Cobalt Salts of Para-Amino-Benzoic Acid Supported on Silica Gel as Oxidizing Catalysts
Para-Aminobenzoic acid is supported on silica gel via reaction of activated silica gel and p-aminobenzoic acid which is then converted to its manganese and cobalt salts. A mixture of the manganese and cobalt salts of the acid is used to catalyze allylic and benzylic alcohols to their corresponding carbonyl compounds in reasonable yields using oxygen or air. Reactions are clean and the catal...
Probiotics mainly reside in host intestinal tract, where they interact with bile salts and ingested cholesterol. This paper reviews the recent progresses of probiotics on the following issues, i.e. bile salts effect on membrane composition; probiotic tolerance and modification of bile salts; the mechanism of probiotic removal of host cholesterol; and the roles that bile salt hydrolase plays. © ...
Vinyl(aryl)iodonium salts are useful compounds in organic synthesis but they are under-utilized and their chemistry is under-developed. Herein is described the solvolysis of some vinyl(phenyl)iodonium salts, bearing an arylsulfonyl group, in aqueous DMSO leading to aldehyde formation. This unusual process is selective and operates under ambient conditions. Furthermore, the addition of aqueous H...
Although the hydrogen-bonding ability of the α hydrogen atoms on tetraalkylammonium salts is often discussed with respect to phase-transfer catalysts, catalysis that utilizes the hydrogen-bond-donor properties of tetraalkylammonium salts remains unknown. Herein, we demonstrate hydrogen-bonding catalysis with newly designed tetraalkylammonium salt catalysts in Mannich-type reactions. The structu...
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