نتایج جستجو برای: preparation of amines
تعداد نتایج: 21171278 فیلتر نتایج به سال:
there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...
A practical method was elaborated for the synthesis of (aminomethylene)bisphosphine oxides comprising the catalyst- and solvent-free microwave-assisted three-component condensation of primary amines, triethyl orthoformate and two equivalents of diphenylphosphine oxide. The method is also suitable for the preparation of (aminomethylene)bisphosphonates using (MeO)2P(O)H/(MeO)3CH or (EtO)2P(O)H/(E...
A simple and convenient method was developed for the preparation of hindered tertiary amines via direct reductive amination of ketones with secondary aryl amines, using trichlorosilane as reducing agent and tetramethylethylenediamine (TMEDA) as organic Lewis base activator. A broad range of ketones were reacted with N-methylaniline to afford the corresponding tertiary amine products in high yie...
The 1,2,4-dithiazolidine-3,5-dione heterocycle, also referred to as a dithiasuccinoyl (Dts)-amine, serves as a readily removable amino protecting group for building blocks used in syntheses of peptides, glycopeptides, and PNA; it is also useful as a masked isocyanate and (inversely) as a sulfurization reagent for trivalent phosphorus. Bis(chlorocarbonyl)disulfane, the two-sulfur analogue of suc...
A sustainable enzymatic strategy for the preparation of amides by using Candida antarctica lipase B as biocatalyst and cyclopentyl methyl ether a green safe solvent was devised. The method is simple efficient it produces with excellent conversions yields without need intensive purification steps. scope reaction extended to 28 diverse four different free carboxylic acids seven primary secondary ...
Bleach oxidizes trimethylsilyl cyanide to generate an electrophilic cyanating reagent that readily reacts with an amine nucleophile. This oxidative N-cyanation reaction allows for the preparation of disubstituted cyanamides from amines without using highly toxic cyanogen halides.
A novel ANRORC mechanism in the reaction of 1-(2,4-dinitrobenzenesulfonyl)inosines with amines has allowed the preparation of 1-alkyladenosines and [1-15N]adenosines in a straightforward way from inosines.
Selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. This catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...
A simple and efficient one-pot method for the preparation of aromatic iodides has been developed by sequential diazotization–iodination of aromatic amines employing sodium nitrite and sodium iodide in the presence of acidic ionic liquid N-methyl-2-pyrrolidonum hydrosulfate ([H-NMP]HSO4). The diazonium salts that are formed by this ionic liquid are stable at room temperature and r...
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