نتایج جستجو برای: pot procedure
تعداد نتایج: 629235 فیلتر نتایج به سال:
Nanocrystalline alumina powder has been synthesized using solution combustion method. The obtained nanocrystalline alumina powder was used as an efficient catalyst for the synthesis of imidazo[1,2-a]azine derivatives from one-pot three component reaction of benzaldehyde, 2-aminoazine and trimethylsilylcyanide under ultrasonic irradiation and refluxing condition. Reusability of catalyst and shor...
پتاسیم قابل استفاده در خاک معیار مهمی برای رشد گیاه و تولید عملکرد است. برخی باکتری های خاک می توانند پتاسیم قابل استفاده را برای رشد گیاهانافزایش دهند. به منظور جداسازی و بررسی میزان کارایی این باکتری ها در خاک، تعداد پنج نمونه خاک از نظر وجود باکتری های آزاد کننده پتاسیم مورد ارزیابی قرار گرفتند و در نهایت شش ایزوله به عنوان باکتری های موثر، جداسازی شدند. براساس بررسی های میکروسکوپی، آزمون ها...
A versatile synthesis of 1,2,3-triazolyl-4-phosphines from the borane complexes of phosphino-alkynes is reported. The efficiency of the procedure relies on the use of readily available silyl-protected alkynylphosphine-boranes, which were subjected to desilylation with TBAF followed by copper-catalyzed azide-alkyne-cycloaddition in one pot. Subsequent treatment with DABCO afforded the targeted t...
We report a new method for the catalytic, asymmetric synthesis of beta-substituted aspartic acid derivatives in which the nucleophilic catalyst serves up to four discrete roles in a one-pot procedure: catalytic dehydrohalogenation of acid chlorides to form ketenes; catalytic dehydrohalogenation of alpha-chloroamines to form the corresponding imines; catalyzed [2 + 2]-cycloaddition to produce in...
The stereoselective synthesis of diethyl (S)or (R)-IX-[( O-pivaloylhexapyranosyl)amino]benzylphosphonates is achieved via Lewis acid catalyzed addition of diethyl phosphite to O-pivaloylated Nbenzylidene-{3-D-galactosylamine or N-benzylidene-IX-D-arabinopyranosylamine. The process can also be performed by a one-pot procedure selectively giving (S)-aminophosphonic acid derivatives from galactosy...
β-acetamido ketones were synthesized in excellent yields through one-pot condensation reaction of aldehydes, acetophenones, acetyl chloride, and acetonitrile in the presence of boric acid as a solid heterogeneous catalyst at room temperature. It is the first successful report of boric acid that has been used as solid acid catalyst for the preparation of β-acetamido ketones. The remarkable advan...
A highly stereoselective one-pot procedure for the synthesis of five-membered annulated hydroxycoumarins has been developed. By merging primary amine catalysis with silver catalysis, a series of functionalized coumarin derivatives were obtained in good yields (up to 91%) and good to excellent enantioselectivities (up to 99% ee) via a Michael addition/hydroalkoxylation reaction. Depending on the...
A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd2(dba)3/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl)lithium can be efficiently converted into substituted vinyl ethers which, after...
An eco-friendly synthesis of highly functionalized epoxides and their incorporation into an organocatalytic multicomponent approach are reported. For this, a modified class of diarylprolinol silyl ethers was designed to enable high catalytic activity in an environmentally benign solvent system. The one-pot procedure showed great efficiency in promoting stereoselective multicomponent transformat...
5,6,7,8-Tetrahydroquinolines and 5,6,7,8-tetrahydronaphthyridines with appended trifluoromethyl groups are valuable chemotypes in medicinal chemistry due to the presence of a partially-saturated bicyclic ring and metabolically-stable CF(3) group. (1)H NMR studies were used to optimize the preparation of such compounds, using a three-step/one-pot procedure, to provide novel 2,6-disubstitued deri...
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