نتایج جستجو برای: pot procedure

تعداد نتایج: 629235  

S. Rasouli S. Sadjadi,

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده کشاورزی 1390

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...

Journal: :Organic & biomolecular chemistry 2014
Romain Veillard Elise Bernoud Ibrahim Abdellah Jean-François Lohier Carole Alayrac Annie-Claude Gaumont

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...

Journal: :Organic letters 2002
Travis Dudding Ahmed M Hafez Andrew E Taggi Ty R Wagerle Thomas Lectka

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...

2001
Sabine Laschat Horst Kunz

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...

2012
Zahed Karimi-Jaberi Korosh Mohammadi

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...

2014
Daniel Hack Pankaj Chauhan Kristina Deckers Gary N. Hermann Lucas Mertens Gerhard Raabe Dieter Enders

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...

Journal: :Chemical science 2015
Valentín Hornillos Massimo Giannerini Carlos Vila Martín Fañanás-Mastral Ben L Feringa

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...

Journal: :Organic & biomolecular chemistry 2012
Anna Maria Deobald Arlene G Corrêa Daniel G Rivera Márcio Weber Paixão

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...

Journal: :Organic & biomolecular chemistry 2013
Russell J Johnson Donogh J R O'Mahony William T Edwards Matthew A J Duncton

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...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید