نتایج جستجو برای: hantzsch synthesis

تعداد نتایج: 409399  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده علوم 1388

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

Journal: :journal of sciences islamic republic of iran 0

hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. reactions are clean and the catalysts can be recovered easily and reused repeatedly.

Gholamreza Karimipour, Massomeh Bahramian Zahra Rafiee

In this work, a polyimide (PI) containing triazole units was synthesized using 3,5-diamino-1,2,4-triazole and pyromellitic dianhydride in N-methyl-2-pyrrolidinone. This polymer was used as the support of manganese (III) tetrakis(4-methoxylphenyl)porphyrin acetate to attain a heterogeneous catalyst; namely Mn(T4-OMePP)OAc@PI. The synthesized PI and Mn(T4-OMePP)OAc@PI were characterized by di...

Hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. Reactions are clean and the catalysts can be recovered easily and reused repeatedly.

2005
T. J. Still S. Al-Haider P. W. Seakins R. Sommariva J. C. Stanton G. Mills S. A. Penkett

Ambient formaldehyde measurements made at a remote marine boundary layer site during the NAMBLEX campaign – a comparison of data from chromatographic and modified Hantzsch techniques T. J. Still, S. Al-Haider, P. W. Seakins, R. Sommariva, J. C. Stanton, G. Mills, and S. A. Penkett School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK School of Environmental Sciences, University of East A...

Journal: :Journal of the American Chemical Society 2005
Stéphane G Ouellet Jamison B Tuttle David W C MacMillan

The first enantioselective organocatalytic hydride reduction has been accomplished. The use of iminium catalysis has provided a new organocatalytic strategy for the enantioselective reduction of beta,beta-substituted alpha,beta-unsaturated aldehydes to generate beta-stereogenic aldehydes. The use of imidazolidinone 2 as the asymmetric catalyst has been found to mediate the transfer of hydrogen ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت دبیر شهید رجایی - دانشکده علوم انسانی 1392

this study investigated the impact of explicit instruction of morphemic analysis and synthesis on the vocabulary development of the students. the participants were 90 junior high school students divided into two experimental groups and one control group. morphological awareness techniques (analysis/synthesis) and conventional techniques were used to teach vocabulary in the experimental groups a...

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