نتایج جستجو برای: nanomagnetic heterogeneous catalyst

تعداد نتایج: 166813  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان زنجان - دانشکده علوم پایه 1389

پیرول ترکیب حلقوی پنج عضوی است که دارای فرمول c4h4nh می باشد. این ماده، مایع فرار و بی رنگی است که به سرعت در مجاورت هوا تیره می شود. مشتقات دارای استخلاف پیرول نیز با این نام شناخته می شوند. به طور مثال n-متیل پیرول ماده اولیه سنتز n- متیل کربوکسیلیک اسید است که واحد سازنده بسیاری از داروها در صنعت داروسازی (داروهایی با خصلت آنتی باکتریایی، آنتی ویروسی، آنتی تومور، آنتی اکسیدان و ضد التهاب)و ه...

Journal: :Chemical communications 2014
Hiroshi Shintaku Kiyotaka Nakajima Masaaki Kitano Michikazu Hara

A new heterogeneous catalyst, hydrophobic TiO4-deposited mesoporous silica, has been designed for the efficient Mukaiyama-aldol condensation, a water-participating Lewis acid-catalyzed reaction between a hydrophobic carbonyl compound and silyl enol ether. The prepared catalyst suspended in water exhibited high catalytic performance as a reusable catalyst for the reaction without a surfactant.

Farshid Ghraghsahar Fatemeh Akbari Leila Youseftabar-Miri

Eggshell was found to be a versatile heterogeneous catalyst for the synthesis of pyrano[3,2-c]quinoline derivatives in good yields. This protocol has the advantages of environmental friendliness, short reaction time, low cost and convenient operation.

2017
John G. Verkade

Homogeneous transition metal complex catalysts for organic industrial processes are converted to catalysts which are heterogeneous with respect to the reactants, and which have substantially equal catalytic activity to the homogeneous catalysts. This is done by reacting a normally homogeneous transition metal complex catalyst with a metal bridging ligand which substantially duplicates the ligan...

Journal: :journal of sciences, islamic republic of iran 2015
s. ghasemi b. tamami r. teymoori h. allahyari

poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. this modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. furthermore, the catalyst was applied for the conversion o...

A simple, efficient, and green practical approach to Knoevenagel condensation of malononitrile and different aldehydes has been developed using an ionic liquid functionalized on Fe3O4 magnetic nanoparticles as heterogeneous catalyst. This nanostructural catalyst has also been applied for the synthesis of 4H-benzo[b]pyran derivatives in water at room temperature in short reaction time. All of th...

Bamboo is one of the important biopolymers which is used in chemistry. In this work, for the first time, a solid acid catalyst from bamboo was prepared from the reaction of sawdust bamboo and chlorosulfonic acid. Relevant properties of catalyst were investigated by FT-IR, XRD, SEM and TGA. The sulfonated bamboo (bamboo-SO3H) with several acid functional groups was utilized as highly ...

Farzaneh Maliji Rahman Hosseinzadeh, Zahra Lasemi

Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reuse...

Journal: :international journal of nanoscience and nanotechnology 2014
a. bamoniri a.r. pourali s.m.r. nazifi

nanosilica periodic acid (nano-spia) is found to be a new, powerful, and reusable heterogeneous catalyst for the rapid synthesis of 2-naphtholazo dyes via diazotization of aromatic amines and followsazo coupling with 2-naphthol under solvent-free conditions at room temperature by grinding. eco-friendly, heterogeneous reaction conditions, high stability of diazonium salt, simple experimental pro...

Journal: :Journal of the American Chemical Society 2013
Elad Gross Jack H Liu Selim Alayoglu Matthew A Marcus Sirine C Fakra F Dean Toste Gabor A Somorjai

Research to develop highly versatile, chiral, heterogeneous catalysts for asymmetric organic transformations, without quenching the catalytic reactivity, has met with limited success. While chiral supramolecular structures, connected by weak bonds, are highly active for homogeneous asymmetric catalysis, their application in heterogeneous catalysis is rare. In this work, asymmetric catalyst was ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید