نتایج جستجو برای: silica supported hclo4

تعداد نتایج: 230206  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده علوم پایه 1391

در این پایان نامه، tio2-hclo4 nano به عنوان یک نانوکاتالیزور قابل بازیافت و موثر به منظور محافظت و محافظت زدایی از گروه های عاملی مختلف و همچنین موثر در تسریع سنتز یکباره چند جزئی ترکیبات آلی معرفی شده است. در این مطالعه سایلیله شدن الکل ها و فنول ها توسط هگزامتیل دی سیلازان و محافظت زدایی از آن ها در حضور کاتالیزور tio2-hclo4 مورد بررسی قرار گرفت. کاتالیزور tio2-hclo4 همچنین ...

Journal: :The Journal of organic chemistry 2001
T Fey H Fischer S Bachmann K Albert C Bolm

The application of silica-supported TEMPO as a recyclable catalyst in the Anelli oxidation of alcohols is reported. The catalyst is easily obtained in a one-step reductive amination procedure starting from a commercially available aminopropyl-functionalized silica. Details of the synthesis of the supported catalyst and its analysis by MAS NMR are presented. Various alcohol oxidations according ...

Journal: :International Journal of Current Science Research and Review 2021

Objective: Many methods can be found in literature for the synthesis a Oxazines and Thiazines. Few are reported one-pot multi component cyclo-condensation of an alkayane urea / Thiourea Aldehyde to 2- amino-4H-1, 3-Oxazines or Different catalysts like Trifluoro-acetic acid, glacial acetic acid under reflux condition Mandal Co-workers have utilized perchloric (HClO4) supported on silica gel as c...

Phosphosulfonic acid as a multi solid site was easilyprepared from the reaction of ammonium dihydrogen phosphatewith chlorosulfonic acid in CCl4and for improved its catalyticactivity was supported nano Silica was extracted from husk ricecontains about 95% of Silica the size of extracted nano silica wasdetermined by SEM efficiency of this solid acid in four componentcondensation reaction of arom...

Nanocrystalline SiO2–HClO4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. The procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. In practice, this method is a combination of a satisfac...

Journal: :organic chemistry research 0
neda ayashi chemistry department, collage of science, shahid chamran university of ahvaz, ahvaz, iran mehdi fallah-mehrjardi department of chemistry, payame noor university, tehran, 19395-4697, iran ali reza kiasat a chemistry department, collage of science, shahid chamran university of ahvaz, ahvaz, iran

the use of a recyclable phase transfer catalyst, sio2-peg-imbr, is demonstrated in a simple and highly efficient synthesis of phenacyl derivatives by nucleophilic substitution reaction of phenacyl halides with different anions in water. advantages of this system are easy work-up, moderate to good yields, and recyclable catalyst. the catalyst can be recycled and reused several times with no loss...

AliReza Kiasat Raziye Najafi Birgani,

Phosphosulfonic  acid  as a  multi  solid site  was  easily  prepared  from  the reaction of ammonium  dihydrogen phosphate with chlorosulfonic acid in CCl4and for improved  its  catalytic activity  was  supported  nano Silica was  extracted from  husk  rice  contains  about 95%  of  Silica the  size of  extracted nano silica was  determined  by  SEM  efficiency of  this solid acid in four comp...

Dadkhoda Chazanfari Mohammad M. Hashemi

Para-Aminobenzoic acid is supported on silica gel via reaction of activated silica gel and p-aminobenzoic acid which is then converted to its manganese and cobalt salts. A mixture of the manganese and cobalt salts of the acid is used to catalyze allylic and benzylic alcohols to their corresponding carbonyl compounds in reasonable yields using oxygen or air. Reactions are clean and the catal...

Journal: :iranian chemical communication 2016
razieh fazaeli zahra mohagheghian

a green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with uhp at room temperature is reported. the reaction is performed in the presence of vanadia catalyst supported on mesocellular silica foam (mcf) with a v content ranging from 2% to 10% as heterogeneous and reusable catalyst. the structural and textural characterization of this catalyst were don...

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