نتایج جستجو برای: heterogeneous nano catalyst
تعداد نتایج: 215380 فیلتر نتایج به سال:
Al-MCM-41 nanoreactors is found to be a remarkable efficient catalyst for one-pot multicomponent cyclocondensation of benzil, aniline or ammonium acetate and aromatic aldehydes for the synthesis of polysubstituted imidazoles under solvent-free conditions. The reaction was efficiently promoted by 10 mg nano-Al-MCM-41 and the heterogeneous catalyst was recycled for four runs in this reaction with...
knoevenagel condensation between barbituric acid and aldehyde was investigated in the presence of sulfonic acid functionalized nanoporous silica (sba-pr-so3h) and resulted in the formation of arylidene and bis-arylidene barbiturates. excellent yields and short reaction times are related to the high efficiency of sba-pr-so3h that the reactions take place easily in its nano-pores. sba-pr-so3h as ...
NOVEL HETEROGENOUS AND MAGNETICALY SEPARABLE CATALYSTS FOR SELECTIVE AND ENANTIOSELECTIVE ORGANIC TRANSFORMATIONS A brief description of the chapters in the thesis is outlined below: Chapter 1 Chapter 2 Chapter 5 Chapter 3 Chapter 4 Section B Section A THESIS CHAPTER-I, describes the various catalysts/process options available for an industrial chemist to effect different organic transformation...
to be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. fe3o4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irra...
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.
bis-(l-tyrosinato)copper(ii) was reacted with 3-(chloropropyl)-trimethoxysilane functionalized silica that has infused magnetite to yield a magnetically separable catalyst in which the copper carboxylate is covalently linked to the silica matrix through the silane linkage. the immobilized catalyst has been characterized by spectroscopic studies (such as ft-ir, epr, magnetic measurement, sem) an...
fe3o4 magnetic nanoparticles were synthesized by co-precipitation of fe2+ and fe3+ in aqueous naoh. then silica was coated on the obtained nanoparticles and the whole composite was functionalized with chlorosulfonic acid in ch2cl2. the obtained nanocomposite (fe3o4@sio2-so3h) was characterized by ft-ir, vsm and xrd techniques and was used as an efficient catalyst in condensation reaction of ind...
a simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (sio2-osbcl2) as a catalyst in ethanol at moderate temperature. operational simplicity, practicability and applicabi...
BACKGROUND Marine sponge/nano-CuO as a natural catalyst efficiently catalyzed the Sulfonylation reaction of p-chlorobenzene sulfonyl chlorides with amines in order to prepare sulfonamides. The advantages included use of a natural catalyst, ease of handling, requirement of a very small amount of catalyst, mild reaction condition and appropriateness to high yield. OBJECTIVES The current study a...
Knoevenagel condensation between barbituric acid and aldehyde was investigated in the presence of sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) and resulted in the formation of arylidene and bis-arylidene barbiturates. Excellent yields and short reaction times are related to the high efficiency of SBA-Pr-SO3H that the reactions take place easily in its nano-pores. SBA-Pr-SO3H as ...
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