نتایج جستجو برای: solvent free reactions
تعداد نتایج: 713967 فیلتر نتایج به سال:
هدف اصلی این رساله ارائه روش های نوین سنتزی در راستای اهداف شیمی سبز می باشد. استفاده از روش های سنتزی مانند انجام واکنش در محیط های مایی، واکنش های بدون حلال و استفاده از کاتالیزگرهای آلی مبنای انجام واکنش ها در طرح حاضر بوده است. بر این اساس تحقیقات انجام شده در این پایان نامه به چهار بخش تقسیم شده است که در ادامه خلاصه ای از هر یک از فصول توضیح داده خواهد شد: در بخش 1، روشی جدید برای تهیه ف...
n-propylsulfamic acid supported onto magnetic fe3o4 nanoparticles (mnps-psa) was investigated as an efficient and magnetically recoverable catalyst for the one-pot synthesis of substituted coumarins from the reaction of coumarin with variety aromatic aldehydes in high to excellent yield at room temperature under solvent-free conditions. the magnetic nanocatalyst can be readily recovered easily ...
the chemistry of 2-oxo-1,2,3,4-tetrahydropyrimidines began to develop toward the end of 1893 year, when the first representatives of this class compounds were reported by p. biginelli. despite prior reports of several really effective catalytic and non-catalytic approaches towards biginelli-type products, an overwhelming number of new catalysts for the biginelli reaction have been recently publ...
various aldoximes and ketoximes synthesis of corresponding aldehydes and ketones in the presence of sio2@feso4 nano composite as recoverable nano catalyst and nh2oh·hcl. the sio2@feso4 nano composite system was carried out between 10 to 15 min in oil bath (70-80 °c) under solvent-free condition in excellent yields in addition this protocol can be used for industrial scales. this method offers s...
the solvent free route for the synthesis of diaryl sulfoxides from arenes and thionyl chloride in the presence of lewis acids such as aluminum chloride and ferric chloride on silica gel are described.
an efficient method for the friedel–crafts acylation of a wide range of aromatic compounds in good to excellent yields under solvent-free conditions, using iron zirconium phosphate (zpfe) was investigated. the catalyst is easy to prepare and shows interesting catalytic properties. the catalyst was characterized by some instrumental techniques such as xrd, icp-oes, sem and tem. a wide variety of...
p2o5-sio2 (30% w/w) was found to be a useful catalyst for the synthesis of various 2-substituted aryl benzimidazoles under solvent-less and in solvent conditions from o-phenylenediamine and aldehydes. the products were directly recrystallized from methanol.
a variety of alcohols readily add to 3,4-dihydro-2h-pyran under solvent free conditions in the presence of catalytic amount of acidic ionic liquid [et3n(ch2)4so3h][ots] to afford the corresponding tetrahydropyranyl ethers in good to excellent yields at room temperature. the use of this procedure allows easy separation of the desired products from ionic liquid and recycling the ionic liquid. som...
This paper describes a hybrid ab initio quantum mechanical/molecular mechanics (QM/MM) method for calculating activation free energies of chemical reactions in solution, using molecular mechanics force fields for the solvent and an ab initio technique that incorporates the potential from the solvent in its Hamiltonian for the solute. The empirical valence bond (EVB) method is used as a referenc...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید