نتایج جستجو برای: multi component reactions

تعداد نتایج: 1195877  

2001
Tzihong Chiueh

Self-consistent dynamics of the multi-component, N -field quintessence and gravity is formulated as relativistic N -body dynamics, embedded in a static viscous flat space and under the forces given by the interacting Lorentz scalar potential via exchanges of field bosons. The Ratra-Peebles power-law potential of effective single-field quintessence can be derived from this ”microscopic” perspect...

Journal: :Journal of Physics A: Mathematical and Theoretical 2011

Abdolhamid Bamoniri, Bi Bi Fatemeh Mirjalili, Seyedeh Azita Fazeli Attar

A highly efficient procedure for the preparation of N,N'-alkylidenebisamides in the presence of BF3.SiO2 as a catalyst is described. N,N'-alkylidenebisamides have been prepared via one-pot three-component condensation reaction of various aldehydes and amides. All of the reactions proceeded in high yields and in moderately short reaction times.

Jilla Saffari, Minoo Ghaani

This paper outlines the synthesis of CuFe2O4 nanoparticles and their catalytic applications. CuFe2O4 nanoparticles were synthesized via microwave-assisted co-precipitation method. The obtained nanoparticles characterized through Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Vibrating sample magnetometer shows nanoparticles exhibit ferromagnetic be...

One-pot, four-component procedure for the synthesis of a small library of new chiral spiro- oxindolopyrrolidines with high regio-, diastereo- (>99:1 dr), and enantioselectivity (up to 80% ee) is described. In this process, the regio- and stereochemical 1,3-dipolar cycloaddition of azomethine ylides, which were generated insitu by the reaction of isatin derivatives and sarcosin,with optically ac...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1389

selective desulfurization of thiocarbonyls to carbonyls thioacetalization of aldehydes and ketones a useful reagent system for the dethioacetalization reactions

A convenient synthesis of different types of polyfunctional dihydropyrrol-2-ones via one-pot four component reactions of formaldehyde, dialkyl acetylenedicarboxylates and amines, catalyzed by trichloroacetic acid (Cl3CCO2H) at room temperature has been investigated. The significant advantages of this synthetic method are mild reaction conditions, available and inexpensive material, short reacti...

Ahmad Shaabani, Peiman Mirzaei

Microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.

Silica sodium carbonate (SSC) has been used as a valuable silica-supported catalyst for the preparation of a range of known and novel pyrano coumarins via the three-component reactions of aryl aldehydes, active methylene compound (malononitrile or ethyl cyanoacetate), and hydroxycoumarin (5,7-dihydroxy-4-substituted coumarins or 4-hydroxycoumarin). The heterogeneous catalyst showed much the sam...

Abdolhamid Bamoniri, Bi Bi Fatemeh Mirjalili, Seyedeh Azita Fazeli Attar

A highly efficient procedure for the preparation of N,N'-alkylidenebisamides in the presence of BF3.SiO2 as a catalyst is described. N,N'-alkylidenebisamides have been prepared via one-pot three-component condensation reaction of various aldehydes and amides. All of the reactions proceeded in high yields and in moderately short reaction times.

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