نتایج جستجو برای: catalytic vinylogous anomeric based oxidation

تعداد نتایج: 3097404  

The vanadium-based catalyst, acts as a homogeneous catalyst for the selective oxidation of various kinds of sulfides with 30% aqueous H2O2. Vanadium-based catalyst was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in a good way to high yields without any detectable over-oxidation to sulfones under normal condi...

Journal: :Chemistry 2023

Modified nucleobases are potentially useful building blocks when containing catalytically active functionalities and could be introduced in chiral tridimensional molecules such as nucleic acids, which creates the premises for development of novel catalytic species. Herein, we describe synthesis a β-C-nucleoside bearing diol group at anomeric position, amenable metal ligand or organocatalyst. An...

By coupling of Fe2O3@SiO2 particles with metal organic Framework (MOF) the magnetic MOF structure was fabricated. Precipitation and hydrothermal methods were applied for synthesis of core and MOF. Silver nanoparticles were deposited on nickel based metal organic framework surface and magnetic Fe2O3@SiO2@MOF@Ag was obtained. Because of strong coupling between silver nanoparticles and metal organ...

Journal: :Journal of molecular biology 2006
Christian Brüx Alon Ben-David Dalia Shallom-Shezifi Maya Leon Karsten Niefind Gil Shoham Yuval Shoham Dietmar Schomburg

beta-D-Xylosidases are glycoside hydrolases that catalyze the release of xylose units from short xylooligosaccharides and are engaged in the final breakdown of plant cell-wall hemicellulose. Here we describe the enzyme-substrate crystal structure of an inverting family 43 beta-xylosidase, from Geobacillus stearothermophilus T-6 (XynB3). Each XynB3 monomeric subunit is organized in two domains: ...

Journal: :Journal of the American Chemical Society 2010
Ravi P Singh Bruce M Foxman Li Deng

Despite their synthetic significance there is a general lack of asymmetric vinylogous aldol reactions that tolerate variations of both the silyloxy furans and aldehydes. We have developed a new chiral organic catalyst based on a carboxylate-ammonium salt prepared from a thiourea-amine and a carboxylic acid. This new catalyst enabled us to develop an efficient asymmetric vinylogous aldol reactio...

An efficient synthetic method for successful synthesis of amine denderon on SBA-15 and related Pd (II) complex has been developed. This modified mesoporous material was characterized by various techniques such as TEM, XRD, atomic absorption spectroscopy, N2 adsorption-desorption, and FT-IR. The catalytic activities of the prepared catalysts were investigated by employing aerobic oxidation of al...

Palladium nanoparticles supported on carbon black powder (Vulcan XC-72) nanocomposite (Pd/C) are synthesized as the catalyst for the anodic oxidation of glucose for use in a direct glucose alkaline fuel cell (DGAFC). Characterization of the catalyst is carried out using physical and electrochemical methods. It is observed that Palladium nanoparticles are uniformly dispersed onto the carbon blac...

Journal: :Chemical communications 2015
Keigo Oyaizu Daisuke Uraguchi Takashi Ooi

The vinylogous reactivity of α,β-disubstituted nitroolefins was uncovered through the facile generation of the corresponding α-substituted vinylogous nitronates and their use in the development of a highly diastereo- and enantioselective aza-Henry reaction with N-Boc aldimines under the catalysis of chiral ammonium betaines. The novel vinylogous nitronates undergo stereoselective bond formation...

Nea Hasanzadeh Raja Ahmadzadeh

NBO analysis, hybrid density functional theory (B3LYP/6-311+G**) based methods were used to study the anomeric effects (AE), Stereoelectronic interactions, dipole-dipole interactions on the conformational properties of 1-Fluoro-N, N-dimethylmethanamine (1) and phosphorus (2) and arsenic (3) analogues.Moreover, relationships between stability of the anti-conformations of 1-Fluoro-N, N-dimethylme...

Abbas Afkhami Hamid Bahrami

A catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(II) id described. The method is based on the catalytic effect of manganese(II) on the oxidation reaction of ferroin by potassium periodate in acidic media. The reaction is monitored spectrophotometrically at 510 nm by a slope method and Mn(II) is determinable in the range of 1-1000ngmL-1</sup...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید