نتایج جستجو برای: nanoparticle iron catalyst

تعداد نتایج: 212890  

Journal: :Nature chemistry 2017
Christopher K Prier Ruijie K Zhang Andrew R Buller Sabine Brinkmann-Chen Frances H Arnold

C-H bonds are ubiquitous structural units of organic molecules. Although these bonds are generally considered to be chemically inert, the recent emergence of methods for C-H functionalization promises to transform the way synthetic chemistry is performed. The intermolecular amination of C-H bonds represents a particularly desirable and challenging transformation for which no efficient, highly s...

Journal: :Dalton transactions 2015
Adrien Boudier Pierre-Alain R Breuil Lionel Magna Hélène Olivier-Bourbigou Pierre Braunstein

Multinuclear aluminum cocatalysts have been obtained by the reaction of various phenols, alcohols or diols with trimethylaluminum and were used in situ or as isolated, well-defined species, for the activation of an iron(ii) or an iron(iii) pre-catalyst for the oligomerization of ethylene. The best cocatalyst candidate involves 2,2'-biphenol () in a /AlMe3 ratio of 2/3.

Journal: :Angewandte Chemie 2012
Andrew T Parsons Todd D Senecal Stephen L Buchwald

An iron(II)-catalyzed trifluoromethylation of potassium vinyltrifluoroborates has been developed. The reactions proceed under mild conditions and provide E/Z selectivities of > 95:5 for 2-aryl and -heteroarylvinyl substrates. Experimental observations suggest that the reaction does not proceed through a transmetallation of the RBF3K to the iron catalyst.

Journal: :تحقیقات دامپزشکی 0
حسن مروتی گروه علوم پایه، دانشکده دامپزشکی دانشگاه تهران، تهران- ایران حسین نجف زاده گروه علوم پایه، دانشکده دامپزشکی دانشگاه شهید چمران اهواز، اهواز- ایران سیده مهسا پورموسوی دانش آموخته بافت شناسی، دانشکده دامپزشکی دانشگاه شهید چمران اهواز، اهواز- ایران علی شهریاری گروه علوم پایه، دانشکده دامپزشکی دانشگاه شهید چمران اهواز، اهواز- ایران بابک محمدیان گروه پاتوبیولوژی، دانشکده دامپزشکی دانشگاه شهید چمران اهواز، اهواز- ایران ایرج کاظمی نژاد گروه فیزیک، دانشکده علوم دانشگاه شهید چمران اهواز، اهواز- ایران

background: the most common metal used in the body is iron and since it may produce ros, it could potentially be a dangerous substance. objectives: regarding the side effects of nanomaterials such as nano iron particles and possibility of environmental contamination including air pollution with nanoscale iron particle, this study was designed to compare the effects of conventional iron oxide wi...

The Fischer-Tropsch synthesis (FTS) has been recognized as a heterogeneous surface-catalyzed polymerization process. During this process, CHx monomers formed via the hydrogenation of adsorbed CO on transition metals produce hydrocarbons and oxygenates with a broad range of chain lengths and functional groups. A series of Fe/Cu Fischer-Tropsch synthesis catalysts incorporated with a calcium prom...

Journal: :Journal of the American Chemical Society 2007
Anna Company Laura Gómez Mireia Güell Xavi Ribas Josep M Luis Lawrence Que Miquel Costas

A nonheme iron catalyst catalyzed stereoselective oxidation of alkanes with H2O2 with remarkable efficiency and exhibiting an unprecedented high incorporation of water into the oxidized products. The present results challenge the canonical description of oxygenases, the standard oxo-hydroxo tautomerism that applies to heme systems and serves as a precedent for alternative pathways for the oxida...

Journal: :Angewandte Chemie 2011
Robert Langer Yael Diskin-Posner Gregory Leitus Linda J W Shimon Yehoshoa Ben-David David Milstein

A highly active iron catalyst for the hydrogenation of carbon dioxide and bicarbonates works under remarkably low pressures and achieves activities similar to some of the best noble metal catalysts. A mechanism is proposed involving the direct attack of an iron trans-dihydride on carbon dioxide, followed by ligand exchange and dihydrogen coordination.

2011
Yan Cai Shou-Fei Zhu Guo-Peng Wang Qi-Lin Zhou

An easily available iron catalyst was developed to accomplish the C H functionalization of indoles with a-aryl-a-diazoesters in high yields under mild conditions. The asymmetric C H functionalization of indoles was also realized by using iron complexes of chiral spiro bisoxazolines with up to 78% ee.

2011
Saveria Santangelo Elpida Piperopoulos Maurizio Lanza Giuliana Faggio Giacomo Messina Candida Milone

The synthesis of carbon nanotubes (CNTs) by chemical vapor deposition (CVD) of isobutane (i‐C4H10) over sodium‐exchanged K10‐montmorillonite based iron‐ catalysts is investigated. By studying the influence of iron‐addition (5–25 wt%) on the catalyst performances, at 700 °C, an empirical relationship is derived relating the mass of CNTs synthesized with the exposed ...

Journal: :Chemical communications 2012
Bryden A F Le Bailly Mark D Greenhalgh Stephen P Thomas

An iron-catalysed, hydride-mediated reductive cross-coupling reaction has been developed for the preparation of alkanes. Using a bench-stable iron(II) pre-catalyst, reductive cross-coupling of vinyl iodides, bromides and chlorides with aryl- and alkyl Grignard reagents successfully gave the products of formal sp(3)-sp(3) cross-coupling reactions.

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