نتایج جستجو برای: hydrogenation

تعداد نتایج: 8711  

Journal: :The Journal of chemical physics 2011
A R McInroy A Uhl T Lear T M Klapötke S Shaikhutdinov S Schauermann G Rupprechter H-J Freund D Lennon

A series of five alumina-supported palladium catalysts have previously been prepared and characterised by a combination of CO chemisorption and infrared spectroscopy. The reactive attributes of these catalysts are examined using the hydrogenation of crotonaldehyde as a test reaction, using a modified infrared gas cell as a batch reactor. Periodic scanning of the infrared spectrum of the gaseous...

Journal: :Organic & biomolecular chemistry 2006
Dhevalapally B Ramachary G Babul Reddy

Economic and environmentally friendly bio-mimetic one-pot three and four-component Knoevenagel-hydrogenation (K-H), five-component Knoevenagel-hydrogenation-alkylation (K-H-A) and six-component Knoevenagel-hydrogenation-alkylation-Huisgen cycloaddition (K-H-A-HC) reactions of aldehydes, CH-acids, o-phenylenediamine, alkyl halides and azides using proline, proline-metal carbonate and proline-met...

Journal: :Dalton transactions 2016
Boon Ying Tay Cun Wang Pim Huat Phua Ludger Paul Stubbs Han Vinh Huynh

Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) was studied by using mono- and bidentate p-cymene ruthenium(ii) N-heterocyclic carbene (NHC) complexes as catalyst precursors. In water, all complexes were found to be reduced in situ to form ruthenium nanoparticles (RuNPs) with a high hydrogenation activity. In organic solvents, complexes with monodentate NHC ligands also formed nan...

Journal: :Chemical communications 2014
Yingming Zhu Dongsheng Liu Ming Meng

Black TiO2 was usually obtained via hydrogenation at high pressure and high temperature. Herein, we reported a facile hydrogenation of TiO2 in the presence of a small amount of Pt at relatively low temperature and atmospheric pressure. The hydrogen spillover from Pt to TiO2 accounts well for the greatly enhanced hydrogenation capability. The as-synthesized Pt/TiO2 exhibits remarkably improved p...

2017

In this chapter the results of kinetic studies of the rhodium-catalyzed asymmetric hydrogenation using monodentate phosphoramidite ligands are described. Together with the data obtained by a number of other techniques a mechanism for the Rhcatalyzed asymmetric hydrogenation with MonoPhosTM is proposed. The formation of the catalyst precursor results in a mixture of diastereomeric Rh-complexes w...

2017
Shahin Shafiee Mary Helen McCay Sarada Kuravi

A safe and efficient method for storing hydrogen is solid state storage through a chemical reaction in metal hydrides. A good amount of research has been conducted on hydrogenation properties of metal hydrides and possible methods to improve them. Background research shows that heat transfer is one of the reaction rate controlling parameters in a metal hydride hydrogen storage system. Consideri...

1998
Guoxin Zhu

Much effort has been devoted to the development of efficient asymmetric synthetic methods for the preparation of enantiomerically enriched compounds.1,2 Among various methods for the enantiomerically selective synthesis of chiral organic compounds from prochiral precursors, enantioselective catalytic hydrogenation of dehydro precursors has been extensively developed.3 In fact, asymmetric hydrog...

Journal: :Chemical science 2015
Jeffrey M Farrell Roy T Posaratnanathan Douglas W Stephan

This manuscript probes the steric and electronic attributes that lead to "frustrated Lewis pair" (FLP)-type catalysis of imine hydrogenation by borenium ions. Hydride abstraction from (ItBu)HB(C6F5)22 prompts intramolecular C-H bond activation to give (CHN)2(tBu) (CMe2CH2)CB(C6F5)23, defining an upper limit of Lewis acidity for FLP hydrogenation catalysis. A series of seven N-heterocyclic carbe...

Journal: :Molecules 2014
Florian Achrainer Hendrik Zipse

The potential of a larger number of sugar models to act as dihydrogen donors in transfer hydrogenation reactions has been quantified through the calculation of hydrogenation energies of the respective oxidized products. Comparison of the calculated energies to hydrogenation energies of nucleobases shows that many sugar fragment radicals can reduce pyrimidine bases such as uracil in a strongly e...

2015
Masayuki Naruto Susumu Saito

Carboxylic acids are ubiquitous in bio-renewable and petrochemical sources of carbon. Hydrogenation of carboxylic acids to yield alcohols produces water as the only byproduct, and thus represents a possible next generation, sustainable method for the production of these alternative energy carriers/platform chemicals on a large scale. Reported herein are molecular insights into cationic mononucl...

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