نتایج جستجو برای: base catalyst

تعداد نتایج: 299630  

2005
Hirohito IKEDA Miho YUKAWA Tokihiro NIIYA

The abstraction of the active hydrogen of RCOCH2R by a base catalyst B M , and the subsequent formation of the enolate [RCOCHR ] M are described in Eq. 1 (deprotonation process). Secondly, the creation of a C–N bond, in which [RCOCHR ] M reacts with R ONO to form complex [RCOCHNO(OR )R ] M , is shown in Eq. 2 (C–N bond formation process). Finally, the reaction between [RCOCHNO(OR )R ] M with ba...

Journal: :Journal of the American Chemical Society 2011
Ilya Popov Sergey Lindeman Olafs Daugulis

A general method has been developed for arylation of readily available 1H-perfluoroalkanes. The method employs aryl iodide and 1H-perfluoroalkane reagents, DMPU solvent, TMP(2)Zn base, and a copper chloride/phenanthroline catalyst. Preliminary mechanistic studies are reported.

Journal: :Chemical communications 2006
Koji Kobayashi Masahiro Ueno Yoshinori Kondo

The t-Bu-P4 base was found to be an excellent catalyst for the condensation of trimethylsilylacetate or trimethylacetonitrile with carbonyl compounds to form functionalized alkenes and beta-enaminoesters were also synthesized by the condensation with formanilides.

Journal: :Chemical communications 2014
Sheri Lense Arnab Dutta John A S Roberts Wendy J Shaw

We report the incorporation of a simple enzyme-inspired proton channel onto a hydrogen oxidation catalyst. This modification facilitates proton transfer and lowers the overpotential for oxidation of H2 by 300 mV when using water as a base.

Journal: :Chemical communications 2013
Philipp Selig Aleksej Turočkin William Raven

The first synthesis of highly substituted 3-alkyl-oxetan-2-ylidenes from allenoates was developed by using the bicyclic guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as an exceptionally active nitrogen Lewis base catalyst.

Journal: :Chemical communications 2011
Yan Zhang Choon Wee Kee Richmond Lee Xiao Fu Julian Ying-Teck Soh Esther Mun Foong Loh Kuo-Wei Huang Choon-Hong Tan

An amino-indanol derived chiral guanidine was developed as an efficient Brønsted base catalyst for the desymmetrization of meso-aziridines with both thiols and carbamodithioic acids as nucleophiles, which provided 1,2-difunctionalized ring-opened products in high yields and enantioselectivities.

Journal: :Chemical communications 2009
Saïd Akzinnay Fabrice Bisaro Catherine S J Cazin

The hydrodehalogenation of polychlorinated phenyls and biphenyls (PCBs), catalysed by palladium N-heterocyclic carbene complexes, proceeds with excellent yields, at very low catalyst loadings and at room temperature, using isopropanol as the hydrogen source and NaOH as the base.

Abbas Ali Khodadadi Alimorad Rashidi, Mohamma Mahdi Akbarnejad Yadollah Mortazavi

Bamboo-structured carbon nanotubes are grown on Co-Mo/MCM-41 catalyst in the temperature range of 873-973 K by thermal chemical vapor deposition of acetylene. This study shows that the purified carbon nanotubes have open tips and the metals of the catalyst are not encapsulated. Thus, the bamboo-structure seems to grow from the base. Pore size distribution of the product is quite narrow and ...

Journal: :organic chemistry research 0
khodabakhsh niknam persian gulf university alireza hosseini persian gulf university

silica-bonded n-propyldiethylenetriamine (7) is employed as a recyclable heterogeneous solid base catalyst for the synthesis of 2-amino-3,5-dicarbonitrile-6-thiopyridines through pseudo four-component condensation reaction between aromatic aldehydes, malononitrile, and 2-amino-thiophenol in refluxing ethanol. silica-bonded n-propyldiethylenetriamine showed much the same efficiency when used in ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

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