64819-72-3Relevant academic research and scientific papers
Palladium-catalyzed direct heteroarylation of chloropyridines and chloroquinolines
Derridj, Fazia,Roger, Julien,Geneste, Florence,Djebbar, Safia,Doucet, Henri
experimental part, p. 455 - 465 (2009/04/14)
The direct coupling of aryl chlorides with heteroarenes would be a considerable advantage for sustainable development due to their lower cost, lower mass, the wider diversity of available compounds and also because of the formation of only HCl associated
Palladium-catalysed direct C-H activation/arylation of heteroaromatics: An environmentally attractive access to bi- or polydentate ligands
Derridj, Fazia,Gottumukkala, Aditya L.,Djebbar, Safia,Doucet, Henri
experimental part, p. 2550 - 2559 (2009/03/11)
Bi- or polydentate ligands based on heterocycles can be easily prepared by palladium-catalysed C-H bond activation of heteroaromatics followed by heteroarylation with heteroaryl bromides. A variety of heteroaromatics such as furans, thiophenes, pyridines, thiazoles or oxazole derivatives have been employed and moderate to good yields were generally obtained using the air-stable complex [PdCl(dppb)(C3H5)] as catalyst. A range of functions such as acetyl, formyl, ester or nitrile on the heteroaromatics is tolerated. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Direct arylation of oxazole and benzoxazole with aryl or heteroaryl halides using a palladium-diphosphine catalyst
Derridj, Fazia,Djebbar, Safia,Benali-Baitich, Ouassini,Doucet, Henri
, p. 135 - 144 (2008/03/30)
Through the use of PdCl(dppb)(C3H5) as a catalyst, a range of aryl bromides and chlorides undergoes coupling via C-H bond activation/functionalization reaction with oxazole or benzoxazole in good yields. This air-stable catalyst can be used at low loadings with several substrates. Surprisingly, better results in terms of substrate/catalyst ratio were obtained in several cases using electron-excessive aryl bromides than with the electron-deficient ones. This seems to be mainly due to the relatively low thermal stability of some of the 2-arylbenzoxazoles formed with electron-deficient aryl halides. With these substrates, in order to obtain higher yields of product, the reactions had to be performed at a lower temperature (100-120 °C) using a larger amount of catalyst. On the other hand, in the presence of the most stable products, the reactions were performed at 150 °C using as little as 0.2 mol% catalyst. Arylation of benzoxazole with heteroaryl bromides also gave the coupling products in moderate to high yields using 0.2-5 mol% catalyst. With this catalyst, electron-deficient aryl chloride such as 4-chlorobenzonitrile, 4-chloroacetophenone or 2-chloronitrobenzene have also been used successfully.
Synthesis of benzoxazolylpyridine nickel complexes and their efficient dimerization of ethylene to α-butene
Gao, Rong,Xiao, Liwei,Hao, Xiang,Sun, Wen-Hua,Wang, Fosong
experimental part, p. 5645 - 5651 (2009/02/07)
A series of new nickel complexes bearing benzoxazolylpyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of two representative complexes were determined by single-crystal X-ray diffraction. The complex [NiCl2{2-(2- benzoxazolyl)-6-methylpyridine}] (5) is a centrosymmetric dinuclear compound with two penta-coordinated Ni(ii) centers, whereas the complex [NiCl 2{2-(5-methyl-2-benzoxazolyl)-6-methylpyridine}] (6) is mononuclear exhibiting a distorted octahedral-coordination geometry around the nickel atom. Upon activation with diethylaluminium chloride (Et2AlCl), all the complexes exhibited moderate to good catalytic activity for ethylene oligomerization (27-415 g mmol-1(Ni) h-1 bar-1) with high selectivity for ethylene dimerization to form α-butene. The observed variance in the catalytic activities of the complexes is attributed to the different ligand environments and effects of reaction parameters.
