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
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.
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.
