Ligand-Free Palladium-Catalyzed Direct Arylation of Thiazoles at Low Catalyst Loadings
作者:Julien Roger、Franc Požgan、Henri Doucet
DOI:10.1021/jo802360d
日期:2009.2.6
Ligand-free Pd(OAc)2 was found to catalyze very efficiently the direct arylation of thiazole derivatives under very lowcatalyst concentration. By using activated aryl bromides, the reaction can be performed employing as little as 0.1−0.001 mol % catalyst. With such substrates, this procedure is economically and environmentally attractive. On the other hand, in the presence of more challenging substrates
Solvent-Free Palladium-Catalyzed Direct Arylation of Heteroaromatics with Aryl Bromides
作者:Souhila Bensaid、Henri Doucet
DOI:10.1002/cssc.201100771
日期:2012.8
course of catalyzed directarylations. Some palladium‐catalyzed directarylations of heteroaromatics can be advantageously performed without any solvent. In the presence of palladiumcatalysts (1 mol %) and potassium acetate as the base, the direct 5‐arylation of some thiazoles, thiophenes, furans, or pyrroles with arylbromides as coupling partners proceeds highly regioselectively and in moderate to
Palladium-catalysed direct arylations of heteroaromatics using more eco-compatible solvents pentan-1-ol or 3-methylbutan-1-ol
作者:Souhila Bensaid、Nouria Laidaoui、Douniazad El Abed、Soufi Kacimi、Henri Doucet
DOI:10.1016/j.tetlet.2011.01.084
日期:2011.3
The palladium-catalysed direct coupling of aryl halides with heteroaromatics in greener solvents than DMF or DMAc, which are often employed for such couplings, would be a considerable advantage for both industrial application and sustainable development. We observed that a range of aryl bromides undergoe coupling via C-H bond activation/functionalisation reaction of thiazoles or imidazoles in moderate to good yields using pentan-1-ol or 3-methylbutan-1-ol as the solvents. Pentan-1-ol and 3-methylbutan-1-ol are less toxic than DMF or DMAc, moreover they are bioresources as they can be obtained by fermentation. Therefore, these reaction conditions are certainly more eco-compatible than those generally employed for such couplings. (C) 2011 Elsevier Ltd. All rights reserved.