Cyclopentyl Methyl Ether: An Alternative Solvent for Palladium-Catalyzed Direct Arylation of Heteroaromatics
作者:Kassem Beydoun、Henri Doucet
DOI:10.1002/cssc.201000405
日期:2011.4.18
Some ethers, such as cyclopentyl methylether and di‐n‐butyl ether, which can be considered as “greener” solvents than N,N‐dimethylacetamide (DMAc) or DMF, can be advantageously employed for the palladium‐catalyzed direct arylation of heteroaromatics. In the presence of such ethers and only 0.5–1 mol % of palladium catalysts at 125–150 °C, the direct 5‐arylation of thiazoles, thiophenes, or furans
products in metal‐catalyzed direct arylation reactions. We found that the use of only 1 mol% of the heterogeneous catalyst Pd/C promotes very efficiently the direct arylations of most heteroaromatics. In the presence of this catalyst and potassium acetate as the base, the direct arylation of thiophenes, furans, pyrroles, thiazoles, imidazoles or isoxazoles, using arylbromides as coupling partners, proceeds
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
Carbonates: eco-friendly solvents for palladium-catalysed direct arylation of heteroaromatics
作者:Jia Jia Dong、Julien Roger、Cécile Verrier、Thibaut Martin、Ronan Le Goff、Christophe Hoarau、Henri Doucet
DOI:10.1039/c0gc00229a
日期:——
The palladium-catalyseddirect2-, 4- or 5-arylation of a wide range of heteroaromatics with aryl halides proceed in moderate to good yields using the eco-friendly solvents carbonates. The best yields were obtained using benzoxazole or thiazole derivatives. The arylation of furan, thiophene, pyrrole, imidazole or isoxazole derivatives was found to require a more elevated reaction temperature.
Benzenesulfonyl Chlorides: Alternative Coupling Partners for Regiocontrolled Palladium-Catalyzed Direct Desulfitative 5-Arylation of Furans
作者:Ridha Ben Salem、Henri Doucet、Anissa Beladhria、Kedong Yuan、Hamed Ben Ammar、Jean-Francois Soulé
DOI:10.1055/s-0033-1340188
日期:——
further transformations. The use of these reactants demonstrates the potential of benzenesulfonylchlorides as coupling partners to access to functionalized 5-arylfurans. The reactivity of furan derivatives in palladium-catalyzed desulfitative arylation was studied. Alkyl-substituted furan derivatives were successfully coupled with a variety of benzenesulfonylchloridesusing a phosphine-free catalyst;