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
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
of an air‐stable, robust palladium/tridentate phosphane catalyst in direct CH and CCl activation reactions is reported (see scheme; DMAc=N,N‐dimethylacetamide, TBAB=tetra‐n‐butylammonium bromide). Electron‐rich, electron‐poor, and polysubstituted furans (X=O), thiophenes (X=S), pyrroles (X=NR5), and thiazoles were arylated with chloroarenes in the presence of the catalyst.
穿上它的环:在直接C中的使用对空气稳定的,坚固的钯/三齿磷烷催化剂 H和13 C 氯活化反应报道(参见方案;的DMAc = Ñ,Ñ二甲基乙酰胺,TBAB =四Ñ -丁基溴化铵)。在催化剂存在下,富电子,贫电子和多取代的呋喃(X = O),噻吩(X = S),吡咯(X = NR 5)和噻唑被氯芳烃芳基化。