摘要通过1,3-二烷基过氢苯并咪唑鎓盐与氧化银(I)的反应以高收率合成了银(I)N-杂环卡宾配合物,并用作合成钯(II)N-杂环卡宾配合物的金属转移试剂。使用元素分析,1 H NMR和13 C NMR光谱对所有配合物进行表征。研究了Pd(II)-NHC配合物在吡咯衍生物直接芳基化中的催化活性。这些Pd(II)-NHC配合物对吡咯衍生物与易得且廉价的芳基氯化物进行直接芳基化反应显示出良好的催化性能。通过使用1mol%的钯络合物,芳基化反应以中等至良好的产率区域选择性地产生C 2或C 5芳基化产物。
Regioselective C-2 or C-5 Direct Arylation of Pyrroles with Aryl Bromides using a Ligand-Free Palladium Catalyst
作者:Julien Roger、Henri Doucet
DOI:10.1002/adsc.200900196
日期:——
acetyl or ester at the C-2 position of the pyrrole is tolerated. This environmentally attractive procedure has also been found to be tolerant to a very wide variety of functional groups on the arylbromides such as formyl, acetyl, propionyl, ester, nitrile, nitro, fluoro, methoxy, amino or trifluoromethyl.
New Pd-NHC complexes have been synthesized and employed for palladium-catalyzed directarylation of pyrrolederivatives by using electron-deficient aryl chlorides as coupling partners. The desired coupling products were obtained in moderate to good yields by using 1 mol % of these air-stable palladium complexes. This is an advantage compared to the procedures employing air-sensitive phosphines, which
and 13 C NMR spectroscopy. The catalytic activity of Pd(II)-NHC complexes in the directarylation of pyrrolederivatives was investigated. These Pd(II)-NHC complexes showed the good catalytic performance for the directarylation of pyrrolederivatives with readily available and inexpensive aryl chlorides. The arylation reactions regioselectively produced C2- or C5-arylation products in moderate to good
摘要通过1,3-二烷基过氢苯并咪唑鎓盐与氧化银(I)的反应以高收率合成了银(I)N-杂环卡宾配合物,并用作合成钯(II)N-杂环卡宾配合物的金属转移试剂。使用元素分析,1 H NMR和13 C NMR光谱对所有配合物进行表征。研究了Pd(II)-NHC配合物在吡咯衍生物直接芳基化中的催化活性。这些Pd(II)-NHC配合物对吡咯衍生物与易得且廉价的芳基氯化物进行直接芳基化反应显示出良好的催化性能。通过使用1mol%的钯络合物,芳基化反应以中等至良好的产率区域选择性地产生C 2或C 5芳基化产物。