diffraction. The catalytic performance of the complexes was screened and the obtained palladium (II) complexes shown effective catalytic activities for direct arylation of (benzo)oxazoles with aryl bromides. Moreover, the 2-(pyridin-2-yl)acetate stabilized NHC–Pd complexes were more efficient than the 3-(pyridin-2-yl)propanoate stabilized NHC–Pd analogues. Further studies exhibited that 2-(pyridin-2-yl)acetate
通过[Pd(μ- Cl)(Cl)(NHC)] 2的桥裂解反应可以方便地合成四种定义明确的N-杂环卡宾-PdCl-[(2-
吡啶基)烷基
羧酸盐]络合物(2-
吡啶基)烷基
羧酸[2-(
吡啶-2-基)
乙酸和3-(
吡啶-2-基)
丙酸]。新的络合物已通过NMR,元素分析,HR-MS和X射线单晶衍射进行了全面表征。筛选了配合物的催化性能,并且所获得的
钯(II)配合物显示出对(苯并)
恶唑与芳基
溴化物直接芳基化的有效催化活性。此外,
乙酸2-(
吡啶-2-基)稳定的NHC-Pd复合物比3-(
吡啶-2-基)
丙酸稳定的NHC-Pd类似物更有效。进一步的研究表明,
乙酸2-(
吡啶-2-基)
乙酸酯作为辅助
配体在反应条件下很容易脱羧并转化为2-
甲基吡啶。