School of Chemistry, Bharathidasan University, Tiruchirappalli-620024, India.
Dalton Trans. 2012 May 7;41(17):5351-61. doi: 10.1039/c2dt12243j. Epub 2012 Mar 8.
A simple route to synthesise palladium(II) complexes from the reaction of N-substituted pyridine-2-thiocarboxamide ligands and PdCl(2)(PPh(3))(2) has been developed. The new complexes are very soluble in common solvents and have been fully characterised (elemental analysis, FT-IR, (1)H, (31)P, (13)C-NMR), including an X-ray diffraction analysis. The molecular structures of all the complexes were determined and reveal the presence of square planar geometry around Pd with little distortion. The complexes were tested in the Suzuki coupling of electronically deactivated aryl and heteroaryl bromides and were found to have much greater activity, without using any promoting additives or phase transfer agent under aerobic conditions. Higher reaction rates are obtained by varying R substituents on the aromatic ring of pyridine-2-thiocarboxamide. The effect of other variables on the cross-coupling reaction, such as temperature, solvent and base, is also reported.
已经开发出一种从 N-取代的吡啶-2-硫代甲酰胺配体和 PdCl2(PPh3)2 的反应中合成钯（II）配合物的简单途径。新的配合物在常见溶剂中非常可溶，并已进行了全面表征（元素分析、FT-IR、1H、31P、13C-NMR），包括 X 射线衍射分析。所有配合物的分子结构均已确定，结果表明 Pd 周围存在近乎平面的正方形几何形状，几乎没有扭曲。这些配合物在电子去活化的芳基和杂芳基溴化物的 Suzuki 偶联中进行了测试，结果发现它们在有氧条件下无需使用任何促进添加剂或相转移剂即可具有更高的活性。通过改变吡啶-2-硫代甲酰胺芳环上的 R 取代基可以获得更高的反应速率。还报告了其他变量（如温度、溶剂和碱）对交叉偶联反应的影响。
