Synthesis, structure and properties of [1,2,4]triazolo[4,3-a]pyridin-3-ylidene rhodium and palladium complexes
作者:Javier Iglesias-Sigüenza、Abel Ros、Elena Díez、Manuel Alcarazo、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1039/b907043e
日期:——
The reaction of [1,2,4]triazolo[4,3-a]pyridinium tetrafluoroborates with [RhCl(COD)]2 and [PdCl(allyl)]2 takes place under mild basic conditions (Et3N, THF, room temperature) to afford the corresponding [RhCl(COD)(Tripy)] and [PdCl(allyl)(Tripy)] complexes, respectively (Tripy = [1,2,4]triazolo[4,3-a]pyridin-3-ylidene), and their structures were analysed by X-ray diffractometry and spectroscopic techniques. The σ-donor ability of the new ligands was estimated by comparative analysis of infrared νCO stretching frequencies of [RhCl(CO)2(Tripy)] complexes, and proved to be strongly dependent on the substitution pattern. Additionally, a first insight into the catalytic properties of the latter in the Suzuki–Miyaura cross coupling demonstrates a good catalytic activity that enables the coupling of aryl chlorides at room temperature.
[1,2,4]三唑并[4,3-a]吡啶鎓四氟硼酸盐与[RhCl(COD)]2和[PdCl(烯丙基)]2在温和碱性条件下(Et3N,THF,室温)反应,分别生成相应的[RhCl(COD)(Tripy)]和[PdCl(烯丙基)(Tripy)]配合物(Tripy = [1,2,4]三唑并[4,3-a]吡啶-3-亚基),其结构通过X射线衍射和光谱技术进行了分析。通过比较[RhCl(CO)2(Tripy)]配合物的红外νCO伸缩频率,对新配体的σ供体能力进行了估算,并证明强烈依赖于取代模式。此外,首次对后者在铃木-宫浦交叉偶联反应中的催化性能进行探究,展示出良好的催化活性,能够在室温下实现芳基氯的偶联。