4-iodopyrazolium salts with 3,5-dimethyl (3a), 3,5-diphenyl (3b), and 3,5-diisopropyl (3c) substituents, respectively, were synthesized using a modular approach. The oxidative addition of 3a−c to Pd2(dba)3/PPh3 afforded products (trans-4a, cis-/trans-4b and 4c) of different geometries or connectivities, indicating a dramatic substituent effect on the formation of pyrazolin-4-ylidene complexes. In addition, the reactions
使用模块化方法合成了分别具有3,5-二甲基(3a),3,5-二苯基(3b)和3,5-
二异丙基(3c)取代基的三种
4-碘吡唑鎓盐。氧化加成的图3a - c ^与Pd 2(
DBA)3 / PPH 3,得到产物(反式- 4a中,顺- /反式-图4b和4c中)不同的几何形状或连接性的,指示在pyrazolin-的形成的戏剧性效果的取代基4-亚烷基络合物。另外,3a - c的反应在
吡啶存在下,用Pd 2(
DBA)3与Pd 2(
DBA)3合成新的
吡唑啉-4-亚烷基/
吡啶复合物(5a - c)。所有配合物均已通过多核NMR光谱,ESI质谱和X射线衍射分析进行了充分表征。此外,对Suzuki-Miyaura和Mizoroki-Heck交叉偶联反应的初步催化研究也显示了对催化活性的重要取代基作用。