4-triazolin-5-ylidene)palladium(II) complexes even when the respective azolium salts are elusive. Bromo-functionalized 1,2,4-triazolium salts were first metalated to form the respective bromo-functionalized bis(NHC) complexes trans-[PdBr2(R-tazy-Br)2] (R = Ph, Cy, 1a,b). Subsequent postcoordinative nucleophilic substitutions converted the bromo into ammonium functions, leading to the water-soluble, charge-tagged complexes
后修饰方法可以方便地使用带电荷标签的
铵官能化双(
1,2,4-三唑啉-5-亚烷基)
钯(II)配合物,即使在各自的偶氮盐都难以捉摸的情况下也是如此。首先将
溴官能化的
1,2,4-三唑鎓盐
金属化,以形成相应的
溴官能化的双(NHC)配合物反式-[PdBr 2(R-tazy-Br)2 ](R = Ph,Cy,1a,b)。随后的配位后亲核取代将
溴转化为
铵功能,从而导致
水溶性,带电荷标签的复合物反式-[PdBr 2(R-tazy-NEt 3)2 ] Br 2(R = Ph,Cy,2a,b)。将2a,b在Suzuki-Miyaura
水溶液中的催化活性与其类似物2c的催化活性进行了比较,d带有更大的
均三甲苯基和
二异丙基苯基取代基,并使用%V bur,HEP和DFT计算对NHC进行了详细的立体电子分析进行了合理化,以促进他们的催化差异。尽管所有的配合物都是活性的,但在0.001mol%的非常低的催化剂负载量下,