cis-[Pd(CH3COO)2(PPh3)(tazy)] (9) were also synthesized as the respective mononuclear equivalents for comparison. A comparative catalytic study revealed the general superiority of dinuclear complexes 1–4 over their respective mononuclear counterparts 6–9 in the direct C5-arylation reaction of 1-methylimidazoles. Overall, mixed dicarbene/diphosphine complex 3 showed the best catalytic performance.
所述二
钯三唑二亚基复杂全反式- [PDBR 2(CH 3 CN)] 2(μ-ditz)(1)(ditz = 1,2,4- trimethyltriazolidine -3,5-二亚基)经由合成原位将前体盐与碱性
金属前体一起去质子化。配位体的置换所有-反式-1与单齿或螯合膦得到dicarbene桥连络合物全-顺- [PDBR 2(PPH 3)] 2(μ-ditz)(2)和[PDBR(
DPPP)] 2(μ -ditz)Br 2(3), 分别。全顺式-2的
溴代取代产生四乙酰基复合物全顺式-[Pd(CH 3 COO)2(PPh 3)] 2(μ-ditz)(4),并且保留了作为主要产物的构型。另外,单
钯三唑啉-5-亚烷基配合物反式-[PdBr 2(CH 3 CN)(tazy)](6,tazy = 1,4-二
甲基三唑啉-5-亚烷基),顺式-[PdBr 2(PPh 3)( tazy)](7),[PdBr(
DPPP)(tazy)]