Syntheses and catalytic activities of pseudo-pincer and CSC pincer-type Pd(II) complexes derived from benzannulated N-heterocyclic carbenes
Syntheses and catalytic activities of pseudo-pincer and CSC pincer-type Pd(II) complexes derived from benzannulated N-heterocyclic carbenes
复制标题
DOI：
10.1039/b907887h
复制
发表时间：
2009-01-01
影响因子：
4
通讯作者：
Han, Yuan
中科院分区：
文献类型：
--
作者：
Huynh, Han Vinh;Yuan, Dan;Han, Yuan
合成了三种新的含硫醚（B中心点2 HBr，B中心点2 HNO（3））和含桥亚砜（C中心点2 HBr）的二苯并咪唑盐作为硫功能化二卡宾的前体。B中心点2 HBr和C中心点2 HBr的钯化得到两个新的假钳形配合物cis-[PdBr 2（B-kappa C-2）]（1）和cis-[PdBr 2（C-kappa C-2）]（2），其中硫给体保持悬挂。另一方面，前体B中心点2 HNO（3）在1当量KBr存在下的反应产生第一个带有两个卡宾部分的CSC-Pd（II）钳形络合物[PdBr（B-kappa（CSC）-C-3）]NO3（3）。所有三个配合物已充分其特征在于多核NMR光谱，ESI质谱和X-射线衍射分析。并对它们在Mizoroki-Heck反应中的催化活性进行了评价。
Three new dibenzimidazolium salts bearing thioether (B center dot 2HBr, B center dot 2HNO(3)) and sulfoxide (C center dot 2HBr) containing bridges have been synthesized as sulfur-functionalized dicarbene precursors. Palladation of B center dot 2HBr and C center dot 2HBr afforded two new pseudo-pincer complexes cis-[PdBr2(B-kappa C-2)] (1) and cis-[PdBr2(C-kappa C-2)] (2), in which the sulfur-donor remains pendant. Reaction of precursor B center dot 2HNO(3) in the presence of 1 equiv of KBr, on the other hand, yields the first CSC-Pd(II) pincer complex [PdBr(B-kappa(CSC)-C-3)]NO3 (3) bearing two carbene moieties. All three complexes have been fully characterized by multinuclei NMR spectroscopies, ESI mass spectrometry and X-ray diffraction analysis. Their catalytic activities in the Mizoroki-Heck reaction have been evaluated as well.