摘要通过1,3-二烷基过氢苯并咪唑鎓盐与氧化银(I)的反应以高收率合成了银(I)N-杂环卡宾配合物,并用作合成钯(II)N-杂环卡宾配合物的金属转移试剂。使用元素分析,1 H NMR和13 C NMR光谱对所有配合物进行表征。研究了Pd(II)-NHC配合物在吡咯衍生物直接芳基化中的催化活性。这些Pd(II)-NHC配合物对吡咯衍生物与易得且廉价的芳基氯化物进行直接芳基化反应显示出良好的催化性能。通过使用1mol%的钯络合物,芳基化反应以中等至良好的产率区域选择性地产生C 2或C 5芳基化产物。
Synthesis of 1,3-Dialkylperhydrobenzimidazolinium Salts and Their Catalytic Properties in Heck Reactions
摘要:
Novel eight 1,3-dialkylperhydrobenzimidazolinium chloride salts 3a-h were prepared as precursors of N-heterocyclic carbenes by reacting N,N'-dialkylcyclohexanediamine, triethyl orthoformate and ammonium chloride. The salts were characterized spectroscopically and the complexes formed in situ from Pd(OAc)(2) and 3 have been tested as catalysts in homogenous Heck coupling reactions.