Phosphine-functionalized NHC Ni(<scp>ii</scp>) and Ni(0) complexes: synthesis, characterization and catalytic properties
作者:S. G. Rull、R. J. Rama、E. Álvarez、M. R. Fructos、T. R. Belderrain、M. C. Nicasio
DOI:10.1039/c7dt01805c
日期:——
families of nickel complexes bearing chelating diphenylphosphine-functionalized NHC ligands [NiII(ArNHCPPh2)(allyl)]Cl 1a (Ar = Mes); -1b, (Ar = 2,6-iPr2-C6H3) and [Ni0(ArNHCPPh2)(alkene)] 2a (Ar = 2,6-iPr2-C6H3, alkene = styrene); -2b (Ar = 2,6-iPr2-C6H3, alkene = diethyl fumarate) have been prepared and fully characterized. VT-NMR experiments in solution reveal that the allyl derivatives 1a-b are stereochemically
带有螯合二苯基膦官能化NHC配体的两个镍配合物族[NiII(ArNHCPPh2)(烯丙基)] Cl 1a(Ar = Mes);-1b,(Ar = 2,6-iPr2-C6H3)和[Ni0(ArNHCPPh2)(烯烃)] 2a(Ar = 2,6-iPr2-C6H3,烯烃=苯乙烯);已经制备了-2b(Ar = 2,6-iPr2-C6H3,烯烃=富马酸二乙酯)并进行了充分表征。溶液中的VT-NMR实验表明,烯丙基衍生物1a-b在立体化学上是非刚性的。还报道了Ni 0衍生物2b的固态结构。这些络合物在各种交叉偶联反应中显示出令人感兴趣的催化性能。发现前催化剂[Ni0(ArNHCPPh2)(苯乙烯)] 2a是最活跃的系统。咪唑环上N取代基的体积大和2a中金属中心的低氧化态说明了其增强的催化性能。