Bis(alkyl)nickel(II) complexes [(tmeda)NiR₂] (R = CH₂SiMe₃ (1a), CH₂CMe₃ (1b), CH₂CMe₂Ph (1c)) can be prepared from [(tmeda)Ni(acac)₂] and MgR₂. This approach is equivalent to and, in some cases, even superior to the frequently employed reaction of [(py)₄NiR₂] with Grignard reagents. With [(tmeda)NiR₂] as the starting material, ligand exchange reactions with N-heterocyclic carbenes and bidentate phosphines were explored. The reaction of [(tmeda)NiR₂] with IiPr₂Me₂ (IiPr₂Me = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) yields three different classes of products: (a) [cis-(IiPr₂Me₂)₂Ni(CH₂SiMe₃)₂] (2a-cis) derived from NHC by tmeda replacement, (b) [(IiPr₂Me₂)(κ-C:C-IiPr₂MeCH₂)Ni(CH₂SiMe₃)] (3a) as a result of C–H bond activation of one iPr group of the NHC ligand, and (c) [cis-(IiPr₂Me₂)₂Ni(κ-C:C-CH₂CMe₂C₆H₄)] (4c-cis), in which an o-C–H bond of the neophyl ligand has been activated. Addition of depe (depe = Et₂PCH₂CH₂PEt₂) to 1a,c results in a clean tmeda replacement to give the corresponding complexes [(dppe)NiR₂] (R = CH₂SiMe₃ (5a), CH₂CMe₂Ph (5c)). All compounds have been fully characterized by various spectroscopic methods and in most cases by single-crystal X-ray diffraction.

中文翻译：

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[（tmeda）NiR ₂ ]（R = CH ₂ CMe ₃，CH ₂ SiMe ₃，CH ₂ CMe ₂ Ph）与N-杂环卡宾和双齿膦的配体交换反应

双（烷基）镍（II）配合物[（tmeda）NiR ₂ ]（R = CH ₂ SiMe ₃（1a），CH ₂ CMe ₃（1b），CH ₂ CMe ₂ Ph（1c））可以由[[ tmeda）Ni（acac）₂ ]和MgR ₂。该方法等效于并且在某些情况下甚至优于[[py] ₄ NiR ₂ ]与Grignard试剂的常用反应。以[（tmeda）NiR ₂ ]为起始原料，研究了N-杂环卡宾与二齿膦的配体交换反应。[（tmeda）NiR的反应₂ ]与I我镨₂我₂（I我镨₂我= 1,3-二异丙基-4,5-二甲基咪唑烷-2-亚基）产生三种不同类别的产品：（A）[顺式- （I我镨₂我₂）₂的Ni（CH ₂森达₃）₂ ]（2A-顺式）通过TMEDA置换，（b）由衍生NHC [（I我镨₂箱₂）（κ- ç：ç -I我镨₂机甲₂镍（CH₂ SiMe ₃）]（3a）是NHC配体的一个i Pr基团通过C–H键活化的结果，以及（c）[顺式-（I i Pr ₂ Me ₂）₂ Ni（κ- C：C -CH ₂ CMe ₂ C ₆ H ₄）]（4c- cis），其中新叶配体的o -C–H键已被激活。将depe（depe = Et ₂ PCH ₂ CH ₂ PEt ₂）加到1a，c结果得到干净的tmeda替代品，得到相应的络合物[（dppe）NiR ₂ ]（R = CH ₂ SiMe ₃（5a），CH ₂ CMe ₂ Ph（5c））。所有化合物均已通过各种光谱方法进行了充分表征，并且在大多数情况下已通过单晶X射线衍射进行了表征。