The incorporation of a PPC donor ligand set onto nickel is described. While C–H activation routes using Ni(II) precursors and benzyl- and phenethyl-substituted diphosphines Bu^t₂PCH₂CH₂P(Bu^t)R failed, success was achieved via oxidative addition of the 2-bromo-benzyl-ligand precursor Bu^t₂PCH₂CH₂P(Bu^t)(CH₂-o-C₆H₄Br) with Ni(COD)₂ to generate [κ³-^BnPPC]NiBr. Subsequent reaction with KBEt₃H resulted in decomposition unless PPh₃ was present, which allowed isolation of the tricoordinate Ni(0) complex [κ²-^BnPP]Ni(PPh₃). Reaction of [κ³-^BnPPC]NiBr with EtMgCl also resulted in the formation of the Ni(0) ethylene complex, [κ²-^BnPP]Ni(η²-C₂H₄), via β-elimination followed by reductive elimination. Deuterium-labeling studies are consistent with a reversible β-elimination process prior to reductive elimination, which scrambles the deuterium isotopes. Reaction of [κ³-^BnPPC]NiBr with CH₃Li results in the formation of the Ni(II) methyl complex, [κ³-^BnPPC]Ni(CH₃). Heating this species in the presence of PPh₃ results in the formation of the Ni(0) derivative, [κ²-^Bn-o-MePP]Ni(PPh₃), in which reductive elimination of the methyl and aryl units has occurred. Reaction of [κ³-^BnPPC]NiBr with heteroatom-containing species such as sodium isopropoxide, sodium 2-propanethiolate, and lithium methylphenylamide resulted in different outcomes depending on the heteroatom; with isopropoxide, the products isolated were geometric isomers of Ni(0) η²-acetone adducts, which presumably arise via a β-elimination–reductive elimination sequence; the analogous sulfur reagent generated isolable Ni(II) isopropyl thiolate species that was resistant to β-elimination upon thermolysis; with methylphenylamide, the Ni(II) amido complex could be isolated and structurally characterized; subsequent heating to 80 °C resulted in β-elimination followed by reductive elimination to generate a Ni(0) phenylimine complex. While the κ³-PPC donor set generates stable Ni(II) derivatives, further functionalization at nickel with hydride, alkyl, and heteroatom-containing moieties can lead to Ni(0) products via a combination of β-elimination and/or reductive elimination.

中文翻译：

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β氢消除和还原消除从κ ³ -PPC镍络合物

描述了将设置在镍上的PPC供体配体掺入。而用Ni CH激活途径（II）前体和苄基和苯乙基取代的二膦卜^吨₂ PCH ₂ CH ₂ P（卜^吨）R失败，成功经氧化加成的2-溴-苄基配体的实现前体卜^吨₂ PCH ₂ CH ₂ P（卜^吨）（CH ₂ - ö -C ₆ ħ ₄溴）用Ni（COD）₂以产生[κ ³ - ^BN PPC] NIBR。随后与KBEt _3的反应小时导致分解除非PPH ₃存在，这使得三配位的Ni（0）络合物的隔离[κ ² - ^BN PP]的Ni（PPH ₃）。的反应[κ ³ - ^BN（0）乙烯络合物，[κNIBR与EtMgCl也导致Ni的形成PPC] ² - ^BN PP]的Ni（η ² -C ₂ H ^ ₄），通过β消去，然后还原消除。氘标记研究与还原消除之前可逆的β消除过程一致，该过程扰乱了氘的同位素。的反应[κ ³ - ^BN PPC] NIBR用CH ₃李导致Ni的形成（II）甲基络合物，[κ ³ - ^BN PPC]的Ni（CH ₃）。在PPH的存在下加热该物种_3个中镍的形成结果（0）衍生物，[κ ² - ^{BN- ø -Me} PP]的Ni（PPH ₃），在其中发生了甲基和芳基单元的还原消除。[κ的反应³ - ^BN PPC]与含有杂原子的种类，例如异丙醇钠，2-丙硫醇，和锂methylphenylamide NIBR导致取决于杂原子不同的结果; 用异丙醇，分离出的产物为（0）的Ni的几何异构体η ²-丙酮加合物，大概是通过β-消除-还原消除序列产生的；类似的硫试剂产生可分离的Ni（II）异丙基硫醇盐，其在热解时具有抗β-消除作用；用甲基苯酰胺可以分离Ni（II）酰胺配合物并进行结构表征。随后加热到80°C，导致β-消除，然后还原消除，生成Ni（0）苯基亚胺配合物。而κ ³ -PPC供体组产生稳定的Ni（II）的衍生物，在与氢化，烷基镍进一步官能化，和含杂原子的基团可导致的Ni（0）经由β-消除和/或还原消除的组合产品。