| 320573-48-6

• CAS: 320573-48-6
• 化学式: C₂₆H₄₂Cl₂N₄Ni₂Si
• 分子量: 627.018
• InChiKey: HVYFGHRMGBCPHM-UHFFFAOYSA-L

反应信息

• 作为产物：
  描述：

  NiCl₂(PEt₃)₂ 、 1-[3-[[3,5-bis[(dimethylamino)methyl]phenyl]-dimethylsilyl]-5-[(dimethylamino)methyl]phenyl]-N,N-dimethylmethanamine 在 t-C₄H₉Li 作用下， 以 正己烷 为溶剂， 以66%的产率得到
  参考文献：
  名称：

  A “Dendritic Effect” in Homogeneous Catalysis with Carbosilane-Supported Arylnickel(II) Catalysts:  Observation of Active-Site Proximity Effects in Atom-Transfer Radical Addition

  摘要：

  Transmetalation of polylithiated, carbosilane (CS) dendrimers functionalized with the potentially terdentate ligand [C6H2(CH2NMe2)(2)-2,6-R-4](-) ( NCN) with NiCl2(PEt3)(2) produced a series of nickel-containing dendrimers [GO]-N-4 (4), [G1]-Ni-12 (5), and [G2]-Ni-36 (7) in moderate to good yields. The metallodendrimers 4, 5, and 7 are catalytically active in the atom-transfer radical addition (ATRA) reaction (Kharasch addition reaction), viz. the 1:1 addition of CCl4 to methyl methacrylate (MMA). The catalytic data were compared to those obtained for the respective mononuclear compound [NiCl(C6H2{CH2NMe2}(2)-2,6-SiMe3-4)] (2). This comparison indicates a fast deactivation for the dendrimer catalysts beyond generation [GO]. The deactivation of [G1]-Ni-12 (5) and [G2]-Ni-36 (7) is caused by irreversible formation of catalytically inactive Ni(III) sites on the periphery of these dendrimers. This hypothesis is supported by results of model studies as well as ESR spectroscopic investigations. Interestingly, the use of two alternative nickelated [G1] dendrimers [G1]*-Ni-12 (11) and [G1]-Ni-8 (15), respectively, in which the distance between the Ni sites is increased, leads to significantly improved catalytic efficiencies which approximate those of the parent derivative 2 and [GO]-Ni-4 (4). Preliminary membrane catalysis experiments with [GO]-Ni-4 (4) and [G1]-Ni-12 (5) show that 5 can be efficiently retained in a membrane reactor system. The X-ray crystal structure of the Ni(III) complex [NiCl2(C6H2{CH2NMe2}(2)-2,6-SiMe3-4)] (16), obtained from the reaction of 2 with CCl4, is also reported.

  DOI：

  10.1021/ja0026612