Cp*Zr(CH3)CH2CH(CH3)2 | 420787-78-6

• 英文名称: Cp*Zr(CH3)CH2CH(CH3)2
• 英文别名: Cp(*)2ZrMe(i-Bu)
• CAS: 420787-78-6
• 化学式: C₂₅H₄₂Zr
• 分子量: 433.832
• InChiKey: QDEWJWYYQFWZBO-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  Cp*Zr(CH3)CH2CH(CH3)2 、 三(五氟苯基)硼烷 以 二氯甲烷-D2 为溶剂， 生成 Cp(*)2Zr(i-Bu)(μ-Me)B(C6F5)3
  参考文献：
  名称：

  Mechanistic Study of β-Methyl and β-Hydrogen Elimination in the Zirconocene Compounds Cp‘₂ZrR(μ-CH₃)B(C₆F₅)₃ (Cp‘ = Cp, Cp*; R = CH₂CMe₃, CH₂CHMe₂)

  摘要：

  A kinetics study of beta-methyl elimination reactions of the compounds Cp2ZrNp(mu-Me)B(C6F5)(3) (in various solvents) and Cp*2ZrNp(mu-Me)B(C6F5)(3) (in CD2Cl2) shows that the reactions are accelerated by polar solvents and by steric crowding in the Cp* system, results consistent with previous findings and conclusions that the methyl migrations are accompanied in a concerted process by borate anion departure from the inner coordination sphere of the metal ion. Surprisingly, however, the isobutyl compound CP*Zr-2(i-Bu)(mu-Me)B(C6F5)(3), which is expected to undergo beta-methyl elimination by analogy with an extensive literature on chain transfer processes during propylene polymerization, undergoes very rapid beta-hydrogen elimination only.

  DOI：

  10.1021/om0504710
• 作为产物：
  描述：

  Cp*Zr(Cl)CH2CH(CH3)2 、 甲基溴化镁 以 四氢呋喃 为溶剂， 以75%的产率得到Cp*Zr(CH3)CH2CH(CH3)2
  参考文献：
  名称：

  Observation of non-chelated bis(pentamethylcyclopentadienyl)zirconium-alkyl–alkene complexes is thwarted by competitive arene or amine coordination or by β-hydride elimination

  摘要：

  The reaction of Cp-2*Zr(CH3)(2) (1) with [(C6H5)(3)C][B(C6F5)(4)] in CD2Cl2 at - 78 degreesC proceeds with the unexpected formation of [Cp-2*Zr(CH3)eta-C6H5C(C6H5)(2)CH3][B(C6F5)(4)] (2). Evidence for the coordination of one of the phenyl rings to zirconium comes from H-1- and C-13-NMR chemical shifts and from nOe experiments showing spin saturation transfer from the Cp* methyl protons to the protons of the bound phenyl ring. No chemical exchange between the bound and free phenyl rings is observed up to 0 degreesC, where decomposition to intractable products occurs. Attempts to disfavor coordination of the arene ring by employing a more sterically protective isobutyl substituent in Cp-2*Zr(CH3)CH2CH(CH3)(2) (7) led to rapid, quantitative beta-hydride elimination producing isobutylene and [Cp-2*Zr(H)eta-C6H5C(C6H5)(2)CH3][B(C6F5)(4)] (8) even at temperatures as low as - 135 degreesC. Addition of propylene to cold solutions of the trityl-coordinated complexes resulted in very rapid formation of polypropylene, This polymerization resulted in no observable changes in the NMR spectra of the zirconium complexes in solution. implying a very rapid rate of propagation following a much slower first monomer insertion. (C) 2002 Elsevier Science B.V. All rights reserved.

  DOI：

  10.1016/s0022-328x(01)01217-7