[(C5H4Me)2Zr(O(t)Bu)(allyltrimethylsilane)][B(C6F5)4] | 775322-79-7

• 英文名称: [(C5H4Me)2Zr(O(t)Bu)(allyltrimethylsilane)][B(C6F5)4]
• 英文别名: [Cp'Zr(O(t)Bu)(allyltrimethylsilane)][B(C6F5)4]
• CAS: 775322-79-7
• 化学式: C₂₂H₃₇OSiZr*C₂₄BF₂₀
• 分子量: 1115.89
• InChiKey: PJDPKGHAQLQBCN-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
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• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  [(C5H4Me)2Zr(O(t)Bu)(ClCD2Cl)][B(C6F5)4] 、 烯丙基三甲基硅烷 以 二氯甲烷-D2 为溶剂， 生成 [(C5H4Me)2Zr(O(t)Bu)(allyltrimethylsilane)][B(C6F5)4]
  参考文献：
  名称：

  Alkyne and Alkene Complexes of a d⁰ Zirconocene Aryl Cation

  摘要：

  The generation and properties of nonchelated Zr-aryl-alkyne and Zr-aryl-alkene complexes that are stabilized by the presence of beta-Si-substituents in the alkyne and alkene ligands and fluorination of the aryl ligand are described. Reaction of [Cp'2Zr(OtBu)(ClCD2Cl)][B(C6F5)4] (1, Cp' = C5H4Me) with alkyne and alkene substrates (L) generates Cp'2Zr(OtBu)(L)+ adducts (L = HCCCH2SiMe3 (2); H2C=CHCH2SiMe3 (3); HCCMe (4); H2C=CHCH2CMe3 (5)). Equilibrium constants for substrate binding (Keq = [Zr-L][1]-1[L]-1; CD2Cl2, -89 degrees C) are much larger for the beta-Si-substituted compounds 2 (1.0(2) x 105 M-1) and 3 (1.7(4) x 103 M-1) than for hydrocarbon analogues 4 (3.6(7) x 102 M-1) and 5 (1.9(1) M-1), which is ascribed to beta-Si stabilization of the partial positive charge on Cint of the bound substrate. [Cp2Zr(C6F5)][B(C6F5)4] (7, Cp = C5H5) was generated by the reaction of Cp2Zr(C6F5)Me with [Ph3C][B(C6F5)4] in C6D5Cl. Reaction of 7 with alkyne and alkene substrates (L) generates Cp2Zr(C6F5)(L)+ adducts (L = HCCCH2SiMe3 (8); H2C=CHCH2SiMe3 (10)). No insertion of the substrate into the Zr-C6F5 bond is observed in 8 (at -38 degrees C) or 10 (up to 22 degrees C). The allyltrimethylsilane ligand in 10 undergoes nondissociative alkene face exchange ("alkene flipping", i.e., exchange of the Cp2Zr(C6F5)+ unit between the two alkene enantiofaces without alkene dissociation), with a first-order rate constant kflip = 23(1) s-1 (C6D5Cl, -38 degrees C). 10 also undergoes slower reversible decomplexation of the alkene (kdissoc = 5.0(8) s-1; C6D5Cl, -38 degrees C).

  DOI：

  10.1021/ja045794m

文献信息

• Nonchelated d⁰ Zirconium−Alkoxide−Alkene Complexes
  作者：Edward J. Stoebenau、Richard F. Jordan

  DOI：10.1021/ja0575225

  日期：2006.6.1

  The reaction of Cp'Zr-2((OBu)-Bu-t)Me (Cp' = C5H4Me) and [Ph3C][B(C6F5)(4)] yields the base-free complex [Cp'Zr-2((OBu)-Bu-t)][B(C6F5)(4)] (6), which exists as Cp'Zr-2((OBu)-Bu-t)(ClR)(+) halocarbon adducts in CD2Cl2 or C6D5Cl solution. Addition of alkenes to 6 in CD2Cl2 solution at low temperature gives equilibrium mixtures of Cp'(2) -Zr((OBu)-Bu-t)(alkene)(+) (12a-I), 6, and free alkene. The NMR data for 12a-I are consistent with unsymmetrical alkene bonding and polarization of the alkene C = C bond with positive charge buildup at C-int and negative charge buildup at C-term. These features arise due to the lack of d-pi(*) back-bonding. Equilibrium constants for alkene coordination to 6 in CD2Cl2 at -89 degrees C, K-eq = [12][6](-1)[alkene](-1), vary in the order: vinylferrocene (4800 M-1) >> ethylene (7.0) approximate to alpha-olefins > cis-2-butene (2.2) > trans-2-butene (< 0.1). Alkene coordination is inhibited by sterically bulky substituents on the alkene but is greatly enhanced by electron-donating groups and the beta-Si effect. Compounds 12a-I undergo two dynamic processes: reversible alkene decomplexation via associative substitution of a CD2Cl2 molecule, and rapid rotation of the alkene around the metal-(alkene centroid) axis.