| 1449115-21-2

• CAS: 1449115-21-2
• 化学式: C₃₁H₇₂NO₂PSi₂W
• 分子量: 761.913
• InChiKey: OWXRQFJVFDAXGD-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：

  以 氘代甲苯 为溶剂， 生成
  参考文献：
  名称：

  Lewis Bases Trigger Intramolecular CH–Bond Activation: ( ^t Bu ₃ SiO) ₂ W=N ^t Bu [rlhar2] ( ^t Bu ₃ SiO)(κ O ,κ C ‐ ^t Bu ₂ SiOCMe ₂ CH ₂ )HW=N ^t Bu

  摘要：

  AbstractThe symmetry‐forbidden cyclometalation of (silox)2W=NtBu (1, silox = OSitBu3) to (silox)(tBuN)W(H)(κO,κC‐OSitBu2CMe2CH2) (2) was investigated by kinetics [ΔH‡ = 19.2(9) kcal/mol; ΔS‡ = –23(3) eu; ΔG‡(25 °C) = 26.1(10) kcal/mol], isotopic labeling {[D54]1 → [D54]2; kH/kD = 2.7(4)}, and equilibrium studies [ΔH° = –6.7(3) kcal/mol; ΔS° = –12.1(8) eu; ΔG°(25 °C) = –3.1(4) kcal/mol]. The crystal structure of 2 reveals a pseudo‐square‐pyramidal structure that can be viewed as a distorted tetrahedron with the W–H and W–C bonds occupying one site. The addition of H2 (or D2) to 1 proceeds similarly to afford (silox)2(tBuN=)WH2 (3), and the addition of H2 to 2 also affords 3, but labeling experiments show that it proceeds via 1. Phosphane bases with cone angles < 160° trigger the cyclometalation of 1 to 2 in < 5 min, and PMe3 catalyzed the dihydrogen addition to 1. Quantum mechanics/molecular mechanics (QM/MM) calculations support the experimental findings and show that Lewis bases promote σ/π mixing. The experimentally observed intermediate (silox)2(tBuN=)WPMe3 (1‐PMe3) has a (dyz)2 (i.e., π2) ground state in contrast to the (d)2 (i.e., σ2) configuration of 1. The σ/π mixing circumvents the constraints of orbital symmetry for both cyclometalation and dihydrogen addition.

  DOI：

  10.1002/ejic.201300234
• 作为产物：
  描述：

  N,3,3,7,7-penta-tert-butyl-2,2,8,8-tetramethyl-4,6-dioxa-3,7-disila-5-tungstennonan-5-imine 、 三甲基膦 以 氘代甲苯 为溶剂， 生成
  参考文献：
  名称：

  Lewis Bases Trigger Intramolecular CH–Bond Activation: ( ^t Bu ₃ SiO) ₂ W=N ^t Bu [rlhar2] ( ^t Bu ₃ SiO)(κ O ,κ C ‐ ^t Bu ₂ SiOCMe ₂ CH ₂ )HW=N ^t Bu

  摘要：

  AbstractThe symmetry‐forbidden cyclometalation of (silox)2W=NtBu (1, silox = OSitBu3) to (silox)(tBuN)W(H)(κO,κC‐OSitBu2CMe2CH2) (2) was investigated by kinetics [ΔH‡ = 19.2(9) kcal/mol; ΔS‡ = –23(3) eu; ΔG‡(25 °C) = 26.1(10) kcal/mol], isotopic labeling {[D54]1 → [D54]2; kH/kD = 2.7(4)}, and equilibrium studies [ΔH° = –6.7(3) kcal/mol; ΔS° = –12.1(8) eu; ΔG°(25 °C) = –3.1(4) kcal/mol]. The crystal structure of 2 reveals a pseudo‐square‐pyramidal structure that can be viewed as a distorted tetrahedron with the W–H and W–C bonds occupying one site. The addition of H2 (or D2) to 1 proceeds similarly to afford (silox)2(tBuN=)WH2 (3), and the addition of H2 to 2 also affords 3, but labeling experiments show that it proceeds via 1. Phosphane bases with cone angles < 160° trigger the cyclometalation of 1 to 2 in < 5 min, and PMe3 catalyzed the dihydrogen addition to 1. Quantum mechanics/molecular mechanics (QM/MM) calculations support the experimental findings and show that Lewis bases promote σ/π mixing. The experimentally observed intermediate (silox)2(tBuN=)WPMe3 (1‐PMe3) has a (dyz)2 (i.e., π2) ground state in contrast to the (d)2 (i.e., σ2) configuration of 1. The σ/π mixing circumvents the constraints of orbital symmetry for both cyclometalation and dihydrogen addition.

  DOI：

  10.1002/ejic.201300234