| 399042-78-5

• CAS: 399042-78-5
• 化学式: C₂₆H₄₃Y
• 分子量: 444.533
• InChiKey: QNYYGAYTYHBPBY-ZGOHZKFSSA-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

• 作为产物：
  描述：

  三聚丙烯 、 butane;1,2,3,4,5-pentamethylcyclopenta-1,3-diene;yttrium(3+) 以 not given 为溶剂， 以95%的产率得到
  参考文献：
  名称：

  Structural Dependence of Thermodynamics of Alkene Binding to Yttrium Alkyl Complexes and of Kinetics of Alkyl Migration to Coordinated Alkenes

  摘要：

  Agostic interactions in yttrium alkyls are structure dependent. Primary alkyl yttrium complexes have beta-CH2 agostic interactions at low temperature, but a shift toward alpha-agostic interactions occurs on warming. For the more crowded beta-disubstituted yttrium alkyls, an alpha-CH2 agostic interaction is seen. The thermodynamics of alkene binding to the primary alkyl yttrium complex CP*2YCH2CH2CH(CH3)(2) (2) depend strongly on the structure of the alkene. A single allylic substituent on the alkene has a small effect on alkene binding, but a second allylic substituent has a large destabilizing effect. Propene binding to yttrium alkyls is largely independent of the nature of the alkyl ligand. Equilibrium constants for propene binding to n-, gamma-substituted, beta-substituted, and secondary alkyl yttrium complexes are similar. The rate of migration of an alkyl group to a coordinated alkene depends strongly on the structure of the alkyl group: n-alkyl; gamma-substituted much greater than beta-substituted much greater than alpha-substituted. The similar to200-fold slower insertion of propene into Cp*2YCH(2)-CH(CH3)(2) (6) than that into CP*(2)gammaCH(2)CH(2)CH(CH3)(2) (2) is therefore due to kinetically slow migration of the beta-disubstituted alkyl group of 6 and not to differences in the equilibrium binding of propene. Processes related to chain transfer and site epimerization at the metal center are also reported.

  DOI：

  10.1021/ja0209971

文献信息

• Kinetics and Mechanism of Formation of Yttrium Alkyl Complexes from (Cp*₂YH)₂ and Alkenes
  作者：Charles P. Casey、Jon A. Tunge、Ting-Yu Lee、Donald W. Carpenetti

  DOI：10.1021/om010817g

  日期：2002.1.1

  dissociation of the dimer (Cp*2YH)2 (2) to the Cp*2YH monomer is an important process in reactions of 2 with alkenes. The rate of dissociation of 2 was measured by NMR line-broadening techniques (14 s-1 at 0 °C, ΔG⧧ = 14.5 kcal mol-1, ΔH⧧ = 14.9(8) kcal mol-1, and ΔS⧧ = 3(2) eu). A full range of dissociative and associative mechanisms for reaction of alkenes with 2 was found. For the most crowded and

  在2与烯烃的反应中，二聚体（Cp * 2 YH）2（2）分解为Cp * 2 YH单体是重要的过程。的解离速率2通过NMR线加宽技术测量（第14号- 1在0℃下，Δ ģ ⧧ = 14.5千卡摩尔- 1，Δ ħ ⧧ = 14.9（8）千卡摩尔- 1，和Δ小号⧧ = 3（2）eu）。烯烃与2的反应的全方位解离和缔合机理被找到。对于研究的最拥挤和反应最少的烯烃，2-丁烯和2-甲基丙烯，与2的反应比二聚体2的离解要慢。动力学研究建立了2到单体Cp * 2 YH的可逆解离，然后通过烯烃竞争性捕集并重组以再生2。较不拥挤的烯烃3-甲基-1-丁烯的动力学研究与二聚体2的限速解离，随后烯烃有效捕集中间体Cp * 2 YH相一致。最不拥挤的末端烯烃（例如1-己烯）与2以比二聚体解离更快的速率；动力学研究建立了一个两组分速率定律，其中涉及烯烃直接攻击二聚体的一个二级术语和一个涉及速率确定二聚体解离，然后与单体Cp