| 156974-28-6

• CAS: 156974-28-6
• 化学式: C₃₂H₃₆B*Li
• 分子量: 438.39
• InChiKey: RUMFADNRLYVFTP-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

• 作为产物：
  描述：

  苯乙基锂 、 trifluoroborane diethyl ether 以 乙醚 、 正戊烷 为溶剂， 生成
  参考文献：
  名称：

  Titanium-Mediated Additions of Borohydride to Alkenes

  摘要：

  This paper concerns additions of borohydride to alkenes promoted by titanium complexes. Isolated Cp(2)-Ti(mu-H)(2)BH2 was shown to be a catalyst precursor for the hydroboration of phenylethene by borohydride. Lithium borohydride appears to be involved in the formation of the true catalytically active complex since borohydride/catalytic Cp(2)Ti(mu-H)(2)BH2 mixtures gave faster hydroboration than stoichiometric Cp(2)Ti(mu-H)(2)BH2 in the absence of borohydride. Furthermore, the catalytic and stoichiometric titanium-mediated hydroboration of phenylethene provided different regioselectivities. Regio- and/or stereoselectivities for the hydroboration of phenylethene and beta-pinene also differ when mediated by BH4-/catalytic Cp(2)Ti(mu-H)(2)BH2, or by BH3 generated in situ. Extensive B-11 NMR experiments indicate the predominant products in the hydroboration of phenylethene with borohydride are tetraalkylborates; minor amounts of alkylborohydrides are formed (mostly trialkylborohydride) and little or no alkylboranes. Alcohols are formed in the transformations mediated by BH4-/catalytic Cp(2)Ti(mu-H)(2)BH2, after treatment with basic peroxide, but these result from oxidation of alkylborohydride intermediates since tetraalkylborates oxidize very slowly under the conditions used. A mechanism is proposed for the hydroboration of phenylethene mediated by Cp(2)Ti(mu-H)(2)BH2; this involves abstraction of BH3 from the complex by borohydride leading to a titanium hydride species, conventional hydroboration of the alkene by BH3, insertion of phenylethene into the titanium-hydride bond, and then alkyl-transfer from titanium to boron giving tetraalkylborates. Differences for the hydroboration of other substrates are discussed also. 1-Decene and beta-pinene react slower than phenylethene in reactions promoted by BH4-/catalytic Cp(2)Ti(mu-H)(2)BH2, and monoalkylborohydrides or boranes tend to be the predominant products. These alkenes gave little or no tetraalkylborates, possibly due to the relatively slow insertion of these alkenes into titanium-hydride bonds or because of lack of titanium-to-boron alkyl transfer.

  DOI：

  10.1021/ja00094a010