[(hydrotris(3,5-dimethylpyrazolyl)borate)Nb(η1-CH2-4-MeC6H4)(cyclopropyl)(η2-MeCCMe)] | 1314027-16-1

• 英文名称: [(hydrotris(3,5-dimethylpyrazolyl)borate)Nb(η1-CH2-4-MeC6H4)(cyclopropyl)(η2-MeCCMe)]
• CAS: 1314027-16-1
• 化学式: C₃₀H₄₂BN₆Nb
• 分子量: 590.421
• InChiKey: HLNMALQFXXMBLX-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 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：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  [(hydrotris(3,5-dimethylpyrazolyl)borate)Nb(η1-CH2-4-MeC6H4)(cyclopropyl)(η2-MeCCMe)] 、 苯 以 苯 为溶剂， 生成 (hydridotris(3,5-dimethypyrazolyl)borate)(phenyl)(cyclopropyl)(MeCCMe)niobium
  参考文献：
  名称：

  Aromatic versus Benzylic CH Bond Activation of Alkylaromatics by a Transient η²-Cyclopropene Complex

  摘要：

  The methyl cyclopropyl hydrotris(3,5-dimethyl-pyrazolyl)borate complex Tp(Me2)NbMe(c-C3H5)(MeCCMe) reacts smoothly with different alkylaromatics XH at 308 K to yield methane and Tp(Me2)NbX(c-C3H5)(MeCCMe). NMR data show that for mesitylene and 1,4-dimethylbenzene, selective benzylic CH bond activation is observed, giving the benzyl cyclopropyl complexes Tp(Me2)Nb(CH2Ar')(c-C3H5)(MeCCMe) (Ar' = 3,5-Me2C6H3, 4-MeC6H4, respectively). Selective arene CH bond activation is observed with 1,2-dimethylbenzene, yielding Tp(Me2)Nb(3,4-Me2C6H3) (C-C3H5) (MeCCMe). With 1,3-dimethylbenzene,a 3:1 mixture of arene and benzylic CH activated prcidutts, Tp(Me2)Nb(3,5-Me2C6H3)(c-C3H5)(MeCCMe) and Tp(Me2)Nb-(CH2-3-MeC6H4)(c-C3H5)(MeCCMe), is observed, translating to a 18:1 preference for aromatic versus benzylic CH bond activation on a per CH bond basis. Kinetic studies are consistent with rate-limiting intramolecular beta-H abstraction of methane to yield a transient unsaturated eta(2)-cyclopropene intermediate. This intermediate reacts rapidly with the aromatic or benzylic CH bond of the arene via 1,3-addition across a Nb(eta(2)-cyclopropene) bond. DFT calculations suggest that the observed selectivities are a result of the steric influence of the methyl groups on the arene ring, which blocks activation of an ortho C-H bond.

  DOI：

  10.1021/om200199e
• 作为产物：
  描述：

  (hydridotris(3,5-dimethypyrazolyl)borate)(methyl)(cyclopropyl)(MeCCMe)niobium 、 对二甲苯 以 xylene 为溶剂， 以46%的产率得到[(hydrotris(3,5-dimethylpyrazolyl)borate)Nb(η1-CH2-4-MeC6H4)(cyclopropyl)(η2-MeCCMe)]
  参考文献：
  名称：

  Aromatic versus Benzylic CH Bond Activation of Alkylaromatics by a Transient η²-Cyclopropene Complex

  摘要：

  The methyl cyclopropyl hydrotris(3,5-dimethyl-pyrazolyl)borate complex Tp(Me2)NbMe(c-C3H5)(MeCCMe) reacts smoothly with different alkylaromatics XH at 308 K to yield methane and Tp(Me2)NbX(c-C3H5)(MeCCMe). NMR data show that for mesitylene and 1,4-dimethylbenzene, selective benzylic CH bond activation is observed, giving the benzyl cyclopropyl complexes Tp(Me2)Nb(CH2Ar')(c-C3H5)(MeCCMe) (Ar' = 3,5-Me2C6H3, 4-MeC6H4, respectively). Selective arene CH bond activation is observed with 1,2-dimethylbenzene, yielding Tp(Me2)Nb(3,4-Me2C6H3) (C-C3H5) (MeCCMe). With 1,3-dimethylbenzene,a 3:1 mixture of arene and benzylic CH activated prcidutts, Tp(Me2)Nb(3,5-Me2C6H3)(c-C3H5)(MeCCMe) and Tp(Me2)Nb-(CH2-3-MeC6H4)(c-C3H5)(MeCCMe), is observed, translating to a 18:1 preference for aromatic versus benzylic CH bond activation on a per CH bond basis. Kinetic studies are consistent with rate-limiting intramolecular beta-H abstraction of methane to yield a transient unsaturated eta(2)-cyclopropene intermediate. This intermediate reacts rapidly with the aromatic or benzylic CH bond of the arene via 1,3-addition across a Nb(eta(2)-cyclopropene) bond. DFT calculations suggest that the observed selectivities are a result of the steric influence of the methyl groups on the arene ring, which blocks activation of an ortho C-H bond.

  DOI：

  10.1021/om200199e