1,3-di-tert-butyl-3,4,5,6-tetrahydripyrimidin-2-ylidene | 1313574-23-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑烷类
• 英文名称: 1,3-di-tert-butyl-3,4,5,6-tetrahydripyrimidin-2-ylidene
• 英文别名: 1,3-di-tert-butyltetrahydropyrimidin-2-ylidene；1,3-di-tert-butylhexahydropyrimidin-2-ylidene；(C4H6N2)(Bu-t)2
• CAS: 1313574-23-0
• 化学式: C₁₂H₂₄N₂
• 分子量: 196.336
• InChiKey: BQEHLGPYDGELHO-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.59
• 重原子数：
  14.0
• 可旋转键数：
  0.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.92
• 拓扑面积：
  6.48
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为反应物：
  描述：

  trimethylaluminium dimer 、 1,3-di-tert-butyl-3,4,5,6-tetrahydripyrimidin-2-ylidene 以 neat (no solvent) 为溶剂， 反应 2.0h， 以99%的产率得到
  参考文献：
  名称：

  Deprotonation of Al₂Me₆ by Sterically Bulky NHCs: Scope, Rationale through DFT Studies, and Application in the Methylenation of Carbonyl Substrates

  摘要：

  The sterically bulky NHCs 1,3-di-tert-butylimidazol-2-ylidene ((IBu)-Bu-t), 1,3-di-tent-butylimidazolin-2-ylidene ((SBu)-Bu-t), and 1,3-di-tert-butyl-3,4,5,6-tetrahydripyrimidin-2-ylidene (C6(t)Bu) were found to readily react with excess Al2Me6 at room temperature to form salts 2, 3, and 4, respectively, consisting of the polynuclear Me3Al(mu(3)-CH2)(AlMe2)(2)(mu(2)-CH3)(-) anion associated with either the cation (IBu)-Bu-t-H+, (SBu)-Bu-t-H+, or C6-Bu-t-H+. Such a reaction involving the deprotonation of an Al2Me6 moiety by a NHC does not proceed with less sterically hindered NHCs such as 1,3-bis(2,6-dii opropylphenyOimidazol-2-ylidene (IDipp) and 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), for which only the classical Lewis pair adducts (NHC)AlMe3 were isolated. In line with experimental and density functional theory (DFT) calculations data, such reactivity thus appears to be driven by steric frustration, resulting in the destabilization of the corresponding (NHC)AlMe3 adducts, then more prone to dissociate and hence allowing Al2Me6 activation/deprotonation. The DFT-estimated profile of the reaction of model adduct ((IBu)-Bu-t)AlMe3 (I) with Al2Me6 agrees with a ready adduct dissociation at low energy cost, with a subsequent deprotonation of Al2Me6 by the NHC fragment to afford model salt II (isostructural to salt 2). Anion Me3Al(mu(3)-CH2)(AlMe2)(2)(mu(2)-CH3)(-) behaves as an efficient CH22- group transfer agent with the methylenation of aldehydes and ketones to afford the corresponding methylene organics in good conversions. Bonding analysis of the latter anion agrees with an enhanced nucleophilicity of the Al-CH2 moiety (compared to the Al-Me groups), in line with the observed reactivity. DFT calculations also allowed a detailed bonding description of the pentacoordinate methylene carbon in the anion Me3Al(mu(3)-CH2)(AlMe2)(2)(mu(2)-CH3)(-).

  DOI：

  10.1021/acs.organomet.6b00159
• 作为产物：
  描述：

  1,3-di-tert-butylhexahydropyrimidine 在 N-溴代丁二酰亚胺(NBS) 、 sodium hexamethyldisilazane 作用下， 以 四氢呋喃 、 乙二醇二甲醚 为溶剂， 反应 6.0h， 生成 1,3-di-tert-butyl-3,4,5,6-tetrahydripyrimidin-2-ylidene
  参考文献：
  名称：

  沮丧的碳-硼-刘易斯对活化双氢：碳变化的实验和理论研究

  摘要：

  各种路易斯酸碱对，由三（五氟苯基）硼烷，B（C 6 F 5）3以及咪唑啉-2-亚基的空间要求的五元和六元N-杂环卡宾（NHC）组成分别研究了咪唑啉二-2-亚胺和咪唑啉二-2-亚烷基类型与通过与二氢（H 2）和四氢呋喃（THF）反应而成为沮丧的路易斯对（FLP）的可能性。通常通过引入1,3-二酯来建立足够的“挫败感”-丁基或1,3-二金刚烷基卡宾取代模式，可实现不猝灭的酸碱反应性，从而导致杂二氢活化和THF开环。相反，1,3-双（2,6-二异丙基苯基）取代的碳烯表现出模棱两可的行为，相应的五元咪唑啉-2-亚烷基形成了稳定的卡宾-B（C 6 F 5）3加合物，而速度很快六元四氢嘧啶-2-亚基中观察到CF活化和两性离子嘧啶-氟硼酸根的形成。还分离出稳定的加合物，用于无环卡宾双（二异丙基氨基）亚甲基与B（C 6 F 5）3的结合，因此对H无反应性观察到2，并观察到THF。为了合理化卡宾-硼烷路易斯

  DOI：

  10.1021/ic201290g