2,5-dimethoxy-1,3-bis(trimethylsilyl)benzene | 1004322-77-3

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯酚醚
• 英文名称: 2,5-dimethoxy-1,3-bis(trimethylsilyl)benzene
• CAS: 1004322-77-3
• 化学式: C₁₄H₂₆O₂Si₂
• 分子量: 282.53
• InChiKey: OJTJRELIXQKXLH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.79
• 重原子数：
  18.0
• 可旋转键数：
  4.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.57
• 拓扑面积：
  18.46
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  甲醇 、 3,5-bis(trimethylsilyl)-4-chloroanisole 在 caesium carbonate 作用下， 反应 16.0h， 以37%的产率得到2,5-dimethoxy-1,3-bis(trimethylsilyl)benzene
  参考文献：
  名称：

  The β Effect of Silicon in Phenyl Cations

  摘要：

  Irradiation of chloroanisoles, phenols, and N,N-dimethylanilines bearing a trimethylsilyl (TMS) group in the ortho position with respect to the chlorine atom caused photoheterolysis of the Ar-Cl bond and formation of the corresponding ortho-trimethylsilylphenyl cations in the triplet state. The beta effect of silicon on these intermediates has been studied by comparing the resulting chemistry in alcoholic solvents with that of the silicon-free analogues and by computational analysis (at the UB3LYP/6-311+G(2d,p) level in MeOH). TMS groups little affect the photophysics and the photocleavage of the starting phenyl chlorides, while stabilizing the phenyl cations, both in the triplet (ca. 4 kcal/mol per group) and, dramatically, in the singlet state (9 kcal/mol). As a result, although triplet phenyl cations are the first formed species, intersystem crossing to the more stable singlets is favored with chloroanisoles and phenols. Indeed, with these compounds, solvent addition to give aryl ethers (from the singlet) competed efficiently with reduction or arylation (from the triplet). In the case of the silylated 4-chloro-NN-dimethylaniline, the triplet cation remained in the ground state and trapping by pi nucleophiles remained efficient, though slowed by the steric bulk of the TMS group. In alcohols, the silyl group was eliminated via a photoinduced protiodesilylation during the irradiation. Thus, the silyl group could be considered as a directing, photoremovable group that allowed shifting to the singlet phenyl cation chemistry and was smoothly eliminated in the same one-pot procedure.

  DOI：

  10.1021/ja074778x