(4R,5R)-2,2-Dimethyl-α,α,α',α'-tetra(4-tert-butyldimethylsilyloxyphenyl)-1,3-dioxolane-4,5-dimethanol | 199277-46-8

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: (4R,5R)-2,2-Dimethyl-α,α,α',α'-tetra(4-tert-butyldimethylsilyloxyphenyl)-1,3-dioxolane-4,5-dimethanol
• CAS: 199277-46-8
• 化学式: C₅₅H₈₆O₈Si₄
• 分子量: 987.625
• InChiKey: IAMQKBKMHXRFCA-URZIEALYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  14.91
• 重原子数：
  67.0
• 可旋转键数：
  14.0
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.56
• 拓扑面积：
  95.84
• 氢给体数：
  2.0
• 氢受体数：
  8.0

反应信息

• 作为反应物：
  描述：

  (4R,5R)-2,2-Dimethyl-α,α,α',α'-tetra(4-tert-butyldimethylsilyloxyphenyl)-1,3-dioxolane-4,5-dimethanol 在 四丁基氟化铵 、 potassium carbonate 作用下， 以 四氢呋喃 、 N,N-二甲基甲酰胺 为溶剂， 反应 39.0h， 生成 [(4R,5R)-5-[hydroxy-bis(4-phenylmethoxyphenyl)methyl]-2,2-dimethyl-1,3-dioxolan-4-yl]-bis(4-phenylmethoxyphenyl)methanol
  参考文献：
  名称：

  Dendritic TADDOLs: Synthesis, Characterization and Use in the Catalytic Enantioselective Addition of Et2Zn to Benzaldehyde

  摘要：

  The versatile chiral ligand for polar metal centers, TADDOL ((R,R)alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-di-methanol), has been incorporated as core building block into dendrimers by way of benzylation of a fourfold phenolic derivative (hexol 2) with Frechet-type branches of up to fourth generation. These carry either benzyl (3-7) or octyl groups (33 -35) at the periphery, or they contain chiral branching units (18 - 20, 36), derived from (R)- or (S)-3-hydroxybutanoic acid. The dendritic compounds of molecular weight up to 13626 have been fully characterized, including by MALDI-TOF mass spectrometry, NMR spectroscopy, and optical activity measurements; one of the branch precursors with four octyl groups crystallized in an intriguing packing pattern. From the spectra and from the specific and molar optical rotations, there was no indication for the formation of chiral secondary structures of up to the third generation. The new TADDOLs were converted to Ti TADDOLates, which were employed as catalysts for the addition of Et2Zn to PhCHO. The stereoselectivities and the reaction rates observed with the novel catalysts were compared with those of the simple Ti TADDOLate: up to the second generation there was no detectable decrease of selectivity (= 98:2), and the rates hardly decreased up to the third generation; also, enantiomeric branches caused no change of stereoselectivity within experimental error. Thus, there may be applications for the special properties (such as high molecular weight, good solubility, spacing of central site from cross-linked polymer matrix) of dendritically modified chiral catalyst ligands.

  DOI：

  10.1002/(sici)1521-3765(19991105)5:11<3221::aid-chem3221>3.0.co;2-p
• 作为产物：
  描述：

  (-)-二甲基-2,3-邻异丙亚基-L-酒石酸酯 、 (4-溴苯氧基)叔丁基二甲基硅烷 在 碘 、 magnesium 作用下， 以 四氢呋喃 为溶剂， 反应 1.0h， 以61%的产率得到(4R,5R)-2,2-Dimethyl-α,α,α',α'-tetra(4-tert-butyldimethylsilyloxyphenyl)-1,3-dioxolane-4,5-dimethanol
  参考文献：
  名称：

  Dendritic TADDOLs: Synthesis, Characterization and Use in the Catalytic Enantioselective Addition of Et2Zn to Benzaldehyde

  摘要：

  The versatile chiral ligand for polar metal centers, TADDOL ((R,R)alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-di-methanol), has been incorporated as core building block into dendrimers by way of benzylation of a fourfold phenolic derivative (hexol 2) with Frechet-type branches of up to fourth generation. These carry either benzyl (3-7) or octyl groups (33 -35) at the periphery, or they contain chiral branching units (18 - 20, 36), derived from (R)- or (S)-3-hydroxybutanoic acid. The dendritic compounds of molecular weight up to 13626 have been fully characterized, including by MALDI-TOF mass spectrometry, NMR spectroscopy, and optical activity measurements; one of the branch precursors with four octyl groups crystallized in an intriguing packing pattern. From the spectra and from the specific and molar optical rotations, there was no indication for the formation of chiral secondary structures of up to the third generation. The new TADDOLs were converted to Ti TADDOLates, which were employed as catalysts for the addition of Et2Zn to PhCHO. The stereoselectivities and the reaction rates observed with the novel catalysts were compared with those of the simple Ti TADDOLate: up to the second generation there was no detectable decrease of selectivity (= 98:2), and the rates hardly decreased up to the third generation; also, enantiomeric branches caused no change of stereoselectivity within experimental error. Thus, there may be applications for the special properties (such as high molecular weight, good solubility, spacing of central site from cross-linked polymer matrix) of dendritically modified chiral catalyst ligands.

  DOI：

  10.1002/(sici)1521-3765(19991105)5:11<3221::aid-chem3221>3.0.co;2-p

文献信息

• Dendritic styryl TADDOLs as novel polymer cross-linkers: First application in an enantioselective Et₂Zn addition mediated by a polymer-incorporated titanate. Preliminary communication
  作者：P. Beat Rheiner、Holger Sellner、Dieter Seebach

  DOI：10.1002/hlca.19970800702

  日期：1997.11.3

  TADDOLs (α,α,α′,α′,-tetraaryl-1,3-dioxolane-4,5-dimethanols) with dendritic branches attached to the aryl groups and with 8 or 16 peripheral styryl double bonds have been synthesized (4 and 5). With these compounds, dendritic molecules were employed for the first time as cross-linkers in a polymerization. The resulting polystyrene was loaded with titanate (Ti(OCHMe2)4) to generate polymer beads incorporating

  TADDOLs（α，α，α'，α'，-tetraaryl-1,3-dioxolane-4,5-dimethanols）具有连接到芳基上的树枝状分支和8或16个周边苯乙烯基双键的TADDOLs（4和5）。对于这些化合物，树枝状分子首次被用作聚合反应中的交联剂。向所得的聚苯乙烯中加载钛酸酯（Ti（OCHMe 2）4），以生成掺入Ti-TADDOLate中心的聚合物珠粒（图1和2），用于对映选择性催化（向PhCHO中添加Et 2 Zn）。与常规的聚合物连接的不溶性Ti-TADDOLate相比（参见 3），新材料具有更高的催化活性，与可溶性类似物相当（图3）。