2-Triisopropylsilanyloxy-propionic acid ethyl ester | 658706-97-9

• 分子结构分类: 有机化合物 - 有机金属化合物 - 有机类金属化合物
• 英文名称: 2-Triisopropylsilanyloxy-propionic acid ethyl ester
• 英文别名: ethyl 2-tri(propan-2-yl)silyloxypropanoate
• CAS: 658706-97-9
• 化学式: C₁₄H₃₀O₃Si
• 分子量: 274.476
• InChiKey: PQBZFXIJDQJJRP-UHFFFAOYSA-N

物化性质

• 沸点：
  282.9±23.0 °C(predicted)
• 密度：
  0.894±0.06 g/cm3(Temp: 20 °C; Press: 760 Torr)(predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  4.13
• 重原子数：
  18.0
• 可旋转键数：
  7.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.93
• 拓扑面积：
  35.53
• 氢给体数：
  0.0
• 氢受体数：
  3.0

反应信息

• 作为反应物：
  描述：

  2-Triisopropylsilanyloxy-propionic acid ethyl ester 在 sodium hydride 、 二异丁基氢化铝 作用下， 以 甲苯 为溶剂， 反应 3.33h， 生成 (E)-4-Triisopropylsilanyloxy-pent-2-enoic acid methyl ester
  参考文献：
  名称：

  Highly Diastereoselective Conjugate Addition of Lithium Dialkylamides to α,β-Unsaturated Esters Having a Chiral Center at the γ-Position

  摘要：

  The conjugate addition of lithium amides 2 to tert-butyl 4-(OR)-substituted-2-pentenoates 1 produced a mixture of the syn-and anti-amino esters (3 and 4) in high yields. Sterically bulky OR groups, such as trityloxy and tert-butyldiphenylsilyloxy, gave the syn diastereomer 3 either exclusively or predominantly. The syn-selectivity may be explained by a modified Felkin-Anh model. The use of tert-butyldimethylsilyloxy as an OR group afforded a nearly 1:1 mixture of diastereoisomers, and the use of the smallest MeO group produced a 63:37 mixture of the syn 3 and anti isomer 4. The presence of Me group at the alpha-position (C-2 position) of the enoate enhanced the syn diastereoselectivity up to 100%; the conjugate addition to tert-butyl 4-methoxy-2-methyl-2-pentenoate (17) gave the syn-isomer 18 exclusively. This enhancement may be explained by the combination of chelation and allylic strain model 19 in which the smallest H orients inside to avoid an allylic strain. A phenyl group at the gamma-position enhanced the anti selectivity in the case of gamma-alkoxy-alpha,beta-enoates such as isopropyl 4-[(tert-butyldimethylsilyl)oxy]-4-phenyl-2-buteonoate (20), and in the case of gamma-alkyl-alpha,beta-enoates such as tert-butyl 4-phenyl-2-pentenoate (27).

  DOI：

  10.1021/jo970435d
• 作为产物：
  描述：

  (S)-ethyl 2-((triisopropylsilyl)oxy)propanoate 在 lithium diisopropyl amide 作用下， 生成 2-Triisopropylsilanyloxy-propionic acid ethyl ester
  参考文献：
  名称：

  Comparative Study of the Diastereoselective Addition of Allenyl Zinc Reagents to α-Alkoxy (or Silyloxy) Aldehydes and Imines. A Straightforward Synthesis of Amino Alcohols from Imines

  摘要：

  The addition of allenylzine bromides to or-chiral imines proceeds with very high diastereoselectivity. This result is in contrast with the addition to the corresponding aldehydes, leading to poor diastereoselectivity. The anti/anti adducts are explained by Felkin-Ahn and Gaudemar-Yamamoto models of the transition state.

  DOI：

  10.1021/jo005509r

文献信息

• Conformationally Biased Ketones React Diastereoselectively with Allylmagnesium Halides
  作者：Nicole D. Bartolo、Krystyna M. Demkiw、Jacquelyne A. Read、Elizabeth M. Valentín、Yingying Yang、Alexandra M. Dillon、Chunhua T. Hu、Michael D. Ward、K. A. Woerpel

  DOI：10.1021/acs.joc.1c02844

  日期：2022.3.4

  The addition of the highly reactive reagent allylmagnesium halide to α-substituted acyclic chiral ketones proceeded with high stereoselectivity. The stereoselectivity cannot be analyzed by conventional stereochemical models because these reactions do not conform to the requirements of those models. Instead, the stereoselectivity arises from the approach of the nucleophile to the most accessible diastereofaces

  高反应性试剂烯丙基卤化镁与α-取代的无环手性酮的加成具有高立体选择性。立体选择性无法通过常规立体化学模型进行分析，因为这些反应不符合这些模型的要求。相反，立体选择性是由于亲核试剂接近酮的最低能量构象的最容易接近的非对映面而产生的。预期具有高立体选择性，并且可以预测立体化学结果，其中构象偏向的酮具有空间上可区分的非对映面，其中只有一个面可进行亲核加成。酮的构象可以通过计算建模和在某些情况下通过 X 射线晶体学确定结构的组合来确定。