Ethyl-zink-hydrid | 108899-21-4

• 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: Ethyl-zink-hydrid
• CAS: 108899-21-4
• 化学式: C₂H₆Zn
• 分子量: 95.4596
• InChiKey: MSZRNGGJGWETDD-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.7
• 重原子数：
  3.0
• 可旋转键数：
  0.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为产物：
  描述：

  diethylzinc 以 gaseous matrix 为溶剂， 生成 zinc dihydride 、 Ethyl-zink-hydrid
  参考文献：
  名称：

  二乙基锌的均相分解机理的拉曼光谱和量子化学计算。

  摘要：

  详细研究了二乙基锌（DEZn）的气相分解途径，二乙基锌是沉积Zn-VI化合物的常见前体。在N2载体中DEZn的均质热分解之后，通过拉曼散射在冲击射流，上流反应器中进行。进行了密度泛函理论计算，以描述化学模型B3LYP / 6-311G（d）的键解离行为，以估计DEZn的最佳几何形状和拉曼活性振动频率，以及预期的中间体和产物。将测得的DEZn分解曲线与2-D流体动力学模拟预测的曲线进行比较，发现锌和碳原子之间的简单键解离是主要的均相热分解途径。计算结果表明，涉及中间体的数个反应和拉曼散射实验证实了二聚体（ZnC2H5）2的形成。在另一组不同的实验中，DEZn的光解作用提供了消除β-氢化物分解的证据。结果表明，β-氢化物消除是二乙基锌气相均相热解的次要途径。确定了消除β-氢化物期间的合理过渡态，并且计算出的能量和热力学性质支持了这些反应步骤的可能性。结果表明，β-氢化物消除是二乙基锌气相均相热

  DOI：

  10.1021/jp7103787

文献信息

• Enantioselective Reduction of Ketones by Polymethylhydrosiloxane in the Presence of Chiral Zinc Catalysts
  作者：Hubert Mimoun、Jean Yves de Saint Laumer、Luca Giannini、Rosario Scopelliti、Carlo Floriani

  DOI：10.1021/ja990522i

  日期：1999.7.1

  Enantioselective reduction of ketones, particularly acetophenones, by polymethylhydrosiloxane (PMHS) to the corresponding secondary alcohols can be achieved with high yields and enantiomeric excesses (ee's) up to 88% in the presence of chiral zinc catalysts (eq 1). Two catalytic systems have been developed giving similar ee's: (i) System A: ZnEt2 + chiral diimine or diamine 1-10, (ii) System B: Zn(carboxylate)(2) + chiral diamine activated by Vitride. System B is inexpensive, stable, and ready to use in toluene, providing either (R) or (S) chiral secondary alcohols with 70-80% ee in the presence of (S,S)- or (R,R)-N,N'-ethylenebis-(1-phenylethylamine) (ebpe, 6). The reduction has been carried out at the 1 kg scale without scale-up problems. The ligand is cheap and is recovered at the end of reaction by simple distillation from residues of the organic phase. Both precursors ZnMe2.(S,S)-ebpe (A) and Zn(dea)2 (S,S)-ebpe(B) for systems A and B, respectively, have been isolated and characterized by X-ray structure and exhibit the same catalytic properties and the same ee's for the reduction of acetophenone as the in situ prepared catalytic system. The complex ZnEt2 (S,S)-ebpe) (A') reacts with benzaldehyde to give the seven-membered ring dimer complex La in which benzaldehyde inserts into the Zn-N bond of complex A'. Acetophenone also reacts with A' to give a similar seven-membered ring dimer complex Lb. Both La and Lb are catalysts for the enantioselective reduction of acetophenone by PMHS and gave activities and ee's similar to those of A'. Synthetic and mechanistic aspects of this new economical method are discussed in this paper.