(R)-4,4,5,5-tetramethyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)but-1-en-2-yl)-1,3,2-dioxaborolane

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 硼酸衍生物
• 英文名称: (R)-4,4,5,5-tetramethyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)but-1-en-2-yl)-1,3,2-dioxaborolane
• 英文别名: 4,4,5,5-tetramethyl-2-[(2R)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)but-3-en-2-yl]-1,3,2-dioxaborolane
• 化学式: C₁₆H₃₀B₂O₄
• 分子量: 308.034
• InChiKey: UEEOSZFDJJGBMY-GFCCVEGCSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.66
• 重原子数：
  22
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.88
• 拓扑面积：
  36.9
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  1,2-丁二烯 、 联硼酸频那醇酯 在 tris-(dibenzylideneacetone)dipalladium(0) 作用下， 以 甲苯 为溶剂， 以77%的产率得到(R)-4,4,5,5-tetramethyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)but-1-en-2-yl)-1,3,2-dioxaborolane
  参考文献：
  名称：

  Development, Mechanism, and Scope of the Palladium-Catalyzed Enantioselective Allene Diboration

  摘要：

  In the presence of a chiral phosphoramidite ligand, the palladium-catalyzed diboration of allenes can be executed with high enantioselectivity. This reaction provides high levels of selectivity with a range of aromatic and aliphatic allene substrates. Isotopic-labeling experiments, stereodifferentiating reactions, kinetic analysis, and computational experiments suggest that the catalytic cycle proceeds by a mechanism involving rate-determining oxidative addition of the diboron to Pd followed by transfer of both boron groups to the unsaturated substrate. This transfer reaction most likely occurs by coordination and insertion of the more accessible terminal alkene of the allene substrate, by a mechanism that directly provides the eta(3) pi-allyl complex in a stereospecific, concerted fashion.

  DOI：

  10.1021/ja070572k

文献信息

• Palladium-Catalyzed Enantioselective Diboration of Prochiral Allenes
  作者：Nicholas F. Pelz、Angela R. Woodward、Heather E. Burks、Joshua D. Sieber、James P. Morken

  DOI：10.1021/ja044167u

  日期：2004.12.1

  Pd-catalyzed diboration of prochiral allenes occurs exclusively at the internal position and is remarkably accelerated in the presence of Lewis basic ligand structures. On the basis of preliminary observations, a chiral ligand was employed, and the enantiomeric excess of a variety of diboration products was found to be in the range of 86-92% ee. The chiral diboron reaction products should be useful in organic synthesis, and preliminary experiments suggest that they may participate in allylation reactions with a high level of chirality transfer.