trans-2-Pentylcyclopropylboronic acid

• 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: trans-2-Pentylcyclopropylboronic acid
• 英文别名: 2-Pentylcyclopropylboronic acid；(2-pentylcyclopropyl)boronic acid
• 化学式: C₈H₁₇BO₂
• 分子量: 156.033
• InChiKey: RXDUKPMEQAWEMH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.43
• 重原子数：
  11
• 可旋转键数：
  5
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  40.5
• 氢给体数：
  2
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  ethyl (2Z)-4,4,4-trifluoro-3-iodobut-2-enoate 、 trans-2-Pentylcyclopropylboronic acid 在 bis-triphenylphosphine-palladium(II) chloride potassium phosphate 作用下， 以 甲苯 为溶剂， 反应 8.0h， 以89%的产率得到ethyl (E)-3-trans-n-pentylcyclopropyl-4,4,4-trifluoro-2-butenoate
  参考文献：
  名称：

  Facile access to stereodefined dienoates and cyclopropylenoates containing a trifluoromethyl group

  摘要：

  Ethyl (2E,4E)-3-trifluoromethyl-2,4-dienoates 1a-e and ethyl (E)-3-trans-alkylcyclopropyl-4,4,4-trifluoro-2-butenoates 2a-e were prepared from the tratis-alkenylboronic acids 3a-e and the trans-cyclopropylboronic acids 4a-e with ethyl (Z)-3-iodo-4,4,4-trifluoro-2-butenoate (5) by the Suzuki cross-coupling reaction in high yields (88-95%). The configurations of both 3a-e or 4a-e and 5 were retained in the reaction. (C) 2003 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/s0022-1139(03)00192-1

文献信息

• Palladium-Catalyzed Cross-Coupling Reaction of Cyclopropylboronic Acids with Aryl Triflates
  作者：Min-Liang Yao、Min-Zhi Deng

  DOI：10.1055/s-2000-6313

  日期：——

  In the presence of appropriate base and NaBr, the Suzuki-type reaction of aryl triflates and trans-cyclopropylboronic acids proceed readily to give pure trans-cyclopropylarenes in good to high yields. For the reaction of general aryl triflates, the base KF · 2 H2O is efficient, but in the case of aryl triflates bearing electron donating groups, KF · 2 H2O as a base makes the unexpected phenyl-aryl exchange between the phenyl of Pd(PPh3)4 and the aryl of triflate to occur. The use of K3PO4 · 3 H2O instead of KF · 2 H2O can inhibit the unexpected phenyl-aryl exchange, but the yield of the product is somewhat decreased. The coupling reaction of aryl triflates with the optically active cyclopropylboronic acids, which were easily obtained in good yield and with good to excellent ee (up to 94%) by the asymmetric cyclopropanation of alkenylboronates with optically pure TMTA auxiliary, was also investigated. During the coupling reaction, the absolute configuration of the cyclopropyl group was retained. Thus, a novel method to prepare aryl-substituted cyclopropanes, including highly optically active cyclopropanes, from phenols or arylamines was provided.

  在适当的碱和 NaBr 存在下，芳基三氟酸酯和反式环丙基硼酸的 Suzuki 型反应很容易进行，并以良好至高产率得到纯的反式环丙基烯烃。对于一般的芳基三氟酸酯反应，碱 KF - 2 H2O 是有效的，但对于带有电子捐赠基团的芳基三氟酸酯，KF - 2 作为碱会使 Pd(PPh3)4 的苯基和三氟酸酯的芳基之间发生意想不到的苯基-芳基交换。使用 K3PO4 - 3 代替 KF - 2 可以抑制意想不到的苯基-芳基交换，但生成物的产率会有所下降。通过烯基硼酸酯与光学纯 TMTA 助剂的不对称环丙烷化反应，可以轻松获得收率高、ee 值好到极好（高达 94%）的光学活性环丙基硼酸。在偶联反应过程中，环丙基的绝对构型得以保留。因此，提供了一种从苯酚或芳基胺制备芳基取代环丙烷（包括高光学活性环丙烷）的新方法。