exo-6-Me-arachno-6,7-PCB8H12 | 491846-50-5

• 英文名称: exo-6-Me-arachno-6,7-PCB8H12
• CAS: 491846-50-5；491610-24-3
• 化学式: C₂H₁₅B₈P
• 分子量: 156.603
• InChiKey: RHYXTGYAXGIPIH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  exo-6-Me-arachno-6,7-PCB8H12 在 LiH or NaH or BuLi 作用下， 以 四氢呋喃 为溶剂， 生成 exo-6-Me-arachno-6,7-PCB8H11(1-)
  参考文献：
  名称：

  Syntheses, Crystallographic/Computational Characterizations, and Reactions of the First 10-Vertex arachno- and nido-Phosphamonocarbaboranes

  摘要：

  A synthetic sequence involving the initial reaction of a substituted phosphorus dihalide (RPCl2, R = CH3, C6H5) with the arachno-CB8H13- (1(-)) monoanion followed by an in situ dehydrohalogenation reaction initiated by Proton Sponge, resulted in phosphorus cage insertion to yield the first 10-vertex arachno- and nido-phosphamonocarbaboranes, exo-6-R-arachno-6,7-PCB8H12 (2a, 2b) and PSH(+)6-R-nido-6,9-PCB8H9- (PSH(+)3a(-), PSH(+)3b(-)) (R = C6H5 (a), CH3 (b)). Alternatively, 2a and 2b were synthesized in high yield as the sole product of the reaction of the arachno-4-CB8H122- (1(2-)) dianion with RPCl2. Crystallographic determinations of PSH(+)3a(-) and PSH(+)3b(-) in conjunction with DFT/GIAO computational studies of the anions have confirmed the expected nido cage framework based on an octadecahedron missing the six-coordinate vertex. DFT/GIAO computational studies have also shown that while the gross cage geometries of the exo-6-R-arachno-6,7-PCB8H12 compounds 2a and 2b resemble the known isoelectronic arachno-6,9- SCB8H12, the phosphorus and carbon atoms are in thermodynamically unfavorable adjacent positions on the six-membered puckered face. They also each have an endo-hydrogen at the P6-position arising from proton transfer to the basic phosphorus during the cage-insertion reaction. Possible stepwise reaction pathways that can account for the formation of both the arachno and nido products are discussed. Deprotonation of 2a and 2b resulted in the,formation of their corresponding conjugate monoanions, 6-R-arachno-6,7-PCB8H11- (2a(-), 2b(-)), in which the proton that had been attached to the P6 atom was removed. Reactions of 2a(-) with O-2, S-8, BH3.THF, or Br-2 further demonstrated the basicity of the P6-phosphorus yielding the new arachno-substituted compounds, endo-6-O-exo-6-(C6H5)-arachno-6,7-PCB8H11- (4a(-)), endo-6-S-exo-6-(C6H5)-arachno-6,7-PCB8H11- (5a(-)), endo-6-BH3-exo-6-(C6H5)-arachno-6,7-PCB8H11- (6a(-)), and endo-6-Br-exo-6-(C6H5)-arachno-6,7-PCB8H11 (7a), respectively, in which the O, S, BH3, and Br substituents are bound to the phosphorus at the endo position.

  DOI：

  10.1021/ja020944j
• 作为产物：
  描述：

  甲基二氯膦 、 arachno-4-CB8H12(2-) 以 四氢呋喃 为溶剂， 生成 exo-6-Me-arachno-6,7-PCB8H12
  参考文献：
  名称：

  Syntheses, Crystallographic/Computational Characterizations, and Reactions of the First 10-Vertex arachno- and nido-Phosphamonocarbaboranes

  摘要：

  A synthetic sequence involving the initial reaction of a substituted phosphorus dihalide (RPCl2, R = CH3, C6H5) with the arachno-CB8H13- (1(-)) monoanion followed by an in situ dehydrohalogenation reaction initiated by Proton Sponge, resulted in phosphorus cage insertion to yield the first 10-vertex arachno- and nido-phosphamonocarbaboranes, exo-6-R-arachno-6,7-PCB8H12 (2a, 2b) and PSH(+)6-R-nido-6,9-PCB8H9- (PSH(+)3a(-), PSH(+)3b(-)) (R = C6H5 (a), CH3 (b)). Alternatively, 2a and 2b were synthesized in high yield as the sole product of the reaction of the arachno-4-CB8H122- (1(2-)) dianion with RPCl2. Crystallographic determinations of PSH(+)3a(-) and PSH(+)3b(-) in conjunction with DFT/GIAO computational studies of the anions have confirmed the expected nido cage framework based on an octadecahedron missing the six-coordinate vertex. DFT/GIAO computational studies have also shown that while the gross cage geometries of the exo-6-R-arachno-6,7-PCB8H12 compounds 2a and 2b resemble the known isoelectronic arachno-6,9- SCB8H12, the phosphorus and carbon atoms are in thermodynamically unfavorable adjacent positions on the six-membered puckered face. They also each have an endo-hydrogen at the P6-position arising from proton transfer to the basic phosphorus during the cage-insertion reaction. Possible stepwise reaction pathways that can account for the formation of both the arachno and nido products are discussed. Deprotonation of 2a and 2b resulted in the,formation of their corresponding conjugate monoanions, 6-R-arachno-6,7-PCB8H11- (2a(-), 2b(-)), in which the proton that had been attached to the P6 atom was removed. Reactions of 2a(-) with O-2, S-8, BH3.THF, or Br-2 further demonstrated the basicity of the P6-phosphorus yielding the new arachno-substituted compounds, endo-6-O-exo-6-(C6H5)-arachno-6,7-PCB8H11- (4a(-)), endo-6-S-exo-6-(C6H5)-arachno-6,7-PCB8H11- (5a(-)), endo-6-BH3-exo-6-(C6H5)-arachno-6,7-PCB8H11- (6a(-)), and endo-6-Br-exo-6-(C6H5)-arachno-6,7-PCB8H11 (7a), respectively, in which the O, S, BH3, and Br substituents are bound to the phosphorus at the endo position.

  DOI：

  10.1021/ja020944j

文献信息

• Syntheses and Structural Characterizations of <i>e</i><i>ndo-</i>η¹-, <i>exo</i>-η¹-, η⁴-, η⁵-, and η⁶-Metallaphosphamonocarbaborane Complexes Derived from a Versatile New Polyborane Ligand:  <i>e</i><i>xo</i>-6-R-<i>a</i><i>rachno</i>-6,7-PCB₈H₁₂
  作者：Daniel E. Kadlecek、Alexandra M. Shedlow、Sang Ook Kang、Patrick J. Carroll、Larry G. Sneddon

  DOI：10.1021/ja020945b

  日期：2003.1.1

  Deprotonation of the phosphamonocarbaborane, exo-6-R-arachno-6,7-PCB8H12 (R = Ph 1a or Me 1b), yields exo-6-R-arachno-6,7-PCB8H11-, which when reacted with appropriate transition-metal reagents affords new metallaphosphamonocarbaborane complexes in which the metals adopt endo-eta(1), exo-eta(1), eta(4), eta(5), or eta(6) coordination geometries bonded to the formal R-arachno-PCB8H11-, R-arachno-PCB8H102-, R-arachno-PCB8H93-, or R-nido-PCB8H9- ligands. The reaction of exo-6-(C6H5)-arachno-6,7-PCB8H11- (1a(-)) with Mn(CO)(5)Br generated the eta(1)-sigma product exo-6-[Mn(CO)(5)]-endo-6-(C6H5)-arachno-6,7-PCB8H11 (2) having the [Mn(CO)(5)] fragment in the thermodynamically favored exo position at the P6 cage atom. On the other hand, reaction of 1a(-) with (eta(5)-C5H5)Fe(CO)(2)1 resulted in the formation of two products, an eta(1)-sigma complex endo-6-[(eta(5)-C5H5)Fe(CO)(2)]-exo-6-(C6H5)-arachno-6,7-PCB8H11 (3) having the (eta(5)-C5H5)Fe(CO)(2) fragment attached at the endo-P6 position and an eta(6)-closo complex, 1-(eta(5)-C5H5)-2-(C6H5)-closo-1,2,3-FePCB8H9 (4a). Rearrangement of the endo-compound 3 to its exo-isomer 5 was observed upon photolysis of 3. Synthesis of the methyl analogue of 4a, 1-(eta(5)-C5H5)-2-CH3-closo-1,2,3-FePCB8H9 (4b), along with a double-insertion product, 1-CH3-2,3-(eta(5)-C5H5)(2)-2,3,1,7-Fe2PCB8H9 (6), containing two iron atoms eta(5)-Coordinated to a formal R-arachno-PCB8H93-, was achieved by reaction of exo-6-CH3-arachno-6,7-PCB8H11- (1b(-)) with FeCl2 and Na+C5H5-. Complexes 4a and 4b can be considered ferrocene analogues, in which an Fe(II) is sandwiched between C5H5- and 6-R-nido-6,9-PCB8H9- anions. Reaction of exo-6-(C6H5)-arachno-6,7-PCB8H11- (1a(-)) with cis-dichlorobis(triphenylphosphine)platinum (11) afforded two compounds, an eta(1)-sigma complex with the metal fragment again in the endo-P6 position, endo-6-[cis-(Ph3P)(2)PtCl]-exo-6-(C6H5)-arachno-6,7-PCB8H11 (7) and an eta(4)-complex, 7-(C6H5)-11-(Ph3P)(2)-nido-11,7,8-PtPCB8H10 (8) containing the formal R-arachno-PCB8H102- anion. The structures of compounds 2, 3, 4a, 4b, 6, 7, and 8 were crystallographically confirmed.