Study on the Preparation of Highly Strained Polycyclic Compounds and Their Transformation into Novel Chemical Species

高应变多环化合物的制备及其向新化学物种转化的研究

• 批准号: 06453031
• 负责人: TSUJI Takashi
• 金额: $ 4.86万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06453031/
• 关键词: cyclophane; Dewar benzene; strained molecule; aromaticity; 高歪み化合物; 多環化合物; 光反応

1. [4] Paracyclophane and its derivatives are the most strained of known paracyclophanes, but their extreme thermal instability has thwarted the exploration of physical and chemical properties. In this study, [4] paracyclophane was kinetically stabilized successfully by introducing sterically demanding substituents which specifically shield the bridgehead carbon atoms from the access of other reagents. The prepared species was sufficiently stable to permit the measurement of ^1H NMR,which suggested the sustenance of significant diamagnetic ring current despite the extreme distortion of the benzene ring. Theoretical calculations also indicated the retention of cyclic delocalization of electrons in the bent benzene of [4] paracyclophane in accord with the experimental observation.2. Dewar benzene is a highly strained valence isomer of benzene, hence the thermal transformation of the former to the latter is generally unattainable. Theoretical calculations suggest that thermal isomerization of extremely strained [4] paracyclophane to the corresponding Dewar benzene is energetically feasible. The process, however, has so far been unobservable owing to the extreme thermal instability of [4] paracyclophane. The successful kinetic stabilization of [4] paracyclophane in the present study allowed the obervation of the process for the first time.3. Tricyclo [4.2.2.2^<2,5>] dodeca-1,3,5,7,9,11-hexaene, a novel fully unsaturated, highly strained hydrocarbon, was successfully generated from a Dewar benzene derivative and chemically intercepted.

1. [4]对环芳烷及其衍生物是已知的对环芳烷中应变最大的，但它们极端的热不稳定性阻碍了对其物理和化学性质的探索。在这项研究中，[4]通过引入空间要求高的取代基成功地在动力学上稳定了对环芳，这些取代基专门保护桥头碳原子不受其他试剂的影响。制备的物质足够稳定，可以进行^1H NMR测量，这表明尽管苯环极度扭曲，但仍维持了显著的抗磁性环电流。理论计算还表明，[4]对环芳烷在弯曲苯中电子的环状离域保留与实验观察结果雅阁.杜瓦瓶苯是苯的高度紧张的价态异构体，因此前者向后者的热转化通常是不可能实现的。理论计算表明，极端应变[4]对环蕃热异构化为相应的杜瓦苯在能量上是可行的。然而，由于[4]对环芳烷的极端热不稳定性，该过程迄今为止还无法观察到。[4]对环芳烷在本研究中的成功动力学稳定化使得该过程首次得以观察.三环[4.2.2.2 ^<2，5>]十二碳-1，3，5，7，9，11-六烯是一种新型的完全不饱和、高张力的烃类化合物。

项目成果

M.Okuyama and T.Tsuji: "Kinetically Stabilized [4] Paracyclophane-the 1,4-Bis (dicyano-methylene)-2-ene Derivative : ^1H NMR Measurement and Assessment of its Diatropicity" Angew.Chem., Int.Ed.Engl.36(in press). (1997)

M.Okuyama 和 T.Tsuji：“动力学稳定的 [4] 对环芳烷 - 1,4-双（二氰基亚甲基）-2-烯衍生物：^1H NMR 测量和评估其双异性” Angew.Chem.，Int。

Masakazu Ohkita: "Direct Synthesis of 2-Norbornanone Dithioacetals from 2-Cyclopentenone Dithioacetals and Dienophiles" Tetrahedron. 52. 9979-9990 (1996)

Masakazu Ohkita：“从 2-环戊烯酮二硫缩醛和亲双烯体直接合成 2-降冰片酮二硫缩醛”四面体。

Takanori Suzuki: "Hexaphenylethane Derivatives Exhibiting Novel Electrochromic Behavior" Angew.Chem.,Int.Ed.Engl.36(in press.). (1997)

Takanori Suzuki：“六苯乙烷衍生物表现出新颖的电致变色行为”Angew.Chem.，Int.Ed.Engl.36（印刷中）。

M.Ohkita, K.Ishigami, and T.Tsuji: "Rraction of C_<60> with 2-Cyclopentenone Acetals. A Convenient Access to Chiral C_<60> Derivative" J.Chem.Soc.Chem.Commun.1769-1770 (1995)

M.Ohkita、K.Ishigami 和 T.Tsuji：“C_<60> 与 2-环戊烯酮缩醛的反应。方便地获得手性 C_<60> 衍生物”J.Chem.Soc.Chem.Commun.1769-1770

Masakazu Ohkita: "Reaction of C_<60> with 2-Cyclopentenone Acetals.A Convenient Access to Chiral C_<60> Derivative" J.Chem.Soc.,Chem.Commun.1769-1770 (1995)

Masakazu Ohkita：“C_<60> 与 2-环戊烯酮缩醛的反应。方便获得手性 C_<60> 衍生物”J.Chem.Soc.,Chem.Commun.1769-1770 (1995)