Synthesis, Structure, and Transannular pi-pi Interaction of Novel [3.3] Cyclophanes

新型环芳烷的合成、结构和跨环 pi-pi 相互作用 [3.3]

基本信息

批准号：
06453042
负责人：
SHINMYOZU Teruo
金额：
$ 4.74万
依托单位：
Kyushu 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

项目摘要

(1) Synthesis, Structure, and Transannular pi-pi Interaction of Multibridged [3_n] cyclophanes[3_6] (1,2,3,4,5,6) cyclophane 1, which is one of the ultimate compound in the field of [3.3] cyclophane chemistry has been synthesized and characterized. We expect 1 to have the fascinating chemical and structural features ; the photochemical isomerization of 1 to propella [3_6] prismane 2 has been predicted based on semiempirical MO calculations. For the synthesis of 1, we examined a stepwise approach starting from [3_3] (1,3,5) cyclophane. The key to the successful synthesis of 1 lay in employing intramolecular aldol condensation between an acetyl group and a pseudogeminally substituted formyl group to construct an additional bridge. This reaction provided enones in very high yields and the enones were readily reduced to trimethylene bridges by way of ketones. Hexabridged ketone, however, could not be reduced by various metal hydrides, but the employment of SmI_2 in THF in the presence of 1 … More N aqueous KOH successfully gave the alcohol, which was readily reduced by LiAlH_4-AlCl_3 to give the desired 1.Electronic absorption bands of [3_n] cyclophanes (n=6,5,4,3) 1,2,3,4 and their charge transfer (CT) bands with tetracyanoethylene (TCNE) in CHCl_3 shift to longer wavelength region with the increase of the number of trimethylene bridges. These results suggest that 1-4 tend to have stronger transannular pi-pi interaction as the number of trimethylene bridges increases. The CT band of 1 (710 nm) is the longest wavelength among those of the CT complexes, of [m. n] cyclophanes and multibridged benzenophanes with TCNE.In the variable temperature ^1H NMR spectra of 1 (toluene-d_8), the energy barriers for the trimethylene bridge inversion process are estimated to be 9.8 kcal/mol. The compound 1 is sensitve to light, and the isolation and identification of the photo-product is in progress.(2) A Synthetic Study of Double-layred Annulene Containing Two 15,16-Dimethyldihydropyrene SkeletonsIn a synthesis of double-layred annulene containing two 15,16-dimethyldihydropyrene skeletons as a model compound for the study of transannular pi-pi interaction, we found that 7,15-di-t-butyl -4,12-dimethyl [2,2] metacyclophane is converted to 2,7-di-t-buty1-15,16-dimethyldihydropyrene in good yield by photo-irradiation in acetic acid. When acetic acid solution of a dimer of the cyclophane, a precursor to the desired double-layred annulene, was irradiated with a low-pressure Hg lamp, the characterictic ^1H NMR signal of the methyl protons of the desired compound was observed. The characterization of the product is in progress. Less

（1）多纤维化的[3_n]环媒体[3_6]（1,2,3,4,5,6）环光1的合成，结构和跨性别PI-PI相互作用，这是[3.3]旋风化学领域的最终化合物之一。我们希望1具有引人入胜的化学和结构特征。基于半经验的MO计算，已经预测了1 propella [3_6] Propella [3_6]的光化学异构化。对于1的合成，我们检查了从[3_3]（1,3,5）环烷开始的逐步方法。成功合成1的关键在于在乙酰基和假替代的甲基基团之间采用分子内醛醇凝结以构建额外的桥。该反应提供了很高的产量，并通过酮很容易将烯酮简化为三甲基桥。 Hexabridged ketone, however, could not be reduced by various metal hydrides, but the employment of SmI_2 in THF in the presence of 1 … More N aqueous KOH successfully gave the alcohol, which was readily reduced by LiAlH_4-AlCl_3 to give the desired 1.Electronic suffering bands of [3_n] cyclophanes (n=6,5,4,3) 1,2,3,4 and their charge transfer （CT）在CHCL_3中具有四环乙烯（TCNE）的条带向更长的波长区域，随着三甲基桥的数量增加。这些结果表明，随着三甲基桥的数量增加，1-4倾向于具有强的跨性别PI-PI相互作用。 1（710 nm）的CT频带是[m的CT复合物中最长的波长。 n]环媒体和带有TCNE的多元苯甲烷。在可变温度 ^1H NMR光谱为1（甲苯-D_8）中，三甲基桥倒置过程的能屏障估计为9.8 kcal/mol。该化合物1对光敏感，并且正在进行光产品的隔离和鉴定。发现7,15-DI-T叔丁基-4,12-二甲基[2,2] Metacyclophane被转换为2,7-DI-T-Buty1-15,15-15-16-二甲基二氢吡啶，乙酸在乙酸中的光辐射良好。当环烷二聚体的乙酸溶液，即所需的双层孔的前体，用低压Hg灯照射，观察到所需化合物的甲基质子的特征 ^1H NMR信号。产品的表征正在进行中。较少的