对于1,3-indenocorannulenes的甲来说令人惊的酸度?
Shi Liu1, Märt Lõkov2, Sofja Tshepelevitsh2
1School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, PR China.
Beilstein journal of organic chemistry
|December 13, 2024
概括
在化 (BFC) 和[3,4-b] (FIC) 中甲基质子的酸度得到量化. 这些化合物呈现出令人惊的高酸度,与替代的烯可比,挑战现有的酸度模型.
科学领域:
- 有机化学 有机化学
- 物理化学 物理化学
背景情况:
- 碳化合物的酸度对于理解反应性至关重要.
- 现有的烯衍生物数据显示了pKa值的广泛范围.
- 影响聚环系统酸度的电子和结构因素需要进一步研究.
研究的目的:
- 量化确定 (BFC) 和 (FIC) 的第一个酸度常数 (pKa).
- 为了比较BFC和FIC的酸度与相关的碳化合物,如环二烯,二烯和二烯.
- 提供一个理论框架,使用克拉尔-洛什米特图,以理解观察到的酸度趋势.
主要方法:
- 酸度常数 (pKa) 的定量评估,使用在乙二 (CH3CN) 中的电位计定位.
- 对pKa值与相关的多环碳化合物的文献数据进行比较分析.
- 应用克拉尔-洛什米特图形方法进行理论解释.
主要成果:
- 在CH3CN.中,BFC的第一个酸度常数 (pKa) 确定为27.6.
- 在CH3CN.中,FIC的第一个酸度常数 (pKa) 确定为27.8.
- 发现BFC和FIC中的甲基质子比环二烯 (pKa 32),二烯 (pKa 34) 和二烯 (pKa 37) 中的甲基质子更为酸性.
- BFC和FIC的酸度与9- perfluorophenylfluorene (pKa 28.14) 的甲质子相当.
结论:
- 在CpH同源碳化合物家族中,BFC和FIC表现出异常高的甲基烯质子酸度.
- 定量pKa值为理解聚合多环系统中的结构-酸度关系提供了关键数据.
- 克拉尔-洛什米特图分析提供了对电子移位和稳定有助于增强酸度的见解.
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