具有高度区域选择性的3-styrylpyridines的无氧光环化
F D Lewis1, R S Kalgutkar, J S Yang
1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA. lewis@chem.northwestern.edu
Journal of the American Chemical Society
|July 18, 2001
概括
styrylpyridines 和 aminostyrylpyridines 的光化学反应产生阿扎芬烯. 在无氧条件下,3- styrylpyridine衍生物通过稳定的二皮里丁中间体选择性地形成2-azaphenanthrenes.
科学领域:
- 有机光化学 有机光化学
- 异环化学 异环化学
- 反应机制 反应机制
背景情况:
- styrylpyridines 和 aminostyrylpyridines 是重要的异环化合物.
- 了解它们的光化学转化对于合成应用至关重要.
研究的目的:
- 为了研究cis-styrylpyridines和aminostyrylpyridines的光化学行为.
- 阐明阿扎芬烯形成的反应机制和区域选择性.
主要方法:
- 在有氧和无氧条件下的光化学辐射.
- 介质的光谱表征 (1H NMR,电子吸收) 的介质.
- 实验和计算频谱的比较.
主要成果:
- 在无氧条件下,从3-styrylpyridine及其3'-amino衍生物中区域选择性形成2-azaphenanthrenes.
- 在氧气的存在下形成混合的2-和4-阿扎芬烯产物.
- 通过1,7-转移形成的一种中等稳定的1,4-二皮里丁中间体的鉴定.
结论:
- 光循环的区域选择性受环开放率,西格马特罗普重新排列和氧气火率的影响.
- 一个拟议的机制涉及到1,7-转移导致二皮里丁中间体,后者随后形成阿扎芬烯产物.
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