催化不对称化2,3,5-三替代型烯的催化不对称化
Ryoichi Kuwano1, Manabu Kashiwabara, Masato Ohsumi
1Department of Chemistry, Graduate School of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. rkuwascc@mbox.nc.kyushu-u.ac.jp
Journal of the American Chemical Society
|December 25, 2007
概括
这项研究引入了一种新型的催化剂,用于 pyrroles 的不对称化,实现高的 enantioselectivity. 这一突破使得能够有效地合成性烯酸衍生物和其他复杂的烯酸结构.
科学领域:
- 有机化学 有机化学
- 不对称的催化剂.
- 合成方法论 合成方法论
背景情况:
- 醇是重要的异环化合物,具有多样化的应用.
- 开发用于pyrrole功能化的enantioselective方法对于合成奇拉分子至关重要.
- 现有的醇降解方法往往缺乏高的立体控制.
研究的目的:
- 为N-Boc受保护的烯酸开发一种高度酶选择性的催化不对称化方法.
- 探索这种新型催化系统对各种烯基基底的范围和效率.
- 建立一种新的途径,用于对有价值的醇衍生物进行立体选择性合成.
主要方法:
- 使用了一种修改了催化剂的转化双 (PhTRAP) 催化剂.
- 研究了N-Boc受保护的pyrroles的不对称化,包括甲基pyrrole-2-carboxylate和替代pyrroles.
- 使用Ru,S,S,R,R,PhTRAP和三乙烯胺的优化催化剂制备.
主要成果:
- 在N-Boc受保护的pyrroles的不对称化中获得高的enantioselectivity.
- 优化的-PhTRAP催化剂产生了一种 (S) - 衍生物,产量为79% ee和92%.
- 证明了对三位置换的pyrroles和高立体控制在减少4,5-dimethylpyrrole-2-carboxylate的优异的enantioselectivity (93-99.7% ee).
结论:
- 这项工作介绍了第一个高度反选择性的 pyrroles 的催化还原.
- 开发的方法提供了一种高效和立体选择性的途径,以获得有价值的性醇衍生物.
- 鲁-PhTRAP系统显示出合成复杂的性分子从pyrrole前体的显著潜力.
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