银催化不对称的Sakurai-Hosomi对子的合
Manabu Wadamoto1, Hisashi Yamamoto
1Department of Chemistry, The University of Chicago, Illinois 60637, USA.
Journal of the American Chemical Society
|October 20, 2005
概括
一种新的白银化物 (AgF) 和 (R) -DIFLUORPHOS催化剂系统有效地催化了子的不对称的萨库拉伊-霍索米结合. 这种方法实现了对三级同质醇的高抗选择性,并使抗选择性化成为可能.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 不对称的合成方法
背景情况:
- 萨库拉伊-霍索米结合是形成碳-碳键的关键反应.
- 开发这种反应的高效和enantioselective催化剂仍然是一个活跃的研究领域.
- 以前的方法通常需要特定的基板或恶劣的条件.
研究的目的:
- 开发一种高分离选择性催化系统,用于简单子的不对称的萨库拉伊-霍索米结合.
- 研究溶剂和添加剂对催化剂性能的影响.
- 探索这个系统对各种基质和合反应的应用.
主要方法:
- 在银化物 (AgF) 和 (R) -DIFLUORPHOS之间形成1:1复合物.
- 反应条件的优化,包括溶剂 (THF) 和甲醇联合催化剂.
- 应用AgF/(R) -DIFLUORPHOS催化剂对一系列简单和合的应用.
- 使用E-或Z-crotyltrimethoxysilane进行区域,异位选择性和异位选择性结的研究.
主要成果:
- AgF / R-DIFLUORPHOS复合体显示出高的催化活性和对简单子的结合 (高达96% ee) 的反选择性.
- 作为溶剂的四氨酸 (THF) 显著提高了反应性.
- 添加甲醇 (1 equiv) 增加了催化剂周转率.
- 该系统只产生与合子的1,2-添加物.
- 成功实现了区域性,二分体选择性和二分体选择性结,对E-和Z-allylsilanes观察到类似的二分体比例.
结论:
- AgF/(R) -DIFLUORPHOS 1:1复合物是不对称的萨库拉伊-霍索米结合的高效催化剂.
- 这种催化系统对各种子具有广泛的适用性,可产生具有优异的酶选择活性的三级同质醇.
- 这些发现凸显了 Racemic Allylsilanes 在 enantioselective 合反应中的实用性,扩大了不对称合成的范围.
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