用催化剂控制的区域选择性乙化及其应用于差分保护的单合成的研究
Sibin Wang1, Oleksii Zhelavskyi1, Jeonghyo Lee2
1Chemistry Department, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
Journal of the American Chemical Society
|October 27, 2021
概括
酸 (CPA) 能够对糖二醇进行区域选择性乙酸保护. 固定聚合物催化剂具有高选择性,可回收性,并可有效合成受保护的碳水化合物衍生物.
科学领域:
- 碳水化合物化学
- 有机合成
- 催化剂
背景情况:
- 碳水化合物的区域选择性功能化对于合成复杂衍生物至关重要.
- 酸 (CPA) 已成为不对称合成的有效催化剂.
- 开发可回收和高度选择性的碳水化合物保护催化剂仍然是一个重要的目标.
研究的目的:
- 调查使用酸 (CPA) 和其固定聚合物变体用于单糖衍生二醇的区域选择性乙酸保护.
- 根据催化剂的选择,探索这些催化剂的区域差异潜力.
- 在可扩展的单合成和机械研究中证明聚合物催化剂的实用性.
主要方法:
- 使用 (R) -Ad-TRIP-PS和 (S) -SPINOL-PS聚合催化剂对各种单糖衍生的1,2-二醇进行区域选择性乙化.
- 聚合物催化剂的回收和再利用,用于格拉姆尺度的功能化.
- 结合乙化与其他基组功能化的单望远镜程序.
- 使用NMR光谱和计算建模的机制研究.
主要成果:
- 在d-glucose,d-galactose,d-mannose和l-fucose衍生的二醇中获得高区域选择性 (高达>25:1 rr).
- 通过选择不同的性催化剂,可以实现区域分离的乙化.
- 聚合物催化剂表现出优异的性能,可回收性,并且在低催化剂负载 (0.1mol%) 的情况下实现了克尺度合成.
- 成功合成了32种区分性纯净的单糖和二糖衍生物.
- 核磁共振和计算研究发现了一种依赖于温度的同加机制,涉及异质酸盐中间体或协同异步乙形成,解释了观察到的选择性.
结论:
- 固定化酸催化剂提供了一种高效,可回收和高度区域选择的方法来保护碳水化合物二醇.
- 开发的方法通过可扩展的单一方法促进了多样化的,区域同位素纯的受保护碳水化合物衍生物的合成.
- 机械洞察力阐明了温度依赖的区域选择性,为合理的催化剂设计铺平了道路.
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