完全采用3,6-O-(o-xylylene) 桥接的轴向丰富的葡萄糖化物进行β选择性糖化
Yasunori Okada1, Noriaki Asakura, Masafumi Bando
1School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda 669-1337, Japan.
Journal of the American Chemical Society
|April 6, 2012
概括
这项研究引入了一种新的糖化法,可以在没有邻近群体参与的情况下实现完美的β选择性. 一个独特的甘氨基基捐赠体,锁定在一个轴向丰富的形状,使得高效和立体控制的合成甘氨基酸.
科学领域:
- 碳水化合物化学 碳水化合物化学
- 有机合成 有机合成
- 立体选择性反应
背景情况:
- 糖化对合成复杂碳水化合物至关重要.
- 实现β-选择性通常依赖于邻近组参与,限制基质范围.
- 开发用于立体选择性糖化新方法仍然是一个关键的挑战.
研究的目的:
- 开发一种完全独立于邻近组参与的β-选择性糖化法.
- 设计和合成一种新型的糖醇捐赠剂,锁定在一个轴向丰富的形状中.
- 阐明观察到的立体控制背后的机制.
主要方法:
- 一种新型的甘氨基基捐赠体的合成:2,4-di-O-benzyl-3,6-O-(o-xylyene) 甘氨基化物.
- 使用SnCl(2)-AgB(C(6)F(5))(4) 催化系统进行糖化反应.
- 利用酸性和性分子来研究反应机制,包括糖化和异构化循环.
主要成果:
- 合成的葡萄糖醇供体有效地与各种酒精反应.
- 在糖化反应中实现了完美的β-选择性.
- 对比实验揭示了一种涉及糖化和异构化循环的机制.
结论:
- 已经建立了一种全新的,完全选择性β-糖化策略.
- 甘氨基基捐赠体和局部生成的HB的轴性丰富构造协同控制立体化学.
- 这种方法提供了一种新的途径,用于在没有邻近组参与的情况下对β-糖化物进行立体选择性合成.
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